When talking about common feline diseases, one cannot fail to mention cancer. Yes, unfortunately, animals, like people, have a fairly high risk of developing cancer. A mammary tumor in a cat is quite common, and in four out of five cases the disease takes a malignant course. This serious illness can be completely cured only with early diagnosis. The owner should closely monitor the health of his pet and, if a small lump or lump appears in the mammary glands, be sure to contact a veterinary clinic for advice.
Today, only a number of factors are known, the presence of which leads to the development of mammary gland cancer in cats. And the exact reasons for this dangerous illness medicine is still unknown. Highest value has a hormonal factor. Fluctuations in hormonal levels in an animal’s body can be caused by various reasons:
In addition, the following factors increase the likelihood of tumor processes in the mammary gland:
There is also a version that cancer of any location, including a breast tumor, has a viral etiology. But definitive proof of it still does not exist.
Most often, mammary tumors in cats occur in older and older adults. Unsterilized cats over 10 years of age are especially susceptible to the disease. Cases of the disease in uncastrated males were much less common, although there is a possibility of such cases. The risk group consists of short-haired cats. Cats of the Siamese and Oriental breeds have the opportunity to get sick in at a young age.
Mammary cancer that occurs in a cat has four stages of development. They are recognized by their clinical signs and have different courses:
The degree of the disease in the clinic is determined by the so-called staging system, which takes into account the size of the tumor and the results aspiration biopsy lymph nodes. In addition, to determine the number and localization of metastases, radiography in three projections, ultrasound examination of the abdominal cavity, computed tomography and magnetic resonance imaging are prescribed.
Most tumors (and there are 4 pairs in total) develop from glandular epithelium and are divided into three large groups:
Carcinoma mammary glands is a mobile nodular formation. On late stages it often opens and may ulcerate or bleed. The mammary glands are most often affected on one side, less often on both sides. The disease is accompanied by enlarged lymph nodes, especially in the groin and axillary areas.
It is not always possible to determine the type of tumor (benign or malignant), especially if it has burst. In this case, the treatment regimen is based on the method of treating a potentially malignant neoplasm.
The main symptoms appear when the disease has already entered the advanced stage. At this stage, the animal’s general well-being worsens and its appearance changes. The tumor may appear as single or multiple nodes. The inguinal and axillary lymph nodes are inflamed. The lesion may involve several lobes mammary gland. Sometimes its true size can only be assessed after shaving the fur over a fairly large area of the body. Basic clinical signs at this stage are:
If a cat's mammary gland is swollen and painful, this is not always associated with cancer. Very often, some non-tumor conditions of the mammary glands have similar symptoms. Basically, these are hyperplasias (tissue growths) of various etiologies and some other conditions:
As already mentioned, with breast cancer, early diagnosis disease is very important, so the owner is required to deliver the animal to a good veterinary facility on time. Only a doctor can make a high-quality diagnosis. He has all kinds of instrumental examination(ultrasound, radiography, magnetic resonance and computed tomography). In addition, a biopsy or fine needle aspiration (penetration) of the lesion for cytological examination helps to make an accurate diagnosis.
A lot depends on how carefully the biopsy material is taken. Additional trauma to the tumor can lead to a sharp increase in the number of metastases, which will make the patient’s condition more severe. The inguinal and axillary lymph nodes must be examined, since they are also often affected by the disease.
In this case, a detailed blood test, including its biochemical formula, is no less informative. It will allow you to determine the degree of the inflammatory process, as well as the presence of concomitant infections, which cannot be ignored when prescribing a treatment regimen.
In most cases, treatment for breast cancer is radical. Surgery to remove the tumor is proposed. It usually takes place in several stages:
The smaller the tumor size, the higher the chances of success of the operation. The prognosis of the disease is considered to be favorable if the diameter does not exceed 3 cm. Degree surgical intervention may vary depending on the size of the affected area:
It is difficult to say how long a cat will live after a mastectomy. The operation is classified as difficult, so a 100% guarantee of success is usually not given. There is also no certainty that the disease will not return in the form of a relapse.
Fine-needle aspiration of regional (associated with the organs in question) lymph nodes makes it possible to determine the degree of their involvement in the pathological process. Usually, surgery is prescribed to remove the affected lymph nodes (inguinal and axillary). Sometimes ovariohysterectomy (removal of the uterus and ovaries) is performed simultaneously, which facilitates postoperative therapy.
Chemotherapy is the final stage of treatment. During it, quite a lot of strong drugs(Doxorubicin, Cyclophosphamide), which help to completely stop the tumor process. But, at the same time, they have quite significant side effects and cause severe intoxication of the body. Therefore, chemotherapy is carried out under careful monitoring of the animal’s condition.
If the cat has contraindications to mastectomy ( old age or poor condition health), chemotherapy becomes the only possibility stop the pathological process and even slightly reduce the size of the tumor.
Chemotherapy is also used when the tumor is small and the attending physician decides to do without surgery.
If your pet has a mammary tumor and is observed purulent discharge, consultation with a veterinarian is necessary. In most cases, the exposed tumor is urgently removed. But, if this path is dangerous, they resort to conservative treatment. Applications of Levomekol ointment are usually prescribed. Before smearing, treat the wound with chlorhexidine. In addition, antibiotic therapy is carried out (Tsiprovet, Fosprenil). The wound is covered with a loose bandage, with free access of air. A loose blanket is put on top.
If a cat has a tumor, it needs to be given maximum attention and care. You can take care of her without fear for your health - the disease is not contagious.
A caring owner should know what to do in the postoperative period. His main task is to accurately follow all medical recommendations:
At the slightest hint of postoperative complications(the stitches have ruptured and pus has come out, or the temperature has risen) you must immediately take the animal to the clinic.
A preventive measure that provides almost one hundred percent protection against of this disease– cat sterilization childhood, even before the onset of the first heat and at the age of up to 1 year.
Regular prevention consists of the following:
Breast tumors are a very serious disease. Any person caring for their pet is interested in the question: how long do cats with this disease live? Given that early detection their life span may not be limited by the disease. In other cases, their average lifespan ranges from 2 to 20 months (if you count from detection).
You should never despair and lose hope for the recovery of your family friend. We must do everything possible and believe, according to the principle: as long as you believe, you live.
Photo magazine Clinician's Brief
Journal of Feline Medicine and Surgery May 2013 15: 391-400,
Translation from English . Vasiliev AB
Practical significance: Mammary tumors are one of the most common tumors in both cats and dogs, but the prevalence of malignant histological types in cats is much higher (the ratio of malignant to benign is at least 4:1).
Clinical problems: The more aggressive nature of mammary tumors in cats poses treatment challenges. The prognosis is influenced by the size of the tumor and, therefore, early detection and treatment of breast tumors is of paramount importance. Although primary tumors can be removed surgically, there are no studies showing that chemotherapy significantly increases survival time; therefore, metastatic spread remains an important clinical problem.
Patient group: Mammary tumors usually affect older female cats, mainly unspayed females. Siamese and Oriental breeds may be predisposed. Male cats can develop neoplasia, but this is rare.
Evidence base: This review summarizes the current literature regarding the etiology, pathology, clinical presentation, diagnosis, staging, treatment, and prognosis of feline mammary tumors.
Mammary tumors are the third most common type affecting female cats, after lymphoma and skin tumors, accounting for 17% of all tumors. The published incidence is 25.4 per 100,000 female cats per year(1). Although precise statistics are not available, the incidence of breast tumors may vary globally, depending on the adoption of sterilization policies. Sterilization is performed less frequently in Scandinavia and some other parts of Europe than in the UK, for example.
Mammary tumors occur in older female cats (average age 10-12 years) and usually in unspayed cats. Mammary tumors also occur in male cats (mean age 12.8 years) (7), but they are rare, accounting for 1–5% of mammary tumors. Siamese cats and other Oriental breeds may be at risk for developing mammary tumors at a younger age, but domestic shorthair cats, which are probably the most common cat breed, are also very often affected by these tumors.
As in humans and dogs, hormonal fluctuations associated with repeated estrous cycles may influence the development of mammary tumors in cats. This is supported by a case-control study reporting that cats neutered before 1 year of age had a reduced risk of developing mammary tumors (9) and that non-neutered cats were 7 times more likely to have mammary tumors in the cat population in comparison. with a control group (10). However, cats spayed before 1 year of age also develop mammary tumors, so early spaying does not eliminate the risk of mammary tumors (8) and early studies reporting an increased incidence of breast tumors may perhaps reflect sterilization practices at the time rather than a true increased risk (11).
Other evidence supporting a hormonal etiology is that estrogen and progesterone receptors are found in normal breast tissue and benign tumors, but are often absent in malignant tumors and metastases (12–17). In addition, exogenous administration of progesterone to prevent pregnancy or suppress aggression has been associated with the development of tumors (benign and malignant) in both male (18) and female cats (19). A possible dose-dependent effect may occur, with an increased risk of breast carcinoma if progesterone is given regularly rather than intermittently (10).
There is no definitive evidence for a viral etiology of mammary tumors in cats, although this has been suggested in early reports. Obesity doesn't matter, but dogs do.
Cats have 4 pairs of mammary glands (2 mammary and 2 abdominal) and although any tumor can be involved, some studies report a predisposition of the caudal glands to mammary tumors (11,20). Mammary tumors appear as solitary subcutaneous nodules or masses in within the mammary glands (Figures 1 and 2), which may be discrete and mobile or associated with underlying tissue and appear ulcerated (Figure 3). Some may look like cysts. In cats, it is difficult to distinguish benign from malignant nodules, so all should be treated as potentially malignant. Multiple tumor masses within multiple lobes are common (usually unilateral but occasionally bilateral) (Figure 4) and, according to one study, occur in 60% of cats (8). Sometimes the true extent of this disease cannot be assessed without removing the fur. Drained lymph nodes (inguinal or axillary) may also be visible or palpable enlarged.
.
Fig.1 Tumor mass in the thoracic lobe of the mammary gland in an 11-year-old unsterilized domestic shorthair cat
Figure 2 Tumor mass in the pectoral lobes and axillary lymph node of an eight-year-old unsterilized domestic shorthair cat.
Figure 3 Ulcerated tumor mass of the second abdominal lobe in a 21-year-old neutered domestic shorthair cat
Figure 4. Bilateral masses in the mammary glands before (a) and after (b) hair removal
In the presence of aggressive inflammatory carcinoma with widespread lymphatic involvement, the breasts may be swollen, hot, and tender (4). This clinical picture may be difficult to distinguish from fibroadenoma hyperplasia (fibroepithelial hypertrophy, feline mammary hypertrophy), although the latter more commonly affects young cats (21).
Differential diagnosis
A variety of non-neoplastic hyperplasias and dysplasias can occur in the mammary glands and, although much less common in cats than in dogs, they can all be mistaken for mammary tumors. These include glandular ductal hyperplasia, ductal ectasia (dilatation), cysts, and lobular hyperplasia, all of which may demonstrate focal fibrosis. Widespread bilateral breast enlargement and swelling may also occur with fibroadenomatous hyperplasia, a type of lobular hyperplasia that may appear after prolonged metestrus, false pregnancy or pregnancy or use of exogenous progesterone.
If the tumor mass is palpable, confirmation that it is neoplasia requires tissue biopsy or fine needle aspiration to perform cytological examination. Because most mammary tumors in cats are malignant, fine needle aspiration is more reliable than in dogs and useful in confirming the diagnosis (Figure 5).
Figure 5. Cytologic examination of feline mammary carcinoma demonstrating a mass of polygonal neoplastic epithelial cells with anisocytosis and anisokaryosis, several multinucleated cells, and visible nucleoli, often several per nucleus.
Most mammary tumors in cats arise from the glandular epithelium and all are strictly adenomas or adenocarcinomas, although the latter are often classified as carcinomas. Benign tumors are uncommon, with fibroadenoma being the most common and simple adenoma or ductal papilloma being rare. The main histological type of mammary tumors in cats is simple adenocarcinoma, arising from the epithelium of the mammary ducts and alveoli (Figure 6). Complex or mixed tumors involving both ductal and myoepithelial cells are rare in cats compared to dogs, although they may be associated with a better prognosis (22,23). In cats, carcinomas may be tubulopapillary, solid, cribriform, or mucinous, although transitional cell carcinoma and mixed carcinosarcoma also occur (24).
Figure 6. Histological examination of simple adenocarcinoma of the mammary glands of cats. Sections show invasion of the primary tumor into the muscle (a), metastasis to the lungs (b) with tumor cells in the blood vessels and lung tissue.
Inflammatory breast carcinoma, which has a particularly poor prognosis due to an additional inflammatory component that blocks lymphatic system and impairing lymphatic drainage, causing glandular swelling and tenderness, was identified in three cats with underlying high-grade, papillary mammary carcinoma (25).
If a breast tumor is suspected or confirmed, then studies should be performed to determine the local extent and degree of invasion into body tissue before surgical removal of the tumor. Because few breast masses are benign and general appearance is not a reliable basis for differentiating benign from malignant tumors, disease staging should be routine when breast masses are present. The WHO staging system is commonly used (Table 1) (26)
Measurement of the primary tumor is important because tumor size affects prognosis: tumors<3 см в диаметре ассоциированы с лучшим выживанием, чем опухоли >3 cm.
Table 1 TNM and clinical staging system for feline mammary tumors
Staging of a confirmed tumor should include palpation and aspiration of lymph nodes draining the tumor site, since more than a quarter of cats have regional metastases at the time of diagnosis (27). Involvement of multiple axillary lymph nodes is usually detected by lymphangiography (58-75% of cases), but involvement single lymph node is more common (84-94% of cats) (28). Although axillary and inguinal lymph nodes are the most commonly involved lymph nodes in feline mammary tumors (80% of cats), obstructive lymph nodes may also be involved (30% of cats) (27). To assess the spread of the tumor in the body, radiography in three projections (mainly performed under anesthesia in the inspiratory phase) and ultrasound examination of the abdominal cavity are performed, since the most common regions of metastases are the lungs, medial iliac lymph nodes and abdominal organs (Figure 7). Pulmonary metastases usually show a miliary pattern on chest x-ray, but the pleural membranes may also be involved and in some cases metastatic lung disease may cause pleural effusion(Image 8). More rarely, metastases can be detected in the bones.
Figure 7. Enlarged left medial iliac lymph node with surrounding hyperechoic fat identified on ultrasound examination to determine the stage of the disease in an eleven-year-old Abyssinian neutered cat with mammary carcinomas in the left caudal abdominal and right cranial thoracic lobes.
Figure 8 Left lateral (a) and dorsoventral (b) radiographs of the cat's chest cavity from Figure 7. These radiographs showed a general increase in radiodensity within the chest cavity with a pronounced collapse of the lung fields below the dorsal wall and a smoothing of the silhouette of the heart and diaphragm, which is characteristic of pleural effusion .
Advanced imaging techniques (including computed tomography) of the lungs provide a more accurate assessment of the presence of metastases and should be used if chest radiography raises questions.
Figure 9. X-ray in the left lateral projection of a 12-year-old unsterilized domestic shorthair cat with carcinoma of the second abdominal lobe of the mammary gland. A pair of faint, ill-defined soft tissue masses superimposed on the silhouette of the heart and raised suspicion for metastases in this view (arrows) but not in the right lateral view. ST chest confirmed the presence of hyperattenuated nodules measuring 2-3 mm in the middle right lobe of the lung and (b) and a hyperattenuated nodule measuring 4.8 mm in the caudal part of the left lobe of the lungs (arrow).
Since most sick animals are aged, it is also necessary to perform general and biochemical tests blood and urine tests to identify concurrent diseases. Paraneoplastic conditions are rare in mammary tumors, and feline leukemia virus and feline immunodeficiency virus are not related to the etiology of the disease. However, if considered further treatment, including chemotherapy, it is important to assess the status of viral infections, since immunosuppression caused by viruses may affect the effectiveness of treatment.
The main method of treating mammary gland tumors is still surgical removal. The volume of surgery is influenced by the lymphatic drainage pathways for mammary gland tumors (see table), since tumor cells quickly spread beyond the primary tumor and complete removal of the tumor must include all possible lymphatic drainage pathways.
Recommendations based on studies of lymphatic drainage pathways include unilateral or bilateral mastectomies, due to possible contact between individual lobes and between the right and left sides. Although radiographic imaging studies suggest that this is not necessary in every case, additional prognostic analyzes support the use of unilateral or bilateral mastectomy because the apparent surgical volume corresponds to a significant difference in local recurrence/disease-free interval (DFI) (33) and survival time (34).
For bilateral mastectomy, a two-week interval between operations is recommended, although simultaneous bilateral mastectomy can also be performed (Figure 10). Fixation of the tumor to the skin or abdominal fascia is an indication for en bloc removal of these structures (35).
Figure 10. Bilateral mastectomy in a cat with mammary carcinoma.
Removal of lymph nodes The inguinal lymph node has a close connection to the caudal lobe of the mammary gland and is therefore removed along with the lobe as part of the gland block being removed. An axillary lymph node should be removed if it is enlarged or if there is tumor extension identified by biopsy or FNA, but there is no evidence that prophylactic removal prolongs survival.
Simultaneous ovariohysterectomy. There is no evidence that ovariohysterectomy at the time of mastectomy has any benefit on survival or tumor recurrence (8), or the development of new tumors or carcinoma progression (10). It may, however, reduce the need for progestin therapy, which may be beneficial.
Because tumor cells spread rapidly from primary focus, complete removal of all known drainage routes must be carried out.
Lymphatic drainage has been studied by dye injection and postmortem examination (29,30) and radiological
using intravital methods healthy cats(28), the latter was more accurate because dynamic blood pressure influences the direction of natural lymphatic flow. The data from most studies agree that the first and second (thoracic) lobes drain cranially into the axillary lymph nodes; although postmortem studies have shown that the second lobe may drain caudally into axillary lymph node, this is not visualized using X-ray methods. The third (abdominal) lobe drains both cranially into the axillary and caudally into the inguinal lymph nodes, and the fourth lobe drains caudally into the inguinal lymph node. Direct drainage from the third and fourth abdominal lobes to the medial iliac lymph node was reported in one cat, however, direct drainage from the first, second, third lobes to the retrosternal lymph node was not confirmed in this cat.
Although connectivity between the lobes of the mammary gland and between the right and left sides has previously been suggested, intravital studies have not confirmed this in healthy cats (28). Drainage may vary between normal and tumor-bearing lobes, making it difficult to determine precise drainage routes (31) and probably making it desirable to use indirect lymphography in each patient to help determine the type of drainage and examine sentinel lymph nodes (32). Potentially, this may encourage more conservative resections.
There is some evidence showing that chemotherapy may be effective in in vitro breast cell lines (36⇓–38) and that in vivo treatment of unresectable disease with doxorubicin and cyclophosphamide can reduce tumor size in 50% of cases and possibly prolong survival (Table 2 ) (38-40). The benefit of using chemotherapy as an adjunct to surgical removal of mammary tumors in cats, however, is not yet clear (Table 3).
Table 2. Effect of chemotherapy (doxorubicin) on breast carcinomas
Table 3 Effect of chemotherapy (doxorubicin) as an adjunct to surgical removal of mammary gland tumors.
DFI - time interval without illness
Doxorubicin1 1 mg/kg IV every 3 weeks
Doxorubicin 2 dose not given
Cyclophosphamide dose not given
Doxorubicin 3 1 mg/kg IV every 3 weeks (one case was given IV vincristine 0.7 mg/m2 and 13 cases were given cyclophosphamide 250 mg/m2 IV 1 week after doxorubicin)
A large multicentric study of 67 cats supplemented with doxorubicin reported a median survival time of 448 days (41). Although this study did not have a control group, this survival time was longer than historical controls and was similar to that obtained in another study of 23 cats without a control group (460 days) when combining supplemental doxorubicin with the COX-2 inhibitor meloxicam (42).
A more recent study of 73 cats, which included a control group of 36 cats undergoing surgical excision alone, reported increased survival time and DFI for cats receiving postoperative doxorubucin and cyclophosphamide (1406 vs 848 days [survival time] and 676 vs 372 days)34 ); however, the difference was not statistically significant.
It is possible that with larger numbers and greater statistical power, the true benefit of aggressive chemotherapy may become apparent. Alternatively, different approaches to antiangiogenic metronomic (low-dose) chemotherapy may be effective, although low-dose chemotherapy using vincristine, cyclophosphamide, and methotrexate does not prevent relapse or metastasis, in one report (8).
Although immunomodulators such as Bacillus Calmette-Guerin (BCG) (43), Corynebacterium parvum (44), liposome-encapsulated muramyl tripeptid ephosphatidylethanolamine (L-MTP-PE) (45) and oral levamisole (46) have been used by injection in tumor (BCG) or in addition to surgical removal of mammary tumors in cats, has not been proven to be present beneficial effect for survival time or changes in recurrence rate. There are no reports on the use of antiestrogens in cats, probably because most malignant tumors Feline mammary glands do not have estrogen receptors and the expected benefit is therefore likely to be minimal.
Small molecule inhibitors that act on receptor tyrosine kinases (receptor tyrosine kinase inhibitors or RTKIs) are effective in treating some types of veterinary tumors, especially those that have impaired TK activity (47). Imatinib and masitinib are well tolerated in cats (48–51), but there is no information available on their effectiveness against feline mammary tumors.
The prognosis is poor for most cats with mammary tumors, and death is usually caused by local recurrence or metastasis. The average time between tumor detection and death is 10–12 months (20.35); however, as already mentioned, the prognosis of breast tumors is influenced by several factors. (Table 4)
Table 4. Prognostic factors for feline mammary tumors
|
Factor |
Details |
|
Tumor size |
Diameter ˂ 3 cm – median survival 21-24 months Diameter ˃ 3 cm – median survival 4-12 months |
|
Stage I - median survival 20 months Stage II – median survival 12.5 months Stage III—median survival 9 months Stage IV – median survival 1 month |
|
|
Operative field area |
Radical surgery(unilateral mastectomy) reduces recurrence rates compared to conservative mastectomy |
|
Histopathological ranking |
A breast tumor (MBT) is a neoplasm associated with pathological tissue growth that increases in size over time. This is one of the most common neoplasms found in cats. Modern medicine located nearby effective techniques on their treatment, but a successful outcome and later life The care of your pet depends primarily on the timeliness of seeking medical help.
The tumor is a lump, the size of which varies from a small nodule to a tennis ball. It can be of two types:
Fibroadenomatous hyperplasia in the Sphynx
Most often, AMF occur in unsterilized elderly individuals (over 7 years old), as well as in those who have suffered trauma to the mammary glands or suffer from hormonal imbalances. And for a share benign formations accounting for 10-15% of cases, while the rest are classified as malignant. Pathology does not occur in animals that were sterilized before the first heat, and all other individuals are already at risk. Moreover, the disease can be detected even in young pets (up to 2 years of age).
A neoplasm can be diagnosed using palpation, x-rays or ultrasound. But its type and nature can only be determined through cytological or histological examination of material taken from the tumor using a syringe. Additionally taken general analysis blood and other studies are carried out that allow us to assess the health of the animal and determine further actions that will be appropriate in a particular case.
The main method of treating breast tumors is surgery, during which the overgrown tissue is completely removed. After surgery, the removed material is sent for histological examination, and based on its results, further treatment is prescribed and its outcome is predicted.
IN postoperative period in some cases, a course of chemotherapy is prescribed to destroy possible remnants of tumor cells in the body. It is a procedure of drip administration of drugs (cytoxan, mitoxantrone, etc.) with an interval of 21 days and is usually well tolerated by cats without causing hair loss.
As additional means for treatment, you can give the animal decoctions of milkweed, calendula, arnica, wild rosemary, and knotweed. They contain substances that block the development of tumor cells. But this can only be done after the veterinarian's approval.
Progress of the operation to remove the tumor:
Depending on the severity of the lesion, the lump, one mammary gland, or an entire line is removed. In particularly severe situations, treatment involves a bilateral mastectomy - removal of two lines of mammary glands, which is carried out in two steps.
The operation to remove a breast tumor belongs to the category of complex surgical interventions. Due to the fairly high percentage of relapses, doctors do not promise fast recovery and a favorable outcome of the operation. One of the factors on which recovery depends is the degree of damage:
The operation is not always possible due to the age of the animal: the older it is, the more difficult it is to tolerate general anesthesia and postoperative period.
If the tumor was not detected in a timely manner and no treatment was carried out, it may open. This phenomenon also indicates the progression pathological process and advanced stage of the disease. In this case, a wound appears from which the contents are released with a sharp unpleasant smell, sometimes pus and blood. In this case, the pet should be immediately taken to the veterinarian to receive recommendations on further actions. The optimal method in this situation is the same surgical removal of the breast cancer, excision of painful tissue. All other methods do not solve the underlying problem and metastases can spread to other organs, which deprives the pet of a chance for recovery. But if a cat’s mammary tumor bursts, and surgery is impossible for health reasons or other reasons, then the following is prescribed:
If any kind of lump is detected in the area of the cat's mammary glands, it should be immediately shown to a veterinarian for a diagnosis. How long a cat diagnosed with a mammary gland tumor will live depends on the timeliness of seeing a doctor, as well as the age general condition health and type of education. One of the main factors that affects life expectancy is the size of the tumor at the time of treatment (measured along the largest side):
If the diagnosis is made on early stages, removal of AMF significantly increases the chances of prolonging the pet’s life. Late diagnosis large sizes neoplasms and the development of metastatic processes gives a prognosis for life within 6-12 months.
That is why it is important for the cat owner to regularly monitor the condition of her mammary glands, and if suspicious lumps appear, not to postpone a visit to the veterinarian.
You can also ask a question to our site's staff veterinarian, who as soon as possible will answer them in the comment box below.
In cats, this is, unfortunately, a common occurrence. This disease takes the lives of four-legged pets who are unable to resist the disease. There are different treatment methods, but none of them gives a 100% result.
Diseases associated with neoplasms are a real scourge of the modern world. Thousands of people and animals die from them every year. Medicine in this area does not stand still, and recently treatment oncological diseases is becoming more and more successful.
However, a medicine has not yet been obtained that would help absolutely everyone. In veterinary medicine, the situation is no better, especially when it comes to treating cats. The main means of stopping tumor growth is chemotherapy, but there is no guarantee that this goal will be achieved. A tumor of the mammary glands in cats will cause a lot of trouble for both the animal and the owner.
The mammary glands in animals are designed to feed newborn kittens. They are located in pairs on the chest and stomach of the cat, their total number normally equals eight. Their work begins before childbirth (swelling) and during false pregnancy (hormonal processes).
Diseases of the mammary glands are reported in adult cats, regardless of whether they have given birth or not. The most common ailments are: mastitis, cancer and mastopathy. In some cases, veterinarians remove the affected glands.
It is difficult for a non-professional to distinguish between them, especially in the early stages. With mastitis, inflammation of the mammary gland occurs. Occurs in cats with excess milk (early weaning of kittens) or false pregnancy. The gland increases in size, redness and increased temperature are observed. There may be discharge from the nipple different colors and composition.
Mastopathy is swelling of the mammary glands, which can be normal or pathological. In the latter case, gray liquid accumulates inside and the skin turns blue.
In order not to confuse these diseases, look at what a mammary tumor in a cat looks like (there is a photo in the article).
Over 85 cases of neoplasms out of 100 are malignant. In the latter, there is a noticeable tendency towards growth and the appearance of metastases in the shortest possible time. And it all starts, as a rule, with a small lump, just like in humans.
What types of mammary tumors are there in cats? It can be malignant and benign. In the latter case, there is no cause for concern, because such neoplasms are characterized by slow growth, clear localization and lack of tendency towards necrotic processes.
Cancerous tumors often appear in several places at the same time. Interestingly, in a kitten up to 6 months of age, it reduces the likelihood of tumors appearing almost to zero and completely eliminates the malignant type. But the owners of animals kept for breeding will not be satisfied with this path. In addition, in the future the cat will need hormonal drugs, to avoid metabolic problems.
Each one goes through several stages of its growth:
What causes mammary tumors to appear in cats? Veterinarians and other specialists do not have a consensus on this matter. However, there is large number versions.
For example, life in big cities with high level Environmental pollution adversely affects the health of the animal. The same factors include monotony of diet, low quality food, and sometimes completely spoiled food. The predisposition to pathology at the genetic level cannot be ignored. By the way, this is why new owners are advised to take a closer look at the pet’s pedigree before purchasing it.
As a rule, the symptoms of a mammary tumor in cats are quite simple. These include:
Pets actively lick the affected area with their rough tongue, which only worsens the situation because it provokes the appearance of ulcers. At the same time, the mammary glands emit a nasty smell of rotting tissue. As a result, the animal feels worse every day: strength and weight are lost, and the existing chronic diseases move into the acute phase.
You can find out whether a cat has a malignant or mammary gland using a biopsy. This should be done very carefully to avoid mechanical damage. In addition, during education serious breaks Metastases may appear - harbingers of the imminent death of the animal.
Timely diagnosis makes it possible to determine the onset of the disease and immediately begin chemotherapy to save pet. They are usually carried out close to the site of the lesion, because it is in them that metastases of neoplasms settle. Ultrasound and X-ray examination make it possible to determine their presence in the lungs and other abdominal organs.
A tumor of the mammary glands in cats requires blood tests: general and biochemical. They are necessary to determine the severity of the disease and the most suitable type chemotherapy for a specific pet.
If a mammary tumor is detected in a cat, treatment should begin immediately. In most cases, surgery can save the pet, but its feasibility is questionable. An old animal that has lost a lot of strength may simply not survive this. In this case, you should limit yourself conservative treatment. Drugs appear regularly that cope better with neoplasms. This gives hope for a favorable outcome in the fight against the disease.
However, if possible, it is worth giving preference to surgical intervention, because it allows you to remove the entire affected area with metastases (the latter is not always the case). This method is indispensable when peripheral lymph nodes are affected. If they are not cut out, the cancer will soon spread throughout the body.
Removal of a mammary gland tumor in a cat is carried out together with the entire organ, since only occasionally it is possible to localize its location (if the tumor is benign).
The situation becomes more complicated when a bilateral mastectomy is necessary, since it is extremely difficult for cats to tolerate. Chemotherapy sessions are not canceled in order to completely stop the development of the tumor. It is required to show your pet to a veterinarian every day to monitor the general condition of the body and prevent its rapid deterioration.
If treatment was decided to be carried out conservatively, then daily visits to the doctor become mandatory. The cat will be tested regularly (almost every day) to monitor the effects of toxic and dangerous substances used in chemotherapy on the four-legged pet's body.
Under no circumstances should you self-medicate. Applying heat (such as heated salt) only makes the situation worse. As a result, the neoplasm begins to develop more intensively, and the malignant one will metastasize. Availability inflammatory processes and necrosis is also a contraindication for the use of heat compresses.
In the most difficult situations, the animal is left in veterinary clinic under the supervision of specialists. The cat is given anesthetics and other important substances.
One of important factors, which has a direct impact on the result of the treatment, is the organization of conditions for the sick animal. If an operation is detected, it will help get rid of it. But after surgery, the pet needs complete rest and feeding only what the veterinarian allows.
Ask him what drug to treat postoperative suture. Strictly follow your doctor's recommendations regarding the timing and dosage of taking medications. A special blanket is put on the cat, which will tighten and protect the seam. If a wound is opened, contact your veterinarian immediately.
The specialist will conduct examinations and take tests every week to monitor the condition of the animal’s body. This way he will be able to timely diagnose a relapse (if it happens). Even if a cat’s mammary tumor is removed, no one can say how long the animal will live.
As already mentioned, before she reaches 6 months of age, it greatly reduces the likelihood of getting cancer. After cutting out the tumor, you cannot refuse to remove the ovaries. This will prevent relapse and prolong the life of your pet.
Always pay attention to any swelling that may be noticed when caring for your animal. Ignoring them can lead to very serious consequences. A festering and burst tumor should not be touched or picked at, as these actions contribute to the appearance of metastases. You cannot simply observe the tumor, hoping that “everything will heal on its own,” because during this time it will grow so much that surgical intervention will no longer be advisable. All that remains is to watch as the pet rots alive.
The sooner the disease is found, and the sooner the veterinarian performs the operation, the higher the chance of a complete cure.
For non-breeding pet owners, it is recommended that cats be spayed. But you need to decide on this as early as possible, then the risk of cancer will decrease almost to zero.
Photo magazine Clinician's Brief
Journal of Feline Medicine and Surgery May 2013 15: 391-400,
Translation from English . Vasiliev AB
Practical significance: Mammary tumors are one of the most common tumors in both cats and dogs, but the prevalence of malignant histological types in cats is much higher (the ratio of malignant to benign is at least 4:1).
Clinical problems: The more aggressive nature of mammary tumors in cats poses treatment challenges. The prognosis is influenced by the size of the tumor and, therefore, early detection and treatment of breast tumors is of paramount importance. Although primary tumors can be removed surgically, there are no studies showing that chemotherapy significantly increases survival time; therefore, metastatic spread remains an important clinical problem.
Patient group: Mammary tumors usually affect older female cats, mainly unspayed females. Siamese and Oriental breeds may be predisposed. Male cats can develop neoplasia, but this is rare.
Evidence base: This review summarizes the current literature regarding the etiology, pathology, clinical presentation, diagnosis, staging, treatment, and prognosis of feline mammary tumors.
Mammary tumors are the third most common type affecting female cats, after lymphoma and skin tumors, accounting for 17% of all tumors. The published incidence is 25.4 per 100,000 female cats per year(1). Although precise statistics are not available, the incidence of breast tumors may vary globally, depending on the adoption of sterilization policies. Sterilization is performed less frequently in Scandinavia and some other parts of Europe than in the UK, for example.
Mammary tumors occur in older female cats (average age 10-12 years) and usually in unspayed cats. Mammary tumors also occur in male cats (mean age 12.8 years) (7), but they are rare, accounting for 1–5% of mammary tumors. Siamese cats and other Oriental breeds may be at risk for developing mammary tumors at a younger age, but domestic shorthair cats, which are probably the most common cat breed, are also very often affected by these tumors.
As in humans and dogs, hormonal fluctuations associated with repeated estrous cycles may influence the development of mammary tumors in cats. This is supported by a case-control study reporting that cats neutered before 1 year of age had a reduced risk of developing mammary tumors (9) and that non-neutered cats were 7 times more likely to have mammary tumors in the cat population in comparison. with a control group (10). However, cats spayed before 1 year of age also develop mammary tumors, so early spaying does not eliminate the risk of mammary tumors (8) and early studies report an increased incidence of mammary tumors , may perhaps reflect sterilization practices at the time more than a true increased risk (11).
Other evidence supporting a hormonal etiology is that estrogen and progesterone receptors are found in normal breast tissue and benign tumors, but are often absent in malignant tumors and metastases (12–17). In addition, exogenous administration of progesterone to prevent pregnancy or suppress aggression has been associated with the development of tumors (benign and malignant) in both male (18) and female cats (19). A possible dose-dependent effect may occur, with an increased risk of breast carcinoma if progesterone is given regularly rather than intermittently (10).
There is no definitive evidence for a viral etiology of mammary tumors in cats, although this has been suggested in early reports. Obesity doesn't matter, but dogs do.
Cats have 4 pairs of mammary glands (2 mammary and 2 abdominal) and although any tumor can be involved, some studies report a predisposition of the caudal glands to mammary tumors (11,20). Mammary tumors appear as solitary subcutaneous nodules or masses in within the mammary glands (Figures 1 and 2), which may be discrete and mobile or associated with underlying tissue and appear ulcerated (Figure 3). Some may look like cysts. In cats, it is difficult to distinguish benign from malignant nodules, so all should be treated as potentially malignant. Multiple tumor masses within multiple lobes are common (usually unilateral but occasionally bilateral) (Figure 4) and, according to one study, occur in 60% of cats (8). Sometimes the true extent of this disease cannot be assessed without removing the fur. Drained lymph nodes (inguinal or axillary) may also be visible or palpable enlarged.
.
Fig.1 Tumor mass in the thoracic lobe of the mammary gland in an 11-year-old unsterilized domestic shorthair cat
Figure 2 Tumor mass in the pectoral lobes and axillary lymph node of an eight-year-old unsterilized domestic shorthair cat.
Figure 3 Ulcerated tumor mass of the second abdominal lobe in a 21-year-old neutered domestic shorthair cat
Figure 4. Bilateral masses in the mammary glands before (a) and after (b) hair removal
In the presence of aggressive inflammatory carcinoma with widespread lymphatic involvement, the breasts may be swollen, hot, and tender (4). This clinical presentation may be difficult to distinguish from fibroadenoma hyperplasia (fibroepithelial hypertrophy, feline mammary hypertrophy), although the latter more commonly affects young cats (21).
Differential diagnosis
A variety of non-neoplastic hyperplasias and dysplasias can occur in the mammary glands and, although much less common in cats than in dogs, they can all be mistaken for mammary tumors. These include glandular ductal hyperplasia, ductal ectasia (dilatation), cysts, and lobular hyperplasia, all of which may demonstrate focal fibrosis. Widespread bilateral breast enlargement and swelling may also occur with fibroadenomatous hyperplasia, a type of lobular hyperplasia that may appear after prolonged metestrus, false pregnancy or pregnancy, or the use of exogenous progesterone.
If the tumor mass is palpable, confirmation that it is neoplasia requires tissue biopsy or fine needle aspiration to perform cytological examination. Because most mammary tumors in cats are malignant, fine needle aspiration is more reliable than in dogs and useful in confirming the diagnosis (Figure 5).
Figure 5. Cytologic examination of feline mammary carcinoma demonstrating a mass of polygonal neoplastic epithelial cells with anisocytosis and anisokaryosis, several multinucleated cells, and visible nucleoli, often several per nucleus.
Most mammary tumors in cats arise from the glandular epithelium and all are strictly adenomas or adenocarcinomas, although the latter are often classified as carcinomas. Benign tumors are uncommon, with fibroadenoma being the most common and simple adenoma or ductal papilloma being rare. The main histological type of mammary tumors in cats is simple adenocarcinoma, arising from the epithelium of the mammary ducts and alveoli (Figure 6). Complex or mixed tumors involving both ductal and myoepithelial cells are rare in cats compared to dogs, although they may be associated with a better prognosis (22,23). In cats, carcinomas may be tubulopapillary, solid, cribriform, or mucinous, although transitional cell carcinoma and mixed carcinosarcoma also occur (24).
Figure 6. Histological examination of simple adenocarcinoma of the mammary glands of cats. Sections show invasion of the primary tumor into the muscle (a), metastasis to the lungs (b) with tumor cells in the blood vessels and lung tissue.
Inflammatory mammary carcinoma, which has a particularly poor prognosis due to an additional inflammatory component that blocks the lymphatic system and impairs lymphatic drainage, causing the glands to become swollen and tender, was identified in three cats with an underlying high-grade, papillary mammary carcinoma (25).
If a breast tumor is suspected or confirmed, then studies should be performed to determine the local extent and degree of invasion into body tissue before surgical removal of the tumor. Because few breast masses are benign and general appearance is not a reliable basis for differentiating benign from malignant tumors, disease staging should be routine when breast masses are present. The WHO staging system is commonly used (Table 1) (26)
Measurement of the primary tumor is important because tumor size affects prognosis: tumors<3 см в диаметре ассоциированы с лучшим выживанием, чем опухоли >3 cm.
Table 1 TNM and clinical staging system for feline mammary tumors
Staging of a confirmed tumor should include palpation and aspiration of lymph nodes draining the tumor site, since more than a quarter of cats have regional metastases at the time of diagnosis (27). Involvement of multiple axillary lymph nodes is usually detected by lymphangiography (58-75% of cases), but involvement single lymph node is more common (84-94% of cats) (28). Although axillary and inguinal lymph nodes are the most commonly involved lymph nodes in feline mammary tumors (80% of cats), obstructive lymph nodes may also be involved (30% of cats) (27). To assess the spread of the tumor in the body, radiography in three projections (mainly performed under anesthesia in the inspiratory phase) and ultrasound examination of the abdominal cavity are performed, since the most common regions of metastases are the lungs, medial iliac lymph nodes and abdominal organs (Figure 7). Pulmonary metastases usually show a miliary pattern on chest x-ray, but the pleural membranes may also be involved and in some cases metastatic lung disease may cause pleural effusion (Figure 8). More rarely, metastases can be detected in the bones.
Figure 7. An enlarged left medial iliac lymph node with surrounding hyperechoic fat identified on staging ultrasound in an eleven-year-old spayed Abyssinian cat with mammary carcinomas in the left caudal abdominal and right cranial thoracic lobes.
Figure 8 Left lateral (a) and dorsoventral (b) radiographs of the cat's chest cavity from Figure 7. These radiographs showed a general increase in radiodensity within the chest cavity with a pronounced collapse of the lung fields below the dorsal wall and a smoothing of the silhouette of the heart and diaphragm, which is characteristic of pleural effusion .
Advanced imaging techniques (including computed tomography) of the lungs provide a more accurate assessment of the presence of metastases and should be used if chest radiography raises questions.
Figure 9. X-ray in the left lateral projection of a 12-year-old unsterilized domestic shorthair cat with carcinoma of the second abdominal lobe of the mammary gland. A pair of faint, ill-defined soft tissue masses superimposed on the silhouette of the heart and raised suspicion for metastases in this view (arrows) but not in the right lateral view. CT scan of the chest confirmed the presence of a 2-3 mm hyperattenuated nodule in the right middle lobe of the lung and (b) and a 4.8 mm hyperattenuated nodule in the caudal left lobe of the lung (arrow).
Since most sick animals are aged, it is also necessary to perform general and biochemical blood tests and a urine test to identify concurrent diseases. Paraneoplastic conditions are rare in mammary tumors, and feline leukemia virus and feline immunodeficiency virus are not related to the etiology of the disease. However, if further treatment, including chemotherapy, is being considered, it is important to assess viral infection status, as immunosuppression caused by viruses may interfere with the effectiveness of treatment.
The main method of treating mammary tumors is still surgical removal. The extent of the operation is influenced by lymphatic drainage pathways for mammary gland tumors (see table), since tumor cells quickly spread beyond the primary tumor and complete removal of the tumor must include all possible lymphatic drainage pathways.
Recommendations based on studies of lymphatic drainage pathways include unilateral or bilateral mastectomies, due to possible contact between individual lobes and between the right and left sides. Although radiographic imaging studies suggest that this is not necessary in every case, additional prognostic analyzes support the use of unilateral or bilateral mastectomy because the apparent surgical volume corresponds to a significant difference in local recurrence/disease-free interval (DFI) (33) and survival time (34).
For bilateral mastectomy, a two-week interval between operations is recommended, although simultaneous bilateral mastectomy can also be performed (Figure 10). Fixation of the tumor to the skin or abdominal fascia is an indication for en bloc removal of these structures (35).
Figure 10. Bilateral mastectomy in a cat with mammary carcinoma.
Removal of lymph nodes The inguinal lymph node has a close connection to the caudal lobe of the mammary gland and is therefore removed along with the lobe as part of the gland block being removed. An axillary lymph node should be removed if it is enlarged or if there is tumor extension identified by biopsy or FNA, but there is no evidence that prophylactic removal prolongs survival.
Simultaneous ovariohysterectomy. There is no evidence that ovariohysterectomy at the time of mastectomy has any benefit on survival or tumor recurrence (8), or the development of new tumors or carcinoma progression (10). It may, however, reduce the need for progestin therapy, which may be beneficial.
Because tumor cells spread rapidly from the primary site, complete removal of all known drainage routes must be performed.
Lymphatic drainage has been studied by dye injection and postmortem examination (29,30) and radiological
intravital methods in healthy cats (28), the latter was more accurate because dynamic blood pressure influences the direction of natural lymphatic flow. The data from most studies agree that the first and second (thoracic) lobes drain cranially into the axillary lymph nodes; although pathological studies have shown that the second lobe may drain caudally into the axillary lymph node, this is not visualized using radiographic techniques. The third (abdominal) lobe drains both cranially into the axillary and caudally into the inguinal lymph nodes, and the fourth lobe drains caudally into the inguinal lymph node. Direct drainage from the third and fourth abdominal lobes to the medial iliac lymph node was reported in one cat, however, direct drainage from the first, second, third lobes to the retrosternal lymph node was not confirmed in this cat.
Although connectivity between the lobes of the mammary gland and between the right and left sides has previously been suggested, intravital studies have not confirmed this in healthy cats (28). Drainage may vary between normal and tumor-bearing lobes, making it difficult to determine precise drainage routes (31) and probably making it desirable to use indirect lymphography in each patient to help determine the type of drainage and examine sentinel lymph nodes (32). Potentially, this may encourage more conservative resections.
There is some evidence showing that chemotherapy may be effective in in vitro breast cell lines (36⇓–38) and that in vivo treatment of unresectable disease with doxorubicin and cyclophosphamide can reduce tumor size in 50% of cases and possibly prolong survival (Table 2 ) (38-40). The benefit of using chemotherapy as an adjunct to surgical removal of mammary tumors in cats, however, is not yet clear (Table 3).
Table 2. Effect of chemotherapy (doxorubicin) on breast carcinomas
Table 3 Effect of chemotherapy (doxorubicin) as an adjunct to surgical removal of mammary gland tumors.
DFI - time interval without illness
Doxorubicin1 1 mg/kg IV every 3 weeks
Doxorubicin 2 dose not given
Cyclophosphamide dose not given
Doxorubicin 3 1 mg/kg IV every 3 weeks (one case was given IV vincristine 0.7 mg/m2 and 13 cases were given cyclophosphamide 250 mg/m2 IV 1 week after doxorubicin)
A large multicentric study of 67 cats supplemented with doxorubicin reported a median survival time of 448 days (41). Although this study did not have a control group, this survival time was longer than historical controls and was similar to that obtained in another study of 23 cats without a control group (460 days) when combining supplemental doxorubicin with the COX-2 inhibitor meloxicam (42).
A more recent study of 73 cats, which included a control group of 36 cats undergoing surgical excision alone, reported increased survival time and DFI for cats receiving postoperative doxorubucin and cyclophosphamide (1406 vs 848 days [survival time] and 676 vs 372 days)34 ); however, the difference was not statistically significant.
It is possible that with larger numbers and greater statistical power, the true benefit of aggressive chemotherapy may become apparent. Alternatively, various approaches to antiangiogenic metronomic (low-dose) chemotherapy may be effective, although low-dose chemotherapy using vincristine, cyclophosphamide, and methotrexate does not prevent relapse or metastasis, in one report (8).
Although immunomodulators such as Bacillus Calmette-Guerin (BCG) (43), Corynebacterium parvum (44), liposome-encapsulated muramyl tripeptid ephosphatidylethanolamine (L-MTP-PE) (45) and oral levamisole (46) have been used by injection in tumor (BCG) or in addition to surgical removal of mammary tumors in cats, has not been shown to have a beneficial effect on survival time or change the rate of recurrence. There are no reports on the use of antiestrogens in cats, probably because most feline mammary malignancies do not have estrogen receptors and the expected benefit is therefore likely to be minimal.
Small molecule inhibitors that act on receptor tyrosine kinases (receptor tyrosine kinase inhibitors or RTKIs) are effective in treating some types of veterinary tumors, especially those that have impaired TK activity (47). Imatinib and masitinib are well tolerated in cats (48–51), but there is no information available on their effectiveness against feline mammary tumors.
The prognosis is poor for most cats with mammary tumors, and death is usually caused by local recurrence or metastasis. The average time between tumor detection and death is 10–12 months (20.35); however, as already mentioned, the prognosis of breast tumors is influenced by several factors. (Table 4)
Table 4. Prognostic factors for feline mammary tumors
|
Factor |
Details |
|
Tumor size |
Diameter ˂ 3 cm – median survival 21-24 months Diameter ˃ 3 cm – median survival 4-12 months |
|
Clinical stage |
Stage I - median survival 20 months Stage II – median survival 12.5 months Stage III—median survival 9 months Stage IV – median survival 1 month |
|
Operative field area |
Radical surgery (unilateral mastectomy) reduces recurrence rates compared with conservative mastectomy |
|
Histopathological ranking |
