Ultrasensitive Assay of Prostate-Specific Antigen for Early Detection of Residual Cancer after Radical Prostatectomy
Article first published online: 2 JUL 2007
International Journal of Urology
Volume 5, Issue 6, pages 550–555, November 1998
How to Cite
Arai, Y., Okubo, K., Aoki, Y., Maekawa, S., Okada, T. and Maeda, H. (1998), Ultrasensitive Assay of Prostate-Specific Antigen for Early Detection of Residual Cancer after Radical Prostatectomy. International Journal of Urology, 5: 550–555. doi: 10.1111/j.1442-2042.1998.tb00411.x
- Issue published online: 2 JUL 2007
- Article first published online: 2 JUL 2007
- Received Dec. 27, 1997; accepted for publication in revised form May 19, 1998.
- prostate specific antigen;
- ultrasensitive assay;
- prostatic neoplasms;
Objectives: Perhaps the greatest value of PSA determination in the treatment of prostate cancer is in determining persistent disease after a radical prostatectomy. We investigated the ability of an ultrasensitive PSA assay to detect residual prostate cancer in men at risk for recurrence after a radical prostatectomy.
Methods: Using the Immulite third-generation PSA assay (detection limit, less than 0.003 ng/mL), and the standard IMx PSA assay, we determined PSA levels in 205 serum samples serially obtained from 34 men after a radical prostatectomy. The average days from surgery to serum sampling was 430 (range, 63 to 1 296). Patients were classified as having nonaggressive or aggressive cancers, based on clinicopathologic findings. A biochemical relapse was arbitrarily defined.
Results: All 1 7 patients with nonaggressive cancers had PSA values of less than 0.02 ng/mL throughout the sampling period. Two of these patients (12%) had 2 or more consecutive PSA increases and were considered as a biochemical relapse. In contrast, 14 (82%) of 1 7 patients with aggressive cancers fit criteria of a biochemical relapse. All of the relapses were identified within 2 years after surgery. The IMx assay detected only 7 biochemical relapses during the same sampling period.
Conclusions: Using the Immulite PSA assay, relapse detection times may be shortened allowing for most serological recurrences to be detected within 2 years after a radical prostatectomy. Patients with aggressive cancers may require frequent postoperative PSA determinations with a highly sensitive PSA assay which would allow early intervention when treatments for relapse are effective.