Diabetics Are Less Likely To Develop Advanced Prostate Cancer

Those who have diabetes are less likely to develop prostate cancer, particularly advanced prostate cancer according to a recent study. Diabetics tend to have lower testosterone levels than non-diabetics which is thought to be responsible for the lower incidence of prostate cancer observed in diabetic individuals.

The study, published in the American Journal of Epidemiology in 2004, involved comparing the diabetes status of 1,110 individuals from the US Physicians Heath Study who had been diagnosed with prostate cancer and comparing them to 1,110 control subjects who were free of prostate cancer.

In the group which had prostate cancer, 50 (4.5%) of the individuals had been diagnosed with diabetes compared to 71 (6.4%) of the individuals in the control group. After adjusting the results for potential confounding factors, people with diabetes were 36% less likely to develop prostate cancer than those without diabetes.

The association was particularly strong for advanced stages of prostate cancer with diabetics 52% less likely to develop advanced prostate cancer. In contrast early stage prostate cancer was not found to be associated with diabetes.

Animal studies have found that diabetes tends to reduce both testosterone levels in the blood and the size of the prostate gland, however once insulin is administered to the animals testosterone and prostate gland size increase to normal levels. This suggests that low levels of insulin inhibits the production of testosterone. High circulating levels of testosterone have been found to increase prostate cancer risk in several studies.

While diabetes may exert a protective effect on the prostate, studies suggest that other forms of cancer are more common in diabetics than the general population, in particular cancers of the gallbladder, colon, liver, pancreas, and bladder.

Prostate cancer is the most common form of cancer in males with 18% of American men developing the disease and 3% dying from it. Prostate cancers tend to be slow growing and if detected early, prostate cancer carries a very good prognosis. The survival rate is 99.8% if prostate cancer is detected before it has metastasized however this figure drops to just 35.4% for prostate cancer that has metastasized to distant locations.