Diabetes and Cancer

Chronic diseases are the scourge of the new age. All over the world people living with diabetes are expected to increase, especially in India.
Epidemiological studies indicate an increased risk of cancer for diabetic people. There is increased risk of hepatocellular cancer, pancreatic cancer, breast cancer, endometrial cancer, colorectal cancer, stomach cancer and bladder cancer. Prostate is the odd guy out as the risk for it is decreased if you have diabetes (possibly because of low testosterone levels).
The causal relationship between diabetes and cancer is not well established. There may be confounding bias, observational bias as the evidence is epidemiological. There are few biological hypothesis. Hyperinsulinemia drives growth and diabetics have hyperinsulinemia. Also cancer cells express IGF-1 (Insulin like growth factor receptors) receptors. Inflammation is more common in diabetics and chronic inflammation is a risk for cancer.
Summary and Actions To Be Taken:

1. Epidemiological evidence is there to say that diabetics are at increased risk for cancer.

2. Causal relationship and biological mechanism still needs further elucidation.

3. Diabetes and cancer share several risk factors, like obesity and physical inactivity. An effort to prevent and control diabetes will have a positive effect on cancer incidence. One need not have to wait for conclusive evidence to implement healthy habits and preventive measures.

4. Researchers and clinicians need to be more aware and collect prospective data. Also design studies to benefit patients.

5. The cancer risk conferred by diabetes may be moderate but considering that 366 million people have diabetes worldwide and it is expected to reach 552 million by 2030 calls for awareness and action.

Reference: Diabetes mellitus and cancer risk: Review of the epidemiological evidence