Thalidomide Treatment in a Canine Mammary Gland Carcinosarcoma Presenting Pulmonary Metastasis

Carcinosarcomas are uncommon in the dog and present an unfavorable prognosis. Thalidomide has been used in the investigational treatment of several diseases due to its known immunomodulatory and anti-angiogenic properties. A female dog underwent radical unilateral mastectomy, which enabled the diagnosis of a stage III and grade III carcinosarcoma, followed by chemotherapy treatment with doxorubicin and carboplatin. Twelve months after the mastectomy, thoracic radiographs revealed the presence of multiple nodules in the lung, and thalidomide administration was initiated at 20 mg/kg/day during three months and then 10 mg/kg/day without discontinuation. The patient did not present any adverse events related to the thalidomide administration and thoracic radiographs demonstrated stable metastatic disease. The patient was euthanized presenting metastasis in several other organs and overall survival was considered 963 days. The progression of distant metastasis in the studied patient was considered hindered by thalidomide.