Evaluation of a discontinuous treatment protocol (VELCAP-S) for canine lymphoma

Eighty-two dogs with lymphoma received a single 15-week course of chemother apy, after which treatment was ceased until relapse. Fifty-six dogs (68%) a chieved complete remission for a median ist remission duration of 20 weeks. Forty-eight dogs relapsed, of which 30 repeated the induction cycle. In 22 of these dogs, Ist remission had been shea, and they received maintenance chemotherapy. the other 8 dogs received 2 or 3 cycles of induction chemothe rapy. Second remission rate for these 30 dogs was 87% (26 dogs). Overall di sease control for the 38 dogs that remained on protocol was 44 weeks, which was not markedly shorter than for dogs treated with a previously reported protocol in which maintenance chemotherapy was instituted in all dogs after an identical Ist induction (VELCAP-L). Dogs that were febrile and dogs tha t were dyspneic were less likely to achieve a complete remission to inducti on chemotherapy. Of dogs that achieved a complete remission, those that wer e thrombocytopenic at entry had a shorter Ist remission, and dogs that were anorexic at entry had shorter overall disease control. There was a correla tion between Ist remission duration and length of any subsequent remission obtained. The incidence of toxicity was high, particularly after the combin ation of doxorubicin and vincristine. Dose reductions because of toxicity d id not markedly reduce remission duration. We conclude that discontinuous c hemotherapy may reduce patient visits in a small number of patients because of long-term disease control. Delaying maintenance chemotherapy until afte r 2nd remission is achieved does not markedly affect overall disease contro l.