Use of Cyclophosphamide, Vincristine, Prednisolone and Vinblastine for the Treatment of Large Cell Lymphoma in Cats

Abstract

Background: The standard chemotherapy treatment for large-cell lymphoma in cats is CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) or COP (cyclophosphamide, vincristine, and prednisolone) chemotherapy protocols. Substituting vinblastine for vincristine might have similar efficacy, with lower severity of gastrointestinal adverse events.

Hypothesis/objectives: To evaluate whether the addition of vinblastine to a low-dose vincristine COP protocol could reduce the frequency and severity of adverse gastrointestinal effects while maintaining or increasing efficacy.

Animals: Medical records of 41 cats with large-cell lymphoma treated with the modified COVP protocol at one veterinary referral institution.

Methods: Retrospective case series study. All relevant clinical data were retrospectively collected. Median progression-free survival, disease-free interval, and survival time were calculated using the Kaplan-Meier Method. Differences between groups were analyzed using the log-rank test, and adverse events were graded using VCOG-CTCAE v2.

Results: Progression-free survival was 264 days (range, 6-1486 days), the disease-free interval was 812 days (range, 39-1486 days) and the median survival time for all cats was 412 days (range, 7-1772 days). Complete response was achieved in 59% of the cases, and partial response was observed in 17%. Cats that achieved CR lived significantly longer, 838 days (range, 81-1772 days) versus 143 days (range, 10-798 days; p = 0.0018). The COVP protocol was generally well tolerated, and the most common adverse effects were mild signs of gastrointestinal disease and hematological abnormalities that did not require a pause in treatment. Grade-1 vomiting was the most common (24%), followed by grade-2 (22%) and grade-1 reduced appetite (20%).

Conclusion: Cats with lymphoma treated with COVP seem to achieve acceptable survival and response rates compared to traditional chemotherapy protocols.

Keywords: cat; chemotherapy; high‐grade; vinca alkaloid.

FIGURE 1

Kaplan–Meier survival curve showing overall progression‐free survival of cats treated with COVP. PFS was 264 days. Vertical bars represent censored cases.

FIGURE 2

Kaplan–Meier survival curve showing the overall disease‐free interval of cats treated with COVP. DFI was 812 days. Vertical bars represent censored cases.

FIGURE 3

Kaplan–Meier survival curve showing the overall median survival time of cats treated with COVP. MST was 412 days. Vertical bars represent censored cases.

FIGURE 4

Kaplan–Meier curve depicting progression‐free survival for 41 cats with large‐cell lymphoma treated with the COVP regimen based on the initial response to COVP. Cats with complete response (PFS 812 days; dotted line) had significantly (p = 0.0002) longer progression‐free survival than those with partial response, stable disease, or progressive disease (PFS 92 days; solid line). Vertical bars represent censored cases.

FIGURE 5

Kaplan–Meier curve depicting median survival time for 41 cats with large‐cell lymphoma treated with COVP regimen based on the initial response to COVP. Cats with complete response (MST 838 days; dotted line) had significantly (p = 0.0018) longer median survival time than those with partial response, stable disease, or progressive disease (MST 143 days; solid line). Vertical bars represent censored cases.

FIGURE 6

Kaplan–Meier curve depicting progression‐free survival for cats with large‐cell lymphoma treated with the COVP regimen based on the initial response to COVP. Cats that completed the treatment course had significantly longer progression‐free survival (PFS 838 days; solid line) compared to cats that did not finish treatment (PFS 92 days; dotted line; p < 0.0001).