Dietary lignan intake and androgen receptor expression in breast tumors
Surace, AnnaLynn Marie
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Emerging research has identified the androgen receptor (AR) as a prognostic factor in breast tumors. Lignans, a phytoestrogen commonly found in the Western diet, have been linked to a decreased breast cancer risk in epidemiologic studies. Limited research has addressed associations between lignan intakes and AR expression in tissues other than prostate. Further, the association of AR expression with tumor stage, grade, and breast cancer survival seems to differ according to estrogen receptor (ER) status. We hypothesize that dietary lignan intake is associated with AR expression in breast tumors, and that the association may differ by ER status. Tumor tissue samples, epidemiological, and clinical data were collected from 273 women with incident, primary, histologically confirmed breast cancer enrolled in Roswell Park Cancer Institute (RPCI) Data Bank and BioRepository (DBBR). On average, three tumor cores from each participant were assembled into a Tissue MicroArray (TMA). After immunohistochemical staining, a trained RPCI pathologist determined nuclear receptor status of each core. Dietary data was calculated from a food frequency questionnaire collected upon enrollment into the DBBR. We found no evidence of a linear relationship between dietary lignan intake and AR expression in this sample (r=0.06). We observed no significant difference in lignan intake across categories of AR expression (p=0.06, R 2 =0.03) and we observed no associations between dietary lignans and AR status, regardless of how this was defined. 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 cohort to determine if lignan intake is truly associated with androgen receptor expression. If lignans are associated with AR expression, they may potentially represent a modifiable risk factor. Identifying new potential mechanisms in breast cancer etiology, as well as potential risk factors, is critical in lessening the burden of breast cancer.