Clinical and Laboratory Findings in Dogs Undergoing Adjuvant Chemotherapy with Gemcitabine/Carboplatin Combination for Mammary Neoplasia

Abstract

Adjuvant chemotherapy might be indicated in some canine mammary cancer cases due to metastatic potential. In this regard, studies to determine adverse events following chemotherapy protocols are valuable. The purpose of this prospective clinical trial was to evaluate the safety and tolerability of gemcitabine and carboplatin combination in dogs with malignant mammary tumors. For this prospective clinical trial, 21 female dogs mastectomized due to malignant mammary neoplasia underwent adjuvant chemotherapy with gemcitabine (3 mg/kg, 60-minute IV infusion) and carboplatin (10 mg/kg, 20-minute IV infusion) based protocol every 21 days for three cycles. They were monitored periodically for treatment-related adverse events by clinical and laboratory evaluations. A total of 17 (80.9%) dogs developed leukopenia, 10 (47.6%) neutropenia, and 15 (71.4%) thrombocytopenia at least once along with the three chemotherapy cycles. All these hematologic toxicities were grade 1, 2, or 3. Two (9.5%) animals had evidence of gastrointestinal toxicity; however, clinical signs were mild to moderate (grades 1 and 2). No dog had life-threatening adverse events (grade 4) or even died (grade 5) of treatment-related complications. The adjuvant chemotherapy protocol with gemcitabine and carboplatin was well-tolerated and safe in female dogs for mammary cancer treatment with self-limiting hematological and gastrointestinal adverse events.