Prostate-specific antigen (PSA) and PSA velocity for prostate cancer detection in men aged <50 years

To identify threshold values of prostate-specific antigen (PSA) levels and PSA velocity (PSAV) to optimize the assessment of the risk of prostate cancer in young men, as prostate cancer is detected increasingly in men aged <50 years.

Data for a group of 12 078 men, including 1622 with prostate cancer, were retrieved from the Duke Prostate Center Database. Based on the latest date for a PSA assay, these men were divided into two age groups of <50 and >/= 50 years, with 904 and 11 174 men in each group, respectively. Receiver operating characteristic curves (ROC) of PSA and PSAV were calculated and the cancer risk was assessed.

The prevalence of prostate cancer was 4.4% (40 men) for men aged <50 years and 14.2% (1582 men) for men aged >/= 50 years. For the group with cancer the median PSA in men aged <50 years was significantly lower than that in men aged >/= 50 (1.3 vs 6.3 ng/mL, P < 0.001). ROC curves of PSA and PSAV showed a breakpoint at a PSA level of 2.3 ng/mL and a PSAV of 0.60 ng/mL/year for men aged <50 years. Both the sensitivity and specificity in the younger group at a PSA level of 2.5 ng/mL were higher than in the older group.

In men aged <50 years the operating characteristics of PSA are more sensitive and specific than in older men. Diagnostic PSA levels in men aged <50 years are significantly lower than suggested by guidelines. Using a 2.0-2.5 ng/mL PSA level threshold for biopsy in men aged <50 years and a PSAV threshold lower than the traditional 0.75 ng/mL/year is reasonable in contemporary practice. Further studies are warranted to validate these thresholds.