A study reported in the current issue of Cancer, the journal of the American Cancer Society, shows that obesity is linked to lower levels of prostate specific antigen (PSA) in men, making early detection tests unreliable.
Since the use of early detection tests for prostate cancer became relatively common (about 1990), the prostate cancer death rate has dropped. But it is still unclear whether the drop is a direct result of screening. Studies are underway to try to determine if early detection tests for prostate cancer in large groups of men will lower the prostate cancer death rate.
Obesity, defined as a body mass index (BMI) over 30, is a growing public health issue in the U.S., and is associated with chronic diseases such as diabetes. A landmark American Cancer Society study in April 2003 added prostate cancer to the list of cancers linked to an unhealthy body weight, with men at the highest BMI at 34 percent higher risk. Studies also show obesity is associated with poor prognostic association as well. Obese men with prostate cancer are diagnosed at more advanced stages and have higher mortality rates. Hypotheses include tumorigenic links to elevated hormones, such as estrogen and insulin-like growth factor.