Chronic alcohol consumption decreases the survival and compromises the antitumor immune response of mice bearing estrogen receptor positive E0771 breast cancer (TUM2P.898)

Abstract

Abstract Epidemiological data convincingly indicate that chronic alcohol consumption increases the risk of breast cancer, especially estrogen receptor positive (ER+) breast cancer in women. The effect of alcohol on antitumor immunity and survival remains to be elucidated. Herein, we implanted ER+ E0771 breast cancer cells into the mammary pad of female C57BL/6 mice consuming 20% w/v alcohol for three months and examined the effect of chronic alcohol consumption on tumor growth, dynamic changes in the antitumor immune response and host survival. Alcohol did not affect primary tumor growth or the body weight of tumor-bearing mice; however, it decreased survival. Alcohol did not alter the percentage of MDSC, Treg, CD4+ T or CD8+ T cells in the spleen and blood, but increased theCD4/CD8 ratio. B cells decreased during tumor growth, and iNKT cells increased in the blood of alcohol-consuming mice. In non-tumor-bearing mice, alcohol increases IFN-γ-producing CD8+ T cells and NK cells. Four weeks after E0771 inoculation, the percentage of IFN-γ-producing CD8+ T cells and NK cells were lower in alcohol-consuming mice compared to water-drinking mice. Alcohol consumption also decreased survival of mice immunized with an E0771 cell lysate and boosted with αGalCer compared to water-drinking counterparts. Collectively, chronic alcohol consumption compromises antitumor immunity and decreases the survival of mice bearing ER+ breast cancer.