Gleason group concordance between biopsy and radical prostatectomy specimens: A cohort study from Prostate Cancer Outcome Registry – Victoria

Abstract

BackgroundA new prostate cancer (PCa) prognostic grading system [Gleason groups (GGs)] has been proposed based on the contemporary Gleason scores (GSs), which has five simplified prognostic categories. The objective of this study was to evaluate the agreement between the GGs of prostate biopsy and radical prostatectomy specimens and to identify predictive factors for upgrading GGs.MethodsA total of 5339 cases of RP notified to the Prostate Cancer Outcomes Registry, Victoria, Australia over 6 years (2009–2014) from 46 hospitals, were included. The upgrading was evaluated using the new PCa prognostic grading system, the International Society of Urologic Pathology grade groups, which has five prognostic categories. GG 1 is GS ≤ 6, GG 2 is GS 3 + 4 = 7, GG 3 is GS 4 + 3 = 7, GG 4 is GS 8, and GG 5 is GS 9 and 10. Predictors of upgrading were assessed using univariate and multivariate models.ResultsThe GG of prostate biopsies and RP specimens were concordant in 54.5% of cases, while 31.1% were upgraded and 14.3% were downgraded. Longer time interval between biopsy and RP [44–99 days: odds ratio (OR) = 1.3, 95% confidence interval (CI) = 1.1–1.6; > 99 days: OR = 3.0, 95% CI = 2.4–3.8), and RP performed in a metropolitan hospital (biopsy in a regional hospital: OR = 2.2, 95% CI = 1.6–3.2, biopsy in a metropolitan hospital: OR = 1.7, 95% CI = 1.2–2.2) were significant predictors of GG upgrading. Patients who were diagnosed by transperineal biopsy compared to transrectal ultrasound (OR = 0.6, 95% CI = 0.5–0.8) and higher percentage of positive biopsy cassettes (25–62.5%: OR = 0.7, 95% CI = 0.6–0.8, > 62.5: OR = 0.6, 95% CI = 0.5–0.8) were significantly associated with less likelihood of upgrade.ConclusionThe lack of concordance among hospitals may be attributable to the specialist expertise of the pathologist. Expert review of specimens may help to overcome this discordance. Clinicians should consider clinical parameters and potential limitations of the GG at biopsy when making treatment decisions with regard to PCa.

The prognostic impact of downgrading and upgrading from biopsy to radical prostatectomy among men with Gleason score 7 prostate cancer

“…After more than four decades, GS remains the most powerful prognostic factor for PC . An accurate assignment of GS at the time of NB is crucial to predict a patient's prognosis and provide adequate counseling regarding treatment options.…”

“…Rajinikanth et al assessed the changes in the concordance rate of NB and RP GS over 15 years and found exact agreement of GS in 69% of cases, undergrading (NB<RP) in 26%, and overgrading (NB>RP) in 5%. Recently, an Australian population‐based study reported that GG of NB and RP specimens were concordant in 54.5% of cases, while 31.1% were upgraded and 14.3% were downgraded …”

“…After more than four decades, GS remains the most powerful prognostic factor for PC. [1][2][3][4] An accurate assignment of GS at the time of NB is crucial to predict a patient's prognosis and provide adequate counseling regarding treatment options. Although GS assessment has good intraobserver and interobserver reliability, the discordance between NB and RP specimens is common.…”

“…Originally introduced in 1966 by Donald Gleason and the Veterans Administration Cooperative Urologic Research Group, Gleason score (GS) remains the most commonly used system for grading prostate cancer (PC) . GS at needle biopsy (NB) is one of the important parameters in evaluation, risk stratification, and treatment of patients with PC . However, discordance regarding upgrading and downgrading between NB and radical prostatectomy (RP) specimens can occur due to the sampling error of NB and the multifocal nature of PC .…”

“…1 GS at needle biopsy (NB) is one of the important parameters in evaluation, risk stratification, and treatment of patients with PC. 2,3 However, discordance regarding upgrading and downgrading between NB and radical prostatectomy (RP) specimens can occur due to the sampling error of NB and the multifocal nature of PC. 4 Several studies have reported that GS discrepancies between NB and RP specimens occur with at frequencies of 31.0% to 62.8%.…”