Efficacy of doxorubicin as an induction agent for cats with lymphosarcoma.
OBJECTIVE
To determine the efficacy of doxorubicin when used alone in inducing remission in cats with lymphosarcoma.


METHODS
Prospective multi-institutional study of naturally occurring disease.


METHODS
Cases were accrued from veterinary institutions in Australia and New Zealand after obtaining consent from informed owners. Cats were treated with doxorubicin every 3 weeks for three treatments. If there was no response to the first dose of doxorubicin or if the cat relapsed during the doxorubicin regimen, the cat was withdrawn from the trial and either euthanased or treated with other agents. Age, breed, gender and anatomic site of the lymphosarcoma (multicentric, alimentary, mediastinal, extranodal) were recorded for each cat. Clinical remission was assessed before each treatment by physical examination, radiography, ultrasonography and computed tomography where appropriate. Complete remission was defined as the disappearance of all clinical signs and clinically detectable tumour.


RESULTS
Twenty-one cases were accrued over a 2-year-period but only 19 were available for data analysis. Young Siamese cats were over-represented and all cats with mediastinal tumours were young Siamese. There was a significant difference between the mean ages of cats with mediastinal or multicentric lymphosarcoma (mean +/- SD: 3.5 +/- 3.0 and 4.3 +/- 2.6 years, respectively) and cats with alimentary or extranodal LSA (11.4 +/- 0.9 and 11.0 +/- 0.9 years, respectively). Of 19 cats treated with doxorubicin alone, 6 (32%) had complete remission, 6 (32%) had partial remission and 7 (36%) did not respond.


CONCLUSIONS
The results suggest that doxorubicin cannot be recommended as a single agent for treatment of feline lymphosarcoma because of the rather poor remission rate achieved.
Peaston
A E
AE
Children's Cancer Research Institute, Sydney Children's Hospital, Randwick, New South Wales.
Maddison
J E
JE
D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001315:Australia; D002371:Cat Diseases / Q000188:drug therapy*; D002415:Cats; D004317:Doxorubicin / Q000627:therapeutic use*; D005260:Female; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D009520:New Zealand; D011446:Prospective Studies; D012074:Remission Induction; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D004317:Doxorubicin