Impact of the 2014 International Society of Urological Pathology Grading System on Concept of High-Risk Prostate Cancer: Comparison of Long-Term Oncological Outcomes in Patients Undergoing Radical Prostatectomy

Do Concomitant Systematic Biopsies Add to Fusion Targeted Biopsies in the Diagnosis and Management of Clinically Significant Prostate Cancer?

OBJECTIVE

Magnetic resonance imaging targeted biopsy clearly detects more clinically significant prostate cancer than systematic biopsy. Whether concomitant systematic biopsy adds to targeted biopsy in the detection of clinically significant prostate cancer remains uncertain. The primary outcome measure of this study was to ascertain the percentage of clinically significant prostate cancer on systematic biopsy missed by targeted biopsy. Furthermore, we sought to determine whether systematic biopsy results influenced the clinical management of patients.

MATERIALS AND METHODS

This prospective observational study included all men undergoing Fusion targeted biopsy in our Health Board. All men had PI-RADS scores of 3-5 on magnetic resonance imaging. Histology from targeted biopsy and systematic biopsy was reviewed to determine any additional benefit of performing systematic biopsy. Clinical outcomes were also reviewed. Clinically significant prostate cancer was defined by (i) International Society of Urological Pathology ≥ 2 and (ii) UCL criteria of any primary Gleason 4 or core length ≥ 6 mm.

RESULTS

A total of 104 men were included in the study of whom 18 patients were biopsy naïve, 65 had at least 1 previous negative biopsy, and 20 had previous biopsies that showed clinically insignificant cancer. The percentage of clinically significant prostate cancer missed on targeted biopsy was between 9.1% and 11.1%. Moreover, 17.1% of patients with clinically significant prostate cancer would not have proceeded to radical treatment if the systematic biopsy had not been performed.

CONCLUSION

Our data support a growing field of evidence that although magnetic resonance imaging targeted biopsy is more sensitive than systematic biopsy at detecting clinically significant prostate cancer, systematic biopsy adds to the number of patients diagnosed with clinically significant prostate cancer in those already undergoing prostate biopsy.

68Ga-PSMA-11 PET/CT Initial Staging in Black and White South African Males with ISUP Grade Group 1 and 2 Prostate Adenocarcinoma

Prostate adenocarcinoma (PCa) is a leading cause of mortality. Black males with high-risk PCa have a poorer prognosis compared to white males. Patients with International Society of Urological Pathology (ISUP) Grade Group (GG) 1 and 2 PCa have little potential for metastases post radical prostatectomy. ⁶⁸Gallium prostate specific membrane antigen (⁶⁸Ga-PSMA) PET/CT imaging for metastatic PCa is superior to conventional imaging in staging high-risk PCa. No strong evidence is available to support imaging low-risk patients. We aimed to evaluate the value of ⁶⁸Ga-PSMA PET/CT in black and white South African (BSA and WSA) males with GG1 and 2 PCa at initial staging. We evaluated 25 WSA and 123 BSA males. The image findings were correlated with prostate specific antigen (PSA). PSA levels significantly correlated with both primary tumor and whole-body PSMA-tumor volume (PSMA-TV) and were higher in BSA males. No differences were noted in the occurrence of metastases; however, PSA, seminal vesicle invasion and black race predicted metastases. Our findings suggest higher PSMA expression and tumor burden in BSA with histologically low-risk PCa, and future research with immunohistochemistry evaluation will be essential to confirm these findings.

A Novel Ferroptosis-Based Molecular Signature Associated with Biochemical Recurrence-Free Survival and Tumor Immune Microenvironment of Prostate Cancer

Objective: To identify ferroptosis-related molecular clusters, and to develop and validate a ferroptosis-based molecular signature for predicting biochemical recurrence-free survival (BCRFS) and tumor immune microenvironment of prostate cancer (PCa). Materials and Methods: The clinical data and transcriptome data of PCa were downloaded from TCGA and GEO database. Ferroptosis-related genes (FRGs) were obtained from FerrDb database. We performed consensus clustering analysis to identify ferroptosis-related molecular subtypes for PCa. Univariate and multivariate Cox regression analysis were used to establish a ferroptosis-based signature for predicting BCRFS. Internal verification, external verification and subgroup survival analysis were then successfully performed. Results: There was a total of 40 differentially expressed FRGs in PCa. We then identified three ferroptosis-related molecular clusters of PCa, which have significantly different immune infiltrating cells, tumor immune microenvironment and PD-L1 expression level. More importantly, a novel ferroptosis-based signature for predicting BCRFS of PCa based on four FRGs (including ASNS, GPT2, NFE2L2, RRM2) was developed. Internal and external verifications were then successfully performed. Patients with high-risk score were associated with significant poor BCRFS compared with those with low-risk score in training cohort, testing cohort and validating cohort, respectively. The area under time-dependent Receiver Operating Characteristic (ROC) curve were 0.755, 0.705 and 0.726 in training cohort, testing cohort and validating cohort, respectively, indicating the great performance of this signature. Independent prognostic analysis indicated that this signature was an independent predictor for BCRFS of PCa. Subgroup analysis revealed that this signature was particularly suitable for younger or stage T III-IV or stage N0 or cluster 1-2 PCa patients. Patients with high-risk score have significantly different tumor immune microenvironment in comparison with those with low-risk score. The results of qRT-PCR successfully verified the mRNA expression levels of ASNS, GPT2, RRM2 and NFE2L2 in DU-145 and RWPE-1 cells while the results of IHC staining exactly verified the relative protein expression levels of ASNS, GPT2, RRM2 and NFE2L2 between PCa and BPH tissues. Conclusions: This study successfully identified three ferroptosis-related molecular clusters. Besides, we developed and validated a novel ferroptosis-based molecular signature, which performed well in predicting BCRFS and tumor immune microenvironment of PCa.

De Novo Radiomics Approach Using Image Augmentation and Features From T1 Mapping to Predict Gleason Scores in Prostate Cancer

OBJECTIVES

The aims of this study were to discriminate among prostate cancers (PCa's) with Gleason scores 6, 7, and ≥8 on biparametric magnetic resonance imaging (bpMRI) of the prostate using radiomics and to evaluate the added value of image augmentation and quantitative T1 mapping.

MATERIALS AND METHODS

Eighty-five patients with subsequently histologically proven PCa underwent bpMRI at 3 T (T2-weighted imaging, diffusion-weighted imaging) with 66 patients undergoing additional T1 mapping at 3 T. The PCa lesions as well as the peripheral and transition zones were segmented pixel by pixel in multiple slices of the 3D MRI data sets (T2-weighted images, apparent diffusion coefficient, and T1 maps). To increase the size of the data set, images were augmented for contrast, brightness, noise, and perspective multiple times, effectively increasing the sample size 10-fold, and 322 different radiomics features were extracted before and after augmentation. Four different machine learning algorithms, including a random forest (RF), stochastic gradient boosting (SGB), support vector machine (SVM), and k-nearest neighbor, were trained with and without features from T1 maps to differentiate among 3 different Gleason groups (6, 7, and ≥8).

RESULTS

Support vector machine showed the highest accuracy of 0.92 (95% confidence interval [CI], 0.62-1.00) for classifying the different Gleason scores, followed by RF (0.83; 95% CI, 0.52-0.98), SGB (0.75; 95% CI, 0.43-0.95), and k-nearest neighbor (0.50; 95% CI, 0.21-0.79). Image augmentation resulted in an average increase in accuracy between 0.08 (SGB) and 0.48 (SVM). Removing T1 mapping features led to a decline in accuracy for RF (-0.16) and SGB (-0.25) and a higher generalization error.

CONCLUSIONS

When data are limited, image augmentations and features from quantitative T1 mapping sequences might help to achieve higher accuracy and lower generalization error for classification among different Gleason groups in bpMRI by using radiomics.

Impact of Grade Groups on Prostate Cancer-Specific and Other-Cause Mortality: Competing Risk Analysis from a Large Single Institution Series

Simple Summary

For prostate cancer patient, information on risk of long-term cancer-specific and other-cause mortality is essential to avoid over- and undertreatment. Patient stratification to low-, intermediate-, and high-risk groups has been used for decades. However, recent evidence has shown that such stratification is not optimal and outcomes differ widely, especially in high-risk prostate cancer patients. Gleason score grading is an important factor for the prediction of cancer-specific survival and has been included in all prostate cancer risk stratification models. Moreover, this parameter could be used as an independent predictor. Recently proposed grade group model demonstrated good predictive probability on short-term outcomes. However, there is a lack of data regarding long-term cancer-specific survival. In the presented study, we analyzed long-term oncological outcomes in different grade groups. Detected ratio between cancer-specific and other-cause mortality could be very informative and helpful in prostate cancer patient risk stratification and more precise clinical decision making.

Abstract

Objective: To assess the risk of cancer-specific mortality (CSM) and other-cause mortality (OCM) using post-operative International Society of Urological Pathology Grade Group (GG) model in patients after radical prostatectomy (RP). Patients and Methods: Overall 1921 consecutive men who underwent RP during 2001 to 2017 in a single tertiary center were included in the study. Multivariate competing risk regression analysis was used to identify significant predictors and quantify cumulative incidence of CSM and OCM. Time-depending area under the curve (AUC) depicted the performance of GG model on prediction of CSM. Results: Over a median follow-up of 7.9-year (IQR 4.4-11.7) after RP, 235 (12.2%) deaths were registered, and 52 (2.7%) of them were related to PCa. GG model showed high and stable performance (time-dependent AUC 0.88) on prediction of CSM. Cumulative 10-year CSM in GGs 1 to 5 was 0.9%, 2.3%, 7.6%, 14.7%, and 48.6%, respectively; 10-year OCM in GGs was 15.5%, 16.1%, 12.6%, 17.7% and 6.5%, respectively. The ratio between 10-year CSM/OCM in GGs 1 to 5 was 1:17, 1:7, 1:2, 1:1, and 7:1, respectively. Conclusions: Cancer-specific and other-cause mortality differed widely between GGs. Presented findings could aid in personalized clinical decision making for active treatment.

Beforehand transection and suturing (BTS) of the dorsal vascular complex: a novel technique in laparoscopic radical prostatectomy

Background

Beforehand transection and suturing (BTS) of the dorsal vascular complex (DVC), a novel technique in non-neurovascular bundle sparing (NVB-sparing) extraperitoneal laparoscopic radical prostatectomy (eLRP), had been proposed; this study aimed to evaluate this technique in clinical laparoscopic procedures.

Methods

Using this new technique, the DVC was transected and sutured after dissection of the pelvic fascia and before dissection of the prostate, especially before ligation of the bilateral prostatic pedicles. This study retrospectively analyzed the data of 90 non NVB-sparing eLRP patients [traditional technique (n=60) and BTS technique (n=30)].

Results

The surgical time in the BTS technique group was 121.73±24.53 min, which was significantly shorter (P=0.0015) than the traditional technique group (144.12±39.68 min). The calculated blood loss in the traditional technique group was 388.45±232.78 mL, and 264.16±130.70 mL in the BTS technique group (P=0.0016). The estimated blood loss in the traditional technique group was 350.34±311.80 mL, which was significantly greater than the BTS technique group (250.33±145.31 mL, P=0.0422). The transfusion rate in the traditional technique group was significantly greater than the BTS technique group (15.00% vs. 0.00%; P=0.0266). The biochemical recurrence rate in traditional technique group was 48.33%, which was higher than in the BTS group (30.00%) (P=0.0465). There was no significant difference between the 2 groups with respect to the pre-operative hemoglobin (Hb) concentration, pre-operative hematocrit (HCT), post-operative Hb concentration, post-operative HCT, ΔHCT, pre-operative blood volume, rectal perforation, open conversion, apical capsule residue, false suture, post-operative bleeding, urinary leakage, re-operation, surgical site infection, post-operative stay, and emission time of urinary incontinence.

Conclusions

In managing the relationship between the DVC and prostate in patients undergoing non NVB-sparing eLRP, the BTS technique was shown to be more effective and safer than the traditional technique.

Beforehand transection and suturing (BTS) of the dorsal vascular complex: a novel technique in laparoscopic radical prostatectomy

BACKGROUND

Beforehand transection and suturing (BTS) of the dorsal vascular complex (DVC), a novel technique in non-neurovascular bundle sparing (NVB-sparing) extraperitoneal laparoscopic radical prostatectomy (eLRP), had been proposed; this study aimed to evaluate this technique in clinical laparoscopic procedures.

METHODS

Using this new technique, the DVC was transected and sutured after dissection of the pelvic fascia and before dissection of the prostate, especially before ligation of the bilateral prostatic pedicles. This study retrospectively analyzed the data of 90 non NVB-sparing eLRP patients [traditional technique (n=60) and BTS technique (n=30)].

RESULTS

The surgical time in the BTS technique group was 121.73±24.53 min, which was significantly shorter (P=0.0015) than the traditional technique group (144.12±39.68 min). The calculated blood loss in the traditional technique group was 388.45±232.78 mL, and 264.16±130.70 mL in the BTS technique group (P=0.0016). The estimated blood loss in the traditional technique group was 350.34±311.80 mL, which was significantly greater than the BTS technique group (250.33±145.31 mL, P=0.0422). The transfusion rate in the traditional technique group was significantly greater than the BTS technique group (15.00% vs. 0.00%; P=0.0266). The biochemical recurrence rate in traditional technique group was 48.33%, which was higher than in the BTS group (30.00%) (P=0.0465). There was no significant difference between the 2 groups with respect to the pre-operative hemoglobin (Hb) concentration, pre-operative hematocrit (HCT), post-operative Hb concentration, post-operative HCT, ΔHCT, pre-operative blood volume, rectal perforation, open conversion, apical capsule residue, false suture, post-operative bleeding, urinary leakage, re-operation, surgical site infection, post-operative stay, and emission time of urinary incontinence.

CONCLUSIONS

In managing the relationship between the DVC and prostate in patients undergoing non NVB-sparing eLRP, the BTS technique was shown to be more effective and safer than the traditional technique.

External validation of Memorial Sloan Kettering Cancer Center nomogram and prediction of optimal candidate for lymph node dissection in clinically localized prostate cancer

Introduction

The aim of our study was to evaluate the external validity of the online Memorial Sloan Kettering Cancer Center (MSKCC) nomogram as a predictor for pelvic lymph node invasion (LNI) in men who underwent radical prostatectomy (RP) with pelvic lymph node dissection (PLND).

Material and methods

The study cohort consisted of 679 men with clinically localized prostate cancer (PCa) who underwent RP with PLND between 2005 and 2017. The area under curve (AUC) of the receiver operator characteristic analysis was used to quantify the accuracy of MSKCC nomogram to predict LNI. The specificity, sensitivity and negative predictive value were calculated to assess LNI probability cut-off.

Results

A total of 81 of 679 patients had LNI (11.9%). The AUC of MSKCC nomogram was 79%. Using the cut-off value of 7% (sensitivity 88.9%, specificity 45.2% and NPV 96.8%) a PLND could be omitted in 41% (279/679) of men. However, 3.2% (9/279) of men with LNI would be missed. MSKCC nomogram showed good calibration characteristics and high net benefit at decision curve analysis.

Conclusions

MSKCC nomogram in patients with PCa undergoing PLND has 79% discriminated accuracy for prediction of LNI in our cohort. Using a 7% nomogram cut-off, roughly 40% of men would be spared PLND with minimal risk to miss LNI.