Differential prognostic impact of different Gleason patterns in grade group 4 in radical prostatectomy specimens

Long term evaluation of optimized Gleason grading in a large cohort of men with prostate cancer in Canada

OBJECTIVES

To evaluate the International Society of Urological Pathology (ISUP) 5-tier grade grouping (GG) system of prostate cancers as well as previously proposed optimizations.

PATIENTS AND METHODS

The PROCURE biobank is a prospective cohort study of patients with localized prostate cancer who underwent radical prostatectomy in Quebec province between 2005 and 2013. Surgical specimens were graded by experienced genitourinary pathologists using 2019 ISUP criteria. Follow-up was conducted until November 2021. The current 5-tier and a proposed 6-tier GG system were evaluated, the latter having two changes: 1) Gleason 3 + 4 and 4 + 3 tumors with minor/tertiary Gleason 5 patterns were upgraded to GG 3 and 4, respectively; and 2) patients in GG5 were separated based on primary Gleason pattern (4 or 5). Cox proportional hazards models and Harrell's concordance (C) indices were used for statistical analyses.

RESULTS

2003 patients were included (median follow-up: 8.7 years). The current 5-tier GG system predicted time to recurrence (hazard ratio [HR] 2.12, 95% confidence interval [95%CI] 1.99-2.25, C 0.717), androgen-deprivation therapy (HR 2.58, 95%CI 2.38-2.80, C 0.790), metastasis (HR 2.48, 95%CI 2.17-2.83, C 0.806), castration-resistant prostate cancer (HR 2.67, 95%CI 2.28-3.13, C 0.829), and cancer-specific mortality (HR 2.80, 95%CI 2.27-3.44, C 0.835). Goodness-of-fit further improved with the proposed 6-tier GG system, with Harrell's C of 0.733, 0.807, 0.827, 0.853, and 0.853, respectively.

CONCLUSIONS

The 5-tier GG system predicted short- and long-term outcomes for patients with localized prostate cancer, and the proposed 6-tier GG system further improved its accuracy.

Prognostic differences among Grade Group 4 subgroups in robotic‐assisted radical prostatectomy

Objectives

To investigate whether the International Society of Urological Pathology Grade Group 4 (GG 4) subgroups have different oncological outcomes in Japanese prostate cancer (PCa) patients undergoing robotic‐assisted radical prostatectomy (RARP).

Patients and Methods

We conducted a retrospective multicentre cohort study in PCa patients undergoing RARP at 10 institutions in Japan. Pre‐ and post‐operative variables were collected from enrolled patients. We evaluated biochemical recurrence and clinical and pathological variables in the different GG 4 subgroups.

Results

A total of 3195 patients were enrolled in the study. Among them, 298 patients with GG 4 tumours (pathological Gleason scores [GSs] of 3 + 5 [N = 37], 4 + 4 [N = 257] and 5 + 3 [N = 4]) based on RARP specimens were analysed. The median follow‐up period was 25.2 months. The 3‐year biochemical recurrence (BCR)‐free survival (BCRFS) rate in the overall population was 74.5%. The 3‐year BCRFS rates in the pathological GS 3 + 5, GS 4 + 4 and GS 5 + 3 subgroups were 93.8%, 71.9% and 50.0%, respectively (P = 0.01). In multivariate analysis, pathological GS based on RARP specimens, PSA levels at surgery, pathological T stage, pathological N stage and surgical margins were independent risk factors significantly associated with BCRFS. In particular, patients with pathological GSs 4 + 4 and 5 + 3 were at higher risk of BCR than patients with pathological GS 3 + 5 (hazard ratio 4.54, P = 0.03 and hazard ratio 11.2, P = 0.01, respectively). The study limitations include the lack of central pathological specimen evaluation.

Conclusions

For patients with localized PCa undergoing RARP, pathological GS 4 + 4 and GS 5 + 3 were significantly associated with worse BCRFS than pathological GS 3 + 5. Pathological GS 3 + 5 may be overrated in GG 4. This observation emphasizes that primary and secondary GS should be considered to accurately stratify the risk of BCR after RARP.

Presence of biopsy Gleason pattern 5 + 3 is associated with higher mortality after radical prostatectomy but not after external beam radiotherapy compared to other Gleason Grade Group IV patterns

BACKGROUND

We hypothesized that Gleason Grade Group (GGG) IV patients treated with radical prostatectomy (RP) or external beam radiotherapy (EBRT) exhibit different cancer-specific mortality (CSM) rates according to underlying Gleason patterns (GP): 4 + 4 versus 3 + 5 versus 5 + 3.

MATERIALS AND METHODS

We identified all GGG IV patients treated with either RP or EBRT within the Surveillance, Epidemiology, and End Results 2004-2016 database. The effect of biopsy GP on CSM (3 + 5 vs. 4 + 4 vs. 5 + 3) was tested in Kaplan-Meier and multivariable competing risks regression models (adjusted for PSA, age at diagnosis, cT-, and cN-stage).

RESULTS

Of 26,458 GGG IV patients, 14,203 (53.7%) were treated with EBRT and 12,255 (46.3%) with RP. Of RP patients, 15.3 versus 81.2 versus 3.4% exhibited biopsy GP 3 + 5 versus 4 + 4 versus 5 + 3 and respective 10-year CSM rates were 6.5 versus 6.2 versus 12.6% (p < .001). In multivariable analyses addressing RP patients, GP 5 + 3 was associated with two-fold higher CSM rate than GP 4 + 4 (p < .001), but not GP 3 + 5 (p = .1). Of EBRT patients, 7.6 versus 89.8 versus 2.6% exhibited biopsy GP 3 + 5 versus 4 + 4 versus 5 + 3 and respective 10-year CSM rates were 12.2 versus 13.8 versus 17.8% (p < .001). In multivariable analyses addressing EBRT patients, no CSM differences according to GP were observed (all p ≥ .4).

CONCLUSION

In GGG IV RP candidates, the presence of biopsy GP 5 + 3 purports a significantly higher CSM than in GP 4 + 4 or 3 + 5. In GGG IV EBRT candidates, no significant CSM differences according to GP were recorded.

Prognostic Impact of Different Gleason Patterns on Biopsy Within Grade Group 4 Prostate Cancer

Background

Grade group (GG) 4 prostate cancer (PC) is considered a single entity; however, there are questions regarding prognostic heterogeneity. This study assessed the prognostic differences among various Gleason scores (GSs) classified as GG 4 PC on biopsy before radical prostatectomy (RP).

Methods

We conducted a multicenter retrospective study, and a total of 1791 patients (GS 3 + 5: 190; GS 4 + 4: 1557; and GS 5 + 3: 44) with biopsy GG 4 were included for analysis. Biochemical recurrence (BCR)-free survival, cancer-specific survival, and overall survival were analyzed using the Kaplan–Meier method and the log-rank test. Logistic regression analysis was performed to identify factors associated with high-risk surgical pathologic features. Cox regression models were used to analyze time-dependent oncologic endpoints.

Results

Over a median follow-up of 75 months, 750 patients (41.9%) experienced BCR, 146 (8.2%) died of any causes, and 57 (3.2%) died of PC. Biopsy GS 5 + 3 was associated with significantly higher rates of GS upgrading in RP specimens than GS 3 + 5 and GS 4 + 4. On multivariable analysis adjusted for clinicopathologic features, different GSs within GG 4 were significantly associated with BCR (p = 0.03) but not PC-specific or all-cause mortality. Study limitations include the lack of central pathological specimen evaluation.

Conclusions

Patients with GG 4 at biopsy exhibited some limited biological and clinical heterogeneity. Specifically, GS 5 + 3 had an increased risk of GS upgrading. This can help individualize patients’ counseling and encourage further study to refine biopsy specimen-based GG classification.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10257-x.

Pattern of Biopsy Gleason Grade Group 5 (4 + 5 vs 5 + 4 vs 5 + 5) Predicts Survival After Radical Prostatectomy or External Beam Radiation Therapy

BACKGROUND

Previous cancer-specific mortality (CSM) analyses for different Gleason patterns in Gleason grade group (GGG) 5 cancer were limited by sample size.

OBJECTIVE

To test for differences in CSM according to biopsy GG 5 patterns (4 + 5 vs 5 + 4 vs 5 + 5) among patients undergoing radical prostatectomy (RP) or external beam radiation therapy (EBRT).

DESIGN, SETTING, AND PARTICIPANTS

Patients in the Surveillance, Epidemiology and End Results database treated with RP and EBRT (2004-2016) were identified and stratified according to Gleason 4 + 5 versus 5 + 4 versus 5 + 5.

INTERVENTION

RP or EBRT.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

Kaplan-Meier and multivariable Cox regression models predicting CSM were constructed.

RESULTS AND LIMITATIONS

Of 17 263 eligible patients with GG 5 cancer at biopsy (RP: n = 7208; EBRT: n = 10 055), 12 705 had Gleason 4 + 5, 3302 had Gleason 5 + 4, and 1256 had Gleason 5 + 5 disease. Median age, prostate-specific antigen (PSA) at diagnosis, and advanced cT and cN stages significantly differed by Gleason pattern (Gleason 4 + 5 vs 5 + 4 vs 5 + 5; all p < 0.001). The 10-yr CSM rate was 18.2% for Gleason 4 + 5, 28.0% for Gleason 5 + 4, and 39.1% for Gleason 5 + 5 (p < 0.001). In multivariable analyses for the entire cohort adjusted for PSA, age at diagnosis, and cT and cN stage, Gleason 5 + 4 and Gleason 5 + 5 were associated with 1.6- and 2.2-fold higher CSM, respectively, relative to Gleason 4 + 5. In addition, Gleason 5 + 4 and Gleason 5 + 5 were associated with 1.6- and 2.5-fold, and 1.5- and 2.1-fold higher CSM rates in the RP and EBRT subgroups, respectively, relative to Gleason 4 + 5 (all p < 0.001).

CONCLUSIONS

For patients with biopsy GG 5 prostate cancer treated with RP or EBRT, there are important CSM differences by Gleason pattern (4 + 5 vs 5 + 4 vs 5 + 5). Ideally, the individual Gleason pattern should be considered in pretreatment risk stratification.

PATIENT SUMMARY

For patients with grade 5 prostate cancer, we found differences in cancer-specific death rates according to the pattern of abnormal cells in the prostate, called the Gleason score. The highest death rate was found for a Gleason pattern score of 5 + 5, followed by Gleason 5 + 4 and then Gleason 4 + 5. These differences were observed for both patients who were treated with prostate removal and patients who underwent radiotherapy.