Vegetable and fruit consumption and the risk of hormone receptor-defined breast cancer in the EPIC cohort.
Emaus MJ., Peeters PHM., Bakker MF., Overvad K., Tjønneland A., Olsen A., Romieu I., Ferrari P., Dossus L., Boutron-Ruault MC., Baglietto L., Fortner RT., Kaaks R., Boeing H., Trichopoulou A., Lagiou P., Trichopoulos D., Masala G., Pala V., Panico S., Tumino R., Polidoro S., Skeie G., Lund E., Weiderpass E., Quirós JR., Travier N., Sánchez M-J., Chirlaque M-D., Ardanaz E., Dorronsoro M., Winkvist A., Wennberg M., Bueno-de-Mesquita HB., Khaw K-T., Travis RC., Key TJ., Aune D., Gunter M., Riboli E., van Gils CH.
BACKGROUND: The recent literature indicates that a high vegetable intake and not a high fruit intake could be associated with decreased steroid hormone receptor-negative breast cancer risk. OBJECTIVE: This study aimed to investigate the association between vegetable and fruit intake and steroid hormone receptor-defined breast cancer risk. DESIGN: A total of 335,054 female participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort were included in this study (mean ± SD age: 50.8 ± 9.8 y). Vegetable and fruit intake was measured by country-specific questionnaires filled out at recruitment between 1992 and 2000 with the use of standardized procedures. Cox proportional hazards models were stratified by age at recruitment and study center and were adjusted for breast cancer risk factors. RESULTS: After a median follow-up of 11.5 y (IQR: 10.1-12.3 y), 10,197 incident invasive breast cancers were diagnosed [3479 estrogen and progesterone receptor positive (ER+PR+); 1021 ER and PR negative (ER-PR-)]. Compared with the lowest quintile, the highest quintile of vegetable intake was associated with a lower risk of overall breast cancer (HRquintile 5-quintile 1: 0.87; 95% CI: 0.80, 0.94). Although the inverse association was most apparent for ER-PR- breast cancer (ER-PR-: HRquintile 5-quintile 1: 0.74; 95% CI: 0.57, 0.96; P-trend = 0.03; ER+PR+: HRquintile 5-quintile 1: 0.91; 95% CI: 0.79, 1.05; P-trend = 0.14), the test for heterogeneity by hormone receptor status was not significant (P-heterogeneity = 0.09). Fruit intake was not significantly associated with total and hormone receptor-defined breast cancer risk. CONCLUSION: This study supports evidence that a high vegetable intake is associated with lower (mainly hormone receptor-negative) breast cancer risk.