I would like to respond to your letter regarding our paper “Dacarbazine as Single-Agent Therapy for Relapsed Lymphoma in Dogs” in J Vet Intern Med 2009. I regret omission of reference to your study in our paper. Your study1 yielded a higher response rate and longer progression-free interval than what was reported in an earlier study.2 The primary aim of our study was to demonstrate that dacarbazine has activity as a single agent for relapsed lymphoma in dogs, which is particularly important for many dogs with refractory lymphoma that have reached their total cumulative dose of doxorubicin or cannot tolerate the drug for other reasons. It was not our intention to dispute the in vitro synergism that exists between an anthracycline and darcarbazine.
Clearly, it is advisable to be cautious when drawing conclusions from retrospective studies with small numbers of dogs, especially when the comparisons have not undergone statistical analysis. Indeed, the study cited by Drs Dervisis and Kitchell3 highlights that small clinical investigations do not necessarily generate results anticipated from in vitro studies or preliminary clinical trials.