Dietary acrylamide intake and estrogen and progesterone receptor-defined postmenopausal breast cancer risk.

Acrylamide, a potential human carcinogen, has been discovered in a variety of heat-treated carbohydrate-rich food products. Previously, dietary acrylamide intake was shown to be associated with endocrine-related cancers in humans. We assessed the association between dietary acrylamide intake and risk of postmenopausal breast cancer stratified by estrogen and progesterone receptor status. This study was embedded within the Netherlands Cohort Study on diet and cancer, which was initiated in 1986 enrolling 62,573 women aged 55-69 years at baseline. After 13.3 years of follow-up, 2225 incident breast cancer cases were ascertained, with hormone receptor status information for 43%. Cox proportional hazards analysis was applied to determine hazard ratios in quintiles of dietary acrylamide intake stratifying on estrogen receptor (ER) and progesterone receptor (PR) and smoking status. No association was observed for overall breast cancer or receptor-negative breast cancer risk, irrespective of smoking status. A statistically non-significantly increased risk of ER positive, PR positive and joint receptor-positive breast cancer was found in never-smoking women. The multivariable-adjusted hazard ratios were 1.31 (95% CI: 0.87-1.97, P (trend) = 0.26) for ER+, 1.47 (0.86-2.51, P (trend) = 0.14) for PR+, and 1.43 (0.83-2.46, P (trend) = 0.16) for ER+PR+, when comparing women in the highest quintile of acrylamide intake (median 36.8 microg/day) to women in the lowest (median 9.5 microg/day). This study showed some indications of a positive association between dietary acrylamide intake and receptor-positive breast cancer risk in postmenopausal never-smoking women. Further studies are needed to confirm or refute our observations.