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 →