Previously presented as an oral presentation at the 25th Annual Conference of the Veterinary Cancer Society, Huntington Beach, CA, October 20–23, 2005.
Dacarbazine as Single-Agent Therapy for Relapsed Lymphoma in Dogs
Version of Record online: 26 AUG 2009
Copyright © 2009 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 23, Issue 6, pages 1227–1231, November/December 2009
How to Cite
Griessmayr, P.C., Payne, S.E., Winter, J.E., Barber, L.G. and Shofer, F.S. (2009), Dacarbazine as Single-Agent Therapy for Relapsed Lymphoma in Dogs. Journal of Veterinary Internal Medicine, 23: 1227–1231. doi: 10.1111/j.1939-1676.2009.0376.x
- Issue online: 27 OCT 2009
- Version of Record online: 26 AUG 2009
- Submitted December 16, 2008; Revised May 5, 2009; Accepted July 8, 2009.
- Rescue protocol
Background: Multidrug resistance is the most common cause of treatment failure in dogs with multicentric lymphoma. 5-(3,3-Dimethyl-1-triazeno)-imidazole-4-carboxamide (DTIC) is an atypical alkylator used as standard treatment in human Hodgkin's lymphoma, and has been effective in combination treatment to treat resistant lymphoma in dogs. However, no data are available on the use of DTIC as a single agent in the treatment of relapsed canine lymphoma.
Hypothesis: Single-agent DTIC is effective and safe in treating dogs with lymphoma that relapsed or failed to respond to previous chemotherapy.
Animals: Forty client-owned dogs with relapsed lymphoma.
Methods: Dogs were eligible for the retrospective study if they had a histologically or cytologically confirmed diagnosis of lymphoma and had relapsed. Dogs received DTIC (800–1,000 mg/m2 every 2–3 weeks as a 4–5-hour IV infusion) and were evaluated for response rate and duration. Hematologic and gastrointestinal toxicity was assessed.
Results: The overall response rate for dogs being treated with DTIC was 35% (14 dogs) with a median progression-free interval of 43 days. Thirteen dogs had a partial response and 1 dog had a complete response. Stable disease was achieved in 3 dogs. Mild gastrointestinal toxicity was reported in 3 dogs posttreatment. Thrombocytopenia was the principal toxicity observed 7–14 days after the treatment. Treatments were delayed because of thrombocytopenia.
Conclusions: DTIC, when used alone, is effective in the treatment of dogs with relapsed lymphoma.