The impact of the 2005 International Society of Urological Pathology consensus guidelines on Gleason grading - a matched-pair analysis

Risk of prostate cancer and death after benign transurethral resection of the prostate-A 20-year population-based analysis

BACKGROUND

The oncological risks after benign histology on a transurethral resection of the prostate (TURP) remain largely unknown. Here, the risk of prostate cancer incidence and mortality following a benign histological assessment of TURP is investigated in a population-based setting.

METHODS

Between 1995 and 2016, 64,059 men in Denmark underwent TURP without prior biopsy of the prostate; 42,558 of these men had benign histology. The risks of prostate cancer, prostate cancer with a Gleason score ≥ 3 + 4, and prostate cancer-specific death were assessed with competing risks. Specific risks for pre-TURP prostate-specific antigen (PSA) levels at 10 and 15 years were visualized by locally estimated scatterplot smoothing.

RESULTS

The median age at TURP was 72 years (interquartile range [IQR], 65-78 years), and the median follow-up was 15 years (IQR, 10-19 years). The 10-year risks of any prostate cancer and prostate cancer with a Gleason score ≥ 3 + 4 and the 15-year risk of prostate cancer death showed clear visual relations with increasing PSA. The 15-year cumulative incidence of prostate cancer-specific death after benign TURP was 1.4% (95% confidence interval [CI], 1.3%-1.6%) for all men and 0.8% (95% CI, 0.6%-1.1%) for men with PSA levels <10 ng/ml. The primary limitation was exclusion due to missing PSA data.

CONCLUSIONS

Men with low PSA levels and a benign TURP can be reassured about their cancer risk and do not need to be monitored differently than any other men. Patients with high PSA levels can be considered for further follow-up with prostate magnetic resonance imaging. These findings add to the literature suggesting that normal histology from the prostate entails a low risk of death from the disease.

LAY SUMMARY

There is little knowledge about the oncological risks after the surgical treatment of benign prostatic hyperplasia. This study shows a very low risk of adverse oncological outcomes in men with prostate-specific antigen (PSA) levels below 10 ng/ml at the time of transurethral resection of the prostate. Patients with higher PSA levels may need more extensive follow-up.

Automatic Prostate Gleason Grading Using Pyramid Semantic Parsing Network in Digital Histopathology

Purpose

Prostate biopsy histopathology and immunohistochemistry are important in the differential diagnosis of the disease and can be used to assess the degree of prostate cancer differentiation. Today, prostate biopsy is increasing the demand for experienced uropathologists, which puts a lot of pressure on pathologists. In addition, the grades of different observations had an indicating effect on the treatment of the patients with cancer, but the grades were highly changeable, and excessive treatment and insufficient treatment often occurred. To alleviate these problems, an artificial intelligence system with clinically acceptable prostate cancer detection and Gleason grade accuracy was developed.

Methods

Deep learning algorithms have been proved to outperform other algorithms in the analysis of large data and show great potential with respect to the analysis of pathological sections. Inspired by the classical semantic segmentation network, we propose a pyramid semantic parsing network (PSPNet) for automatic prostate Gleason grading. To boost the segmentation performance, we get an auxiliary prediction output, which is mainly the optimization of auxiliary objective function in the process of network training. The network not only includes effective global prior representations but also achieves good results in tissue micro-array (TMA) image segmentation.

Results

Our method is validated using 321 biopsies from the Vancouver Prostate Centre and ranks the first on the MICCAI 2019 prostate segmentation and classification benchmark and the Vancouver Prostate Centre data. To prove the reliability of the proposed method, we also conduct an experiment to test the consistency with the diagnosis of pathologists. It demonstrates that the well-designed method in our study can achieve good results. The experiment also focused on the distinction between high-risk cancer (Gleason pattern 4, 5) and low-risk cancer (Gleason pattern 3). Our proposed method also achieves the best performance with respect to various evaluation metrics for distinguishing benign from malignant.

Availability

The Python source code of the proposed method is publicly available at https://github.com/hubutui/Gleason. All implementation details are presented in this paper.

Conclusion

These works prove that the Gleason grading results obtained from our method are effective and accurate.

miR-145-5p: A Potential Biomarker in Predicting Gleason Upgrading of Prostate Biopsy Samples Scored 3+3=6

Background

The Gleason grading system is a major tool used for prediction of prostate cancer (PCa) behavior. Because of heterogeneity and sampling errors, prognosis is variable even among patients with the same Gleason score (GS). Therefore, more accurate biomarkers that complement the Gleason system are needed to improve the clinical management of PCa.

Methods

Formalin-fixed, paraffin embedded tissue samples were obtained from radical prostatectomy (RP) (patient set 1, n=53) and needle biopsy (patient set 2, n=107; patient set 3, n=119). Cancer tissues from pure regions of each Gleason pattern (GP) were separately collected using laser-captured microdissection, followed by Real-time-PCR to determine the relative expression of miRNAs, including miR-1-5p, miR-21-5p, miR-30d-5p, miR-100-5p, miR-145-5p, miR-224-5p, and miR-708-5p. miRNA’s association with Gleason upgrading (GU) was evaluated using receiver operator characteristics (ROC) curve and multivariate logistic regression analysis. The integrated miRNA targets prediction and enrichment analyses were performed to determine the potential functions of miRNA.

Results

It was found that miR-145-5p in GP3 from radical prostatectomy (RP) were overexpressed in patients with GS6 PCa compared with GS7 patients, which was further confirmed in a larger biopsy cohort. ROC curve analysis revealed that miR-145-5p in biopsy was significantly associated with GU upon RP. In multivariate analyses, miR-145-5p was an independent predictor of GU.

Conclusion

Our study indicated that differential expression of miRNAs existed in GP3 from pure GS6 and GS7 PCa, highlighting a path toward the clinical use of miRNAs in predicting GU and assisting in treatment modality selection.

Detection of Clinically Significant Prostate Cancer by Systematic TRUS-Biopsies in a Population-Based Setting Over a 20 Year Period

OBJECTIVE

To assess the performance of systematic TRUS-biopsies in a population-based setting to detect clinically significant PCa (csPCa) in combination with age, clinical tumor category (cT), and prostate-specific antigen (PSA) in men referred for the first biopsy.

METHODS

We identified all men referred for PCa work-up because of elevated PSA who underwent initial TRUS-biopsies in the nationwide Danish Prostate Cancer Registry (DaPCaR) between January 1st, 1995 and December 31st, 2016, in Denmark. Risk of histologic findings in initial TRUS-biopsies categorized as non-malignant, insignificant PCa, or significant PCa (csPCa). We defined csPCa as any biopsy containing Gleason score 3 + 4 or above as in the PRECISION trial. We assessed risk of csPCa with absolute risk, logistic regression model, and predicted risks.

RESULTS AND LIMITATIONS

After exclusions, our cohort included 39,886 men. The diagnostic hit rate for csPCa was 40.8 %. Men with PSA > 20 ng/mL and ≥cT2 harbor a risk >75% for finding csPCa in the first TRUS biopsy-set. Men with cT1 tumors and PSA < 20 ng/mL have a risk of non-malignant histology of at least 58%. Limitations include the high number of exclusions based on missing information.

CONCLUSION

The diagnostic accuracy of systematic TRUS-biopsies is high for men with palpable tumors and high PSA. Our data point to the fact that not all men need pre-biopsy MRI to find csPCa.

Gleason Score Evolution and the Effect on Prostate Cancer Outcomes

OBJECTIVES

We evaluated how the changes in Gleason grading affected the long-term outcomes of a large prostatectomy cohort.

METHODS

We obtained long-term follow-up (16.7 years) in 581 patients having undergone radical retropubic prostatectomy between 1985 and 1995. We excluded those with seminal vesicle and/or lymphatic involvement. We regraded the specimens according to contemporary guidelines and compared how this affected outcomes compared with their original (pre-1995) Gleason scoring. In total, 499 patients were evaluable.

RESULTS

A Gleason score of 6 or less declined from 73% to 29%, and the number increased from 25% to 63% for a Gleason score of 7 and from 5% to 8% for a Gleason score of 8 to 9. As a result, for a Gleason score less than 7, biochemical failure decreased from 28% to 23%, metastatic disease 5% to 2%, and prostate cancer death from 5% to 3%. The same results were 50% to 37%, 11% to 7%, and 10% to 6% for a Gleason score of 7 and 86% to 71%, 43% to 32%, and 29% to 26% for a Gleason score more than 7, respectively. With the most recent grade grouping, for groups 1 to 5, biochemical failure occurred in 23%, 32%, 45%, 69%, and 78%, respectively. Metastatic disease occurred in 2%, 4%, 12%, 24%, and 56%, respectively. Prostate cancer-related death occurred in 2%, 4%, 9%, 21%, and 44%, respectively.

CONCLUSIONS

The revised Gleason scores improved the outcomes in all risk groups. Based on Gleason score, patients with prostate cancer will appear to have better outcomes than they did before 2005, making any comparison tenable. The current grading system shows a consistent increased risk in biochemical failure, metastatic disease, and prostate cancer-related death with each successive grade.

The presence of secondary circulating prostate tumour cells determines the risk of biochemical relapse for patients with low- and intermediate-risk prostate cancer who are treated only with external radiotherapy

Introduction

The classification of patients with prostate cancer is used to determine treatments based on risk factors. The presence of secondary circulating prostate tumour cells (CPCs) detected in peripheral blood after a curative treatment has been associated with a worse prognosis. We present a prospective study of CPC detection post radiotherapy and the oncological results.

Patients and methods

All of the patients classified as low and intermediate risk that were treated with radiotherapy were included. Three months after finishing treatment, an 8-ml blood sample was taken to detect CPCs. Mononuclear cells were obtained using gel centrifugation, and CPCs were identified using immunocytochemistry with anti-prostate-specific antigen. Patients were classified as low-risk CPC positive or negative and intermediate-risk CPC positive or negative. The biochemical relapse-free survival analysis was determined based on a follow-up of up to 15 years using the Kaplan–Meier and Cox regression models. Biochemical failure was defined according to the Pheonix II criteria.

Results

Of 241 patients, 181 (75.1%) were classified as low risk and 60 (24.9%) as intermediate risk. Biochemical failure was observed in 27.1% (49/181) of the low-risk prostate cancer participants and in 53.3% (32/60) of intermediate-risk participants after 15 years of follow-up. 20.4% (37/181) of the low-risk cancer participants had detectable CPCs in comparison with 43.3% (26/60) of the intermediate-risk cancer participants (p < 0.001 overall risk 2.98, confidence interval (CI) 95% 1.59–5.56; relative risk 2.12, CI 95% 1.41–3.19). Positive CPC patients had a worse prognosis, and a shorter time period until biochemical relapse, regardless of risk group. The biochemical relapse-free survival curves show that intermediate-risk participants who were CPC negative had a higher survival rate and slower disease progression than those participants who were low risk but CPC positive.

Conclusions

CPC detection is a risk factor for biochemical relapse and could be useful in identifying patients that will need additional treatment.

Contemporary Gleason grading and novel Grade Groups in clinical practice

PURPOSE OF REVIEW

The Gleason grading system provides important information for guiding prostate cancer patients' management and prognostication. The grading system underwent significant modifications over the past decade. In 2005 and more recently in 2014, the International Society of Urological Pathology (ISUP) held two consensus conferences to update prostate cancer grading. Recently, five prognostic grade groups have been proposed to be used in parallel to the Gleason grading system. The purpose of this review is to highlight the key changes in the Gleason grading system and the utility of the grade groups to better reflect biologic behavior for both patients and clinicians.

RECENT FINDINGS

At the 2014 ISUP consensus conference, prostate cancer Gleason grading was updated and a previously proposed concept of five prognostic grade groups, from 1 to 5 was supported. The Grade Groups, used in parallel to the modified Gleason grading system, translate Gleason scores in five distinct risk categories where Grade Group 1 is defined as Gleason score 6 or less, Grade Group 2 as Gleason score 3 + 4 = 7, Grade Group 3 as Gleason score 4 + 3 = 7, Grade Group 4 as Gleason score 4 + 4 = 8, and Grade Group 5 as Gleason score 9/10. This 5-tiered grade group system better reflects biologic behavior and guides clinical care. The Grade Groups have been endorsed by the ISUP and the World Health Organization. The performance of the Grade Groups has been examined in several recent studies.

SUMMARY

This review summarizes developments over the last year in the use of grade groups and outlines their value in clinical practice.

Contemporary grading of prostate cancer: 2017 update for pathologists and clinicians

The Gleason grading system for prostate cancer (PCa) was developed in the 1960s by DF Gleason. Due to changes in PCa detection and treatment, the application of the Gleason grading system has changed considerably in pathology routine practice. Two consensus conferences were held in 2005 and in 2014 to update PCa Gleason grading. This review provides a summary of the changes in the grading of PCa from the original Gleason grading system to the prognostic grade grouping, as well as a discussion of the clinical significance of the percentage of Gleason patterns 4 and 5.

Risk of prostate cancer diagnosis and mortality in men with a benign initial transrectal ultrasound-guided biopsy set: a population-based study

BACKGROUND

The risk of missing prostate cancer in the transrectal ultrasound-guided systematic biopsies of the prostate in men with suspected prostate cancer is a key problem in urological oncology. Repeat biopsy or MRI-guided biopsies have been suggested to increase sensitivity for diagnosis of prostate cancer, but the risk of disease-specific mortality in men who present with raised prostate-specific antigen (PSA) concentration and a benign initial biopsy result remains unknown. We investigated the risk of overall and prostate cancer-specific mortality in men with a benign initial biopsy set.

METHODS

Data were extracted from the Danish Prostate Cancer Registry-a population-based registry including all men undergoing histopathological assessment of prostate tissue. All men who were referred for transrectal ultrasound-guided biopsy for assessment of suspected prostate cancer between Jan 1, 1995, and Dec 31, 2011, in Denmark were eligible for inclusion. Follow-up data were obtained on April 28, 2015. The primary endpoint was the cumulative incidence of prostate cancer-specific mortality, analysed in a competing risk setting, with death from other causes as the competing event.

FINDINGS

Between Jan 1, 1995, and Dec 31, 2011, 64 430 men were referred for transrectal ultrasound-guided biopsy, of whom 63 454 were eligible for inclusion. Median follow-up was 5·9 years (IQR 3·8-8·5) and the total follow-up time, from the enrolment of the first patient on Jan 1, 1995, until the extraction of causes of death on April 28, 2015, was 20 years. 10 407 (30%) of 35 159 men with malignant initial biopsy sets died from prostate cancer, compared with 541 (2%) of 27 181 men with benign initial biopsy sets. Estimated overall 20-year mortality was 76·1% (95% CI 73·0-79·2). In all men referred for transrectal ultrasound-guided biopsy, the cumulative incidence of prostate cancer-specific mortality after 20 years was 25·6% (24·7-26·5) versus 50·5% (47·5-53·5) for mortality from other causes. In men with benign initial biopsy sets, the cumulative incidence of prostate cancer-specific mortality was 5·2% (3·9-6·5) versus 59·9% (55·2-64·6) for mortality from other causes. In men with PSA concentrations 10 μg/L or lower and benign initial biopsy sets (2779 men), the cumulative incidence of prostate cancer-specific mortality was 0·7% (0·2-1·3). Cumulative incidence of prostate cancer specific mortality in men with benign initial biopsy sets was 3·6% (95% CI 0·1-7·2) for men with a PSA higher than 10 ng/mL but 20 ng/mL or less (855 men) and 17·6% (12·7-22·4) and for men with a PSA higher than 20 ng/mL (454 men).

INTERPRETATION

The first systematic transrectal ultrasound-guided biopsy set holds important prognostic information. The 20-year risk of prostate cancer-specific mortality in men with benign initial results is low. Our findings question whether men with low PSA concentration and a benign initial biopsy set should undergo further diagnostic assessment in view of the high risk of mortality from other causes.

FUNDING

Capital Region of Denmark's Fund for Health Research, Danish Cancer Society, Danish Association for Cancer Research, and Krista and Viggo Petersen's Foundation.

Prognostic implications of 2005 Gleason grade modification. Population-based study of biochemical recurrence following radical prostatectomy

OBJECTIVE

To assess the impact of the 2005 modification of the Gleason classification on risk of biochemical recurrence (BCR) after radical prostatectomy (RP).

PATIENTS AND METHODS

In the Prostate Cancer data Base Sweden (PCBaSe), 2,574 men assessed with the original Gleason classification and 1,890 men assessed with the modified Gleason classification, diagnosed between 2003 and 2007, underwent primary RP. Histopathology was reported according to the Gleason Grading Groups (GGG): GGG1 = Gleason score (GS) 6, GGG2 = GS 7(3 + 4), GGG3 = GS 7(4 + 3), GGG4 = GS 8 and GGG5 = GS 9-10. Cumulative incidence and multivariable Cox proportional hazards regression models were used to assess difference in BCR.

RESULTS

The cumulative incidence of BCR was lower using the modified compared to the original classification: GGG2 (16% vs. 23%), GGG3 (21% vs. 35%) and GGG4 (18% vs. 34%), respectively. Risk of BCR was lower for modified versus original classification, GGG2 Hazard ratio (HR) 0.66, (95%CI 0.49-0.88), GGG3 HR 0.57 (95%CI 0.38-0.88) and GGG4 HR 0.53 (95%CI 0.29-0.94).

CONCLUSION

Due to grade migration following the 2005 Gleason modification, outcome after RP are more favourable. Consequently, outcomes from historical studies cannot directly be applied to a contemporary setting. J. Surg. Oncol. 2016;114:664-670. © 2016 Wiley Periodicals, Inc.