Key Findings
In this large population-based prospective cohort of postmenopausal women, a significant inverse association between lignan intake and overall breast cancer risk, especially among postmenopausal hormone (PMH) users was observed. There was no evidence of heterogeneity across ER/PR tumours. These results are similar to a previous study with a significant inverse association between cereal fibre and breast cancer risk among PMH. A lack of association among overweight women may be due to the relatively high circulating oestrogen levels from PMH use having a stronger effect than the endogenous oestrogens formed in peripheral tissues.
ABSTRACT
Among the 51,823 postmenopausal women in the Swedish Mammography Cohort, we investigated breast cancer risk in relation to the FFQ-based estimated lignan intake by oestrogen receptor (ER) and progesterone receptor (PR) subtypes. A significant 17% risk reduction for breast cancer overall in the high lignan quartile was observed, especially among PMH user (P interaction<0.010), but no heterogeneity across ER/PR subtypes.