The updated grading system of prostate carcinoma: an inter‐observer agreement study among general pathologists in an academic practice

Abstract

In 2016, the grading criteria for Gleason scoring (GS) have been updated in the WHO classification of tumors of the prostate, and a new set of grade groups (GG) was introduced. As the inter-observer discordance is a well-known concern in Gleason grading before the update and no reproducibility study testing the grade groups exists, we planned to evaluate the inter-observer agreement of the most updated grading system. Four pathologists assessed 126 cores of prostatic carcinoma, and Kappa (k) test was calculated. The agreements for both GS and GG were substantial (k = 0.753 and 0.752; respectively). Discerning GG 2 from 3 also attained reasonable outcome (k = 0.675). Based on our results, the updated grading system seems to be reproducible, with satisfactory inter-observer concordance rate.

Predicting Prostate Cancer Death with Different Pretreatment Risk Stratification Tools: A Head-to-head Comparison in a Nationwide Cohort Study

“…The agreement between the pathologists in Study III was better than the agreement in the studies evaluating the pre-2005 and ISUP 2005 Gleason score regardless of the experience of the pathologists (general or uropathologists). For the ISUP 2014 Gleason score and GGs our pathologist agreed better than the general pathologists in previous studies (116,117). Only one previous study has evaluated the agreement between uropathologists for the GGs and their results were similar to ours (118).…”

“…Overall, we found better repeatability and reproducibility of the ISUP 2014 Gleason grading system compared to previous studies which evaluated the pre-2005 Gleason score (103)(104)(105)(106)(107)143), ISUP 2005 Gleason score (109-115, 122, 142), ISUP 2014 Gleason score (116,117) and GGs (116,117). The agreement between the pathologists in Study III was better than the agreement in the studies evaluating the pre-2005 and ISUP 2005 Gleason score regardless of the experience of the pathologists (general or uropathologists).…”

“…However, the agreement for the ISUP 2005 Gleason score ranged from 0.48-0.68 among uropathologists (109)(110)(111)(112)(113) and from -0.13-0.68 among general pathologists (110,(113)(114)(115), indicating no obvious improvement in agreement (Table 1.3). Similarly, the agreement for the ISUP 2014 Gleason score ranged from 0.43-0.75 among general pathologists (116,117), while for the GGs it ranged from 0.39-0.75 among general pathologists (116,117) and 0.48-0.89 among uropathologists (118) ( Table 1.3).…”

Comparison of machine learning algorithms to predict clinically significant prostate cancer of the peripheral zone with multiparametric MRI using clinical assessment categories and radiomic features

“…Gleason Grading suffers from interobserver variance with the differentiation between GrG = 2 and GrG = 3 being especially challenging [ 39 ]. New decision support tools are critical to reduce over- and undertreatment [ 10 , 11 , 14 , 39 ].…”

“…Gleason Grading suffers from interobserver variance with the differentiation between GrG = 2 and GrG = 3 being especially challenging [ 39 ]. New decision support tools are critical to reduce over- and undertreatment [ 10 , 11 , 14 , 39 ]. Qualitative mean ADC is part of the PI-RADS [ 15 ], but further features inherit independent data though not being part of the current assessment categories [ 3 , 22 , 23 , 25 , 40 ].…”