Impact of weight loss on breast cancer

Obesity has been linked to increased incidence and poorer outcomes in many health conditions. One of these is breast cancer. A recent article in Journal of Clinical Oncology by Jennifer Ligibel addresses the connection between obesity and breast cancer outcomes.

An analysis of 43 studies showed that obese women with breast cancer had a 33 percent increase in risk of dying relative to nonobese women with breast cancer. Similarly, a study called WINS (Women’s Interventional Nutrition Study) demonstrated that women who consumed a low-fat diet, compared to a normal diet, had a 24% reduction in recurrence rate, after early stage treatment.

It is not known why weight loss might be associated with lower recurrence rates and death rates for breast cancer. However, one hypothesis is that losing weight also reduces the amount of sex steroids and insulin circulating in the body. High levels of estrogen and insulin have been associated, in past studies, with poor breast cancer outcomes.

A recent study called the NEW (Nutrition and Exercise for Women) trial reinforces support that exercise leading to weight loss is the key to reducing risk of recurrence of breast cancer, not just exercise for its own sake.  This finding may help to guide future studies and recommendations of oncologists to women diagnosed with early stage breast cancer.

Source: Journal of Clinical Oncology