Better postdiagnosis diet quality is associated with reduced risk of death among postmenopausal women with invasive breast cancer in the Women's Health Initiative.

Publication Type:

Journal Article

Source:

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, Volume 23, Issue 4, p.575-83 (2014)

Keywords:

2014, Center-Authored Paper, February 2014, Nutrition Assessment Core Facility, Public Health Sciences Division, Shared Resources

Abstract:

Background: Few studies have evaluated whether adherence to dietary recommendations is associated with mortality among cancer survivors. In breast cancer survivors, we examined how postdiagnosis Healthy Eating Index (HEI)-2005 scores were associated with all-cause and cause-specific mortality. Methods: Our prospective cohort study included 2317 postmenopausal women, aged 50-79 years, in the Women's Health Initiative's Dietary Modification Trial (n=1205) and Observational Study (n=1112) who were diagnosed with invasive breast cancer and completed a food frequency questionnaire after being diagnosed. We followed women from this assessment forward. We used Cox proportional hazards models to estimate multivariate-adjusted hazard ratios (HR) and 95% confidence intervals (CI) for death from any cause, breast cancer, and causes other than breast cancer, according to HEI-2005 quintiles. Results: Over 9.6 years, 415 deaths occurred. After adjustment for key covariates, women consuming better quality diets had a 26% lower risk of death from any cause (HRQ4:Q1: 0.74; 95% CI: 0.55, 0.99, ptrend=0.043) and a 42% lower risk of death from non-breast-cancer causes (HRQ4:Q1: 0.58; 95% CI: 0.38, 0.87, ptrend=0.011). HEI-2005 score was not associated with breast cancer death (HRQ4:Q1: 0.91; 95% CI: 0.60, 1.40, ptrend=0.627). In analyses stratified by tumor estrogen receptor (ER) status, better diet quality was associated with a reduced risk of all-cause mortality among women with ER+ tumors (n=1758; HRQ4:Q1: 0.55, 95% CI: 0.38. 0.79, ptrend=0.0009). Conclusion: Better postdiagnosis diet quality was associated with reduced risk of death, particularly from non-breast-cancer causes. Impact: Breast cancer survivors may experience improved survival by adhering to US dietary guidelines.