Treatment of vascular and soft-tissue sarcomas in dogs using an alternating protocol of ifosfamide and doxorubicin.

A retrospective analysis was done to assess the toxicity and efficacy associated with an alternating chemotherapy protocol of ifosfamide (375 mg m(-2)) and doxorubicin (30 mg m(-2)) for adjuvant treatment of 39 dogs with sarcomas. Twelve dogs had various soft-tissue sarcomas and 27 dogs had hemangiosarcoma (HSA). Complete blood counts were evaluated 7 days after the first dose of ifosfamide and doxorubicin. One dog had grade 4 neutropenia (<500 microL(-1)) after treatment with ifosfamide and one dog had grade 3 neutropenia (500-1000 microL(-1)) after treatment with doxorubicin. One dog treated with doxorubicin was hospitalized for 24 h due to vomiting. The median survival time (ST) for the 27 dogs with HSA treated by surgery and with doxorubicin/ifosfamide was 149 days (mean 366 days). Although the protocol of alternating ifosfamide and doxorubicin was well tolerated, it failed to result in a statistically significant improvement in the ST when compared to a historical population of dogs with stage 2 splenic HSA treated by surgery alone.