Dietary Modification and Breast Cancer Mortality: Long-Term Follow-Up of the Women's Health Initiative Randomized Trial

Abstract

During 8.5 years of dietary intervention, breast cancer incidence and deaths as a result of breast cancer were nonsignificantly lower in the intervention group, while deaths after breast cancer were statistically significantly lower both during intervention and through a 16.1-year (median) follow-up. Now, after a long-term, cumulative 19.6-year (median) follow-up, the significant reduction in deaths after breast cancer persists (359 [0.12%] v 652 [0.14%] deaths; hazard ratio [HR], 0.85; 95% CI, 0.74 to 0.96; P = .01), and a statistically significant reduction in deaths as a result of breast cancer (breast cancer followed by death attributed to the breast cancer) emerged (132 [0.037%, annualized risk] v 251 [0.047%] deaths, respectively; HR, 0.79; 95% CI, 0.64 to 0.97; P = .02).