Efficacy and toxicity of doxorubicin and cyclophosphamide for the neoadjuvant treatment of locally advanced stage canine mammary tumors

Abstract

The aim of this study was to investigate the effect and toxicity of a doxorubicin cyclophosphamide combination for neoadjuvant use in dogs with locally advanced mammary tumors. A total of 16 dogs with locally advanced mammary tumors aged 8-14 years was used in this study. Samples were taken from all the dogs via Tru-Cut biopsy and fine needle aspiration biopsy of the lymph nodes prior to neoadjuvant chemotherapy. The samples were sent to the pathology laboratory for histopathological examination. Based on the histopathology results, mammary tumors were diagnosed as adenocarcinoma (n=13), tubulopapillary carcinoma (n=2) and malignant mixed tumors (n=1). For the neoadjuvant chemotherapy, doxorubicin (25-30 mg/m(2)) and cyclophosphamide (100 mg/m(2)) were administered via slow IV injection 4 times at 3-week intervals. Clinical findings such as fever, vomiting, anorexia, lethargy, weight loss, alopecia, enteritis, hematuria, and skin ulceration and laboratory findings such as a decrease in neutropenia and hematocrit values were observed. Based on the longest diameter of the tumors before and after four weeks of chemotherapy, a complete response was detected in 2 dogs (12.5%), a partial response was observed in 9 dogs (56.25%) and the disease was stable in 5 dogs (31.25%). According to results, the toxicity, and efficacy of a doxorubicin and cyclophosphamide combination for neoadjuvant chemotherapy in dogs with locally advanced mammary tumors is acceptable, and the treatment is promising.