Chlebowski RT, et al. - Researchers investigated the association of a low-fat dietary pattern with breast cancer overall survival (breast cancer followed by death from any cause measured from cancer diagnosis) in this secondary analysis of the Women’s Health Initiative trial that was conducted at 40 US clinical centers recruiting study participants from 1993-1998. In women who received a diagnosis of breast cancer during the dietary intervention period, researchers noted an increased overall survival rate in those in the dietary group. The increase was partially attributed to better survival from several causes of death.

Methods

• For this investigation, 48,835 postmenopausal women with no previous breast cancer and dietary fat intake of > 32% by food frequency questionnaire were randomized either to a dietary intervention group (40%; n=19,541)—which aimed to reduce fat intake to 20% of energy and increase fruit, vegetable, and grain intake—or a usual-diet comparison group (60%; n=29,294).
• In subsequent dietary intervention activities, dietary group participants with incident breast cancers continued to participate.
• Breast cancer overall survival for incident breast cancers diagnosed during the 8.5-year (median) dietary intervention, examined in post hoc analyses after 11.5 years (median) postdiagnosis follow-up was the main outcome and measure analyzed.

Results

• According to the findings obtained, mean (SD) age at screening was 62.7 (6.7) years and age at diagnosis was 67.6 (6.9) years of 1,764 women who received a diagnosis of breast cancer during the dietary intervention period.
• Breast cancer overall survival was significantly greater for women in the dietary intervention group vs the usual-diet comparison group, with 516 total deaths.
• Fewer deaths were documented from breast cancer, other cancers, and cardiovascular disease in the dietary group.