Long-term dietary acrylamide intake and breast cancer risk in a prospective cohort of Swedish women.

The association between dietary acrylamide intake and the incidence of invasive breast cancer was examined among 61,433 Swedish women who were cancer free and completed a food frequency questionnaire in 1987-1990 and again in 1997. During a mean follow-up of 17.4 years, a total of 2,952 incident cases of breast cancer were diagnosed in the cohort. In multivariate analyses controlling for breast cancer risk factors, no statistically significant association was observed between long-term acrylamide intake (assessed at baseline and in 1997) and the risk of breast cancer, overall or by estrogen receptor (ER) and progesterone receptor (PR) status. The multivariate rate ratios comparing extreme quartiles of acrylamide intake were 0.91 (95% confidence interval (CI): 0.80, 1.02) for overall breast cancer, 0.89 (95% CI: 0.74, 1.08) for ER+PR+ tumors, 1.17 (95% CI: 0.84, 1.64) for ER+PR- tumors, and 0.91 (95% CI: 0.61, 1.38) for ER-PR- tumors. The association between acrylamide intake and breast cancer risk did not differ by smoking status. These findings for Swedish women do not support the hypothesis that dietary acrylamide is positively associated with risk of breast cancer, at least not within the ranges of acrylamide consumed by this population.