Early detection of prostate cancer local recurrence by urinary prostate-specific antigen.

PURPOSE

We assessed the role of urinary prostate-specific antigen (uPSA) in the follow-up of prostate cancer after retropubic radical prostatectomy (RRP) for the early detection of local recurrences.

METHODS

We recruited 50 patients previously treated for prostate cancer with RRP and who had not experienced a prostate-specific antigen (PSA) recurrence within their first postoperative year into a cross-sectional laboratory assessment and prospective 6-year longitudinal follow-up study. We defined biochemical failure as a serum PSA (sPSA) of 0.3 μg/L or greater. Patients provided blood samples and a 50-mL sample of first-voided urine. We performed Wilcoxon rank-sum and Fisher exact tests for statistical analysis.

RESULTS

The median sPSA was 0.13 μg/L. The median uPSA was 0.8 μg/L, and was not significantly different when comparing Gleason scores or pathological stages. Of the 50 patients, 27 initially had a nondetectable sPSA but a detectable uPSA, and 11 patients experienced sPSA failure after 6 years. Six patients had detectable sPSA and uPSA initially. Fifteen patients were negative for both sPSA and uPSA, and 13 remained sPSA-free after 6 years. The odds ratio (OR) of having sPSA failure given a positive uPSA test was 4.5 if sPSA was undetectable, but was reduced to 2.6 if sPSA was detectable. The pooled Mantel-Haenszel OR of 4.2 suggested that a detectable uPSA quadrupled the risk of recurrence, independent of whether sPSA was elevated or not. The sensitivity of uPSA for detecting future sPSA recurrences was 81% and specificity was 45%.

CONCLUSION

Urinary PSA could contribute to an early detection of local recurrences of prostate cancer after a radical prostatectomy.