A recent population-based study of both white and black men diagnosed with prostate cancer found that there is not an association between the aggressiveness of prostate cancer in either white or black men who also have diabetes. However white American men who were obese but without a diagnosis of diabetes, did have an association of more aggressive prostate cancer.
“This study points to the fact of obesity’s significance on possibly driving prostate cancer into a more aggressive condition,” stated Dr. Samadi. “What is interesting is that men diagnosed with diabetes did not have an association even though they often are overweight to obese. This is not the first study to link obesity with aggressive prostate cancer but what is different is that it was only associated in white men and not black men.”
For the year 2016, it is estimated that 180,890 new cases of men with prostate cancer will be diagnosed and 26,120 men will succumb to the disease.
Using data from the North Carolina-Louisiana Prostate Cancer project, the study consisted of 1,058 white Americans and 991 black Americans. Each man self-reported whether they had diabetes or not while determination of obesity was based on anthropometric measurements. The determination of high aggressive prostate cancer was defined as a Gleason sum equal or greater than 8 or a prostate-specific antigen higher than 20 ng/ml or A Gleason sum equal to 7 with a clinical stage of cT3-cT4.
This particular study is one of just a few studies that have investigated the role of race in the association of diabetes and obesity with prostate cancer aggressiveness.
“There is a discrepancy between white and black men when it comes to prostate cancer,” noted Dr. Samadi. “It has been known that black men are more likely to be diagnosed with and die from prostate cancer than white men. In fact, the incidence is really quite startling. From 2008 to 2012, the incidence of prostate cancer in black men was 214.5 cases per 100,000 compared to 130.4 cases per 100,000 in white men.”
The findings from the study did not show an association between self-reported diabetes and high aggressive prostate cancer in either white or black men. The researchers did however find that obesity, independent of diabetes, was associated with high aggressive prostate cancer in white men according to the composite measuring of prostate cancer aggressiveness used for the study.
The data from the study also showed that black men with a normal body mass index (BMI) were more likely to have high aggressive prostate cancer (22%) than white men (12%) with a normal BMI. But the prevalence of high aggressive prostate cancer in obese men who were white was 20% which is actually lower than the prevalence of high aggressive prostate cancer in black men with a normal BMI. This is probably why there was a significant association only among white men.
“There are several possibilities for the outcome from this study,” observed Dr. Samadi. “It is known that insulin is a growth factor for prostate cancer and it has been hypothesized that the lower insulin levels in men with diabetes may actually slow down the development of incident prostate cancer. It also depends on how long a man has had a diabetes diagnosis, how well his diabetes is controlled, and his level of testosterone. Another factor is that obese men are at an increased risk for both hyperinsulinemia and lower testosterone levels even if they do not have diabetes. Having those two factors alone can contribute to prostate cancer aggressiveness at the time of diagnosis.”
Dr. Samadi added, “This study, like so many others, demonstrates the importance for all men, no matter what their race is, to start adopting or modifying lifestyle habits that promote reaching and maintaining a healthy body weight. Eating a diet of healthy foods and regular exercise are two ways any man can choose to reduce his risk of developing prostate cancer and particularly aggressive prostate cancer.”
Patients newly diagnosed with prostate cancer can contact world renowned prostate cancer surgeon and urologic oncologist, Dr. David Samadi, for a free phone consultation and to learn more about prostate cancer risk, call 212-365-5000.Health articles