Time without PSA recurrence after radical prostatectomy as a predictor of future biochemical recurrence, metastatic disease and prostate cancer death: a prospective Scandinavian cohort study

Abstract

Objective: Although surveillance after radical prostatectomy routinely includes repeated prostate specific antigen (PSA)-testing for many years, biochemical recurrence often occurs without further clinical progression. We therefore hypothesised that follow-up can be shortened for many patients without increasing the risk of prostate cancer death. We investigated the long-term probabilities of PSA recurrence, metastases and prostate cancer death in patients without biochemical recurrence five and 10 years after radical prostatectomy.

Design: Prospective cohort study. Stratification by Gleason score (≤3+4=7 or ≥4+3=7), pathological tumour stage (pT2 or ≥pT3) and negative or positive surgical margins.

Setting: Between 1989 and 1998, 14 urological centres in Scandinavia randomised patients to the Scandinavian Prostate Cancer Group study number 4 (SPCG-4) trial.

Participation: All 306 patients from the SPCG-4 trial who underwent radical prostatectomy within 1 year from inclusion were eligible. Four patients were excluded due to surgery-related death (n=1) or salvage radiotherapy or hormonal treatment within 6 weeks from surgery (n=3).

Primary outcome measures: Cumulative incidences and absolute differences in metastatic disease and prostate cancer death.

Results: We analysed 302 patients with complete follow-up during a median of 24 years. Median preoperative PSA was 9.8 ng/mL and median age was 65 years. For patients without biochemical recurrence 5 years after radical prostatectomy the 20-year probability of biochemical recurrence was 25% among men with Gleason score ≤3+4=7 and 57% among men with Gleason score ≥4+3=7; the probabilities for metastases were 0.8% and 17%; and for prostate cancer death 0.8% and 12%, respectively. The long-term probabilities were higher for pT ≥3 versus pT2 and for positive versus negative surgical margins. Limitations include small size of the cohort.

Conclusion: Many patients with favourable histopathology without biochemical recurrence 5 years after radical prostatectomy could stop follow-up earlier than 10 years after radical prostatectomy.

Keywords: Epidemiology; Prostate disease; Urological tumours.

Figure 1

Patient selection and complementary treatment after radical prostatectomy. HT, hormonal treatment; RP, radical prostatectomy; RT, radiotherapy; SPCG4, Scandinavian Prostate Cancer Group study nr. 4.

Figure 2

Cumulative incidence of biochemical recurrence, metastasis and death from prostate cancer after radical prostatectomy. BCR, biochemical recurrence; PC, prostate cancer; pT, pathological T-stage; RP, radical prostatectomy.

Figure 3

20-year probability of event conditioned on time after radical prostatectomy without biochemical recurrence. Y-axis represents the probability of an event (biochemical recurrence, metastasis and PC-death) for the different subgroups within 20 years after radical prostatectomy; X-axis represents time after radical prostatectomy without biochemical recurrence. The green circle in (A) exemplifies the probability to experience a biochemical recurrence within 20 years from radical prostatectomy for a patient with GS ≤3+4=7 who was free from biochemical recurrence 6 years after radical prostatectomy. The red circle in (F) exemplifies the probability to die from prostate cancer within 20 years from radical prostatectomy for a patient with ≥pT3 who was free from biochemical recurrence 8 years after radical prostatectomy. BCR, biochemical recurrence; GS, Gleason score; PC, prostate cancer; pT, pathological T-stage; RP, radical prostatectomy.