Purpose: Monitoring the serum level of prostate specific antigen (PSA) is indispensable for surveillance after radical therapy, and the aim of this study was to establish the optimal follow-up schedule.
Materials and methods: We retrospectively reviewed the clinicopathological data of 1,010 consecutive patients who underwent radical prostatectomy. After excluding patients who received neoadjuvant or adjuvant therapy and those without a nadir PSA level<0.2ng/ml, the remaining 779 patients were enrolled. Biochemical recurrence (BCR) was defined as elevation of PSA to >0.2ng/ml. We investigated the PSA doubling time (PSA-DT) following BCR at various times after surgery.
Results: During a mean follow-up of 8.8 years, BCR occurred in 180/779 patients. The annual BCR rate was 6% in the first year after surgery, 6% between 1 and 2 years, 3% between 2 and 3 years, 3% between 3 and 5 years, and 2% at >5 years postoperatively. During these periods, the minimum PSA-DT after BCR was 1.6, 2.4, 3.1, 6.1, and 6.4 months, respectively. These minimum PSA-DTs were used to determine the optimal follow-up interval during each period after surgery. If the baseline level is 0.1ng/ml, PSA should be measured at approximately 3-month intervals for the first year, at 4-month intervals between 1 and 2 years, at 6-month intervals between 2 and 3 years, and annually thereafter to definitely detect BCR before the serum PSA level exceeds 0.4ng/ml.
Conclusion: The PSA-DT following BCR varies according to the time after surgery. Our data on minimum PSA-DT values after BCR are useful for setting the optimal follow-up schedule.
Keywords: Biochemical recurrence; Follow-up; PSA doubling time; PSA monitoring; Radical prostatectomy.
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