CCNU in the Treatment of Canine Epitheliotropic Lymphoma

This retrospective study examined the use of CCNU (1-[2-chloroethyl]3-cyclohexyl-1-nitrosurea) in 36 dogs with epitheliotropic lymphoma. Thirty-one (86%) dogs had the cutaneous form of disease, and 5 (14%) dogs had the oral form of disease. Nineteen (51%) dogs were treated with other chemotherapeutic agents before receiving CCNU. All dogs had detectable disease at the time CCNU therapy was initiated. Dogs received a median starting CCNU dosage of 70 mg/m2 (range, 50–100 mg/m2). The median number of treatments administered was 3 (range, 1–12 treatments). After the initial treatment, the CCNU dosage was adjusted in 9 of 26 (35%) dogs in which CCNU was continued: 7 had dosage reductions, and 2 had dosage escalations. Twenty-eight of 36 (78%) dogs had a measurable response to CCNU for a median duration of 106 days (95% confidence interval [CI], 75–182). Six dogs (17%) had a complete response, including 5 dogs with the cutaneous form and 1 dog with the oral form. Twenty-two dogs (61%) had a partial response, including 20 dogs with the cutaneous form and 2 dogs with the oral form, for a median duration of 88 days (95% CI, 62–170). Toxicoses after CCNU chemotherapy included myelosuppression in up to 29% of the dogs, gastrointestinal signs in up to 22% of the dogs, and liver enzyme activity increases in up to 86% of the dogs. This study demonstrates that CCNU chemotherapy can be considered a reasonable option for the treatment of canine epitheliotropic lymphoma in dogs.