For decades, scientists have been sure about the close connection between diabetes and cancer but had no idea about the reason of relationship. Now they have solved the riddle and identified the causes. High glucose concentration in the blood, which is a major symptom of diabetes, may cause cancer. Furthermore, cancer treatments may also cause a spike in blood sugar levels.
Causes of Diabetes
Insulin is produced in the Beta cells of Islets of Langerhans in Pancreas. Insulin converts glucose into energy. Diabetes happens if pancreas cannot produce enough of insulin or stops the hormone production. You can also get the disease if your body cannot process insulin.
Every year, 14th November is celebrated as the World’s Diabetes Day. According to a 2020 estimate by the International Diabetes Federation, there are 46.3 million of diabetic patients in the world and of them, 77 millions are Indians.
Diabetes has long been strongly linked to heart disease, stroke, kidney disease and blindness. And now scientists have come up with strong evidence of link between diabetes and cancer. Diabetes is often said to be a silent killer. Let us now take a close look at how cancer and diabetes are related.
How Diabetes May Cause Cancer
According to a July 2018 study, both type 1 and type 2 diabetes increase the risk of developing certain cancers. The risk of getting cancer is more for diabetic women than their male counterparts.
Which cancers are caused by diabetes?
Diabetes puts a man at a higher risk of developing liver cancer whereas the diabetic women have an elevated risk of getting oral cancer, stomach cancer, kidney cancer and leukaemia.
Patients with type 2 diabetes, informally known as adult-onset diabetes, may put you at an increased risk of getting breast, pancreatic, endometrial, liver, pancreatic, colon and kidney cancers.
Scientists have discovered a few factors that contribute to cancer development and these are as follows:
- The hormone insulin, which controls blood sugar levels, also triggers cell growth and it may lead to cancer in some patients.
- The fatty tissues in overweight and obese persons produce a higher amount of adipokines. The hormone may induce inflammation, which is another big risk factor for cancer.
- The scientists have also identified a DNA connection between diabetes and cancer. The high glucose levels change the DNA structure and destroy its normal repairing ability, which increases the chance of cancer.
Cancer Treatment and Diabetes
Cancer treatment increases the risk of getting diabetes. A 2018 study by JAMA Oncology claims that cancer patients have six times higher incidence of diabetes than the non-diabetic cancer patients. It may not be due to cancer itself but the treatments to fight the disease.
Radiation therapy attacks cancer cells but the treatment in some regions of the body may destroy insulin-producing cells as well. Cancer patients, who are undergoing chemotherapy, take steroids for nausea which is a very common problem in them. The drug also raises the sugar levels in their blood.
Immunotherapy, which has emerged as a promising treatment for some types and sub-types of cancers, also contributes to developing diabetes. The JAMA Oncology study has found that the risk of getting diabetes is highest within the two years of a patient’s completing his/her cancer treatment. After that, the risk comes down but always stays elevated.