TRUS-Guided Target Biopsy for a PI-RADS 3–5 Index Lesion to Reduce Gleason Score Underestimation: A Propensity Score Matching Analysis

Abstract

BackgroundMagnetic resonance imaging (MRI) and transrectal ultrasound (TRUS)-guided cognitive or image fusion biopsy is performed to target a prostate imaging reporting and data system (PI-RADS) 3–5 lesion. Biopsy Gleason score (GS) is frequently underestimated compared to prostatectomy GS. However, it is still unclear about how many cores on target are necessary to reduce undergrading and if additional cores around the target may improve grade prediction on surgical specimen.PurposeTo determine the number of target cores and targeting strategy to reduce GS underestimation.Materials and MethodsBetween May 2017 and April 2020, a total of 385 patients undergoing target cognitive or image fusion biopsy of PI-RADS 3–5 index lesions and radical prostatectomies (RP) were 2:1 matched with propensity score using multiple variables and divided into the 1–4 core (n = 242) and 5–6 core (n = 143) groups, which were obtained with multiple logistic regression with restricted cubic spline curve. Target cores of 1–3 and 4–6 were sampled from central and peripheral areas, respectively. Pathologic outcomes and target cores were retrospectively assessed to analyze the GS difference or changes between biopsy and RP with Wilcoxon signed-rank test.ResultsThe median of target cores was 3 and 6 in the 1–4 core and 5–6 core groups, respectively (p < 0.001). Restricted cubic spline curve showed that GS upgrade was significantly reduced from the 5th core and there was no difference between 5th and 6th cores. Among the matched patients, 35.4% (136/385; 95% confidence interval, 0.305–0.403) had a GS upgrade after RP. The GS upgrades in the 1–4 core and 5–6 core groups were observed in 40.6% (98/242, 0.343–0.470) and 26.6% (38/143, 0.195–0.346), respectively (p = 0.023). Although there was no statistical difference between the matched groups in terms of RP GS (p = 0.092), the 5–6 core group had significantly higher biopsy GS (p = 0.006) and lower GS change from biopsy to RP (p = 0.027).ConclusionFive or more target cores sampling from both periphery and center of an index tumor contribute to reduce GS upgrade.

Sextant Systematic Biopsy Versus Extended 12-Core Systematic Biopsy in Combined Biopsy for Prostate Cancer

“…In the present study, to improve the CDR and Gleason score underestimation, a targeted biopsy with a large number of cores (approximately six cores), including index lesion peripheral biopsy, was performed to compensate for the weakness of cognitive biopsy. 18 In our previous study, we reported that a target biopsy of five cores or more, including the center of index lesion and peripheral tissues, can expect optimal CDR and avoid Gleason score underestimation. 18 In the present study, a mean of 5.96 core biopsy were performed on the index lesions.…”

“… 18 In our previous study, we reported that a target biopsy of five cores or more, including the center of index lesion and peripheral tissues, can expect optimal CDR and avoid Gleason score underestimation. 18 In the present study, a mean of 5.96 core biopsy were performed on the index lesions.…”

“…The number of target biopsy cores for index lesions in combined biopsies is increasingly recommended, ranging from at least two to more than 5 cores. 17 18 26 27 In addition to target biopsy. a combined biopsy requires systematic biopsy.…”

“… 9 According to Tu et al, 17 more than four target biopsy cores showed a significantly greater CDR. Moreover, Chung et al 18 recently reported that five or more target cores could reduce the underestimation of PCa. Although the number of target biopsy cores varies according to the clinician, multiple samplings may be needed, including a peripheral biopsy of the index lesion.…”

Prostate Biopsy in the Case of PIRADS 5—Is Systematic Biopsy Mandatory?

“…Several recent studies indicate that SB may reduce the likelihood of Gleason score underestimation [36,37]. Moreover, taking cores from areas surrounding a suspicious lesion (focal systematic biopsy) can overlap sampling error and may provide a better estimation of the Gleason score [38]. Similarly, several technical issues of TB are also under investigation.…”