Combination chemotherapy in feline lymphoma: treatment outcome, tolerability, and duration in 23 cats.

BACKGROUND

Different chemotherapy regimes have been described for feline lymphoma with varying outcomes.

HYPOTHESIS

In cats with lymphoma, a long-term, multiagent chemotherapy protocol will be effective and carry acceptable toxicity.

ANIMALS

Twenty-three cats with histologically or cytologically confirmed diagnosis of lymphoma.

METHODS

Prospective, single-arm clinical trial in which cats were treated with a chemotherapy protocol consisting of a cyclic combination of l-asparaginase, vincristine, cyclophosphamide, doxorubicin, methotrexate, and prednisolone with a planned total treatment time of 122 weeks.

RESULTS

Complete remission (CR) rate was 74% (n = 17). Fourteen percent of cats attained partial remission (PR). Median duration of first CR was 264 days (range, 45-2,485 days). Six-month, 1-, and 2-5-year remission rates were 75, 50, and 34%, respectively. Duration of PR ranged between 23 and 63 days. Median survival in cats with CR was 296 days (range, 50-2,520 days). Six-month, 1-, 2-, and 3-5-year survival rates in cats with CR were 82, 47, 34, and 27%, respectively. Survival of cats achieving PR ranged between 38 and 120 days. Of the analyzed variables, only anatomical location had a significant influence on remission duration (P=.022). Actual median treatment time in cats with CR was 128 days (18 weeks). Hematologic and gastrointestinal toxicosis was infrequent and mostly low grade.

CONCLUSIONS AND CLINICAL IMPORTANCE

In this population of cats with lymphoma, chemotherapy was effective. With infrequent and mostly low-grade toxicosis, tolerability of the protocol may be considered good.