The number of cores at first biopsy may suggest the need for a confirmatory biopsy in patients eligible for active surveillance-implication for clinical decision making in the real-life setting

Objective: To assess whether the number of cores at first prostate biopsy affect pathologic findings at radical prostatectomy (RP) in potential candidates for active surveillance (AS).

Material and methods: Two hundred seventy-five patients fulfilling Prostate Cancer Research International: Active Surveillance criteria (prostate-specific antigen level ≤ 10 ng/mL, prostate-specific antigen density <0.2 ng/mL/cm(3), number of positive cores ≤ 2, T1c-T2 clinical stage, Gleason score [GS] ≤ 6) underwent RP between 2005 and 2013 at a single institution. Patients were stratified into 3 groups according to different biopsy schemes (≤ 12 vs 13-18 vs ≥ 19 cores). Rates of pathologically confirmed insignificant prostate cancer (pIPCa; defined as RP GS ≤ 6, tumor volume ≤ 0.5 mL, and organ-confined disease) and unfavorable disease (UD, defined as non-organ-confined disease and/or pathologic GS ≥ 7) at RP were stratified according to the biopsy schemes. Logistic regression analyses tested the effect of preoperative variables in predicting pIPCa and UD at RP.

Results: Of all, 23.3% and 33.4% patients harbored pIPCa and UD, respectively. pIPCa and UD were found in 15.7%, 32.1%, 25.3% (P = .04) and in 48.1%, 23.8%, 24.1% (P <.001) patients with ≤ 12, 13-18, ≥ 19 cores, respectively. At multivariate analyses, number of biopsy cores emerged as an independent predictor of both pIPCa (≤ 12 vs 13-18 cores: odds ratio [OR] = 2.34; P = .02) and UD (≤ 12 vs 13-18 cores: OR = 0.39; P <.01; ≤ 12 vs ≥ 19 cores: OR = 0.38; P <.01).

Conclusion: Among candidates for AS, number of biopsy cores emerged as an independent predictor of pIPCa and UD at RP. These findings would suggest that the extent of initial biopsy sampling should be considered when addressing patients to AS and before planning any surveillance strategies.