Low-Fat Dietary Pattern and Breast Cancer Mortality in the Women's Health Initiative Randomized Controlled Trial.

Abstract

Purpose Earlier Women's Health Initiative Dietary Modification trial findings suggested that a low-fat eating pattern may reduce breast cancers with greater mortality. Therefore, as a primary outcome-related analysis from a randomized prevention trial, we examined the long-term influence of this intervention on deaths as a result of and after breast cancer during 8.5 years (median) of dietary intervention and cumulatively for all breast cancers diagnosed during 16.1 years (median) of follow-up. Patients and Methods The trial randomly assigned 48,835 postmenopausal women with normal mammograms and without prior breast cancer from 1993 to 1998 at 40 US clinical centers to a dietary intervention with goals of a reduction of fat intake to 20% of energy and an increased intake of fruits, vegetables, and grains (40%; n = 19,541) or to a usual diet comparison (60%; n = 29,294). Results In the dietary group, fat intake and body weight decreased (all P < .001). During the 8.5-year dietary intervention, with 1,764 incident breast cancers, fewer deaths occurred as a result of breast cancer in the dietary group, which was not statistically significant (27 deaths [0.016% per year] v 61 deaths [0.024% per year]; hazard ratio [HR], 0.67; 95% CI, 0.43 to 1.06; P = .08). During the same period, deaths after breast cancer (n = 134) were significantly reduced (40 deaths [0.025% per year] v 94 deaths [0.038% per year]; HR, 0.65; 95% CI, 0.45 to 0.94; P = .02) by the dietary intervention. During the 16.1-year follow-up, with 3,030 incident breast cancers, deaths after breast cancer also were significantly reduced (234 deaths [0.085% per year] v 443 deaths [0.11% per year]; HR, 0.82; 95% CI, 0.70 to 0.96; P = .01) in the dietary group. Conclusion Compared with a usual diet comparison group, a low-fat dietary pattern led to a lower incidence of deaths after breast cancer.

• Authors: Rowan T Chlebowski, Aaron K Aragaki, Garnet L Anderson, Cynthia A Thomson, JoAnn E Manson, Michael S Simon, Barbara V Howard, Thomas E Rohan, Linda Snetselar, Dorothy Lane, Wendy Barrington, Mara Z Vitolins, Catherine Womack, Lihong Qi, Lifang Hou, Fridtjof Thomas, Ross L Prentice
• Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology (J Clin Oncol) Vol. 35 Issue 25 Pg. 2919-2926 (Sep 01 2017) ISSN: 1527-7755 [Electronic] United States
• PMID: 28654363 (Publication Type: Journal Article, Randomized Controlled Trial)

Topics

• Aged
• Breast Neoplasms (mortality, prevention & control)
• Diet, Fat-Restricted (methods, statistics & numerical data)
• Female
• Humans
• Middle Aged
• Postmenopause
• United States (epidemiology)
• Women's Health