Exploring the Link between Breast Cancer and Obesity

Obese and overweight women with a BMI of 25 and above are at high risk of developing breast cancer compared to those with a healthy weight, especially after menopause. Being obese can also increase the risk of breast cancer recurring in women who have been treated for the disease. Obesity has been connected to increased risks of developing other malignancies as well.

Evidence has shown that obesity at the time of diagnosis of breast cancer increases the risk of breast cancer-specific and the overall mortality in both postmenopausal and premenopausal women with early-stage breast cancer. Currently, there is no data from the randomized trials that have tested the impact of weight loss on breast cancer outcomes.

Here’s how obesity is linked to breast cancer:

• The high risk is attributed to the fact that fat cells make estrogen and the more extra fat cells means more estrogen in the body. Estrogen makes hormone receptor-positive breast cancers to develop and grow. The link between obesity and breast cancer is still a complicated matter and is affected by secondary factors such as the location of the extra weight. A lot of fat around the belly poses a higher risk than the extra fat around the hips or thighs.

• Recent randomized trials have indicated that weight loss interventions are feasible in breast cancer survivors with obesity with results of 5%-6% loss in body weight. Randomized phase 3 clinical trials are ongoing to evaluate the effect of weight loss interventions on the outcomes of breast cancer. The studies are going to give more insight into the role of weight loss in managing obese women with early breast cancer.

• Scientists are still figuring out why obesity contributes to the development of breast cancer. It seems there is a connection between the fatty tissue in the body, the hormones and inflammation. The adipose tissue secretes a lot of hormones and an increase in the circulating hormones can result to inflammation which in turn could lead to the development of cancer.

Research shows that obese women have a high risk of developing breast cancer after menopause compared to their lean counterparts. It also noted that obese women have a lower survival rate after diagnosis. The risk rises as the body mass index of the woman increases. However, in premenopausal women with a high-fat mass, the risk of getting breast cancer is low. The reason behind this discovery is not known yet.