Overall and worst gleason scores are equally good predictors of prostate cancer progression

Abstract

BackgroundGleason scoring has experienced several modifications during the past decade. So far, only one study has compared the prognostic abilities of worst (WGS) and overall (OGS) modified Gleason scores after the ISUP 2005 conference. Prostatic needle biopsies are individually paraffin-embedded in 57% of European pathology laboratories, whereas the rest of laboratories embed multiple (2 - 6) biopsies per one paraffin-block. Differences in the processing method can have a far-reaching effect, because reporting of the Gleason score (GS) is different for individually embedded and pooled biopsies, and GS is one of the most important factors when selecting treatment for patients.MethodsThe study material consisted of needle biopsies from 236 prostate cancer patients that were endocrine-treated in 1999-2003. Biopsies from left side and right side were embedded separately. Haematoxylin-eosin-stained slides were scanned and analyzed on web-based virtual microscopy. Worst and overall Gleason scores were assessed according to the modified Gleason score schema after analyzing each biopsy separately. The compound Gleason scores (CGS) were obtained from the original pathology reports. Two different grade groupings were used: GS 6 or less vs. 7 vs. 8 or above; and GS 7(3 + 4) or less vs. 7(4 + 3) and 8 vs. 9-10. The prognostic ability of the three scoring methods to predict biochemical progression was compared with Kaplan-Meier survival analysis and univariate and multivariate Cox regression analyses.ResultsThe median follow-up time of the patients was 64.5 months (range 0-118). The modified GS criteria led to upgrading of the Gleason sums compared to the original CGS from the pathology reports 1999-2003 (mean 7.0 for CGS, 7.5 for OGS, 7.6 for WGS). In 43 cases WGS was > OGS. In a univariate analysis the relative risks were 2.1 (95%-confidence interval 1.8-2.4) for CGS, 2.5 (2.1-2.8) for OGS, and 2.6 (2.2-2.9) for WGS. In a multivariate analysis, OGS was the only independent prognostic factor.ConclusionsAll of the three Gleason scoring methods are strong predictors of biochemical recurrence. The use of modified Gleason scoring leads to upgrading of GS, but also improves the prognostic value of the scoring. No significant prognostic differences between OGS and WGS could be shown, which may relate to the apparent narrowing of the GS scale from 2-10 to 5-10 due to the recent modifications.

One is the new six: The International Society of Urological Pathology (ISUP) patient-focused approach to Gleason grading

“…11 Over the years, numerous grade grouping systems have been proposed and the current system is a natural progression of this (Table 1). [12][13][14][15][16][17][18][19][20][21][22][23][24][25] The ISUP grades, which are based on the grouping of Gleason scores and patterns, are shown in Table 2. Arguably, the most significant element of the new system is the grouping of all cases with Gleason scores ≤6 as grade 1.…”

Characteristics and outcome of prostate cancer patients with overall biopsy Gleason score 3 + 4 = 7 and highest Gleason score 3 + 4 = 7 or > 3 + 4 = 7

“…Discordancy between overall and highest GS particularly affects men with GS 7, as optimal individual therapeutic strategies are not well defined in this subgroup . Studies on overall and highest GS show conflicting results, and have not focused on GS 3 + 4 = 7 in particular . We aimed to compare the clinicopathological characteristics and outcome of men with overall biopsy GS 3 + 4 = 7 with highest GS 3 + 4 = 7 (HI = OV) to those with highest GS > 3 + 4 = 7 (HI > OV).…”

Comparison of Classic and International Society of Urological Pathology 2005 Modified Gleason Grading Using Needle Biopsies From the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) Trial

“…Tolonen and colleagues 12 reread needle biopsies from 236 cases diagnosed in 1999-2003 and found that overall scores based on the ISUP 2005 modified Gleason scoring system were higher (mean, 7.5) than the compound Gleason scores (defined as the sum of the most common and second most common scores) assigned in the original pathology report (mean, 7.0), with a j coefficient of 0.44 between the 2 reviews.…”