SALIVARY GLAND TUMORS IN CATS
Background
Most salivary gland tumors are carcinomas. In contrast to dogs, enlargement of a salivary gland in cats is more likely to signal a tumor than inflammation or any other condition.
The median age of affected cats is 10 years, and there is no gender predilection. Siamese cats are at higher risk for developing salivary gland tumors; 7 (26%) of 27 cats were Siamese in one survey.Clinical Parameters
Cats usually have a mass in the cervical region, which may be accompanied by other signs, such as anorexia, dysphagia, and salivation due to secondary infections and ulceration.
Clinical Work-up
Most reported cats have regional lymph node metastases, and one cat developed lung metastases 5 months after surgery. Careful palpation of regional lymph nodes followed by fine-needle aspiration or biopsy of enlarged nodes, as well as blood work, urinalysis, and thoracic radiographs, should precede any definitive treatment for these tumors. In one study, median survival for cats with this disease was 516 days. Staging was not shown to be prognostic in cats, and a low mitotic index was associated with a poorer prognosis. There was no difference in surgery alone versus surgery with chemotherapy or surgery with radiation.
Therapeutic Approach
Cats treated with surgery alone had recurrence or metastasis within 6 months in one study.There are no reports of adjunctive radiation therapy, but limited success in dogs suggests that this therapy may be worthwhile to reduce the risk of local recurrence. There are no reports of chemotherapy for this tumor; however, carboplatin and doxorubicin have been used with favorable results by some.