Commentary from Dr. Adil Akhtar:

Dr. Adil Akhtar is an Oncologist and Palliative Care Expert.  He is Associate Professor, Department of Medical Oncology & Hematology, Oakland University-William Beaumont School of Medicine. Director, Inpatient Clinical Operations, Karmanos-McLaren Oakland Cancer Center in Michigan. Chief, Division of Palliative & End of Life Care, Michigan Health Professionals.  Dr. Akhtar’s medical specializations are oncology, palliative care and end of life/hospice care.

  1. Is excess body fat linked to cancer?

Yes, is it clearly linked to an overall increased risk of cancer. According to research from the American Cancer Society, excess body weight is thought to be responsible for about 8% of all cancers in the United States, as well as about 7% of all cancer deaths. 

  1. What are some of the cancers linked to excess body fat/obesity?

Following are common types and more strongly linked 

  • Cancer of the endometrium, which is the inner lining of the uterus
  • Cancer of the esophagus, which is the part of digestive system taking food from the throat to the stomach.  A form of cancer adenocarcinomas is linked to obesity. 
  • Breast cancer in the women who has achieved menopause
  • Cancer of Colon/rectum
  • Cancer of pancreas
  1. How are these cancers linked to the body fat?

The short answer is we don’t completely understand how these cancers are linked to the body fat.  But following are some of the proposed links/mechanisms:

  • The most common association is chronic inflammation caused by excess body fat. An example is chronic acid reflux from stomach to the esophagus caused in overweight people causing inflammation and ultimately cancer of esophagus
  • Changes in the body immune system
  • Fat tissue produces excess amounts of hormone estrogen, which have been associated with increased risks of breast, endometrial, ovarian, and some other cancers
  • Other hormones or factors are also elevated in overweight individuals like insulin and insulin-like growth factors
  • Alterations in the cell growth and division regulators causing cancers
  1. What is the impact of weight loss on cancer risk reduction?
  • The is little data on this topic, but some of the studies have found decreased risks of breast, endometrial, colon, and prostate cancers among people who have lost weight.
  • American Cancer Society recommends that people who are overweight or obese should be encouraged and supported if they try to lose weight.
  1. How does age factor in to the equation?
  • Yes, in some cancers, the age at which someone gains weight is important.  For example, incidence of some forms of ovarian cancers is high when the weight gain was in the teen years
  • Breast cancer risk is higher is people after menopause