Active Surveillance as Preferred Treatment for ISUP Grade I Prostate Cancer: Confronting the ProtecT Trial

Background: The advantages of active surveillance (AS) in low-risk prostate cancer (PC) have already been widely demonstrated. The 15-year results of the Prostate Testing for Cancer and Treatment (ProtecT) trial were published recently, reflecting worse oncological outcomes of their active monitoring programme (AMP) compared with radical prostatectomy (RP) or radiotherapy (RDT). Our objective was to analyse the survival of patients with International Society of Urological Pathology (ISUP) grade I PC depending on the treatment received and point out the differences between an AS protocol and the AMP established in the ProtecT trial.

Methods: A retrospective study of patients with ISUP grade I PC managed by AS, RP or RDT was conducted. A comparative intention-to-treat survival analysis was performed. Our AS protocol included routine 18-core surveillance biopsies of all patients. On the basis of this assumption, the patients included in AS were divided into two groups: Those who met the rebiopsy criteria of the ProtecT trial and those who should not have been biopsied in accordance with this trial.

Results: Of the total 2865 patients, 981 met the selection criteria with a median follow-up of 7.7 years: 448 (45.7%) in AS, 399 (40.7%) in RP and 134 (13.7%) in RDT. The median age at diagnosis was 66.9, 63.2 and 69.2 years, respectively. The AS and RP groups were comparable in all the variables. The overall and cancer-specific survival results were similar, but the AS group had better metastasis-free survival. The RDT group presented worse clinical features in prostate-specific antigen and stage and worse survival outcomes compared with the other groups (p < 0.005). Out of the 448 patients included in AS, 100 met some of the criteria for rebiopsy of the ProtecT trial. Amongst the 348 patients who did not meet any criteria, 138 (39.6%) ended up receiving active treatment due to Gleason progression, increasing number of positive cores or both in the majority of cases (94.4%).

Conclusions: Surveillance biopsy is a major factor that contributes to achieving good oncological results in AS. Active monitoring is not comparable with an AS protocol, and thus, the results of the ProtecT trial are poorly assessable.