Pre-Diagnostic Enterolactone Concentrations And Survival After Breast Cancer

Cecilie KYRØ, Danish Cancer Society Research Center, Denmark

1 Unit of Diet, Genes and Environment, Danish Cancer Society Research Center, Copenhagen, Denmark

Purpose: The high incidence of breast cancer in combination with a high relative survival, leads to a high prevalence of breast cancer in western countries and thereby a large interest in initiatives aimed at optimizing survivorship. Lignans are polyphenolic compounds found in seeds, whole grains, nuts, and in some fruits and vegetables. During digestion, lignans are converted to enterolignans (mainly enterolactone), which have estrogen-like activity. Biological evidence supports a role of enterolactone in breast cancer development and prognosis. The objective of the present study is therefore to investigate the association between enterolactone and breast cancer survival (all-cause and breast-cancer specific mortality).
Methods: We measured enterolactone using LC-MS/MS in pre-diagnostic plasma samples from 1511 incident breast cancer cases from the Danish part of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. We followed the breast cancer cases from date of diagnosis until death, end of follow-up or last day of contact. During a median of 10 years, 433 of the women died (262 of breast cancer). We related pre-diagnostic enterolactone concentrations to all-cause and breast cancer-specific mortality using Cox Proportional Hazard Models with follow-up-time as underlying time scale. Analyses were adjusted for potential confounders. Analyses on recurrence as well as by clinical characteristics are ongoing.
Preliminary results: High pre-diagnostic enterolactone concentrations were related to improved survival. A doubling in the plasma enterolactone concentration was associated with a 7% lower both all-cause (HRdoubling,log2:0.93, 95%CI: 0.88–0.98) and breast cancer-specific mortality (HRdoubling,log2:0.93, 95%CI: 0.86–1.00).
Conclusions: High levels of enterolactone may be related to an improved survival among women diagnosed with breast cancer.
Funding Source: This work was funded by Innovation Fund Denmark (ELIN: 0603-00580B), and Danish Cancer Society