Obesity is a condition in which the body has too much fat tissue. Obesity increases the risk of various diseases and complications including many types of cancer. There are many factors that can cause obesity-related cancer. These include chronic inflammation, higher levels of hormones and an excess of glucose in the blood. All such factors cause disturbance and changes to normal cells that can result in cancer.
The possible cause of the association between obesity and cancer are:
- Raised levels of insulin and insulin growth factor-1 that may help the development of cancer
- Chronic inflammation, which is more common in obese people that increase the risk of cancer
- Higher amounts of estrogen produced by fat tissues that increases the risk of certain cancers, such as breast and endometrial cancers
- Fat cells may also affect the regulation process of cancer cell growth.
Obesity has been associated with various types of cancer, but the risk is higher for breast, esophageal and endometrial cancers. Following are the other types of cancer that have an association with obesity:
- Endometrial cancer : Women who are obese are at much higher risk of developing endometrial cancer. The risk rises with increasing body weight in adulthood, especially in women who have never taken menopausal hormone therapy.
- Esophageal cancer : People with obesity are two times more susceptible to develop a type of esophageal cancer called esophageal adenocarcinoma.
- Gastric cardia cancer : People with obesity are more susceptible to develop cancer in the upper part of the stomach.
- Liver cancer : Obese people are two times more prone to develop liver cancer as compared to normal weight people.
- Kidney cancer : An individual with obesity is at higher risk of developing kidney cancer as compared to people with normal body weight.
- Pancreatic cancer : Obese people are nearly 1.5 times more prone to have pancreatic cancer as compared to people with normal weight.
- Colorectal cancer : Overweight people tend to develop colorectal cancer. The risk is greater in men than in women.
- Gallbladder cancer : Obese people have a 60% increase in the risk of gallbladder cancer.
- Breast cancer : Studies have shown that, in postmenopausal women, a higher BMI is linked with a moderate increase in the risk of breast cancer. The risk is higher in women who have never taken menopausal hormone therapy.
- Ovarian cancer : High BMI is linked with a slight rise in the risk of ovarian cancer. The risk is especially higher in women who have never taken menopausal hormone therapy.
- Thyroid cancer : Higher BMI is also linked with a slight rise in the risk of thyroid cancer.