Single agent chemotherapy with doxorubicin for feline lymphoma: A retrospective study of 19 cases (1994-1997)

Medical records of 21 cats with confirmed lymphoma treated with single-agen t doxorubicin were reviewed. Nineteen cats met the inclusion criteria for t his retrospective study. Doxorubicin was given at a dosage of 25 mg/m(2) (n = 8) or 1 mg/kg (n = II) IV, every 3 weeks for a total of 5 treatments. Fo ur of 16 tested cats were positive for feline leukemia virus (FeLV) and all 16 cats tested negative for feline immunodeficiency virus. Eight of the 19 cats (42%) responded to doxorubicin for a median duration of. 64 days (ran ge. 35-575 days). Five cats (26%) achieved a complete response (CR) to doxo rubicin for a median duration of 92 days (range. 54-575 days). Partial resp onse was observed in :I cats. Institution was the only significant prognost ic indicator for response, with cats treated at Colorado State University b eing more likely to achieve CR than cats treated at Tufts University. Cats that achieved CR to doxorubicin and FeLV-negative cats had significantly lo nger survival times. Loss of appetite was the most common toxicity, observe d in 9 cats (47%). and was severe in 5 cats (26%). Other toxicoses were les s frequent and included vomiting. diarrhea. and myelosuppression. Doxorubic in was not very effective at inducing and maintaining remission in the cats in this study. Therefore, if doxorubicin is used for the treatment of feli ne lymphoma, it should be combined with other effective chemotherapeutic dr ugs in a combination protocol.