The Dangers of Obesity in Breast Cancer Treatment

breast cancerBreast cancer is the most common type of cancer amongst American women and although the death rate for it is dropping, breast cancer still remains the second leading cause of cancer-related death for women in America. Given the fact that 34 percent of Americans are obese and that 1 in 8 women will eventually suffer from breast cancer, correlations between weight and the effectiveness of different types of breast cancer treatment therapies are definitely worth investigating.

Breast Cancer and Obesity


A recent breast cancer study found anastrozole (an aromatase inhibitor drug) that is considered markedly more effective as a breast cancer treatment amongst the general population than its predecessor tamoxifen, is actually no more effective when it comes to the treatment of obese women. With this study in mind, researchers at the Institute of Cancer Research in London and The Royal Marsden NHS Foundation set out to examine whether tamoxifen is simply more effective for obese women or if aromatase inhibitor drugs are simply less effective for obese women then they are for women with a lower body mass.

The purpose of anastrozole and other aromatase inhibitor drugs is to lower estrogen levels. These drugs are helpful for breast cancer treatment because over 66 percent of breast cancer tumors require estrogen to grow and survive and the drugs block the production and action of estrogen in the body. For the Institute of Cancer Research study, the scientists prescribed a 6 month course of aromatase inhibitor drugs to 54 postmenopausal women with estrogen related breast cancer. The body mass and estrogen levels of the women were measured both before and after the study. The researchers found that although anastrozole did lower the estrogen levels of the obese women with breast cancer, the levels of estrogen in these women still remained twice as high as the levels found in women of normal body weight after treatment. These findings suggest that breast cancer treatment may not be a one-size-fits-all type of therapy and that the most effective and appropriate form of breast cancer treatment therapy may be dependent upon a women’s body mass index.

The Study – Obesity and Breast Cancer Treatment

According to Professor Alan Ashworth, Chief Executive of The Institute of Cancer Research, “Aromatase inhibitors have played an increasing role in breast cancer treatment over the past decade, so it is important to understand the factors that affect how well they work in individual women in order to allow doctors to choose the best possible drug from the range available.” Senior author Professor Mitch Dowsett adds “Our findings are based on laboratory studies, so we would need to carry out clinical trials to tell us whether women with a higher BMI would benefit from changes to their treatment. Women with higher BMIs should certainly not be alarmed by this finding or stop taking their treatment. Our study takes us a step closer to understanding which of the treatment options available might be the most suitable for individual women.”

All breast cancer drugs come with a range of unwanted side-effects and none of them provide any guarantees of effectiveness. Until more research is done, your best bet for surviving breast cancer is preventing the development of it in the first place. Some preventative breast cancer measures that you can take include eating a high fiber, whole-foods based diet, reducing your intake of alcohol and minimizing your exposure to toxins such as the BPA found in plastic food containers and the parabens found in cosmetics. Perhaps the two most vitally important preventative steps that you can take however, are exercising regularly and maintaining a healthy body weight—both of which help to dramatically reduce circulating estrogens levels.