Rescue Protocols for Canine Non‐Indolent B Cell Lymphoma: A Systematic Review

Canine lymphoma is a heterogenous group of diseases. The most common subtype is diffuse large B cell lymphoma (DLBCL), though definitive diagnosis beyond non‐indolent = multicentric B cell lymphoma is not often achieved in clinical practice as it requires histopathology. Most dogs respond well to standard‐of‐care multiagent chemotherapy (CHOP) but relapse and eventual CHOP‐resistance is likely. Less commonly there is a lack of complete response to initial CHOP treatment. CHOP‐resistant cases are treated with rescue chemotherapy protocols, of which many are published, but the most effective is unknown. In this systematic review we aimed to determine the most effective rescue chemotherapy protocol for dogs with multicentric non‐indolent B cell lymphoma resistant to initial chemotherapy with a CHOP‐based protocol. After initial screening, 65 full‐text articles were reviewed. However, outcomes for the population of interest could not be identified in any, leaving our research question unanswered. Future publications of rescue treatment for canine lymphoma should report outcomes separately for groups of dogs where disease characteristics and prior treatment may affect outcome.