Autologous tumor-based vaccines in canine oncology: a systematic review of safety, immunogenicity, and therapeutic potential

BACKGROUND: Autologous tumor vaccines have been investigated as immunotherapeutic strategies in veterinary oncology and may represent relevant translational models for comparative cancer immunotherapy. However, reported clinical outcomes in dogs remain heterogeneous. OBJECTIVE: To evaluate the safety, clinical outcomes, and immunological assessment methods of autologous tumor vaccines in dogs. METHODS: A systematic review of PubMed, Web of Science, and Scopus identified 24 eligible studies evaluating autologous tumor vaccines in dogs. Vaccine platforms, safety data, clinical outcomes, and immunological assessments were analyzed descriptively. Exploratory pooled hazard ratio analyses were performed using random-effects models when applicable. RESULTS: Autologous tumor vaccines were generally reported as well tolerated, with predominantly mild and transient adverse events. Clinical outcomes varied substantially across tumor types and study designs. Canine lymphoma represented the setting with the greatest concentration of evidence, including the few randomized and controlled studies identified. Several lymphoma studies reported longer time to progression and lymphoma-specific survival in vaccinated dogs compared with chemotherapy-alone or historical comparator groups, although findings were not consistent across all studies. Exploratory pooled analyses suggested a trend toward reduced risk of progression and lymphoma-related mortality in immunotherapy-treated dogs; however, these findings should be interpreted cautiously given the limited number of studies and methodological heterogeneity. In solid tumors, outcomes were more variable and evidence remained predominantly exploratory. CONCLUSIONS: Current evidence suggests that autologous tumor vaccines in dogs are generally feasible and well tolerated, although methodological limitations restrict interpretation of therapeutic efficacy. Further prospective and standardized studies are needed to clarify their role in veterinary oncology and comparative cancer immunotherapy.