Trends in risk classification and primary therapy of Japanese patients with prostate cancer in Nara urological research and treatment group (NURTG) - comparison between 2004-2006, 2007-2009, and 2010-2012

Development and Validation of a Multimodality Model Based on Whole-Slide Imaging and Biparametric MRI for Predicting Postoperative Biochemical Recurrence in Prostate Cancer

Purpose To develop and validate a machine learning multimodality model based on preoperative MRI, surgical whole-slide imaging (WSI), and clinical variables for predicting prostate cancer (PCa) biochemical recurrence (BCR) following radical prostatectomy (RP). Materials and Methods In this retrospective study (September 2015 to April 2021), 363 male patients with PCa who underwent RP were divided into training (n = 254; median age, 69 years [IQR, 64-74 years]) and testing (n = 109; median age, 70 years [IQR, 65-75 years]) sets at a ratio of 7:3. The primary end point was biochemical recurrence-free survival. The least absolute shrinkage and selection operator Cox algorithm was applied to select independent clinical variables and construct the clinical signature. The radiomics signature and pathomics signature were constructed using preoperative MRI and surgical WSI data, respectively. A multimodality model was constructed by combining the radiomics signature, pathomics signature, and clinical signature. Using Harrell concordance index (C index), the predictive performance of the multimodality model for BCR was assessed and compared with all single-modality models, including the radiomics signature, pathomics signature, and clinical signature. Results Both radiomics and pathomics signatures achieved good performance for BCR prediction (C index: 0.742 and 0.730, respectively) on the testing cohort. The multimodality model exhibited the best predictive performance, with a C index of 0.860 on the testing set, which was significantly higher than all single-modality models (all P ≤ .01). Conclusion The multimodality model effectively predicted BCR following RP in patients with PCa and may therefore provide an emerging and accurate tool to assist postoperative individualized treatment. Keywords: MR Imaging, Urinary, Pelvis, Comparative Studies Supplemental material is available for this article. © RSNA, 2024.

Novel Multiparametric Magnetic Resonance Imaging-Based Deep Learning and Clinical Parameter Integration for the Prediction of Long-Term Biochemical Recurrence-Free Survival in Prostate Cancer after Radical Prostatectomy

Radical prostatectomy (RP) is the main treatment of prostate cancer (PCa). Biochemical recurrence (BCR) following RP remains the first sign of aggressive disease; hence, better assessment of potential long-term post-RP BCR-free survival is crucial. Our study aimed to evaluate a combined clinical-deep learning (DL) model using multiparametric magnetic resonance imaging (mpMRI) for predicting long-term post-RP BCR-free survival in PCa. A total of 437 patients with PCa who underwent mpMRI followed by RP between 2008 and 2009 were enrolled; radiomics features were extracted from T2-weighted imaging, apparent diffusion coefficient maps, and contrast-enhanced sequences by manually delineating the index tumors. Deep features from the same set of imaging were extracted using a deep neural network based on pretrained EfficentNet-B0. Here, we present a clinical model (six clinical variables), radiomics model, DL model (DLM-Deep feature), combined clinical-radiomics model (CRM-Multi), and combined clinical-DL model (CDLM-Deep feature) that were built using Cox models regularized with the least absolute shrinkage and selection operator. We compared their prognostic performances using stratified fivefold cross-validation. In a median follow-up of 61 months, 110/437 patients experienced BCR. CDLM-Deep feature achieved the best performance (hazard ratio [HR] = 7.72), followed by DLM-Deep feature (HR = 4.37) or RM-Multi (HR = 2.67). CRM-Multi performed moderately. Our results confirm the superior performance of our mpMRI-derived DL algorithm over conventional radiomics.

Clinical significance of limited and extended pelvic lymph node dissection during robot-assisted radical prostatectomy for patients with localized prostate cancer: A retrospective, propensity score matching analysis

OBJECTIVES

We investigated the diagnostic and therapeutic benefits of limited or extended pelvic lymph node dissection during a robot-assisted radical prostatectomy for localized prostate cancer.

METHODS

Diagnostic and therapeutic benefits were assessed according to the rates of pN1 and biochemical recurrence, respectively. The primary outcome was the biochemical recurrence-free rate, and secondary outcomes included the diagnostic and therapeutic benefits of pelvic lymph node dissection.

RESULTS

A total of 534 patients were analyzed. Out of the 534 patients, 207 (38.8%) received limited pelvic lymph node dissection while 134 (25.1%) received extended dissection. There were 297 patients with a Briganti index ≥5%. Extended dissections yielded significantly more resected lymph nodes (p < 0.0001), and 72.2% of cases of pN1 were located outside the obturator. The incidence rate of pN1 was 6.1%, and performance of extended lymph node dissection was an independent predictor for pN1 (odds ratio 9.0, 95% confidence interval 2.5-33.1). The rate of biochemical recurrence was 14.9%, and Cox proportional hazards regression analysis of the propensity score matched population revealed that patients with high or very-high risk tended to benefit from limited lymph node dissection (hazard ratio 8.4, 95% confidence interval 0.8-82.3) while the therapeutic benefit of extended dissection was unclear by comparison.

CONCLUSIONS

Extended pelvic lymph node dissection significantly improves diagnostic accuracy; however, the therapeutic benefit of pelvic lymph node dissection was not observed in this study.

Trends in primary treatment for localized prostate cancer according to the availability of treatment modalities and the impact of introducing robotic surgery

OBJECTIVES

We aimed to investigate the effect of available treatment modalities on primary treatment selection in patients with localized prostate cancer and that of introducing robotic surgery.

METHODS

We retrospectively studied 12 061 patients diagnosed with localized prostate cancer between 2004 and 2018 from 21 institutions. These institutions were divided into five groups according to the availability of surgery and radiotherapy. Differences in primary treatment selection between the institutions were investigated, and the predictive factors involved in the selection were explored.

RESULTS

Surgery, radiotherapy, androgen deprivation therapy, and active surveillance/watchful waiting were selected as primary treatment in 4115, 3621, 3188, and 821 patients, respectively, while the remaining 316 patients selected other modalities. The number of patients, particularly young patients, was much higher in institutions with both surgery and radiotherapy. With the introduction of robotic surgery, open radical prostatectomy has decreased, and robotic surgery made up approximately 70% of all prostatectomies. Institutions with both surgery and radiotherapy tended to treat patients with very low or low risk by surgery or radiotherapy, while institutions without surgery and radiotherapy tended to select active surveillance or watchful waiting. Multivariate analysis revealed that primary treatment selection for prostate cancer was affected not only by clinical factors, but also by the available modalities in each institution.

CONCLUSIONS

Differences in available treatment modalities affect the selection of primary treatment for localized prostate cancer. Introduction of robotic surgery also has a strong influence on the number of patients in each institution.

A randomized controlled trial evaluating the effect of low-dose chlormadinone in patients with low-risk prostate cancer: PROSAS study

OBJECTIVES

This study was conducted to evaluate the effect of low-dose chlormadinone acetate, an antiandrogen agent, on the persistence rate of active surveillance in patients with low-risk prostate cancer.

METHODS

The study was a multicenter, placebo-controlled, double-blind, randomized controlled trial conducted at 38 sites in Japan. Low-risk prostate cancer patients were randomly assigned to the chlormadinone group or the placebo group and the persistence rate of active surveillance was evaluated for 3 years.

RESULTS

Seventy-one patients in the chlormadinone group and 72 patients in the placebo group were analyzed. The persistence rate of active surveillance [95% CI] at 3 years was 75.5% [62.5-84.6] in the chlormadinone group and 50.1% [36.7-62.2] in the placebo group, showing a significant difference between the groups (P = 0.0039). The hazard ratio [95% CI] of the chlormadinone group to the placebo group for discontinuation of active surveillance was 0.417 [0.226-0.770]. The chlormadinone group showed a significant decrease in prostate specific antigen level, testosterone level and prostate volume. The number of positive cores at 12 and 36 months biopsy was significantly lower in the chlormadinone group. The incidence of adverse events was 43.7% in the chlormadinone group and 12.5% in the placebo group. The most common adverse event in the chlormadinone group was constipation in 22.5%, followed by hepatobiliary disorders in 9.9%.

CONCLUSIONS

In patients with low-risk prostate cancer, low-dose chlormadinone showed a reduced number of positive cores and prostate volume, and an increased persistence rate of active surveillance (UMIN000012284).

Trends in risk classification at diagnosis and choice of primary therapy for prostate cancer: An analysis of 10 839 patients from the Nara Urological Research and Treatment Group registry between 2004 and 2015

OBJECTIVE

To evaluate trends in risk classification at diagnosis and choice of primary therapy in patients diagnosed with prostate cancer.

METHODS

This retrospective study included 10 839 patients who were newly diagnosed with prostate cancer between 2004 and 2015 at 23 Japanese institutions. Risk classification and primary therapies between 2004 and 2015 were evaluated. The trends in risk classification and primary therapy were evaluated using chi-squared tests for trend during four periods (2004-2006; 2007-2009; 2010-2012; and 2013-2015). Binary logistic analysis was used to evaluate the extent to which factors such as age, risk classification, and institution influenced primary therapy choice in the 2013-2015 cohort.

RESULTS

The number of patients with very-low or low-risk classification (P < 0.001) and metastasis (P = 0.04) decreased and the number with intermediate-risk classification (P < 0.001) increased during the four periods. A tendency to choose radical prostatectomy as primary therapy for prostate cancer was not observed during the four periods (P = 0.90). The number of patients who chose radiation therapy (P < 0.001) and active surveillance/watchful waiting (P < 0.001) as primary therapies increased during the four periods and the number of patients who chose androgen deprivation therapy (P < 0.001) decreased. Age, institution, and risk classification significantly influenced primary therapy choice.

CONCLUSIONS

We have shown the trends in risk classification of prostate cancer and primary therapy choices between 2004 and 2015 in Japan. Age, institution, and risk classification significantly influenced the decision on primary therapy for prostate cancer.

Deep Learning with Quantitative Features of Magnetic Resonance Images to Predict Biochemical Recurrence of Radical Prostatectomy: A Multi-Center Study

Simple Summary

Biochemical recurrence after radical prostatectomy is vitally important for long-term oncological control and subsequent treatment of these patients. We applied radiomic technique to extract features from MR images of prostate cancer patients, and used deep learning algorithm to establish a predictive model for biochemical recurrence with high accuracy. The model was validated in 2 indepented cohorts with superior predictive value than traditional stratification systems. With the aid of this model, we are able to distinghuish patients with higher risk of developing biochemical recurrence at early stage, thus providing a window to initiate neoadjuvant or adjuvant therapies for prostate cancer patients.

Abstract

Biochemical recurrence (BCR) occurs in up to 27% of patients after radical prostatectomy (RP) and often compromises oncologic survival. To determine whether imaging signatures on clinical prostate magnetic resonance imaging (MRI) could noninvasively characterize biochemical recurrence and optimize treatment. We retrospectively enrolled 485 patients underwent RP from 2010 to 2017 in three institutions. Quantitative and interpretable features were extracted from T2 delineated tumors. Deep learning-based survival analysis was then applied to develop the deep-radiomic signature (DRS-BCR). The model’s performance was further evaluated, in comparison with conventional clinical models. The model achieved C-index of 0.802 in both primary and validating cohorts, outweighed the CAPRA-S score (0.677), NCCN model (0.586) and Gleason grade group systems (0.583). With application analysis, DRS-BCR model can significantly reduce false-positive predictions, so that nearly one-third of patients could benefit from the model by avoiding overtreatments. The deep learning-based survival analysis assisted quantitative image features from MRI performed well in prediction for BCR and has significant potential in optimizing systemic neoadjuvant or adjuvant therapies for prostate cancer patients.

Epidemiology and genomics of prostate cancer in Asian men

Prostate cancer is a global health problem, but incidence varies considerably across different continents. Asia is traditionally considered a low-incidence area, but the incidence and mortality of prostate cancer have rapidly increased across the continent. Substantial differences in epidemiological features have been observed among different Asian regions, and incidence, as well as mortality-to-incidence ratio, is associated with the human development index. Prostate cancer mortality decreased in Japan and Israel from 2007 to 2016, but mortality has increased in Thailand, Kyrgyzstan and Uzbekistan over the same period. Genomic analyses have shown a low prevalence of ERG oncoprotein in the East Asian population, alongside a low rate of PTEN loss, high CHD1 enrichments and high FOXA1 alterations. Contributions from single-nucleotide polymorphisms to prostate cancer risk vary with ethnicity, but germline mutation rates of DNA damage repair genes in metastatic prostate cancer are comparable in Chinese and white patients from the USA and UK. Pharmacogenomic features of testosterone metabolism might contribute to disparities seen in the response to androgen deprivation between East Asian men and white American and European men. Overall, considerable diversity in epidemiology and genomics of prostate cancer across Asia defines disease characteristics in these populations, but studies in this area are under-represented in the literature. Taking into account this intracontinental and intercontinental heterogeneity, translational studies are required in order to develop ethnicity-specific treatment strategies.

Whole Pelvic Radiotherapy With Stereotactic Body Radiotherapy Boost vs. Conventionally Fractionated Radiotherapy for Patients With High or Very High-Risk Prostate Cancer

Background: Whole pelvic radiotherapy (WPRT) with stereotactic body radiotherapy (SBRT) boost has been shown to be effective in patients with high-risk prostate cancer (PC). However, no study has directly compared the efficacy of WPRT with SBRT boost with that of conventionally fractionated radiotherapy (CFRT). We compared the clinical outcomes between CFRT and WPRT with SBRT boost in patients with high or very high-risk PC (National Comprehensive Cancer Network definition).

Methods: In total, 132 patients treated with CFRT and 121 patients treated with WPRT followed by SBRT boost were retrospectively analyzed. For the CFRT group, the prescribed dose range was 74–79.2 Gray (Gy) administered at 1.8–2 Gy per fraction. For WPRT with SBRT boost, the prescribed doses were 45 Gy administered in 25 fractions to the whole pelvis followed by 21 Gy boost (3 fractions of 7 Gy each) to prostate and seminal vesicles. The overall survival (OS) and biochemical failure (Phoenix definition) free survival (bFFS) were assessed by using the Kaplan–Meier method or the Cox proportional hazards regression model. The gastrointestinal (GI) and genitourinary (GU) tract toxicity were assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) v3.0.

Results: The estimated 4-years overall survival in the CFRT and WPRT with SBRT boost groups was 91.6 and 97.7%, respectively (P = 0.18). The estimated 4-years biochemical failure-free survival in the CFRT and WPRT with SBRT boost groups was 89.1 and 93.9%, respectively (P = 0.41). No acute grade 3 or higher GI and GU toxicity was observed in both groups. Late grade 3 GI and GU toxicity occurred in 2.3 and 2.3% in the CFRT group, and in 1.7 and 0.8% in the WPRT with SBRT boost group, respectively. There was no significant between-group difference with respect to acute or late toxicity.

Conclusions: In patients with high or very high-risk localized PC, compared with CFRT, WPRT with SBRT boost resulted in similar biochemical-free and overall survival rate with minimal toxicity. WPRT with SBRT boost is a feasible option for patients with high or very high-risk PC.

[Evolution of the number of incident cases, stage and first treatments for prostate cancer in France between 2001 and 2016]

INTRODUCTION

No studies of French hospital registries for prostate cancer (PCa) have been published since the 2012 USPSTF recommendations.

MATERIAL

This is a multicenter cohort study based on hospital data of prostate biopsies (PB) in 3 health centers between 2001 and 2016. The main objective is to describe the evolution of incident cases of PCa. The secondary objectives are to describe the number of cases per stage of PCa and the distribution of the first treatments.

RESULTS

In total, 11,491 PB series diagnosed 5927 cases of PCa. The median age was 67 [61-73] years and the median PSA was 7.8 [5.5-13] ng/mL. The number of cases increased until 2006 before decreasing from 2006 to 2013 and then stabilizing from 2013 to 2016. The proportion of incident cases was: (1) for the stable metastatic stage around 8 [7-10]%, (2) for cases with PSA<10 ng/mL increasing from 46% to 75% in 2010 down to 64% in 2016, (3) for the grade 1 group decreasing from 59% to 33 % between 2011 and 2016. The proportion of active surveillance treatment for low-risk cancers increased from 5 to 60% and surgery decreased from 73 to 33%.

CONCLUSION

The evolution of the incident cases showed a decrease from 2006 to 2013 and a stability until 2016. The number of cases with PSA<10 ng/mL decreased since 2010 and the proportion of the options of treatment by surveillance increased strongly to the detriment of the surgery for low risks.

LEVEL OF EVIDENCE

3.

The impact of the definition of biochemical recurrence following salvage radiotherapy on outcomes and prognostication in patients with recurrent prostate cancer after radical prostatectomy: a comparative study of three definitions

Purpose

The clinical management and follow-up of patients with recurrent prostate cancer after salvage radiotherapy (SRT) has not yet been established, and no standardized definition of biochemical recurrence (BCR) after SRT exists. We compared the impact of applying three different definitions of BCR following SRT on patient outcomes and prognostication.

Subjects

Patients who received salvage androgen-deprivation therapy before the completion of SRT were excluded. The data of 118 men who had undergone salvage radiation as monotherapy for BCR after radical prostatectomy were reviewed. In all patients, SRT comprised irradiation to the prostatic bed (70 Gy) using three-dimensional conformal radiotherapy techniques. Treatment outcomes, including BCR-free survival and prognostic factors, were analyzed and compared among three definitions: The Nara, Radiation Therapy Oncology Group (RTOG) 9601, and GETUG-AFU 16 definitions.

Results

The BCR rate differed significantly among the applied definitions. Multivariate analyses identified the same four independent prognostic factors, including primary Gleason pattern 4 or 5, negative resection margin, prostate-specific antigen (PSA) level before SRT 0.5 or more, and PSA doubling time before SRT <6 months, using the RTOG 9601 and GETUG-AFU 16 definitions, whereas only two of the four factors were identified using the Nara definition. Although the results obtained using the RTOG 9601 and GETUG-AFU 16 definitions were similar, the prognostic value of the four factors differed. According to the RTOG 9601 definition of BCR, a negative resection margin on prostatectomy specimens and short PSA doubling time before SRT were associated with no subsequent response in PSA level.

Conclusions

The applied definition of BCR after SRT can influence the reported BCR-free rate and the potential prognostic factors. Establishment of the standardized definition is needed for the optimal management of patients with recurrent prostate cancer undergoing SRT.

Epigenetic silencing of S100A2 in bladder and head and neck cancers

S100A2, a member of the S100 protein family, is known to be downregulated in a number of human cancers, leading to its designation as a potential tumor suppressor gene. Here, we investigated the expression and methylation status of S100A2 in head&neck and bladder cancer. Reduced mRNA and protein expression was observed in 8 head&neck and bladder cancer cell lines. To explore the mechanism responsible for the downregulation of S100A2, we treated six cell lines with 5-aza-2'-deoxycytidine. We found S100A2 is silenced in association with aberrant promoter-region methylation and its expression is restored with 5-aza-2'-deoxycytidine treatment. Of 31 primary head&neck cancer cases and 31 bladder cancer cases, promoter methylation was detected in 90% and 80% of cases, respectively. Interestingly, only 1/9 of normal head&neck tissues and 2/6 of normal bladder tissues showed promoter methylation. S100A2 promoter methylation can be detected in urine and is more frequent in bladder cancer patients than in healthy subjects (96% vs 48% respectively). Moreover, increased methylation of S100A2 is linked to the progression of the tumor in bladder cancer (p<0.01). Together, this data shows that methylation-associated inactivation of S100A2 is frequent and may be an important event in the tumorigenesis of head&neck and bladder cancer.