Dutelle AL, Bulman-Fleming JC, Lewis CA and Rosenberg MP. Evaluation of lomustine as a rescue agent for cats with resistant lymphoma. J Feline Med Surg. 2012; 14: 694-700.
Treating cases of resistant lymphoma is very challenging for veterinarians. The study reported here evaluated the use of lomustine as a rescue agent for 39 cases of resistant lymphoma in cats. The aims of the study were to evaluate lomustine as a rescue agent in this scenario, to determine prognostic factors for progression-free interval, and to detail toxicities noted in the course of the study. Progression-free interval (PFI) was defined as the time from when a cat was placed on lomustine to subsequent progression of disease necessitating a protocol change or euthanasia. The different parameters evaluated were lymphocyte cell size, number of previous chemotherapy drugs and number of chemotherapy protocols received, time from lymphoma diagnosis to initiation of lomustine therapy, body weight, and anatomic location of lymphoma.
The results demonstrated that the significant prognostic factors for PFI were cell size, number of previous chemotherapeutic drugs, number of previous chemotherapeutic protocols, and anatomic location. Cats with large cell lymphoma were 9.8 times more likely to have disease progression. Twenty-one cats (54%) received more than 1 dose of lomustine. Cats that had received 3 to 4 prior protocols were 3.6 times more likely to have disease progression than cats receiving 1 or 2 prior protocols. And cats with non-GI lymphoma were 4.7 times more likely to have progression of disease as ones with GI lymphoma. The most commonly noted toxicities in this study were vomiting, diarrhea, thrombocytopenia, leukopenia, and elevated ALT. It was noted that strict monitoring of the CBC while cats are on this drug is very important. [VT]