Study: How Exercise May Decrease Breast Cancer Risk

For postmenopausal breast cancer, there’s a strong body of evidence that shows exercising reduces the risk. But cancer can take years to develop. A new study that may help explain the link now suggests that when young women jog and are aerobically activecanstockphoto13529535 it causes changes in estrogen metabolism, which then plays a role in reducing later breast cancer risk.

The study, published in Cancer Epidemiology, Biomarkers & Prevention, is one of only a few clinical trials to focus on exercise and estrogen metabolism among younger women.

Study researchers wanted to focus on estrogen metabolism because the majority of breast cancers are related to the hormone estrogen. Research suggests that a higher lifetime exposure to estrogen increases a woman’s risk for breast cancer. Yet there are many forms of estrogen and they appear to play a different role in risk.

Lab studies have suggested that two of the forms, estradiol and estrone, play a role in cancer development. These forms of estrogen break down or metabolize into compounds and it’s the ratio of these metabolites that studies have suggested may influence breast cancer risk.

For this study, researchers randomly divided almost 400 sedentary young women into two groups: about half of the women were asked to exercise regularly and the others continued with their inactive lifestyle. All the women were premenopausal and the groups included women who were roughly the same age and weight. Continue reading


Higher Weight Links to Earlier Death for Some Breast Cancer Survivors

Research is clear that obesity increases the risk of developing breast cancer. Now, a large study suggests that women who are overweight or obese when they are diagnosed with the most common form of breast cancer have the greatest risk of an earlier death and recurrence, even when undergoing optimal treatment.

The study was published early online in the journal CANCER. Here’s the abstract.

The link was seen among women who had hormone-receptor positive breast cancer, which make up about two-thirds of breast cancers.

In all, the study included almost 7,000 women who went through treatment. The researchers pulled data from three National Cancer Institute trials that were studying the effects of chemotherapy, tamoxifen and/or other treatments on women with breast cancer. Their breast cancers ranged from the early stage to the later stage III, where the cancer could have spread to nearby lymph nodes.

The largest of the three trials tracked the women’s health for an average of 8 years; the other two followed the women for 14 years. Continue reading