Prognostic Value of Percent Gleason Grade 4 at Prostate Biopsy in Predicting Prostatectomy Pathology and Recurrence.

PURPOSE: The importance of primary Gleason grade among men with Gleason score 7 disease has been well-defined. However, this dichotomization may oversimplify the continuous spectrum of absolute percent Gleason grade 4 disease (G4%). In this study we report the prognostic value of G4% in cancer related outcomes of men undergoing radical prostatectomy. MATERIALS AND METHODS: Patients who underwent radical prostatectomy for clinically localized Gleason 6-8 prostate cancer from 2005 to 2013 were included in the study. G4% was determined as biopsy tumor length containing Gleason pattern 4/total tumor length, which performed better than alternative quantifications of pattern 4 involvement. G4% was correlated with time to biochemical recurrence and presence of adverse radical prostatectomy pathology, defined as primary Gleason 4 or pT3 or greater, by multivariable Cox and logistic regressions. RESULTS: Of 1,691 patients 517 (30.6%) had adverse pathological features and 86 (5.6%) experienced biochemical recurrence. On multivariable analyses G4% was a significant predictor of adverse pathology (OR 1.04, 95% CI 1.03-1.05) and time to biochemical recurrence (HR 1.02, CI 1.01-1.03). G4% was also a significant independent predictor of adverse pathology in subsets of patients with Gleason score 7 (OR 1.05, 95% CI 1.03-1.06), 3+4 (OR 1.06, 95% CI 1.04-1.08) and 4+3 cancer (OR 1.05, 95% CI 1.03-1.06). We found a significantly increased risk of adverse pathology at potentially meaningful G4% thresholds (1% to 10% vs 20% to 30%). CONCLUSIONS: The incremental percentage of Gleason grade 4 disease in biopsy specimens is an important predictor of adverse pathology and biochemical recurrence across the entire range of G4% disease. Accounting for G4% can improve risk assessment even among those patients with Gleason 3+4 or 4+3 cancer and may help inform patient counseling.

Independent surgical validation of the new prostate cancer grade-grouping system.

OBJECTIVE: To report the independent prognostic impact of the new prostate cancer grade-grouping system in a large external validation cohort of patients treated with radical prostatectomy (RP). PATIENTS AND METHODS: Between 1994 and 2013, 3 694 consecutive men were treated with RP at a single institution. To investigate the performance of and validate the grade-grouping system, biochemical recurrence-free survival (bRFS) rates were assessed using Kaplan-Meier tests, Cox-regression modelling, and discriminatory comparison analyses. Separate analyses were performed based on biopsy and RP grade. RESULTS: The median follow-up was 52.7 months. The 5-year actuarial bRFS for biopsy grade groups 1-5 were 94.2%, 89.2%, 73.1%, 63.1%, and 54.7%, respectively (P < 0.001). Similarly, the 5-year actuarial bRFS based on RP grade groups was 96.1%, 93.0%, 74.0%, 64.4%, and 49.9% for grade groups 1-5, respectively (P < 0.001). The adjusted hazard ratios for bRFS relative to biopsy grade group 1 were 1.98, 4.20, 5.57, and 9.32 for groups 2, 3, 4, and 5, respectively (P < 0.001), and for RP grade groups were 2.09, 5.27, 5.86, and 10.42 (P < 0.001). The five-grade-group system had a higher prognostic discrimination compared with the commonly used three-tier system (Gleason score 6 vs 7 vs 8-10). CONCLUSIONS: In an independent surgical cohort, we have validated the prognostic benefit of the new prostate cancer grade-grouping system for bRFS, and shown that the benefit is maintained after adjusting for important clinicopathological variables. The greater predictive accuracy of the new system will improve risk stratification in the clinical setting and aid in patient counselling.

Reliability of surgeon-specific reporting of complications after colectomy.

OBJECTIVE: We sought to determine the reliability of surgeon-specific postoperative complication rates after colectomy. BACKGROUND: Conventional measures of surgeon-specific performance fail to acknowledge variation attributed to statistical noise, risking unreliable assessment of quality. METHODS: We examined all patients who underwent segmental colectomy with anastomosis from 2008 through 2010 participating in the Michigan Surgical Quality Collaborative Colectomy Project. Surgeon-specific complication rates were risk-adjusted according to patient characteristics with multiple logistic regression. Hierarchical modeling techniques were used to determine the reliability of surgeon-specific risk-adjusted complication rates. We then adjusted these rates for reliability. To evaluate the extent to which surgeon-level variation was reduced, surgeons were placed into quartiles based on performance and complication rates were compared before and after reliability adjustment. RESULTS: A total of 5033 patients (n = 345 surgeons) undergoing partial colectomy reported a risk-adjusted complication rate of 24.5%. Approximately 86% of the variability of complication rates across surgeons was explained by measurement noise, whereas the remaining 14% represented true signal. Risk-adjusted complication rates varied from 0% to 55.1% across quartiles before adjusting for reliability. Reliability adjustment greatly diminished this variation, generating a 1.2-fold difference (21.4%-25.6%). A caseload of 168 colectomies across 3 years was required to achieve a reliability of more than 0.7, which is considered a proficient level. Only 1 surgeon surpassed this volume threshold. CONCLUSIONS: The vast majority of surgeons do not perform enough colectomies to generate a reliable surgeon-specific complication rate. Risk-adjusted complication rates should be viewed with caution when evaluating surgeons with low operative volume, as statistical noise is a large determinant in estimating their surgeon-specific complication rates.

Should all prostate needle biopsy Gleason score 4 + 4 = 8 prostate cancers be high risk? Implications for shared decision-making and patient counselling.

OBJECTIVES: To estimate the probability of downgrading to Gleason score ≤7 at radical prostatectomy for men with a prostate needle biopsy demonstrating Gleason score 8 (4 + 4). METHODS: This is a retrospective review of men with Gleason score 8 (4 + 4) prostate cancer on needle biopsy who then underwent a radical prostatectomy at the Karmanos Cancer Institute or the University of Michigan. Men with any pattern 5 on the diagnostic biopsy were excluded. The objective was to estimate the proportion of patients whose tumors were downgraded to Gleason score ≤7 at radical prostatectomy and to identify clinical and biopsy parameters associated with downgrading. RESULTS: Median age of our cohort was 63 years (IQR: 59, 67.5) and median follow-up was 15 months (IQR: 7, 37). Of the 105 men that met inclusion criteria, 59% (62/105) were downgraded to Gleason score ≤7 at radical prostatectomy. Having ≤2 cores demonstrating Gleason score 8, ≤50% maximal tumor involvement of any individual core positive for Gleason score 8, or the presence of Gleason pattern 3 (such as 3 + 4, 4 + 3, or 3 + 3) in other biopsy cores were all independently associated with downgrading in our multivariable model. Depending on the absence, presence, or combination of these 3 factors, patients had an estimated 6% to 82% probability of having their tumor downgraded at radical prostatectomy. CONCLUSIONS: Men with low volume Gleason 8 (4 + 4) and/or the presence Gleason pattern 3 on prostate needle biopsy often have their tumors downgraded at radical prostatectomy. The presence of these preoperative biopsy parameters could affect pretreatment counseling and impact patient management.