Review of Canine Lymphoma Treated with Chemotherapy—Outcomes and Prognostic Factors

SIMPLE SUMMARY: Canine lymphoma is a common cancer of one of the white blood cells that is commonly treated with chemotherapy. Many papers have been published about this disease and treatment, but few comprehensive reviews of the outcomes reported after chemotherapy, and the prognostic factors that influence the outcomes, have been published. Knowledge of the potential outcomes for this disease is important for veterinarians as they guide dog owners in the decision making about treatment options. This review evaluated the papers published on this topic and found that there is a wide variation in outcomes reported, as well as the factors that influence the outlook. Additionally, while individual papers have shown a much better survival, over the last 40 years, the overall improvement in outcome has been modest at best. The use of uniform reporting in the studies is needed, and novel approaches are likely needed to significantly improve the outlook for dogs with this disease. ABSTRACT: While canine lymphoma is a relatively common and important disease seen by veterinarians, there are limited comprehensive reviews of the literature regarding the remission and survival times following chemotherapy, and the associated prognostic factors. This comprehensive thematic review covers the available veterinary literature covering treatment outcomes and identified prognostic factors. A lack of standardised approaches to evaluate and report the outcomes was identified, including factors that would alter the duration of responses by weeks, or occasionally months. After publication of the suggested reporting criteria, this has improved but is still not uniformly applied. The prognostic factors included for evaluation varied from as few as three to seventeen, with over 50 studies using only univariate analysis. Individual papers reported much longer outcomes than others, but assessing the outcomes overall, there has been minimal change over the last 40 years. This supports the belief that novel approaches for lymphoma therapy will be required to substantively improve outcomes.