The association between China's Great famine and risk of breast cancer according to hormone receptor status: a hospital-based study.

PURPOSE: The Great Chinese Famine afflicted almost all Chinese people between 1959 and 1961. No study has explicitly assessed the association between an exposure to Chinese Famine and risk of overall breast cancer and tumor subtype. We evaluated the unique historical environmental influences of famine exposure on breast cancer subtypes. METHODS: 16,469 Chinese women who were diagnosed with invasive breast cancer in the Fudan University Shanghai Cancer Center (FUSCC) from 1999 to 2014 were analyzed. Four tumor subtypes were defined by both estrogen-receptor (ER) and progesterone-receptor (PR) status. Multinomial logistic regression models were used to estimate the odds ratios (ORs) of ER-PR-, ER+PR-, and ER-PR+ relative to ER+PR+ breast cancer for exposure to famine and age at the exposure. RESULTS: Compared with cases not exposed to the Famine, exposed cases were more likely to be diagnosed with ER-PR- (OR 1.60, 95 % CI 1.43-1.81), ER-PR+ (OR 4.85, 95 % CI 3.80-6.19), and ER+PR- (OR 1.99, 95 % CI 1.67-2.37) than ER+PR+ breast cancer after controlling for established breast cancer risk factors. Women exposed to Famine after first birth had a higher risk of EP-PR- (OR 1.66, 95 % CI 1.28-2.15), ER-PR+ (OR 9.75, 95 % CI 5.85-16.25), and ER+PR- (OR 2.35, 95 % CI 1.69-3.26) compared to those with ER+PR+ breast cancer. CONCLUSIONS: Women exposed to the Famine, particularly those exposed after first birth, were more likely to be diagnosed with ER-PR-, ER-PR+, and ER+PR- breast cancer. This retrospective analysis suggests that famine, malnutrition, or the associated lack of fruit and vegetable consumption in adulthood may be related to epidemiological heterogeneity within breast cancer subtypes.