Obesity is commonly associated with many other diseases and health risks, including heart disease and diabetes. However, there is also a significantly increased risk of developing many different cancers when you are obese. These include but are not limited to cancers that primarily affect women such as breast, endometrial and ovarian cancer. Not only is the risk of developing cancer amplified, but studies have also shown that obese women are less likely to get the preventative screening to find these cancers early and have higher overall mortality once diagnosed.
The Risk:
Many studies have shown that postmenopausal women who are obese have a 20-40% increase in the risk of developing breast cancer. Additionally, endometrial cancer (cancer of the lining of the uterus), is 2-7 times more common in overweight and obese women than it is in women with a healthy BMI. This risk increases as weight increases throughout adulthood. Ovarian cancer risk is also affected by obesity in that a 5-point increase in BMI conveys a 10% increase in risk. All in all, it has been estimated that in the U.S. 20% of all cancer deaths in women are due to obesity.
Why:
Adipose (fatty) tissue produces an excess of the hormone estrogen. Estrogen plays a significant role in the cancers mentioned above. As estrogen levels increase so does the risk of developing these cancers. Furthermore, obese individuals also have increased levels of insulin and insulin-like growth factor-1 which have been linked to the development of many cancers. These, as well as numerous other molecules that are made in fat cells, play an important role in the progression of cancer.
How Weight Loss Helps:
Studies have shown that people that have lost weight have a decreased risk of developing cancer when compared to obese patients that did not lose weight. There is even strong evidence supporting the role of bariatric surgery. Research has shown that obese people who undergo bariatric surgery have lower rates of obesity-related cancers than obese individuals who do not have bariatric surgery. After the substantial weight loss with bariatric surgery, patients are more likely to undergo the preventative screening measures needed. Those screenings (such as mammograms) become more accurate. Moreover, death rates from cancer have been shown to be significantly reduced in people who have undergone weight loss surgery compared to obese people that did not.
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