The Nature of Progression on Active Surveillance for Favorable-risk Gleason Grade Group 2 Prostate Cancer.

BACKGROUND

Active surveillance (AS) is a recommended option for favorable-risk Gleason grade group 2 (GG2) prostate cancer (PCa), but uptake varies.

OBJECTIVE

To describe the nature of progression of confirmed GG2 disease in a well-annotated AS cohort.

DESIGN, SETTING, AND

PARTICIPANTS

Participants at the University of California, San Francisco, were diagnosed with cT1-2N0/xM0/x, prostate-specific antigen (PSA) <20 ng/ml, core positivity ≤50%, and GG2 PCa without expansile cribriform or intraductal carcinoma (EC/IDC) at diagnosis, with two or more biopsies on AS from 2000 to 2025.

INTERVENTION: Active surveillance.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Outcomes were upgrade (GG3 or higher), volume increase to >50%, EC/IDC, disease progression (upgrade, volume increase, or EC/IDC), active treatment, recurrence (biochemical recurrence or salvage treatment) after radical prostatectomy (RP), metastasis, and PCa-specific mortality (PCSM). Cox proportional hazards regression models were used to identify risk factors for AS outcomes.

RESULTS AND LIMITATIONS: A total of 329 men were included. At 5 and 10 yr of follow-up, respectively, the upgrade rate was 31% and 58%, volume increase rate was 22% and 31%, EC/IDC development rate was 10% and 41%, disease progression rate was 44% and 79%, active treatment rate was 46% and 65%, and metastasis rate was 0.80% and 3.3%. The 5-yr post-RP recurrence rate was 32%. No PCSM events were recorded within 10 yr. PSA density (PSAD) and positive baseline multiparametric magnetic resonance imaging (mpMRI; Prostate Imaging Reporting and Data System 4-5) were associated with disease progression and active treatment. Limitations include the single-institution cohort, a largely Caucasian population, and incomplete mpMRI and genomic testing.

CONCLUSIONS

Men with confirmed favorable-risk GG2 PCa on AS have moderate rates of disease progression requiring treatment at 10 yr. Metastasis and PCSM rates were low, but confidence intervals are wide and require external validation. Positive mpMRI and increased PSAD were associated with disease progression and can help tailor AS intensity.