Objectives: To assess the correlation between age, height, body weight, body mass index, body surface area (BSA), prostate volume, and prostate-specific antigen (PSA) level, and to determine the significant factors for predicting the PSA level in men with a low risk of having prostate cancer.
Methods: Men who had undergone at least one ultrasound-guided extended prostate biopsy at the M.D. Anderson Cancer Center from 1998 to 2003 and were proven, on pathologic examination, to be without cancer were included in this study. All patients underwent clinical evaluations, including digital rectal examination, serum PSA determination, transrectal ultrasound examination, and anthropometric measurements. The relationship between the clinical parameters and PSA level was examined by the Mann-Whitney U test and determination of the Pearson correlation coefficient.
Results: A total of 653 men were eligible for analysis in our study. The median age was 62.0 years; the median prostate volume was 48.3 cm3; and the median PSA level was 5.5 ng/mL. The PSA level correlated with age (P < 0.001) and prostate volume (P < 0.001), but not with height, body weight, body mass index, or BSA. The prostate volume correlated with age (P < 0.001), body weight (P < 0.001), body mass index (P < 0.01), and BSA (P < 0.01), but not with height. Multivariate analysis revealed that prostate volume and BSA were significant factors for predicting the PSA level.
Conclusions: Of the variables tested, prostate volume was most significantly related to the PSA level. The anthropometric parameters were not directly associated with the PSA level, but were associated with the prostate volume. Our findings suggest that differences in the PSA level may be influenced by body size, if the prostate volume is held constant in men with a low risk of having prostate cancer.