Accuracy of Grading Gleason Score 7 Prostatic Adenocarcinoma on Needle Biopsy: Influence of Percent Pattern 4 and Other Histological Factors

Abstract

When pattern 4 is scattered amongst pattern 3 as opposed to being discrete foci, there is less interobserver reproducibility in grading Gleason score 7 cancer, and in this setting pathologists should consider obtaining second opinions either internally within their group or externally. Prostate 77: 681-685, 2017. © 2017 Wiley Periodicals, Inc.

Prostate Cancers Detected by Magnetic Resonance Imaging–Targeted Biopsies Have a Higher Percentage of Gleason Pattern 4 Component and Are Less Likely to Be Upgraded in Radical Prostatectomies

“…36 Targeted biopsies also outperformed standard biopsies in detection of overall positive cores, percentage area of cores positive for cancer, cancer length of positive cores, perineural invasion, and more anteriorly located PCas. [37][38][39][40][41][42] GP 4 quantity in GS 7 PCa is an important pathologic parameter that may also influence treatment decisions. In GS 7 PCa, GP 4 is associated with adverse histopathologic outcomes and an increased risk of biochemical failure in patients undergoing radical prostatectomy.…”

“…The quantity of GP 4 has been used in determining candidacy for active surveillance and for selection of different radiation therapy protocols. 42 In this study, we explored the possibility that MRI-targeted biopsy may detect GS 7 PCa with greater GP 4 quantity. We indeed found that the mean percentage of GP 4 detected by MRI-targeted biopsy was significantly higher than that detected by standard biopsy (31.0% versus 25.2%).…”

Essential Updates in Grading, Morphotyping, Reporting, and Staging of Prostate Carcinoma for General Surgical Pathologists

“…1 Distinction between some GP 3 and GP 4 glands can be challenging, particularly between small and tangentially sectioned GP 3 glands versus poorly formed GP 4 glands and between tight clusters of GP 3 glands versus fused GP 4 glands. [30][31][32] Interobserver studies have shown that pathologists usually have problems classifying poorly formed glands as GP 4, particularly when seen admixed with intervening GP 3 glands versus when seen as a discrete cluster of GP 4 glands. 31,32 Although a practical approach is to ensure that tangential sectioning is not the cause of glands that appear poorly formed, some authors have proposed that interobserver reproducibility may be improved in the interpretation of poorly formed glands as GP 4 when a minimum number (.5) of poorly formed glands are in a cluster and not intermixed with well-formed glands.…”

“…[30][31][32] Interobserver studies have shown that pathologists usually have problems classifying poorly formed glands as GP 4, particularly when seen admixed with intervening GP 3 glands versus when seen as a discrete cluster of GP 4 glands. 31,32 Although a practical approach is to ensure that tangential sectioning is not the cause of glands that appear poorly formed, some authors have proposed that interobserver reproducibility may be improved in the interpretation of poorly formed glands as GP 4 when a minimum number (.5) of poorly formed glands are in a cluster and not intermixed with well-formed glands. 31 This approach has limitations in applications while dealing with extremely small foci of cancer.…”

Percent Gleason pattern 4 in stratifying the prognosis of patients with intermediate-risk prostate cancer

“…It has been documented that interobserver reproducibility for the recognition of Gleason pattern 4 in prostate needle biopsies is not high. In particular, the rate of the agreement between an expert genitourinary pathologist and general pathologists was lower in cases where pattern 4 was scattered among pattern 3 than in those with discrete tumor foci ( 26 ). In a recent study ( 27 ), interobserver reproducibility of percent Gleason pattern 4 in prostate needle biopsy was also assessed in a prospective manner.…”