Prostate-specific antigen (PSA) levels may be lower in obese men, which could lead to inaccurate screening and delays in cancer diagnosis.

A study published in the March issue of Cancer (2005; 103 [5], 1092–95), looked at the association between body mass index (BMI) and PSA in 2,779 men who did not have prostate cancer. Researchers found that the mean PSA value decreased as BMI increased, falling from 1.01 nanograms per milliliter (ng/ml) in normal-weight men to 0.69 ng/ml in obese men. They concluded that the lower levels “could mask biologically consequential prostate carcinoma.”