Page 1244 - Cote clinical veterinary advisor dogs and cats 4th

622 Mammary Gland Neoplasia, Cat

Initial Database • Adjuvant chemotherapy is advised for cats PROGNOSIS & OUTCOME
• Physical exam with poor prognostic factors, although • Local recurrence rate > 50% with incomplete
VetBooks.ir ○ Describe possible signs of invasiveness combinations/protocols that are most effective • Prognostic factors for cats with mammary
○ Measure primary tumor (T).
clinical studies to determine chemotherapy
excision
(ulceration, fixation).
for increasing survival time need to be
○ Evaluate regional lymph nodes (N):
○ Tumor size (survival times with surgery
palpation and cytologic analysis performed. gland carcinomas
• Thoracic radiographs (three views) for Acute General Treatment alone):
pulmonary metastasis Surgery: ■ > 3 cm: median survival of 4-6 months
• Abdominal ultrasound in case of suspected • Radical mastectomy of the affected mammary (female), 1.6 months (male)
metastasis to abdominal organs or lymph chain(s) is recommended to reduce the risk ■ 2-3 cm: median survival of 1-2 years
nodes of local recurrence. (female), 5.2 months (male)
• Fine-needle aspiration and cytologic evalua- • In contrast to individual mastectomies or ■ < 2 cm: median survival of > 3 years
tion: limited utility but may be useful in dif- lumpectomies, radical mastectomy sig- after mastectomy (female), 14 months
ferentiating neoplasia from fibroadenomatous nificantly reduces the risk for local tumor (male)
hyperplasia recurrence. ○ Type of surgery
• CBC, serum biochemistry profile, urinalysis, • Affected lymph node(s) should be removed ■ Radical mastectomy significantly
coagulation profile in cases of suspected along with the mammary chain. reduces the risk of local tumor recur-
inflammatory carcinoma • Fixation of the tumor to underlying muscle rence compared with conservative
or fascia necessitates en bloc removal of these surgery but does not appear to improve
Advanced or Confirmatory Testing structures. survival time.
• Definitive diagnosis is by biopsy and histo- • In cats with advanced metastatic disease, local ○ Histologic grade: high grade is associated
pathologic evaluation of mammary masses mastectomy to remove ulcerated or infected with a shorter survival time.
and associated lymph nodes mammary tumors may be palliative. ○ Clinical stage at presentation: median
○ Histologic grading scheme is based • Inflammatory carcinoma is nonresectable. survival times for cats with stage I, II,
primarily on mitotic activity, degree of III, and IV disease are 29, 12.5, 9, and
tubule formation, and nuclear/cellular Chronic Treatment 1 month(s), respectively.
pleomorphism. Chemotherapy: ○ Ulceration may be a poor prognostic
○ Because > 85% of feline mammary • Single-agent doxorubicin, doxorubicin in indicator but likely is related to tumor
tumors are malignant, histopathologic combination with cyclophosphamide, single- size.
exam most often is performed on agent carboplatin, alternating doxorubicin • Benign tumors and low-grade malignant
tumor tissue obtained from a radical and carboplatin or toceranib phosphate tumors may be cured by wide excision.
mastectomy. (Palladia) may lead to complete and partial
○ When fibroepithelial hyperplasia (see Dif- responses in cats with metastatic disease or PEARLS & CONSIDERATIONS
ferential Diagnosis) or other nonmammary nonresectable mammary gland tumors.
tumors are suspected, incisional (wedge) • Adjuvant chemotherapy using the previ- Comments
biopsies can be done. ously mentioned drugs as single agents or • Palpation of the mammary glands should
• Lymph node evaluation in combination is recommended in cats after routinely be performed as part of the physical
○ In general, the ipsilateral inguinal or axil- radical mastectomy. However, a true survival exam.
lary lymph node(s) should be removed benefit has yet to be proven. • Mammary carcinoma in the cat is a highly
during radical mastectomy and assessed • Special handling requirements and potentially malignant neoplastic disease that warrants
histopathologically. severe, life-threatening adverse patient effects early diagnosis and an aggressive treatment
○ Axillary lymph nodes may be difficult exist for these drugs. Consultation with a approach.
to isolate, but fine-needle aspiration medical oncologist is recommended. • Adjuvant chemotherapy should be considered
or biopsies can be done if they are Radiation therapy: in cats with resectable mammary carcinoma
enlarged. Ultrasound-guided aspira- • Used to palliate nonresectable disease may after radical mastectomy.
tion cytology may be possible in some be an option in some cats • In cats with advanced disease, palliative
cases. Immunotherapy: measures, including surgery, chemother-
• Distant metastasis • Treatment with levamisole, bacterial vaccines, apy, radiation, and analgesics, may be
○ Cytologic evaluation of pleural effusion and other immunomodulators has not led considered.
can aid in the diagnosis of thoracic to improvement in local tumor control or
metastatic disease. survival. Prevention
○ Advanced imaging (CT, MRI) may Hormonal therapy: • OHE before age 6 months reduces the risk
increase diagnostic accuracy of metastatic • Because most malignant feline mammary but does not prevent mammary carcinoma
lesions in the thoracic and abdominal gland tumors lack estrogen receptors, in female cats.
cavities. anti-estrogen therapy (tamoxifen) is not • Castration does not prevent mammary
effective. carcinoma in male cats.
TREATMENT Analgesics:
• Should be used in cats that present with Technician Tips
Treatment Overview advanced disease Because the timing of OHE is an important
• Treatment consists of complete surgical contributor to the risk of mammary tumor
removal of the mammary tumor(s). The Possible Complications development, it is important to inquire about
recommended surgical approach for cats is Inflammatory carcinoma after mastectomy for its timing when collecting a history on new
radical mastectomy. mammary carcinoma is rare. patients.
• Staged bilateral radical mastectomy is recom-
mended for bilateral disease; bilateral radical Recommended Monitoring Client Education
mastectomy for cats with unilateral disease Regular examinations of the surgical site, local • Early OHE of queens not intended for
is of unproven benefit. lymph nodes, and lung fields breeding

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