Evidence linking diabetes and kidney cancer has grown stronger over the past decade, leading researchers to investigate the reasons behind these links.
What is Kidney Cancer?
Kidney cancer is a disease in which kidney cells become cancerous and grow into a tumor.
Most kidney cancers are found before they spread to distant organs. Caught early, they can usually be treated successfully. Tumors can grow large if not detected.
This year, the American Cancer Society reports there will be at least 64,000 new cases of kidney cancer, affecting mostly men. Up to 15,000 people could die this year from this type of cancer.
What is Diabetes?
Diabetes is a group of diseases resulting in high blood glucose (too much sugar in the blood). As of 2014, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) reports 29.1 million people, or 9.3 percent of the U.S. population, have diabetes – both diagnosed and undiagnosed.
Type 1 and type 2 diabetes are the two most common forms of diabetes, but there are other kinds, including one which occurs during pregnancy. Up to 95 percent of diabetics have type 2, according to NIDDK.
You are more likely to have type 2 if you are 45 or older, have a family history of diabetes, or are overweight and inactive. Other health problems, such as high blood pressure, also contribute to the development of type 2 diabetes.
Kidney Cancer-Diabetes Connection
Diabetes is just one of the many risk factors for kidney cancer. Obesity, smoking, high blood pressure, and family history are also potential risk factors, among others.
How diabetes is linked to kidney cancer has been an issue of debate.
One 2012 study out of the University of Texas finds the most advanced cases of cancer are found in those who have the worst control over blood sugar. At least a quarter of the kidney cancer study participants also had diabetes.
Another study from 2011 out of Harvard School Medicine finds that diabetic women had a much higher risk for developing kidney cancer than diabetic men. What is interesting about this is that men, in general, are at higher risk for kidney cancer than women.
A 2015 report out of the National Taiwan University College of Medicine, Taipei, Taiwan, aimed to determine the link between incidences of kidney cancer and type 2 diabetes mellitus. The large study looked at close to a million people worldwide with and without diabetes who did not have kidney cancer at the start of the study.
The Taiwanese researchers concluded type 2 diabetics had a significantly higher risk for kidney cancer. They also noted some possible risk factors for both conditions were age, diabetic nephropathy (kidney disease or damage), and end-stage renal disease (kidney failure).
Diabetes is also associated with decreased overall survival rates for patients with kidney cancer, as reported by researchers at the 2014 Genitourinary Cancers Symposium. According to their report, diabetics with kidney cancer had 44 percent increased risk for death than non-diabetics.