Chemotherapy with Cyclophosphamide, Vincristine, and Prednisolone (COP) in Cats with Malignant Lymphoma: New Results with an Old Protocol

Abstract

This retrospective study in 61 cats with malignant lymphomas examined the efficacy of a well-established chemotherapy protocol (cyclophosphamide, vincristine, and prednisolone [COP]) in the Netherlands, a country with a low prevalence of feline leukemia virus (FeLV). Twenty-two cats (36.1%) had mediastinal lymphoma, 11 (18.0%) had alimentary lymphoma, 7 (11.5%) had peripheral lymphoma, 8 (13.1%) had nasal lymphoma, and 13 (21.3%) had miscellaneous lymphoma (including renal lymphoma in 2 [3.3%]). Of the 54 cats that were tested, only 4 (7.4%) were FeLV positive. Complete remission (CR) was achieved in 46 of the 61 cats (75.4%). The estimated 1- and 2-year disease-free periods (DFPs) in the 46 cats with CR were 51.4 and 37.8%, respectively, whereas the median duration of remission was 251 days. The overall estimated 1-year survival rate in all cats was 48.7%, and the 2-year survival rate was 39.9%, with a median survival of 266 days. The median survival time and the 1-year survival rate for mediastinal lymphoma were 262 days and 49.4%. respectively. Siamese cats had a more favorable prognosis for survival and remission than other breeds. Response to therapy in this study was shown to be a significant prognostic indicator. CR is necessary for long-term survival. Cats that did not achieve CR had little chance of survival for longer than I year. Young Siamese cats in this study had a greater tendency to develop mediastinal malignant lymphoma at a young age, and all were FeLV negative. In comparison with results reported in other studies with different combination chemotherapy protocols, these are among the highest percentages of remission and the longest survival rates for cats with malignant lymphoma.

Efficacy and Toxicosis of VELCAP‐C Treatment of Lymphoma in Cats

“…The addition of l ‐asparaginase with or without doxorubicin to the traditional COP protocol provided longer survival times in cats with alimentary lymphoma when compared cats treated with COP alone or single agent therapy 3,14–17 . In contrast to the recent reports from the United States, a Netherlands study reported a median survival time of 266 days and response rates of greater than 75% in cats treated with the COP protocol, figures that appear similar to earlier reports from the United States despite a relatively low occurrence of FeLV in the Netherlands 5 . The Netherlands population had a low prevalence of gastrointestinal involvement compared with more recent studies from the United States 5 .…”

“…Few useful prognostic factors in cats with lymphoma have been identified in the veterinary literature. Cats that are clinically ill (substage b), 2,3 have advanced disease, including multiple organ involvement, 4 and fail to achieve complete remission 2,3,5 and cats that are FeLV positive have a poorer prognosis 2,4 . Staging, as done routinely for dogs and human patients, is not consistently prognostic in cats 6 .…”

Pericardial lymphoma in seven cats

“…This is consistent with studies showing that response to therapy is the strongest reported prognostic factor for cats treated for lymphoma. 5,11 …”

Palliative care in small animal oncology

“…Numerous well-tolerated protocols are described with good response rates and short- to medium-term survivals in many patients (Teske and others 2002, Chun 2009) (Fig 6). …”