Treatment of canine mast cell tumors with CCNU (lomustine).
The efficacy and toxicity of CCNU (1-[2-chloroethyl]3-cyclohexyl-1-nitrosourea) were evaluated in 23 dogs with measurable mast cell tumors (MCT). Twenty-two dogs had cutaneous MCT and 1 dog had an intranasal MCT Nineteen (83%) dogs had biopsy of their original mass performed and 4 (17%) had aspiration cytology of masses. Of the 19 tumors histologically graded, 1 (5%) neoplasm was classified as grade I, 10 (53%) were grade II, and the remaining 8 (42%) were grade III. Dogs were treated with CCNU at a dosage of 90 mg/m2 body surface area every 3 weeks. Response could be evaluated in 19 dogs. Eight of the 19 dogs (42%) had a measurable response to CCNU. One dog had a durable complete response for 440 days. Seven dogs (37%) had a partial response for a median and mean duration of 77 days and 109 days, respectively (range, 21-254 days). Treatment with CCNU resulted in stable disease in 6 dogs (32%) for a median and mean duration of 78 days and 122 days, respectively (range, 42-347 days). The acute dose-limiting toxicity was neutropenia 7 days after administration of CCNU. The median and mean neutrophil counts 7 days after CCNU were 1,452 cells/microL and 1,683 cells/microL, respectively (n = 17). Other toxicoses were uncommon. CCNU should be considered an active agent in the treatment of MCT in dogs.
Rassnick
K M
KM
Harrington Oncology Program, Tufts University, School of Veterinary Medicine, North Grafton, MA 01536, USA. krassnick@infonet.tufts.edu
Moore
A S
AS
Williams
L E
LE
London
C A
CA
Kintzer
P P
PP
Engler
S J
SJ
Cotter
S M
SM
D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000009:adverse effects / Q000627:therapeutic use*; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D008130:Lomustine / Q000009:adverse effects / Q000627:therapeutic use*; D012515:Mast-Cell Sarcoma / Q000188:drug therapy / Q000662:veterinary*; D009296:Nasal Cavity; D009503:Neutropenia / Q000139:chemically induced; D009669:Nose Neoplasms / Q000188:drug therapy / Q000662:veterinary*; D012878:Skin Neoplasms / Q000188:drug therapy / Q000662:veterinary*; D016896:Treatment Outcome
D018906:Antineoplastic Agents, Alkylating; D008130:Lomustine