Murine oral cancer cells cultured with and without blueberry extract

Novel therapies are needed to improve survival outcomes for established tumors and to prevent progression of premalignant lesions. Antioxidant botanicals, such as green tea extract, have shown promise as a chemoprevention strategy.

In multiple immunocompetent murine models of oral cancer, blueberry extract (BE) added to drinking water provided robust tumor growth delay, resulting in frequent tumor rejection when combined with anti-PD-1 immunotherapy in an immunogenic model. Tumor immune profiling, RNA sequencing, and cell depletion studies suggest that the efficacy of BE monotherapy is primarily via non-immune mechanisms. When given to mice in a carcinogenesis model using 4-NQO, BE showed modest activity as a chemoprevention strategy; in a model mimicking minimal residual disease, BE showed no appreciable benefit.