Introduction

Dogs diagnosed with T-cell lymphoma (TCL) generally have a poor prognosis even with the use of multi-agent chemotherapy protocols. Lomustine has shown promise when used to treat TCL; however, it is unclear if a multi-agent protocol utilizing lomustine is superior to standard CHOP chemotherapy. Our objective is to determine the prognosis and associated prognostic factors for dogs that were diagnosed with TCL via flow cytometry and treated with either a modified CHOP chemotherapy protocol (including lomustine) or a single-agent lomustine protocol.

Methods

Retrospective medical record review of 109 dogs diagnosed with TCL from May 2010 to December 2019. Data extracted from medical records included signalment, weight, location of disease, stage, substage, anemia, neutropenia, monocytopenia, chemotherapy protocol, completion of chemotherapy protocol, recurrence, date of death, and cause of death. Dogs were separated into two cohorts based on chemotherapy protocol. Ninety-five dogs received a modified CHOP protocol where lomustine was substituted for cyclophosphamide. Fourteen dogs received a single-agent lomustine protocol.

Results

Forty patients completed their chemotherapy protocol, thirty-five in the modified CHOP group and five in the single-agent lomustine group. Of these, twenty-nine patients had documented recurrence with a median disease-free interval (DFI) of 263 days. Additional data to be presented.

Conclusion

Although TCL continues to be a difficult disease to treat, multi-agent protocols utilizing lomustine provide reasonable DFIs and mean survival times (MST). As expected, dogs receiving multi-agent protocols experienced longer MST than dogs receiving single-agent lomustine.