Practice patterns in reporting tertiary grades at radical prostatectomy survey of a large group of experienced urologic pathologists

Abstract

Context.-In prostate cancer, ''tertiary'' higher-grade patterns (TPs) have been associated with biochemical recurrence after radical prostatectomy. Objective.-To determine variation regarding definition and application of TPs. Design.-Online survey regarding TPs in a range of grading scenarios circulated to 105 experienced urologic pathologists. Results.-Among 95 respondents, 40 of 95 (42%) defined TPs as ''third most common pattern'' and 55 (58%) as ''minor pattern/less than 5% of tumor.'' In a tumor with pattern 3 and less than 5% pattern 4, of the 95 respondents, 35 (37%) assigned 3 + 3 = 6 with TP4, while 56 (59%) assigned 3 + 4 = 7. In a tumor with pattern 4 and less than 5% pattern 5, of the 95 respondents, 51 (54%) assigned 4+4 = 8 with TP5, while 43 (45%) assigned 4 + 5 = 9. Six scenarios were presented in which the order of most common patterns was 3, 4, and 5 (Group 1) or 4, 3, and 5 (Group 2) with varying percentages. In both groups, when pattern 5 was less than 5%, we found that 98% and 93% of respondents would assign 3 + 4 = 7 or 4 + 3 = 7 with TP5. In scenarios with 15% or 25% pattern 5, most respondents (70% and 80%, respectively) would include pattern 5 as the secondary grade, that is, 3 + 5 = 8 (Group 1) or 4 + 5 = 9 (Group 2). For 85 of 95 (89%), a TP would not impact Grade Group assignment. Conclusions.-This survey highlights substantial variation in practice patterns regarding definition and application of ''tertiary'' grading in radical prostatectomy specimens. High consistency was observed in 3 + 4 = 7/4 + 3 = 7 scenarios with truly minor pattern 5. These findings should inform future studies assessing the standardization and predictive value of ''tertiary'' patterns.