Dietary lignan intake and androgen receptor expression in breast tumors.

Abstract

Lignans, a class of phytoestrogen commonly found in the Western diet, have been linked to decreased breast cancer risks in epidemiologic studies. Similar to estrogen receptors, the androgen receptor (AR), a prognostic factor in breast tumors, may be affected by lignans. However, few studies have investigated this link in the context of breast cancer etiology. We evaluated the relationship between dietary lignan intake and AR expression in incident breast tumors. Tumor tissue, epidemiological, and clinical data were collected from 216 women with incident, primary, histologically confirmed breast cancer enrolled in the Roswell Park Cancer Institute (RPCI) Data Bank and BioRepository (DBBR). On average, three tumor cores from each participant were assembled into a tissue micro array. After immunohistochemical staining, a trained RPCI pathologist determined AR status of each core. Lignan intake was calculated from a food frequency questionnaire collected upon enrollment into the DBBR. We observed a weak positive association between dietary lignans and AR expression [β (SE) 27.6 (17.0), p 0.10], and there was no significant difference in lignan intake across categories of AR expression (p=0.09, R (2)=0.35). Our results do not support a clear relationship between dietary lignan intake and AR expression. This investigation is the first, to our knowledge, to examine dietary lignan intake and AR expression in breast tumors. Further research is needed within a larger, more representative sample to determine whether lignan intake is truly associated with AR expression.