# A Retrospective Investigation of 28 Cats with Intermediate- to Large-Cell Lymphoma Treated with Lomustine and Prednisolone as a First-Line Chemotherapy

## TL;DR

This study shows that lomustine and prednisolone can be an effective first treatment for some cats with lymphoma, especially those who achieve complete cancer remission.

## Contribution

The study evaluates lomustine and prednisolone as a first-line treatment for feline intermediate- to large-cell lymphoma, revealing survival and response data.

## Key findings

- Cats achieving complete response had significantly longer progression-free intervals and survival times.
- Most cats showed temporary improvement or disease stabilization with the treatment.
- Alimentary lymphoma was the most common type among the studied cats.

## Abstract

Lymphoma is one of the most common cancers in cats, and choosing an effective treatment that is also practical for owners is an important challenge in veterinary medicine. Lomustine is an oral anticancer drug that can be given at home, but its use as an initial treatment for feline lymphoma has not been well studied. In this study, we evaluated how cats with intermediate- to large-cell lymphoma responded to treatment with lomustine combined with prednisolone. Twenty-eight cats were treated and monitored for treatment response, length of survival, and time until the disease worsened. Most cats showed either temporary improvement or stabilization of their disease, and a small number achieved complete disappearance of detectable cancer. Cats that achieved complete response lived significantly longer and had a longer period without disease progression than cats with other responses. These results suggest that lomustine combined with prednisolone may be a useful first treatment option for selected cats with intermediate- to large-cell lymphoma and may help veterinarians and owners make informed treatment decisions.

Lymphoma is the most common neoplastic disease in cats; however, lomustine has been insufficiently evaluated as a first-line chemotherapeutic agent. This study assessed treatment response, survival, and progression-free interval (PFI) in cats with intermediate-to-large cell lymphoma treated with lomustine and prednisolone as first-line therapy. Twenty-eight cats with cytologically or histopathologically confirmed lymphoma received lomustine (10 mg/cat every 3 weeks) and prednisolone until disease progression or unacceptable toxicity. All cats were feline leukemia virus- and feline immunodeficiency virus-negative, with a mean age of 9.93 years; alimentary lymphoma was most common (75%). Treatment responses included complete response (CR, 5/28), partial response (5/28), stable disease (11/28), and progressive disease (7/28). The median PFI for all cats was 51 days, and the median survival time was not reached during the study period. No significant associations were identified between PFI or survival and age, sex, packed cell volume, drug dosage, tumor size, or tumor location. Cats achieving CR showed significantly prolonged PFI compared with cats with other responses (median, 561 vs. 42 days; p = 0.0004), and overall survival was also significantly longer (p = 0.0009). These findings may serve as a clinically meaningful guide for the use of lomustine and prednisolone in the treatment of feline lymphoma.