How Many Cores Should Be Sampled during Systematic Prostate Biopsy in Case of Negative Multiparametric Magnetic Resonance Imaging? Analysis of 274 Men with Clinical Suspicion of Prostate Cancer

Abstract

Introduction: This study aimed to investigate the number of cores needed in a systematic biopsy (SB) in men with clinical suspicion of prostate cancer (PCa) but negative prebiopsy multiparametric magnetic resonance imaging and to test prostate-specific antigen (PSA) density as an indicator for reduced SB. Methods: Two hundred and seventy-four patients were analyzed, extracted from an institutional database. Detection rates of any PCa and clinically significant (CS) PCa for different reduced biopsy protocols were compared by using Fisher’s exact test. Results: In total, 12-core SB revealed PCa in 103 (37.6%) men. Detection rates of reduced biopsy protocols were 74 (27%, 6-core) and 82 (29.9%, 8-core). Regarding CSPCa, 12-core SB revealed a detection rate of 26 (9.5%). Reduced biopsy protocols detected less CSPCa: 15 (5.5%) and 18 (6.6%), respectively. All differences were statistically significant, p < 0.05. PSA density ≥0.15 did not help to filter out men in whom a reduced biopsy may be sufficient. Conclusions: Twelve-core SB still has the highest detection rate of any PCa and CSPCa compared to reduced biopsy protocols. If the investigator and patient agree – based on individual risk calculation – to perform a biopsy, this SB should contain at least 12 cores regardless of PSA density.