Fruit and Vegetable Intake and Risk of Breast Cancer by Hormone Receptor Status

Jung S, Spiegelman D, Baglietto L, Bernstein L, Boggs DA, van den Brandt PA, Buring JE, Cerhan JR, Gaudet MM, Giles GG, Goodman G, Hakansson N, Hankinson SE, Helzlsouer K, Horn-Ross PL, Inoue M, Krogh V, Lof M, McCullough ML, Miller AB, Neuhouser ML, Palmer JR, Park Y, Robien K, Rohan TE, Scarmo S, Schairer C, Schouten LJ, Shikany JM, Sieri S, Tsugane S, Visvanathan K, Weiderpass E, Willett WC, Wolk A, Zeleniuch-Jacquotte A, Zhang SM, Zhang X, Ziegler RG, Smith-Warner SA (2013) Fruit and Vegetable Intake and Risk of Breast Cancer by Hormone Receptor Status. J Natl Cancer Inst 105:219-236

BackgroundEstrogen receptor-negative (ER(-)) breast cancer has few known or modifiable risk factors. Because ER(-) tumors account for only 15% to 20% of breast cancers, large pooled analyses are necessary to evaluate precisely the suspected inverse association between fruit and vegetable intake and risk of ER(-) breast cancer.MethodsAmong 993 466 women followed for 11 to 20 years in 20 cohort studies, we documented 19 869 estrogen receptor positive (ER(+)) and 4821 ER(-) breast cancers. We calculated study-specific multivariable relative risks (RRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression analyses and then combined them using a random-effects model. All statistical tests were two-sided.ResultsTotal fruit and vegetable intake was statistically significantly inversely associated with risk of ER(-) breast cancer but not with risk of breast cancer overall or of ER(+) tumors. The inverse association for ER(-) tumors was observed primarily for vegetable consumption. The pooled relative risks comparing the highest vs lowest quintile of total vegetable consumption were 0.82 (95% CI = 0.74 to 0.90) for ER(-) breast cancer and 1.04 (95% CI = 0.97 to 1.11) for ER(+) breast cancer (P (common-effects) by ER status < .001).="" total="" fruit="" consumption="" was="" non-statistically="" significantly="" associated="" with="" risk="" of="" er(-)="" breast="" cancer="" (pooled="" multivariable="" rr="" comparing="" the="" highest="" vs="" lowest="" quintile="0.94," 95%="" ci="0.85" to="" 1.04).conclusionswe="" observed="" no="" association="" between="" total="" fruit="" and="" vegetable="" intake="" and="" risk="" of="" overall="" breast="" cancer.="" however,="" vegetable="" consumption="" was="" inversely="" associated="" with="" risk="" of="" er(-)="" breast="" cancer="" in="" our="" large="" pooled="">