Cancers Linked to Obesity
Many studies have demonstrated that specific types of cancer have been linked to obesity. These types of cancer include:
- Breast Cancer
The risk of postmenopausal breast cancer has been shown to rise in women who are obese. When the ovaries stop producing estrogen after menopause, the most important source of this hormone becomes fat tissues. These higher levels of estrogen can potentially lead to more rapid growth of estrogen-responsive breast tumors.
- Endometrial Cancer
Although we do not know why obesity has been linked to cancer in the lining of the uterus, obese and overweight women are two to four times more likely to develop endometrial cancer, regardless of whether they are pre- or postmenopausal.
- Colorectal Cancer
Higher BMI and increased waist circumference in men have been associated with colorectal cancer. It is not certain why, though there seems to be a link with being obese in the abdominal area. This connection can also be seen in obese women, though it is weaker.
- Kidney Cancer
The most common form of kidney cancer is renal cancer, which has been consistently associated with obesity, both in men and women. The specific mechanism, however, is not understood.
- Esophageal Cancer
Overweight and obese people are almost twice as likely as people of healthy weight to develop a cancer of the esophagus called esophageal adenocarcinoma. The mechanisms are not well-understood; however, an increased risk of this type of cancer has been associated with gastroesophageal reflux disease or Barrett’s esophagus, which is more common in obese people.
- Pancreatic Cancer
A slight increase in risk of pancreatic cancer has been linked to obesity.
- Thyroid Cancer
Excess weight has been shown to have an association with thyroid cancer, though it is not clear why.
- Gallbladder Cancer
Though the reasons are not known, there is a correspondence between a rise in BMI and a rise in the risk of gallbladder cancer.
- Other Cancers
Though the studies are not conclusive, possible links have been shown between obesity and prostate cancer, ovarian cancer, and liver cancer.
 “Obesity and Cancer Risk,” National Cancer Institute, http://www.cancer.gov/about-cancer/causes-prevention/risk/obesity/obesity-fact-sheet, accessed July 7, 2016.