Weight loss associated with lower risk of breast cancer: study

WASHINGTON, Oct. 8 - A study published on Monday in the journal Cancer showed that weight loss was linked to lower risk of developing invasive breast cancer for postmenopausal women.

Obesity has been strongly related to breast cancer risk, but previous studies examining whether weight loss might reduce postmenopausal women's risk resulted in mixed results.

Researchers from the City of Hope National Medical Center in California analyzed data on 61,335 women who had no prior breast cancer. Those women's body weight, height and body mass index (BMI) had been assessed at the start of the study and again three years later.

During an average follow-up of 11.4 years, 3,061 new cases of invasive breast cancer were reported. It showed that women with weight loss of 5 percent or more had a 12-percent lower breast cancer risk compared with stable weight women.

Also, weight gain of 5 percent or more was not associated with breast cancer risk but was associated with a 54-percent higher incidence of triple-negative breast cancer, a hard-to-treat type of breast cancer.

"Our study indicates that moderate, relatively short-term weight reduction was associated with a statistically significant reduction in breast cancer risk for postmenopausal women," said Rowan Chlebowski, the corresponding author of the paper.