Risk of missing advanced stage or high grade tumors during active surveillance (AS) even in favorable-risk prostate cancer (PC).

5069 Background: Owing to tumor heterogeneity, no standard selection criteria exist among prospective AS cohorts. Generally, men with low-stage, -volume, and -grade PC and low prostate-specific antigen (PSA) are eligible. In our prospective single-institution AS trial, men with early-stage PC were stratified: Gr I (favorable risk), II (pt’s choice), or III [competing comorbidities prevent local therapy (Tx)]. We report our experience with Gr I. Methods: Eligibility for Gr I: Gleason score (GS) ≤6, 1 positive (pos) core (<3 mm), and PSA <4 ng/mL or GS 7 (3+4), 1 pos core (<2 mm), and PSA <4 ng/mL. Monitoring q6mo included PSA, testosterone, and digital rectal exam. All pts had repeat biopsy (re-BX) at 1 y and then on predetermined BX scheme. Later, re-BX was required within 6 mo of study entry per an 11-core BX scheme (also used during AS). Definitive Tx was offered to pts who met reclassification based on clinical, BX (upgrading, ↑ in pos core BX, and/or ↑ tumor length), and/or radiographic progression. I...