Diabetes is associated with a lower risk of prostate cancer (PCa), but with a higher risk of other cancers in both men and women. The data, which were presented at the American Association for Cancer Research 102nd annual meeting, also showed an association between diabetes and higher cancer mortality rates.
“Our results provide further evidence that abnormal insulin and glucose signaling may contribute to cancer initiation and development,” said Gabriel Lai, PhD, a cancer prevention fellow at the National Cancer Institute in Bethesda, Md.
He and his colleagues conducted a prospective study using data from 295,287 men and 199,665 women aged 50-71 years. From 1995-1996, participants completed questionnaires asking about diet, lifestyle, and whether they had diabetes. Researchers followed the subjects for 11 years.
Diabetes was associated with an 8% increased risk for cancer among women and a 4% decreased risk for men. In previous studies, a decreased risk for PCa was associated with diabetes, which researchers believe might be due to the lower testosterone levels associated with diabetes. After excluding PCa from their evaluation, diabetes was associated with a 9% increased risk for cancer in men, the researchers reported.
As for mortality, diabetes was associated with an 11% increased risk in women and a 17% increased risk in men. “These risk factors appeared to be independent from other cancer risk factors, such as obesity and cigarette smoking,” Dr. Lai said.
After evaluating by cancer site, the researchers found that diabetes was associated with a significant increase in the risk for colon, rectal, and liver cancers among men and women. No association was found between diabetes and lung, skin, and other cancers.