Active surveillance for patients with prostate cancer aged ≥75 years: the Prostate Cancer Research International:...

To investigate clinical outcomes, treatment, and survival rates of men aged ≥75 years with prostate cancer in Japan.

The study used data from the Prostate Cancer Research International: Active Surveillance (PRIAS)-JAPAN, a nationwide, multicentre prospective cohort study of men with clinically localised prostate cancer managed with active surveillance (AS). The original eligibility criteria were clinical stage T1c-T2 disease, prostate-specific antigen (PSA) level ≤10 ng/mL, PSA density (PSAD) <0.20 ng/mL/mL, and Gleason Score ≤3 + 3 with two or fewer positive biopsy cores. In 2021, magnetic resonance imaging use expanded eligibility to include patients with a PSA level ≤20 ng/mL, PSAD <0.25 ng/mL/mL, and Gleason Score ≤3 + 4 with <50% of biopsy cores positive. PSA was monitored every 3-6 months, and biopsies were scheduled at 1, 4, 7, and 10 years, and every 5 years thereafter. The outcomes in those aged ≥75 years (older group) were compared with those aged <75 years (younger group).

Of the 1274 eligible patients enrolled by 29 February 2024, 231 were in the older group and 1043 were in the younger group. In the older group, the median age at enrolment was 77 years. At diagnosis, patients in the older group had significantly larger prostate volumes, higher proportion of Gleason Score 3 + 4, and more T2 disease than those in the younger group. The protocol biopsy acceptance rate decreased over time (first: 82.9%, second: 63.6%, third: 42.2%, fourth: 22.4%), with no significant difference between age groups. The 10-year AS persistence rate in the older group was 8.8%. The overall survival was significantly lower in the older group than in the younger group (hazard ratio: 0.32, 95% confidence interval 0.14-0.74); however, the 10-year metastasis-free survival and cancer-specific survival rates in the older group were both 100%.

In some patients aged ≥75 years an observation-focused management approach may be appropriate, in which AS is initiated as a structured monitoring phase with planned de-intensification and transition to watchful waiting, to prevent overtreatment while maintaining excellent cancer-specific outcomes.