(RxWiki News) A simple change in diet could make a world of difference for women with certain types of breast cancer.
Among women with early-stage breast cancer who ate a low-fat diet for 5 years after their diagnosis, survival rates were significantly improved in those who had breast cancers unrelated to hormone levels, according to findings from a recent study.
In other words, eating less fat reduced deaths from any cause among women with estrogen receptor-negative and progesterone receptor-negative breast cancers.
"Overall, while the death rate was somewhat lower in the [low-fat diet] group compared with control group (13.6 percent vs 17 percent, respectively), the difference was not statistically significant," said lead researcher Rowan Chlebowski, MD, PhD, medical oncologist at the Los Angeles Biomedical Research Institute at the Harbor-UCLA Medical Center.
"However, in exploratory subgroup analyses, in women with estrogen receptor-negative cancers, a 36 percent statistically significant reduction in deaths was seen in women in the [low-fat diet] group," Dr. Chlebowski said in a press statement. That reduction was even greater for women with both estrogen receptor-negative and progesteron receptor-negative cancers — these women had a 56 percent reduction in deaths.
A hormone receptor-positive breast cancer means that the cancer cells may receive signals from hormones like estrogen or progesterone that promote cancer cell growth. A hormone receptor-negative cancer does not receive such hormone signals.
In this study, the women who seemed to benefit most from the low-fat diet intervention were those with hormone receptor-negative cancers.
Dr. Chlebowski and colleagues came to their conclusions through studying data from the Women's Intervention Nutrition Study (WINS).
WINS was a trial that included 2,437 women ages 48 to 79 receiving standard care for early-stage breast cancer. Of these women, 1,597 had estrogen receptor-positive breast cancer, 478 had estrogen receptor-negative breast cancer, and 362 had estrogen receptor-negative and progesterone receptor-negative breast cancer.
Within 6 months of being diagnosed with breast cancer, these women were randomly assigned to eat a low-fat diet or to no diet.
After 5 years, the women on the low-fat diet reduced fat calories by 9.2 percent and cut body weight by nearly 6 pounds, compared to the women who did not eat the low-fat diet.
These findings were presented at the 2014 San Antonio Breast Cancer Symposium.
This research was funded by the National Cancer Institute and the American Institute of Cancer Research. Dr. Chlebowski has received consulting support from Pfizer, Novartis, Amgen, Genomic Health and Novo Nordisk, as well as honorarium from Novartis.