Recent studies suggest that testing blood for prostate specific antigen (PSA) alone does not produce an ideal predictor of prostate cancer, and emerging data suggest this is especially true for obese men.
A recent study by Oregon Health & Science University Cancer Institute researchers shows that a simple adjustment in how clinical measurements are interpreted in the diagnosis of prostate cancer can accurately predict the presence of prostate cancer in obese men.
"Some studies have shown that obese men are more likely to have deadly prostate cancer, yet diagnostic tools like PSA are less likely to accurately predict the presence of cancer in this population," said Mark Garzotto, M.D., an Oregon Health & Science University Cancer Institute researcher presented the study at the 2006 annual meeting of the American Society of Clinical Oncology.
PSA is a protein made only by prostate cells. Certain prostate conditions, including prostate cancer, are associated with high levels of PSA in the blood. However, obesity or high body mass index (BMI) has been tied to lower PSA levels. BMI measures weight in relation to height.
Compounding this diagnostic difficulty is that increasing BMI leads to increasing prostate size, but, again, lower PSA. Larger prostates produce more PSA in men with normal BMI's, not less.