Intermediate clinical endpoints for surrogacy in localised prostate cancer: an aggregate meta-analysis

Circulating Biomarkers Predictive of Treatment Response in Patients with Hormone-sensitive or Castration-resistant Metastatic Prostate Cancer: A Systematic Review

BACKGROUND AND OBJECTIVE

Metastatic prostate cancer (mPCa) harbors genomic alterations that may predict targeted therapy efficacy. These alterations can be identified not only in tissue but also directly in biologic fluids (ie, liquid biopsies), mainly blood. Liquid biopsies may represent a safer and less invasive alternative for monitoring patients treated for mPCa. Current research focuses on the description and validation of novel predictive biomarkers to improve precision medicine in mPCa. Our aim was to systematically review the current evidence on liquid biopsy biomarkers for predicting treatment response in mPCa.

METHODS

We systematically searched Medline, Web of Science, and evidence-based websites for publications on circulating biomarkers in mPCa between March 2013 and February 2024 for review. Endpoints were: prediction of overall survival, biochemical or radiographic progression-free survival after treatment (chemotherapy, androgen deprivation therapy, androgen receptor pathway inhibitors [ARPIs], immunotherapy, or PARP inhibitors [PARPIs]). For each biomarker, the level of evidence (LOE) for clinical validity was attributed: LOE IA and IB, high level of evidence; LOE IIB and IIC, intermediate level; and LOE IIIC and LOE IV-VD, weak level.

KEY FINDINGS AND LIMITATIONS

The predictive value of each biomarker for the response to several therapies was evaluated in both metastatic hormone-sensitive (mHSPC) and castration-resistant prostate cancer (mCRPC). In patients with mCRPC, BRCA1/2 or ATM mutations predicted response to ARPIs (LOE IB) and PARPIs (LOE IIB), while AR-V7 transcripts or AR-V7 protein levels in circulating tumor cells (CTCs) predicted response to ARPIs and taxanes (LOE IB). CTC quantification predicted response to cabazitaxel, abiraterone, and radium-223 (LOE IIB), while TP53 alterations predicted response to 177Lu prostate-specific membrane antigen radioligand treatment (LOE IIB). AR copy number in circulating tumor DNA before the first treatment line and before subsequent lines predicted response to docetaxel, cabazitaxel, and ARPIs (LOE IIB). In mHSPC, DNA damage in lymphocytes was predictive of the response to radium-223 (LOE IIB).

CONCLUSIONS AND CLINICAL IMPLICATIONS

BRCA1/2, ATM, and AR alterations detected in liquid biopsies may help clinicians in management of patients with mPCa. The other circulating biomarkers did not reach the LOE required for routine clinical use and should be validated in prospective independent studies.

PATIENT SUMMARY

We reviewed studies assessing the value of biomarkers in blood or urine for management of metastatic prostate cancer. The evidence indicates that some biomarkers could help in selecting patients eligible for specific treatments.

Impact of Preoperative LUTS on Health-related Quality of Life Following Radical Prostatectomy: A Propensity Score Matched Longitudinal Study

OBJECTIVE

To assess the impact of preoperative lower urinary tract symptoms (LUTS) on long-term health-related quality of life (HRQOL) up to 10 years after radical prostatectomy (RP) for prostate cancer (PC).

METHODS

Within our prospective institutional database of 6487 patients treated with RP for PC (2008-2020), 2727 patients with preoperative LUTS (IPSS score of ≥8) were identified. A 1:1 propensity-score matched analysis of 3056 men (n = 1528 LUTS, n = 1528 no LUTS) was conducted. Primary endpoint was HRQOL (based on EORTC QLQ-C30 and PR25). Linear regression models tested the effect of preoperative LUTS on the net change in general HRQOL (P <.05).

RESULTS

Median follow-up was 48 months. Preoperative mean global health status (GHS) score (67.4 vs 75.7) was significantly lower in the LUTS cohort (P <.001). Post-RP the difference in general HRQOL between the LUTS cohort and the no-LUTS cohort became smaller (65.7 vs 67.8), however, remaining statistically significant (P = .037). In long-term follow-up, general HRQOL was comparable between both subcohorts (P-range 0.716-0.876). Multivariable linear regression analysis revealed increased preoperative IPSS as an independent predictor for increased perioperative improvement of IPSS (P <.001) CONCLUSION: For patients undergoing RP, preoperative LUTS were associated with a postoperative improvement of HRQOL outcomes. In long-term follow-up, HRQOL was comparable to patients without preoperative LUTS. Hence, RP is an efficient option to treat PC as well as LUTS in those patients.

SABR-Dual: a phase II/III trial of two-fraction versus five-fraction stereotactic radiotherapy for localized low- and favorable intermediate-risk prostate cancer

BACKGROUND

Dose-escalated radiotherapy is known to improve progression free survival in patients with localized prostate cancer, and recent advances have led to the standardization of ultrahypofractionated stereotactic ablative radiotherapy (SABR) delivered in just 5-fractions. Based on the known effectiveness of the accepted though invasive 2-fraction treatment method of high-dose-rate brachytherapy and given the ubiquity of prostate cancer, a further reduction in the number of treatments of external-beam SABR is possible. This study aims to evaluate the safety, efficacy, and non-inferiority of generalizable 2-fraction SABR compared to the current 5-fraction regimen.

METHODS

502 patients will be enrolled on this phase II/III randomized control trial. Eligible patients will have previously untreated low- or favorable intermediate-risk adenocarcinoma of the prostate. Patients will be randomized between standard SABR of 40 Gy in 5 fractions given every-other-day and 27 Gy in 2 fractions at least two days apart but completing within seven days. MRI-based planning, radiopaque hydrogel spacer insertion, and fiducial marker placement are required, and SABR will be delivered on either a standard CT-guided linear accelerator or MR-LINAC. The primary endpoint will be freedom from disease progression, with additional secondary clinical, toxicity, and quality of life endpoints.

DISCUSSION

This study will be the largest prospective randomized trial, adequately powered to demonstrate non-inferiority, comparing 2-fraction SABR to standard 5-fraction SABR for localized prostate cancer. As the protocol does not obligate use of an MRI-LINAC or other adaptive technologies, results will be broadly generalizable to the wider community.

TRIAL REGISTRATION

This trial is registered on Clinicaltrials.gov: ClinicalTrials.gov Identifier: NCT06027892.

PRESTO: A Phase III, Open-Label Study of Intensification of Androgen Blockade in Patients With High-Risk Biochemically Relapsed Castration-Sensitive Prostate Cancer (AFT-19)

PURPOSE

Patients with biochemically recurrent prostate cancer (BRPC) after radical prostatectomy and a short PSA doubling time are at risk for distant metastases. Apalutamide, an androgen receptor antagonist, and abiraterone acetate plus prednisone (AAP) prolong survival in the metastatic setting. We evaluated whether intensification of androgen-deprivation therapy (ADT) improves outcomes in BRPC.

PATIENTS AND METHODS

PRESTO is a randomized phase III, open-label trial in patients with BRPC and PSA doubling time ≤9 months (ClinicalTrials.gov identifier: NCT03009981). Patients were randomly assigned 1:1:1 to receive a finite 52-week treatment course with ADT control, ADT + apalutamide, or ADT + apalutamide + AAP. The primary end point was PSA progression-free survival (PSA-PFS), defined as serum PSA >0.2 ng/mL after treatment completion.

RESULTS

Five hundred three patients were enrolled. The median PSA was 1.8 ng/mL (IQR, 1.0-3.6). At the first planned interim analysis, both experimental arms significantly prolonged PSA-PFS compared with the control arm (median, 24.9 months for ADT + apalutamide v 20.3 months for ADT; hazard ratio [HR], 0.52 [95% CI, 0.35 to 0.77]; P = .00047; median, 26.0 months for ADT + apalutamide + AAP v 20.0 months for ADT; HR, 0.48 [95% CI, 0.32 to 0.71]; P = .00008). Median time to testosterone recovery did not differ across treatment arms. The most common grade ≥3 adverse event was hypertension (7.5%, 7.4%, and 18% in ADT, ADT + apalutamide, and ADT + apalutamide + AAP arms, respectively).

CONCLUSION

Intensified AR blockade for a finite duration prolongs PSA-PFS with a manageable safety profile, without adversely affecting time to testosterone recovery. The addition of apalutamide to ADT should be considered in patients with high-risk BRPC.

Validation of metastasis-free survival as a surrogate endpoint for overall survival in localized prostate cancer in the era of docetaxel for castration-resistant prostate cancer

BACKGROUND

Prior work from the Intermediate Clinical Endpoints in Cancer of the Prostate (ICECaP) consortium (ICECaP-1) demonstrated that metastasis-free survival (MFS) is a valid surrogate for overall survival (OS) in localized prostate cancer (PCa). This was based on data from patients treated predominantly before 2004, prior to docetaxel being available for the treatment of metastatic castrate-resistant prostate cancer (mCRPC). We sought to validate surrogacy in a more contemporary era (ICECaP-2) with greater availability of docetaxel and other systemic therapies for mCRPC.

PATIENTS AND METHODS

Eligible trials for ICECaP-2 were those providing individual patient data (IPD) after publication of ICECaP-1 and evaluating adjuvant/salvage therapy for localized PCa, and which collected MFS and OS data. MFS was defined as distant metastases or death from any cause, and OS was defined as death from any cause. Surrogacy was evaluated using a meta-analytic two-stage validation model, with an R2 ≥ 0.7 defined a priori as clinically relevant.

RESULTS

A total of 15 164 IPD from 14 trials were included in ICECaP-2, with 70% of patients treated after 2004. The median follow-up was 8.3 years and the median postmetastasis survival was 3.1 years in ICECaP-2, compared with 1.9 years in ICECaP-1. For surrogacy condition 1, Kendall's tau was 0.92 for MFS with OS at the patient level, and R2 from weighted linear regression (WLR) of 8-year OS on 5-year MFS was 0.73 (95% confidence interval 0.53-0.82) at the trial level. For condition 2, R2 was 0.83 (95% confidence interval 0.64-0.89) from WLR of log[hazard ratio (HR)]-OS on log(HR)-MFS. The surrogate threshold effect on OS was an HR(MFS) of 0.81.

CONCLUSIONS

MFS remained a valid surrogate for OS in a more contemporary era, where patients had greater access to docetaxel and other systemic therapies for mCRPC. This supports the use of MFS as the primary outcome measure for ongoing adjuvant trials in localized PCa.

Surrogate endpoints in clinical trials of p16-positive squamous cell carcinoma of the oropharynx: an individual patient data meta-analysis

BACKGROUND

The increased incidence of human papillomavirus (HPV)-related cancers has motivated efforts to optimise treatment for these patients with excellent prognosis. Validation of surrogates for overall survival could expedite the investigation of new therapies. We sought to evaluate candidate intermediate clinical endpoints in trials assessing definitive treatment of p16-positive oropharyngeal cancer with chemotherapy or radiotherapy.

METHODS

We did a retrospective review of five multicentre, randomised trials (NRG/RTOG 9003, 0129, 0234, 0522, and 1016) that tested radiotherapy with or without chemotherapy in patients (aged ≥18 years) with p16-positive localised head or neck squamous-cell carcinomas. Eight intermediate clinical endpoints were considered as potential surrogates for overall survival: freedom from local progression, freedom from regional progression, freedom from distant metastasis, freedom from locoregional progression, freedom from any progression, locoregional progression-free survival, progression-free survival, and distant metastasis-free survival. We used a two-stage meta-analytical framework, which requires high correlation between the intermediate clinical endpoint and overall survival at the patient level (condition 1), and high correlation between the treatment effect on the intermediate clinical endpoint and the treatment effect on overall survival (condition 2). For both, an r2 greater than 0·7 was used as criteria for clinically relevant surrogacy.

FINDINGS

We analysed 1373 patients with oropharyngeal cancer from May 9, 2020, to Nov 22, 2023. 1231 (90%) of patients were men, 142 (10%) were women, and 1207 (88%) were White, with a median age of 57 years (IQR 51-62). Median follow-up was 4·2 years (3·1-5·1). For the first condition, correlating the intermediate clinical endpoints with overall survival at the individual and trial level, the three composite endpoints of locoregional progression-free survival (Kendall's τ 0·91 and r2 0·72), distant metastasis-free survival (Kendall's τ 0·93 and r2 0·83), and progression-free survival (Kendall's τ 0·88 and r2 0·70) were highly correlated with overall survival at the patient level and at the trial-group level. For the second condition, correlating treatment effects of the intermediate clinical endpoints and overall survival, the composite endpoints of locoregional progression-free survival (r2 0·88), distant metastasis-free survival (r2 0·96), and progression-free survival (r2 0·92) remained strong surrogates. Treatment effects on the remaining intermediate clinical endpoints were less strongly correlated with overall survival.

INTERPRETATION

We identified locoregional progression-free survival, distant metastasis-free survival, and progression-free survival as surrogates for overall survival in p16-positive oropharyngeal cancers treated with chemotherapy or radiotherapy, which could serve as clinical trial endpoints.

FUNDING

NRG Oncology Operations, NRG Oncology SDMC, the National Cancer Institute, Eli Lilly, Aventis, and the University of Michigan.

Optimizing anti-androgen treatment use among men with pathologic lymph-node positive prostate cancer treated with radical prostatectomy: the importance of postoperative PSA kinetics

BACKGROUND

Optimal postsurgical management of prostate cancer (PCa) patients with nodal metastasis at the time of radical prostatectomy remains unclear. We sought to examine the role of postoperative PSA kinetics and pathologic tumor characteristics in guiding additional hormonal therapy use in pN1 men.

METHODS

In total, 297 pN1 PCa patients treated with radical prostatectomy and ePLND between 2002 and 2018 were identified within our prospectively maintained institutional cancer data-registry. Following surgery, these patients were managed with either immediate androgen deprivation therapy (iADT) or observation with deferred ADT (dADT). The former was defined as ADT given within ≤6 months of surgery and the latter as >6 months. The primary outcome was metastasis. Regression-tree analysis was used to stratify patients into novel risk-groups based on post-prostatectomy tumor characteristics and PSA kinetics and the corresponding metastasis risk. Multivariable Cox regression analyses tested the impact of iADT versus observation ± dADT on metastasis, cancer-specific mortality, and overall mortality within each risk-group separately.

RESULTS

The median follow-up was 6.1 years (IQR 3.2-9.0). Regression-tree analysis stratified patients into 3 novel risk-groups (Harrell's C-index 0.79) based on PSA-nadir and time to biochemical failure: group 1 (low-risk) included patients with time to biochemical recurrence >6 months (n = 115), while groups 2 and 3 included patients with biochemical failure within ≤6 months with a postoperative PSA-nadir <1.05 ng/mL (group 2 [intermediate-risk], n = 125) or ≥1.05 ng/mL (group 3 [high-risk], n = 57), respectively. No other patient or tumor characteristics were significant for risk stratification. Within each risk-group, the 10-year metastasis-free survival rates with iADT versus observation ± dADT use were: group 1, 100% versus 95.4% (Log-rank p = 0.738), group 2, 80.6% versus 53.5% (Log-rank p = 0.016), and group 3, 41.5% versus 0% (Log-rank p = 0.015), respectively. Adjusted Cox regression analyses confirmed the benefit of iADT utilization in reducing metastasis in group 2 (p = 0.029) and group 3 (p = 0.008) patients, with no benefit for group 1 patients (p = 0.918). Similar results were noted for cancer-specific and overall mortality.

CONCLUSIONS

Following radical prostatectomy, early postoperative PSA kinetics may provide valuable information for guiding the timing of ADT initiation-this may reduce over- and undertreatment of pN1 PCa men.

Comparing Bayesian hierarchical meta-regression methods and evaluating the influence of priors for evaluations of surrogate endpoints on heterogeneous collections of clinical trials

BACKGROUND

Surrogate endpoints, such as those of interest in chronic kidney disease (CKD), are often evaluated using Bayesian meta-regression. Trials used for the analysis can evaluate a variety of interventions for different sub-classifications of disease, which can introduce two additional goals in the analysis. The first is to infer the quality of the surrogate within specific trial subgroups defined by disease or intervention classes. The second is to generate more targeted subgroup-specific predictions of treatment effects on the clinical endpoint.

METHODS

Using real data from a collection of CKD trials and a simulation study, we contrasted surrogate endpoint evaluations under different hierarchical Bayesian approaches. Each approach we considered induces different assumptions regarding the relatedness (exchangeability) of trials within and between subgroups. These include partial-pooling approaches, which allow subgroup-specific meta-regressions and, yet, facilitate data adaptive information sharing across subgroups to potentially improve inferential precision. Because partial-pooling models come with additional parameters relative to a standard approach assuming one meta-regression for the entire set of studies, we performed analyses to understand the impact of the parameterization and priors with the overall goals of comparing precision in estimates of subgroup-specific meta-regression parameters and predictive performance.

RESULTS

In the analyses considered, partial-pooling approaches to surrogate endpoint evaluation improved accuracy of estimation of subgroup-specific meta-regression parameters relative to fitting separate models within subgroups. A random rather than fixed effects approach led to reduced bias in estimation of meta-regression parameters and in prediction in subgroups where the surrogate was strong. Finally, we found that subgroup-specific meta-regression posteriors were robust to use of constrained priors under the partial-pooling approach, and that use of constrained priors could facilitate more precise prediction for clinical effects in trials of a subgroup not available for the initial surrogacy evaluation.

CONCLUSION

Partial-pooling modeling strategies should be considered for surrogate endpoint evaluation on collections of heterogeneous studies. Fitting these models comes with additional complexity related to choosing priors. Constrained priors should be considered when using partial-pooling models when the goal is to predict the treatment effect on the clinical endpoint.

Proteomic-based stratification of intermediate-risk prostate cancer patients

Gleason grading is an important prognostic indicator for prostate adenocarcinoma and is crucial for patient treatment decisions. However, intermediate-risk patients diagnosed in the Gleason grade group (GG) 2 and GG3 can harbour either aggressive or non-aggressive disease, resulting in under- or overtreatment of a significant number of patients. Here, we performed proteomic, differential expression, machine learning, and survival analyses for 1,348 matched tumour and benign sample runs from 278 patients. Three proteins (F5, TMEM126B, and EARS2) were identified as candidate biomarkers in patients with biochemical recurrence. Multivariate Cox regression yielded 18 proteins, from which a risk score was constructed to dichotomize prostate cancer patients into low- and high-risk groups. This 18-protein signature is prognostic for the risk of biochemical recurrence and completely independent of the intermediate GG. Our results suggest that markers generated by computational proteomic profiling have the potential for clinical applications including integration into prostate cancer management.

Association of PSA kinetics after testosterone recovery with subsequent recurrence: secondary analysis of a phase III randomized controlled trial

PURPOSE

After cessation of androgen deprivation therapy (ADT), testosterone gradually recovers to supracastrate levels (> 50 ng/dL). After this, rises in prostate-specific antigen (PSA) are often seen. However, it remains unknown whether early PSA kinetics after testosterone recovery are associated with subsequent biochemical recurrence (BCR).

METHODS

We performed a secondary analysis of a phase III randomized controlled trial in which newly diagnosed localized prostate cancer patients were randomly allocated to ADT for 6 months starting 4 months prior to or simultaneously with prostate RT. We calculated the PSA doubling time (PSADT) based on PSA values up to 18 months after supracastrate testosterone recovery. Competing risk regression was used to evaluate the association of PSADT with relative incidence of BCR, considering deaths as competing events.

RESULTS

Overall, 313 patients were eligible. Median PSADT was 8 months. Cumulative incidence of BCR at 10 years from supracastrate testosterone recovery was 19% and 11% in patients with PSADT < 8 months and ≥ 8 months (p = 0.03). Compared to patients with PSADT of < 4 months, patients with higher PSADT (sHR for PSADT 4 to < 8 months: 0.36 [95% CI 0.16-0.82]; 8 to < 12 months: 0.26 [0.08-0.91]; ≥ 12 months: 0.20 [0.07-0.56]) had lower risk of relative incidence of BCR.

CONCLUSIONS

Early PSA kinetics, within 18 months of recovery of testosterone to a supracastrate level, can predict for subsequent BCR. Taking account of early changes in PSA after testosterone recovery may allow for recognition of potential failures earlier in the disease course and thereby permit superior personalization of treatment.

A US real-world study of treatment patterns and outcomes in localized or locally advanced prostate cancer patients

PURPOSE

Men with localized or locally advanced prostate cancer (LPC/LAPC) are at risk of progression after radiotherapy (RT) or radical prostatectomy (RP). Using real-world data, we evaluated patient characteristics, treatment patterns, and outcomes in LPC/LAPC.

METHODS

Optum claims and electronic health records (EHR) data from January 2010 to December 2021 were queried for men with LPC/LAPC who received primary RT, RP, or androgen deprivation therapy alone within 180 days after diagnosis. Survival outcomes were analyzed using descriptive statistics and Kaplan-Meier curves. Real-world overall survival (rwOS) was compared in patients with and without evidence of disease (i.e., disease recurrence, metastasis, diagnosis of castration-resistant PC) at defined time points.

RESULTS

61,772 and 62,361 men in claims and EHR cohorts met the inclusion criteria. Median follow-up was 719 and 901 days, respectively. Most men received primary RT (51.0% claims, 35.0% EHR) or RP (39.4% claims, 53.8% EHR). Survival was greatest among men treated with RP, followed by RT. Adjusted for age and comorbidity, rwOS was shorter among men with evidence of disease within 1, 3, 4, and 5 years after primary treatment than those without at the same time points.

CONCLUSION

Real-world claims and EHR data show that survival among men with LPC/LAPC differs by primary treatment and time point of disease recurrence thereafter. Poor outcomes in men with LPC/LAPC who progress early indicate an unmet medical need for more effective primary treatment. If validated for surrogacy, no evidence of disease at specific time points could represent an intermediate efficacy endpoint in future trials.

Handling missing within-study correlations in the evaluation of surrogate endpoints

Rigorous evaluation of surrogate endpoints is performed in a trial-level analysis in which the strength of the association between treatment effects on the clinical and surrogate endpoints is quantified across a collection of previously conducted trials. To reduce bias in measures of the performance of the surrogate, the statistical model must account for the sampling error in each trial's estimated treatment effects and their potential correlation. Unfortunately, these within-study correlations can be difficult to obtain, especially for meta-analysis of published trial results where individual patient data is not available. As such, these terms are frequently partially or completely missing in the analysis. We show that improper handling of these missing terms can meaningfully alter the perceived quality of the surrogate and we introduce novel strategies to handle the missingness.

Biochemical Recurrence Surrogacy for Clinical Outcomes After Radiotherapy for Adenocarcinoma of the Prostate

PURPOSE

The surrogacy of biochemical recurrence (BCR) for overall survival (OS) in localized prostate cancer remains controversial. Herein, we evaluate the surrogacy of BCR using different surrogacy analytic methods.

MATERIALS AND METHODS

Individual patient data from 11 trials evaluating radiotherapy dose escalation, androgen deprivation therapy (ADT) use, and ADT prolongation were obtained. Surrogate candidacy was assessed using the Prentice criteria (including landmark analyses) and the two-stage meta-analytic approach (estimating Kendall's tau and the R2). Biochemical recurrence-free survival (BCRFS, time from random assignment to BCR or any death) and time to BCR (TTBCR, time from random assignment to BCR or cancer-specific deaths censoring for noncancer-related deaths) were assessed.

RESULTS

Overall, 10,741 patients were included. Dose escalation, addition of short-term ADT, and prolongation of ADT duration significantly improved BCR (hazard ratio [HR], 0.71 [95% CI, 0.63 to 0.79]; HR, 0.53 [95% CI, 0.48 to 0.59]; and HR, 0.54 [95% CI, 0.48 to 0.61], respectively). Adding short-term ADT (HR, 0.91 [95% CI, 0.84 to 0.99]) and prolonging ADT (HR, 0.86 [95% CI, 0.78 to 0.94]) significantly improved OS, whereas dose escalation did not (HR, 0.98 [95% CI, 0.87 to 1.11]). BCR at 48 months was associated with inferior OS in all three groups (HR, 2.46 [95% CI, 2.08 to 2.92]; HR, 1.51 [95% CI, 1.35 to 1.70]; and HR, 2.31 [95% CI, 2.04 to 2.61], respectively). However, after adjusting for BCR at 48 months, there was no significant treatment effect on OS (HR, 1.10 [95% CI, 0.96 to 1.27]; HR, 0.96 [95% CI, 0.87 to 1.06] and 1.00 [95% CI, 0.90 to 1.12], respectively). The patient-level correlation (Kendall's tau) for BCRFS and OS ranged between 0.59 and 0.69, and that for TTBCR and OS ranged between 0.23 and 0.41. The R2 values for trial-level correlation of the treatment effect on BCRFS and TTBCR with that on OS were 0.563 and 0.160, respectively.

CONCLUSION

BCRFS and TTBCR are prognostic but failed to satisfy all surrogacy criteria. Strength of correlation was greater when noncancer-related deaths were considered events.

Managing postoperative biochemical relapse in prostate cancer, from the perspective of the Francophone group of Urological radiotherapy (GFRU)

Up to 50% of patients treated with radical surgery for localized prostate cancer may experience biochemical recurrence that requires appropriate management. Definitions of biochemical relapse may vary, but, in all cases, consist of an increase in a PSA without clinical or radiological signs of disease. Molecular imaging through to positron emission tomography has taken a preponderant place in relapse diagnosis, progressively replacing bone scan and CT-scan. Prostate bed radiotherapy is currently a key treatment, the action of which should be potentiated by androgen deprivation therapy. Nowadays perspectives consist in determining the best combination therapies, particularly thanks to next-generation hormone therapies, but not exclusively. Several trials are ongoing and should address these issues. We present here a literature review aiming to discuss the current management of biochemical relapse in prostate cancer after radical surgery, in lights of recent findings, as well as future perspectives.

Outcomes after definitive radiation therapy for localized prostate cancer in a national health care delivery system

PURPOSE

Accurate information regarding real-world outcomes after contemporary radiation therapy for localized prostate cancer is important for shared decision-making. Clinically relevant end points at 10 years among men treated within a national health care delivery system were examined.

METHODS

National administrative, cancer registry, and electronic health record data were used for patients undergoing definitive radiation therapy with or without concurrent androgen deprivation therapy within the Veterans Health Administration from 2005 to 2015. National Death Index data were used through 2019 for overall and prostate cancer-specific survival and identified date of incident metastatic prostate cancer using a validated natural language processing algorithm. Metastasis-free, prostate cancer-specific, and overall survival using Kaplan-Meier methods were estimated.

RESULTS

Among 41,735 men treated with definitive radiation therapy, the median age at diagnosis was 65 years and median follow-up was 8.7 years. Most had intermediate (42%) and high-risk (33%) disease, with 40% receiving androgen deprivation therapy as part of initial therapy. Unadjusted 10-year metastasis-free survival was 96%, 92%, and 80% for low-, intermediate-, and high-risk disease. Similarly, unadjusted 10-year prostate cancer-specific survival was 98%, 97%, and 90% for low-, intermediate-, and high-risk disease. The unadjusted overall survival was lower across increasing disease risk categories at 77%, 71%, and 62% for low-, intermediate-, and high-risk disease (p < .001).

CONCLUSIONS

These data provide population-based 10-year benchmarks for clinically relevant end points, including metastasis-free survival, among patients with localized prostate cancer undergoing radiation therapy using contemporary techniques. The survival rates for high-risk disease in particular suggest that outcomes have recently improved.

The impact of previous inguinal mesh hernioplasty on oncological and patient-reported outcomes following radical prostatectomy

BACKGROUND

The impact of previous inguinal mesh hernioplasty (MH) with non-resorbable mesh prostheses on surgical performance of radical prostatectomy (RP) has been controversially discussed, with unknown impact of MH on oncologic outcomes and health-related quality of life (HRQOL) following RP. We therefore aimed to assess the influence of previous MH on metastasis-free survival (MFS), biochemical recurrence-free survival (BRFS), and HRQOL following RP.

METHODS

We identified 344 patients with previous MH prior RP within our prospectively assessed institutional database of 6275 patients treated with RP for PC (2008-2019). A 1:3 propensity-score matched analysis of 1345 men (n = 319 previous MH, n = 1026 no previous MH) was conducted. Primary endpoint was MFS and secondary endpoints were BRFS and HRQOL (based on EORTC QLQ-C30). Binary logistic regression, Kaplan-Meier, and Cox regression models tested the effect of previous MH on MFS, BRFS, and HRQOL (p < 0.05).

RESULTS

Median follow-up was 47 months. Patients with previous MH had significantly lower 5-year MFS (72% vs. 85%, p < 0.001) and 5-year BRFS estimates (43% vs. 57%, p < 0.001). In multivariate analysis, previous MH was confirmed as an independent predictor for impaired MFS (hazard ratio [HR]: 3.772, 95% CI 1.12-12.64, p = 0.031) and BRFS (HR: 1.862, 95% CI: 1.22-2.85, p = 0.004). These results held true if stratified for surgical approach or limited to patients with successful PLND. We found significantly shorter median time to continence recovery for patients without previous MH (p = 0.001) without significant differences in total continence recovery rates, erectile function recovery, and HRQOL.

CONCLUSIONS

Our findings show an impaired oncologic outcome for patients with previous MH following RP with no significant differences regarding continence recovery, erectile function recovery, and general HRQOL.

Intermediate endpoints as surrogates for outcomes in cancer immunotherapy: a systematic review and meta-analysis of phase 3 trials

Background

Cancer immunotherapy shows unique efficacy kinetics that differs from conventional treatment. These characteristics may lead to the prolongation of trial duration, hence reliable surrogate endpoints are urgently needed. We aimed to systematically evaluate the study-level performance of commonly reported intermediate clinical endpoints for surrogacy in cancer immunotherapy.

Methods

We searched the Embase, PubMed, and Cochrane databases, between database inception and October 18, 2022, for phase 3 randomised trials investigating the efficacy of immunotherapy in patients with advanced solid tumours. An updated search was done on July, 15, 2023. No language restrictions were used. Eligible trials had to set overall survival (OS) as the primary or co-primary endpoint and report at least one intermediate clinical endpoint including objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and 1-year overall survival. Other key inclusion and exclusion criteria included: (1) adult patients (>18 years old) with advanced solid tumour; (2) no immunotherapy conducted in the control arms; (3) follow-up is long enough to achieve OS; (4) data should be public available. A two-stage meta-analytic approach was conducted to evaluate the magnitude of the association between these intermediate endpoints and OS. A surrogate was identified if the coefficient of determination (R2) was 0.7 or greater. Leave-one-out cross-validation and pre-defined subgroup analysis were conducted to examine the heterogeneity. Potential publication bias was evaluated using the Egger's and Begg's tests. This trial was registered with PROSPERO, number CRD42022381648.

Findings

52,342 patients with 15 types of tumours from 77 phase 3 studies were included. ORR (R2 = 0.11; 95% CI, 0.00-0.24), DCR (R2 = 0.01; 95% CI, 0.00-0.01), and PFS (R2 = 0.40; 95% CI, 0.23-0.56) showed weak associations with OS. However, a strong correlation was observed between 1-year survival and clinical outcome (R2 = 0.74; 95% CI, 0.64-0.83). These associations remained relatively consistent across pre-defined subgroups stratified based on tumour types, masking methods, line of treatments, drug targets, treatment strategies, and follow-up durations. No significant heterogeneities or publication bias were identified.

Interpretation

1-year milestone survival was the only identified surrogacy endpoint for outcomes in cancer immunotherapy. Ongoing investigations and development of new endpoints and incorporation of biomarkers are needed to identify potential surrogate markers that can be more robust than 1-year survival. This work may provide important references in assisting the design and interpretation of future clinical trials, and constitute complementary information in drafting clinical practice guidelines.

Funding

None.

Exploring the Onset and Progression of Prostate Cancer through a Multicellular Agent-based Model

Over 10% of men will be diagnosed with prostate cancer during their lifetime. Arising from luminal cells of the prostatic acinus, prostate cancer is influenced by multiple cells in its microenvironment. To expand our knowledge and explore means to prevent and treat the disease, it is important to understand what drives the onset and early stages of prostate cancer. In this study, we developed an agent-based model of a prostatic acinus including its microenvironment, to allow for in silico studying of prostate cancer development. The model was based on prior reports and in-house data of tumor cells cocultured with cancer-associated fibroblasts (CAF) and protumor and/or antitumor macrophages. Growth patterns depicted by the model were pathologically validated on hematoxylin and eosin slide images of human prostate cancer specimens. We identified that stochasticity of interactions between macrophages and tumor cells at early stages strongly affect tumor development. In addition, we discovered that more systematic deviations in tumor development result from a combinatorial effect of the probability of acquiring mutations and the tumor-promoting abilities of CAFs and macrophages. In silico modeled tumors were then compared with 494 patients with cancer with matching characteristics, showing strong association between predicted tumor load and patients' clinical outcome. Our findings suggest that the likelihood of tumor formation depends on a combination of stochastic events and systematic characteristics. While stochasticity cannot be controlled, information on systematic effects may aid the development of prevention strategies tailored to the molecular characteristics of an individual patient.

Significance

We developed a computational model to study which factors of the tumor microenvironment drive prostate cancer development, with potential to aid the development of new prevention strategies.

A hybrid radioactive and fluorescence approach is more than the sum of its parts; outcome of a phase II randomized sentinel node trial in prostate cancer patients

OBJECTIVE

To determine the diagnostic accuracy of the hybrid tracer indocyanine green (ICG)-Technetium-99 m(99mTc)-nanocolloid compared to sequential tracers of 99mTc-nanocolloid and free-ICG in detecting tumor-positive lymph nodes (LN) during primary surgery in prostate cancer (PCa) patients.

INTRODUCTION

Image-guided surgery strategies can help visualize individual lymphatic drainage patterns and sentinel lymph nodes (SLNs) in PCa patients. For lymphatic mapping radioactive, fluorescent and hybrid tracers are being clinically exploited. In this prospective randomized phase II trial, we made a head-to-head comparison between ICG-99mTc-nanocolloid (hybrid group) and 99mTc-nanocolloid and subsequent free-ICG injection (sequential group).

METHODS

PCa patients with a  >5% risk of lymphatic involvement according to the 2012 Briganti nomogram and planned for prostatectomy were included and randomized (1:1) between ultrasound-guided intraprostatic tracer administration of ICG-99mTc-nanocolloid (n = 69) or 99mTc-nanocolloid (n = 69) 5 h before surgery. Preoperative lymphoscintigraphy and SPECT/CT were performed to define the locations of the SLNs. Additionally, all participants in the sequential group received an injection of free-ICG at time of surgery. Subsequently, all (S)LNs were dissected using fluorescence guidance followed by an extended pelvic lymph node dissection (ePLND). The primary outcome was the total number of surgically removed (S)LNs and tumor-positive (S)LNs.

RESULTS

The total number of surgically removed (S)LN packages was 701 and 733 in the hybrid and sequential groups, respectively (p = 0.727). The total number of fluorescent LNs retrieved was 310 and 665 nodes in the hybrid and sequential groups, respectively (p < 0.001). However, no statistically significant difference was observed in the corresponding number of tumor-positive nodes among the groups (44 vs. 33; p = 0.470). Consequently, the rate of tumor-positive fluorescent LNs was higher in the hybrid group (7.4%) compared to the sequential group (2.6%; p = 0.002), indicating an enhanced positive predictive value for the hybrid approach. There was no difference in complications within 90 days after surgery (p = 0.78).

CONCLUSIONS

The hybrid tracer ICG-99mTc-nanocolloid improved the positive predictive value for tumor-bearing LNs while minimizing the number of fluorescent nodes compared to the sequential tracer approach. Consequently, the hybrid tracer ICG-99mTc-nanocolloid enables the most reliable and minimal invasive method for LN staging in PCa patients.

Neoadjuvant versus Concurrent Androgen Deprivation Therapy in Localized Prostate Cancer Treated with Radiotherapy: A Systematic Review of the Literature

BACKGROUND

There is an ongoing debate on the optimal sequencing of androgen deprivation therapy (ADT) and radiotherapy (RT) in patients with localized prostate cancer (PCa). Recent data favors concurrent ADT and RT over the neoadjuvant approach.

METHODS

We conducted a systematic review in PubMed, EMBASE, and Cochrane Databases assessing the combination and optimal sequencing of ADT and RT for Intermediate-Risk (IR) and High-Risk (HR) PCa.

FINDINGS

Twenty randomized control trials, one abstract, one individual patient data meta-analysis, and two retrospective studies were selected. HR PCa patients had improved survival outcomes with RT and ADT, particularly when a long-course Neoadjuvant-Concurrent-Adjuvant ADT was used. This benefit was seen in IR PCa when adding short-course ADT, although less consistently. The best available evidence indicates that concurrent over neoadjuvant sequencing is associated with better metastases-free survival at 15 years. Although most patients had IR PCa, HR participants may have been undertreated with short-course ADT and the absence of pelvic RT. Conversely, retrospective data suggests a survival benefit when using the neoadjuvant approach in HR PCa patients.

INTERPRETATION

The available literature supports concurrent ADT and RT initiation for IR PCa. Neoadjuvant-concurrent-adjuvant sequencing should remain the standard approach for HR PCa and is an option for IR PCa.

Oligometastasis in Prostate Cancer: Can We Learn from Those "Excluded" from a Phase 2 Trial?

We conducted and previously published a phase 2 trial of metastasis-directed therapy (MDT) in men with recurrence of prostate cancer at a low prostate-specific antigen level following radical prostatectomy and postoperative radiotherapy. All patients had negative conventional imaging and underwent prostate-specific membrane antigen (PSMA) positron emission tomography (PET). Patients without visible disease (n = 16) or with metastatic disease not amenable to MDT (n = 19) were excluded from the interventional study. The remaining patients with disease visible on PSMA-PET received MDT (n = 37). We analyzed all three groups to identify distinct phenotypes in the era of molecular imaging-based characterization of recurrent disease. Median follow up was 37 mo (interquartile range 27.5-43.0). There was no significant difference in time to the development of metastasis on conventional imaging among the groups; however, castrate-resistant prostate cancer-free survival was significantly shorter for patients with PSMA-avid disease not amenable to MDT (p = 0.047). Our findings suggest that PSMA-PET findings can help in discriminating diverging clinical phenotypes among men with disease recurrence and negative conventional imaging after local therapies with curative intent. There is a pressing need for better characterization of this rapidly growing population of patients with recurrent disease defined by PSMA-PET to derive robust selection criteria and outcome definitions for ongoing and future studies.

Patient summary

In men with prostate cancer with rising PSA levels following surgery and radiation, a newer type of scan called PSMA-PET (prostate-specific membrane antigen positron emission tomography) can be used to characterize and differentiate the patterns of recurrence, and inform future cancer outcomes.

Fifteen-Year Outcomes after Monitoring, Surgery, or Radiotherapy for Prostate Cancer

BACKGROUND

Between 1999 and 2009 in the United Kingdom, 82,429 men between 50 and 69 years of age received a prostate-specific antigen (PSA) test. Localized prostate cancer was diagnosed in 2664 men. Of these men, 1643 were enrolled in a trial to evaluate the effectiveness of treatments, with 545 randomly assigned to receive active monitoring, 553 to undergo prostatectomy, and 545 to undergo radiotherapy.

METHODS

At a median follow-up of 15 years (range, 11 to 21), we compared the results in this population with respect to death from prostate cancer (the primary outcome) and death from any cause, metastases, disease progression, and initiation of long-term androgen-deprivation therapy (secondary outcomes).

RESULTS

Follow-up was complete for 1610 patients (98%). A risk-stratification analysis showed that more than one third of the men had intermediate or high-risk disease at diagnosis. Death from prostate cancer occurred in 45 men (2.7%): 17 (3.1%) in the active-monitoring group, 12 (2.2%) in the prostatectomy group, and 16 (2.9%) in the radiotherapy group (P = 0.53 for the overall comparison). Death from any cause occurred in 356 men (21.7%), with similar numbers in all three groups. Metastases developed in 51 men (9.4%) in the active-monitoring group, in 26 (4.7%) in the prostatectomy group, and in 27 (5.0%) in the radiotherapy group. Long-term androgen-deprivation therapy was initiated in 69 men (12.7%), 40 (7.2%), and 42 (7.7%), respectively; clinical progression occurred in 141 men (25.9%), 58 (10.5%), and 60 (11.0%), respectively. In the active-monitoring group, 133 men (24.4%) were alive without any prostate cancer treatment at the end of follow-up. No differential effects on cancer-specific mortality were noted in relation to the baseline PSA level, tumor stage or grade, or risk-stratification score. No treatment complications were reported after the 10-year analysis.

CONCLUSIONS

After 15 years of follow-up, prostate cancer-specific mortality was low regardless of the treatment assigned. Thus, the choice of therapy involves weighing trade-offs between benefits and harms associated with treatments for localized prostate cancer. (Funded by the National Institute for Health and Care Research; ProtecT Current Controlled Trials number, ISRCTN20141297; ClinicalTrials.gov number, NCT02044172.).

Meta-Analysis of Candidate Surrogate End Points in Advanced Prostate Cancer

BACKGROUND: The Intermediate Clinical Endpoints in Cancer of the Prostate (ICECaP) working group identified metastasis-free survival as a valid surrogate end point for overall survival (OS) for patients with localized prostate cancer. No comparably validated surrogate end points exist in advanced prostate cancer. METHODS: We searched for trials in advanced prostate cancer, defined as node-positive, metastatic castration-sensitive, nonmetastatic, or metastatic castration-resistant prostate cancer. Eligible randomized trials reported OS and one or more intermediate clinical end points, including biochemical failure (BF), clinical failure, biochemical failure–free survival (BFS), progression-free survival (PFS), and radiographic PFS. Candidacy for surrogacy was assessed by using the second condition of the meta-analytic approach; R2 was weighted by the inverse variance of the log intermediate clinical end point hazard ratio and defined as R2>0.70. RESULTS: A total of 143 randomized trials (n=75,601 patients) were included. No candidate end points met the criteria for surrogacy (R2 BF [n=28,922], 0.42 [95% confidence interval (CI), 0.18 to 0.64]; BFS [n=25,741], 0.57 [95% CI, 0.37 to 0.73]; clinical failure [n=22,616], 0.31 [95% CI, 0.075 to 0.56]; PFS [n=52,639], 0.50 [95% CI, 0.35 to 0.63]; and radiographic PFS [n=52,548], 0.50 [95% CI, 0.35 to 0.63]). Within preplanned subgroups according to castration-sensitive or castration-resistant disease or according to treatment type, neither BFS nor PFS consistently met criteria for surrogacy. Sensitivity analyses showed that candidacy for surrogacy of all end points tested did not change over time. CONCLUSIONS: Our aggregate screening method for surrogate end points in advanced prostate cancer showed that commonly used clinical end points are not clear valid surrogate end points for OS. (Funded by the Prostate Cancer Foundation and the National Cancer Institute.)

Brachytherapy boost improves survival and decreases risk of developing distant metastases compared to external beam radiotherapy alone in intermediate and high risk group prostate cancer patients

BACKGROUND AND PURPOSE

Despite several prospective trials showing a clinical benefit of combining external beam radiotherapy (EBRT) with brachytherapy boost (BTB) for the treatment of intermediate- and high-risk prostate cancer (PCa) patients, none of these trials were designed to test for a survival difference. In this study, we aimed to collect a large multi-institutional database to determine whether BT boost was associated with a statistically significant improvement in survival and a reduction of distant metastases based on real-world data.

MATERIAL AND METHODS

We collected the data of patients treated for intermediate- or high-risk PCa with definitive EBRT or BTB, with or without androgen deprivation therapy (ADT), between January 2003 and December 2014 at two tertiary institutions. The statistical endpoints included overall survival (OS), freedom from distant metastases (FFDM), and metastases-free survival (MFS). The impact of treatment modality was assessed using Cox regression models and log-rank testing after one-to-one propensity score matching.

RESULTS

A total of 1641 patients treated with EBRT (n=1148) or high-dose-rate BTB (n=493) were analyzed. The median survival and clinical follow-up were 117.8 (IQR 78-143.3) and 60.7 months, respectively. The radiotherapy modality (BTB) remained an independent prognostic factor for OS (HR 0.75; 95% CI 0.63-0.88; p<0.001), FFDM (HR 0.54; 95% CI 0.4-0.73; p<0.001), and MFS (HR 0.72; 95% CI 0.61-0.85; p<0.001). After propensity score matching, the remaining 986 patients were well-balanced in terms of age, maximum PSA, ISUP grade group, and TNM T stage. OS (p=0.001), FFDM (p<0.001) and MFS (p<0.001) were significantly higher in the BTB group.

CONCLUSIONS

There is a strong positive association between BTB and OS, FFDM, and MFS in PCa patients treated with definitive RT for intermediate- or high-risk PCa.

Is time to castration resistant prostate cancer a potential intermediate end-point for time to metastasis among men initiating androgen deprivation therapy for non-metastatic prostate cancer with rapid PSA doubling time (<9 months)?

PURPOSE

Metastasis-free survival (MFS) is a surrogate for overall survival (OS) in men with non-metastatic castration-resistant prostate cancer (CRPC), but this endpoint may take years to develop in men with non-metastatic castrate-sensitive disease. The study objective was to examine whether progression to CRPC is a potential intermediate endpoint for developing metastatic disease in patients with biochemical recurrence (BCR) after radical prostatectomy (RP).

MATERIALS AND METHODS

Men with BCR following RP who had PSA doubling times (PSADT) < 9 months and no metastasis at the time of initiating androgen deprivation therapy (ADT) (n = 210) were included. The primary objective was to assess the correlation between CRPC-free survival (CRPC-FS) and MFS, and the secondary objective was to assess the correlation between time to metastasis and time to CRPC. Kendall's Tau was used to test the correlation for the primary and secondary outcomes.

RESULTS

The median MFS was 104 months (95% CI: 83-114) and median CRPC-FS was 100 months (95% CI: 80-114). Based on the Kaplan-Meier curve, the greatest difference in time to MFS and CRPC-FS was around 70% free survival, which was reached at 61.2 months for MFS and 49.6 months for CRPC-FS. Kendall's Tau for the correlation between CRPC-FS and MFS and between time to CRPC and time to metastasis was 0.867 (95% CI: 0.765-0.968) and 0.764 (95% CI: 0.644-0.884), respectively.

CONCLUSIONS

Given the high correlation between CRPC-FS and MFS, after validation, CRPC-FS may serve as a potential intermediate endpoint in trials for men with BCR initiating ADT following local therapy.

Phase II Randomized Study of Salvage Radiation Therapy Plus Enzalutamide or Placebo for High-Risk Prostate-Specific Antigen Recurrent Prostate Cancer After Radical Prostatectomy: The SALV-ENZA Trial

PURPOSE

We sought to investigate whether enzalutamide (ENZA), without concurrent androgen deprivation therapy, increases freedom from prostate-specific antigen (PSA) progression (FFPP) when combined with salvage radiation therapy (SRT) in men with recurrent prostate cancer after radical prostatectomy (RP).

PATIENTS AND METHODS

Men with biochemically recurrent prostate cancer after RP were enrolled into a randomized, double-blind, phase II, placebo-controlled, multicenter study of SRT plus ENZA or placebo (ClinicalTrials.gov identifier: NCT02203695). Random assignment (1:1) was stratified by center, surgical margin status (R0 v R1), PSA before salvage treatment (PSA ≥ 0.5 v < 0.5 ng/mL), and pathologic Gleason sum (7 v 8-10). Patients were assigned to receive either ENZA 160 mg once daily or matching placebo for 6 months. After 2 months of study drug therapy, external-beam radiation (66.6-70.2 Gy) was administered to the prostate bed (no pelvic nodes). The primary end point was FFPP in the intention-to-treat population. Secondary end points were time to local recurrence within the radiation field, metastasis-free survival, and safety as determined by frequency and severity of adverse events.

RESULTS

Eighty-six (86) patients were randomly assigned, with a median follow-up of 34 (range, 0-52) months. Trial arms were well balanced. The median pre-SRT PSA was 0.3 (range, 0.06-4.6) ng/mL, 56 of 86 patients (65%) had extraprostatic disease (pT3), 39 of 86 (45%) had a Gleason sum of 8-10, and 43 of 86 (50%) had positive surgical margins (R1). FFPP was significantly improved with ENZA versus placebo (hazard ratio [HR], 0.42; 95% CI, 0.19 to 0.92; P = .031), and 2-year FFPP was 84% versus 66%, respectively. Subgroup analyses demonstrated differential benefit of ENZA in men with pT3 (HR, 0.22; 95% CI, 0.07 to 0.69) versus pT2 disease (HR, 1.54; 95% CI, 0.43 to 5.47; Pinteraction = .019) and R1 (HR, 0.14; 95% CI, 0.03 to 0.64) versus R0 disease (HR, 1.00; 95% CI, 0.36 to 2.76; Pinteraction = .023). There were insufficient secondary end point events for analysis. The most common adverse events were grade 1-2 fatigue (65% ENZA v 53% placebo) and urinary frequency (40% ENZA v 49% placebo).

CONCLUSION

SRT plus ENZA monotherapy for 6 months in men with PSA-recurrent high-risk prostate cancer after RP is safe and delays PSA progression relative to SRT alone. The impact of ENZA on distant metastasis or survival is unknown at this time.

Exploring new frontiers in prostate cancer research: Report from the 2022 Coffey-Holden prostate cancer academy meeting

INTRODUCTION

The 2022 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Exploring New Frontiers in Prostate Cancer Research," was held from June 23 to 26, 2022, at the University of California, Los Angeles, Luskin Conference Center, in Los Angeles, CA.

METHODS

The CHPCA Meeting is an annual discussion-oriented scientific conference organized by the Prostate Cancer Foundation, that focuses on emerging and next-step topics deemed critical for making the next major advances in prostate cancer research and clinical care. The 2022 CHPCA Meeting included 35 talks over 10 sessions and was attended by 73 academic investigators.

RESULTS

Major topic areas discussed at the meeting included: prostate cancer diversity and disparities, the impact of social determinants on research and patient outcomes, leveraging real-world and retrospective data, development of artificial intelligence biomarkers, androgen receptor (AR) signaling biology and new strategies for targeting AR, features of homologous recombination deficient prostate cancer, and future directions in immunotherapy and nuclear theranostics.

DISCUSSION

This article summarizes the scientific presentations from the 2022 CHPCA Meeting, with the goal that dissemination of this knowledge will contribute to furthering global prostate cancer research efforts.

Trial Participation is Not Associated with Better Biochemical Recurrence-free Survival in a Large Cohort of External Beam Radiotherapy-Treated Intermediate- and High-Risk Prostate Cancer Patients

AIMS

There is a widespread belief that outcomes of cancer patients treated within clinical trials might not be representative of the outcomes obtained within standard clinical settings. We sought to investigate the effect of trial participation on biochemical recurrence (BCR) in localised, D'Amico intermediate- and high-risk prostate cancer patients treated with external beam radiotherapy (EBRT).

MATERIALS AND METHODS

We relied on a study population treated with EBRT between January 2001 and January 2021 at a single tertiary care centre, stratified according to trial enrolment. Separate Kaplan-Meier and multivariable Cox regression models tested BCR-free survival at 60 months within intermediate- and high-risk EBRT patients, after adjustment for covariables. Additionally, the analyses were refitted after inverse probability treatment weighting was performed separately for both risk subgroups.

RESULTS

Of 932 eligible patients, 635 (68%) and 297 (32%) had intermediate- and high-risk prostate cancer, respectively. Overall, 53% of patients were trial participants. BCR rates were 11 versus 5% (P = 0.27) and 12 versus 14% (P = 0.08) in trial participants versus non-participants for intermediate- and high-risk subgroups, respectively. Differences in patient and clinical characteristics were recorded. Trial participation status failed to reach predictor status in multivariable Cox regression models for BCR in both intermediate-risk (hazard ratio 1.34; 95% confidence interval 0.71-2.49; P = 0.4) and high-risk patients (hazard ratio 1.03; 95% confidence interval 0.45-2.34; P = 0.9). Virtually the same results were recorded in inverse probability treatment weighting cohorts.

CONCLUSIONS

Relying on a large cohort of EBRT-treated intermediate- and high-risk patients, no BCR differences were recorded between trial participants and non-participants after accounting for confounders.

The 17-Gene Genomic Prostate Score Test Is Prognostic for Outcomes After Primary External Beam Radiation Therapy in Men With Clinically Localized Prostate Cancer

PURPOSE

The Oncotype DX Genomic Prostate Score (GPS) assay has been validated as a strong prognostic indicator of adverse pathology, biochemical recurrence, distant metastasis (DM), and prostate cancer (PCa)-related death (PCD) in men with localized PCa after radical prostatectomy. However, it has yet to be tested in men undergoing external beam radiation therapy (EBRT), for whom assessing PCa progression risk could inform decisions on treatment intensity. We analyzed whether GPS results are associated with time to biochemical failure (BCF), DM, and PCD after EBRT in men with localized PCa and whether the association is modified by race.

METHODS AND MATERIALS

We conducted a retrospective study of men with localized PCa treated with EBRT at the VA Health Care System in Durham, NC from 2000 to 2016. Study endpoints were time to BCF per the Phoenix criteria, DM, and PCD. The association of GPS results, per 20-unit increase or dichotomous variable (0-40 vs 41-100), was evaluated with each endpoint using univariable and multivariable Cox proportional hazards models. Results were then stratified by race.

RESULTS

A total of 238 patients (69% Black) met the eligibility criteria. Median follow-up for patients who did not experience BCF was 7.6 years. GPS results per 20-unit increase were significantly associated with BCF (hazard ratio [HR], 3.62; 95% confidence interval [CI], 2.59-5.02), DM (HR, 4.48; 95% CI, 2.75-7.38), and PCD (HR, 5.36; 95% CI, 3.06-9.76) in univariable analysis. GPS results remained significant in multivariable models adjusted for baseline clinical and pathological factors, with HRs being similar to the univariable analysis. There was no significant interaction between the GPS assay and race (P = .923). HRs for BCF were similar in Black men (HR, 3.88; 95% CI, 2.40-6.24) versus non-Black men (HR, 4.01; 95% CI, 2.42-6.45).

CONCLUSIONS

Among men treated with EBRT, the GPS assay is a strong, independent prognostic indicator of time to BCF, DM, and PCD, and performs similarly in Black and non-Black men.

Focal High-Intensity Focused Ultrasound vs. Active Surveillance for ISUP Grade 1 Prostate Cancer: Medium-Term Results of a Matched-Pair Comparison

INTRODUCTION/BACKGROUND

Only 1 randomized controlled trial has compared focal therapy and active surveillance (AS) for the low-risk prostate cancer (PCa). We investigated whether focal HIFU (fHIFU) yields oncologic advantages over AS for low-risk PCa.

MATERIALS AND METHODS

We included 2 non-randomized prospective series of 132 (fHIFU) and 421 (AS) consecutive patients diagnosed with ISUP 1 PCa between 2008 and 2018. A matched pair analysis was performed to decrease potential bias. Study main outcomes were freedom from radical treatment (RT) or androgen-deprivation therapy (ADT), treatment-free survival (TFS), time to metastasis, and overall survival (OS).

RESULTS

Median fHIFU follow-up was 50 months (interquartile range, 29-84 months). Among matched variables, no major differences were recorded except for AS having more suspicious digital rectal examination findings (P = .0074) and recent enrollment year (P = .0005). Five-year intervention-free survival from RT or ADT was higher for the fHIFU cohort (67.4% vs. 53.8%; P = .0158). Time to treatment was approximately 10 months shorter for AS than for fHIFU (time to RT, P = .0363; time to RT or ADT, P = .0156; time to any treatment, P = .0319). No differences were found in any-TFS (fHIFU, 61.4% vs. AS, 53.8%; P = .2635), OS (fHIFU, 97% vs. AS, 97%; P = .9237), or metastasis (n = 0 in fHIFU and n = 2 in AS; P = .4981). Major complications (≥ Clavien 3) were rare (n = 4), although 36.4% of men experienced complications. No relevant changes were noted in continence (P = .3949).

CONCLUSION

At a 4-year median follow-up, fHIFU for mainly low-risk PCa (ISUP grade 1) is safe, may decrease the need for radical treatment or ADT and may allow longer time to treatment compared to AS. Nonetheless, no advantages are seen in PCa progression and/or death (OS).

Local Failure Events in Prostate Cancer Treated with Radiotherapy: A Pooled Analysis of 18 Randomized Trials from the Meta-analysis of Randomized Trials in Cancer of the Prostate Consortium (LEVIATHAN)

CONTEXT

The prognostic importance of local failure after definitive radiotherapy (RT) in National Comprehensive Cancer Network intermediate- and high-risk prostate cancer (PCa) patients remains unclear.

OBJECTIVE

To evaluate the prognostic impact of local failure and the kinetics of distant metastasis following RT.

EVIDENCE ACQUISITION

A pooled analysis was performed on individual patient data of 12 533 PCa (6288 high-risk and 6245 intermediate-risk) patients enrolled in 18 randomized trials (conducted between 1985 and 2015) within the Meta-analysis of Randomized Trials in Cancer of the Prostate Consortium. Multivariable Cox proportional hazard (PH) models were developed to evaluate the relationship between overall survival (OS), PCa-specific survival (PCSS), distant metastasis-free survival (DMFS), and local failure as a time-dependent covariate. Markov PH models were developed to evaluate the impact of specific transition states.

EVIDENCE SYNTHESIS

The median follow-up was 11 yr. There were 795 (13%) local failure events and 1288 (21%) distant metastases for high-risk patients and 449 (7.2%) and 451 (7.2%) for intermediate-risk patients, respectively. For both groups, 81% of distant metastases developed from a clinically relapse-free state (cRF state). Local failure was significantly associated with OS (hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.06-1.30), PCSS (HR 2.02, 95% CI 1.75-2.33), and DMFS (HR 1.94, 95% CI 1.75-2.15, p < 0.01 for all) in high-risk patients. Local failure was also significantly associated with DMFS (HR 1.57, 95% CI 1.36-1.81) but not with OS in intermediate-risk patients. Patients without local failure had a significantly lower HR of transitioning to a PCa-specific death state than those who had local failure (HR 0.32, 95% CI 0.21-0.50, p < 0.001). At later time points, more distant metastases emerged after a local failure event for both groups.

CONCLUSIONS

Local failure is an independent prognosticator of OS, PCSS, and DMFS in high-risk and of DMFS in intermediate-risk PCa. Distant metastasis predominantly developed from the cRF state, underscoring the importance of addressing occult microscopic disease. However a "second wave" of distant metastases occurs subsequent to local failure events, and optimization of local control may reduce the risk of distant metastasis.

PATIENT SUMMARY

Among men receiving definitive radiation therapy for high- and intermediate-risk prostate cancer, about 10% experience local recurrence, and they are at significantly increased risks of further disease progression. About 80% of patients who develop distant metastasis do not have a detectable local recurrence preceding it.

Medium-term Oncological Efficacy and Patient-reported Outcomes After Focal High-intensity Focused Ultrasound: The FOXPRO Trial

BACKGROUND

Multiparametric magnetic resonance imaging (mpMRI)/transrectal ultrasound (TRUS) fusion-guided high-intensity focused ultrasound (HIFU) is a focal treatment option for MRI-visible localized prostate cancer (PCa). High-quality evidence regarding the clinical efficacy remains limited.

OBJECTIVE

To assess medium-term oncological efficacy along with patient-reported outcome measures (PROMs).

DESIGN, SETTING, AND PARTICIPANTS

This prospective single-center cohort study was performed from 2014 to 2020. Patients with primary International Society of Urological Pathologists (ISUP) grade group (GG) ≤2 by combined MRI/TRUS fusion and systematic prostate biopsy and prostate-specific antigen (PSA) <10 ng/ml were included.

INTERVENTION

MRI/TRUS fusion-guided focal HIFU therapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was the cancer-free rate of the HIFU-treated lesion by biopsy after 1 yr. Secondary endpoints included salvage treatment-free survival (STFS), metastasis-free survival (MFS), overall survival (OS), and PROMs according to International Consortium for Health Outcomes Measurement recommendations.

RESULTS AND LIMITATIONS

Fifty patients were included (median [range] age 68 [48-80] yr; median PSA 6.5 [1.2-9.9] ng/ml; GG 1 54% [n = 27], and GG 2 46% [n = 23]). The median (range) PSA decrease from baseline to 12 mo was 51% (35.9-72.7%). In total, 37/50 patients (74%) underwent a 1-yr biopsy. PCa was detected in 23 patients (46%; GG 1 20% [n = 10]; GG >1 26% [n = 13]; infield 40% [n = 20]). At a median follow-up of 42 (13-73) mo, PCa was detected in 30 men (60%). Among all patients, 19 (38%) underwent salvage treatments (median [95% confidence interval] STFS 53 [44.3-61.7] mo). MFS and OS were 100% and 98%, respectively. The Expanded Prostate Cancer Index Composite-26 sexual domain decreased by 20.8 points (p = 0.372).

CONCLUSIONS

MRI/TRUS-guided focal HIFU therapy results in complete cancer ablation in only half of the treated patients after 1 yr, with further recurrences at medium-term follow-up. A decline of potency occurs in a subset of patients.

PATIENT SUMMARY

Focal image-guided high-intensity focused ultrasound therapy controls cancer in one of two patients. Its impact on urinary continence and erectile function is low.

Does brachytherapy boost improve survival outcomes in Gleason Grade Group 5 patients treated with external beam radiotherapy and androgen deprivation therapy? A systematic review and meta-analysis

•

Adding a BT boost to external beam radiation can be used to intensify treatment.

•

BT boost improves DMFS but not PCSS or OS in Gleason GG5 prostate cancer.

•

There is no prospective data evaluating BT boost in Gleason GG5 disease.

Background

Localized Gleason Grade Group 5 (GG5) prostate cancer has a poor prognosis and is associated with a higher risk of treatment failure, metastases, and death. Treatment intensification with the addition of a brachytherapy (BT) boost to external beam radiation (EBRT) maximizes local control, which may translate into improved survival outcomes.

Methods

A systematic review and meta-analysis was performed to compare survival outcomes for Gleason GG5 patients treated with androgen deprivation therapy (ADT) and either EBRT or EBRT + BT. The MEDLINE (PubMed), EMBASE and Cochrane databases were searched to identify relevant studies. Survival probabilities for distant metastasis-free survival (DMFS), prostate cancer-specific survival (PCSS), and overall survival (OS) were extracted and pooled to create a summary survival curve for each treatment modality, which were then compared at fixed points in time. An additional analysis was performed among studies directly comparing EBRT and EBRT + BT using a random-effects model.

Results

Eight retrospective studies were selected for inclusion, representing a total of 1393 EBRT patients and 877 EBRT + BT patients. EBRT + BT was associated with higher DMFS starting at 6 years (86.8 % vs 78.8 %; p = 0.018) and extending out to 10 years (81.8 % vs 66.1 %; p < 0.001), with an overall hazard ratio of 0.53 (p = 0.02). There was no difference in PCSS or OS between treatment modalities. Differences in toxicity were not assessed. There was a wide range of heterogeneity between studies.

Conclusion

The addition of BT boost is associated with improved long-term DMFS in Gleason GG5 prostate cancer, but its impact on PCSS and OS remains unclear. These results may be confounded by the heterogeneity across study populations with concern for a risk of bias. Therefore, prospective studies are necessary to further elucidate the survival advantage associated with BT boost, which must ultimately be weighed against the toxicity-related implications of this treatment strategy.

Definitions of "Cure" After Low-Dose-Rate Brachytherapy in Low- and Intermediate-Risk Prostate Cancer: Phoenix or Surgical?

Purpose

The aim of this study was to compare a surgical with a Phoenix-derived definition of cure at 4 years after treatment by ¹²⁵J low-dose-rate brachytherapy (LDR-BT) in patients with low- and intermediate-risk prostate cancer.

Methods and Materials

A total of 427 evaluable men with low-risk (62.8%) and intermediate-risk (37.2%) prostate cancer were treated with LDR-BT (160 Gy). Cure was defined at 4 years either as not having experienced a biochemical recurrence by the Phoenix definition, or by a surgical definition, using a posttreatment prostate-specific antigen of ≤0.2 ng/mL. Biochemical recurrence-free survival (BRFS), metastasis-free survival (MFS), and cancer-specific survival were calculated at 5 and 10 years using the Kaplan-Meier method. Standard diagnostic test evaluations were used to compare both definitions with regard to later metastatic failure or cancer-specific death.

Results

At 48 months, 427 patients were evaluable with a Phoenix-defined and 327 with a surgical-defined cure. At 5 and 10 years BRFS was 97.4% and 89% and MFS was 99.5% and 96.3% in the Phoenix-defined cure cohort, and BRFS was 98.2% and 92.7% and MFS was 100% and 99.4% in the surgical-defined cure cohort. Specificity for cure was 100% for both definitions. Sensitivity was 97.4% for the Phoenix and 96.3% for the surgical definition. The positive predictive value was 100% for both, whereas the negative predictive value was 29% for the Phoenix and 7.7% for the surgical definition. Accuracies of a correct prediction of cure were 94.8% and 96.3% for the Phoenix and the surgical definition, respectively.

Conclusions

Both definitions are useful for a reliable assessment of cure after LDR-BT in patients with low-risk and intermediate-risk prostate cancer. Cured patients might follow a less stringent follow-up schedule from 4 years onward, whereas patients not achieving cure at 4 years should be monitored for an extended time.

Ultra-Hypofractionated Stereotactic Body Radiotherapy for Localized Prostate Cancer: Clinical Outcomes, Patterns of Recurrence, Feasibility of Definitive Salvage Treatment, and Competing Oncological Risk

A cohort of 650 patients treated for localized prostate cancer (PCa) with CyberKnife^TM ultra-hypofractionated radiotherapy between 2011 and 2018 was retrospectively analyzed in terms of survival, patterns of failure, and outcomes of second-line definitive salvage therapies. The analysis was performed using survival analysis including the Kaplan-Meier method and Cox regression analysis. At a median follow-up of 49.4 months, the main pattern of failure was local-regional failure (7.4% in low-, and 13% in intermediate/high-risk group at five years), followed by distant metastases (3.6% in low-, and 6% in intermediate/high-risk group at five years). Five-year likelihood of developing a second malignancy was 7.3%; however, in the vast majority of the cases, the association with prior irradiation was unlikely. The 5-year overall survival was 90.2% in low-, and 88.8% in intermediate/high-risk patients. The independent prognostic factors for survival included age (HR 1.1; 95% CI 1.07-1.14) and occurrence of a second malignancy (HR 3.67; 95% CI 2.19-6.15). Definitive local salvage therapies were feasible in the majority of the patients with local-regional failure, and uncommonly in patients with distant metastases, with an estimated second-line progression free survival of 67.8% at two years. Competing oncological risks and age were significantly more important for patients' survival compared to primary disease recurrence.

Clinical endpoints in trials of palliative radiotherapy: A systematic meta-research analysis

PURPOSE

Up to 50% of radiotherapy courses are delivered in palliative intent for various indications. Despite the large number of treated patients, we know little about the choice of endpoints in trials of palliative radiotherapy. Our primary aim was, therefore, to analyze primary endpoints in trials of palliative radiotherapy.

METHODS

We conducted a pre-registered (https://doi.org/10.17605/OSF.IO/GMCAF) meta-research analysis searching Pubmed/MEDLINE, EMBASE, CENTRAL, and "ClinicalTrials.gov" for clinical trials of palliative radiotherapy published 1990-2020. Endpoints were categorized in "patient-centered endpoints", including overall survival and patient-reported outcomes, and "tumor-centered endpoints" such as local control. The remainder were "other endpoints" including toxicity or observer-rated symptoms. We applied descriptive statistics to summarize data and logistic regression to assess if year of publication predicted the choice of primary endpoints.

RESULTS

Of 7379 records screened, 292 were eligible. Trials were characterized by small sample sizes and use of external beam radiotherapy for metastases or thoracic primaries. Median patient age was 64 and median ECOG was 1. Only 64.4%(145/225) of published trials clearly stated their primary endpoint. Published trials employed a "patient-centered primary endpoint" in 45.5%(66/145) and a "tumor-centered primary endpoint" in 17.3%(25/145) of the cases. There was no statistically significant trend in time for the use of "patient-centered primary endpoints". Registered ongoing trials used a "patient-centered primary endpoint" in 32.8%(22/67) and a "tumor-centered primary endpoint" in 26.9%(18/67) of the cases.

CONCLUSION

Although "patient-centered primary endpoints" appear relatively prevalent in published trials of palliative radiotherapy, their use is still suboptimal and appears to be lower in currently ongoing trials.

The Role of Long Non-Coding RNAs in Epithelial-Mesenchymal Transition-Related Signaling Pathways in Prostate Cancer

Prostate cancer (PCa) is one of the most common male malignancies with frequent remote invasion and metastasis, leading to high mortality. Epithelial-mesenchymal transition (EMT) is a fundamental process in embryonic development and plays a key role in tumor proliferation, invasion and metastasis. Numerous long non-coding RNAs (lncRNAs) could regulate the occurrence and development of EMT through various complex molecular mechanisms involving multiple signaling pathways in PCa. Given the importance of EMT and lncRNAs in the progression of tumor metastasis, we recapitulate the research progress of EMT-related signaling pathways regulated by lncRNAs in PCa, including AR signaling, STAT3 signaling, Wnt/β-catenin signaling, PTEN/PI3K/AKT signaling, TGF-β/Smad and NF-κB signaling pathways. Furthermore, we summarize four modes of how lncRNAs participate in the EMT process of PCa via regulating relevant signaling pathways.

High-dose Radiotherapy or Androgen Deprivation Therapy (HEAT) as Treatment Intensification for Localized Prostate Cancer: An Individual Patient-data Network Meta-analysis from the MARCAP Consortium

BACKGROUND

The relative benefits of radiotherapy (RT) dose escalation and the addition of short-term or long-term androgen deprivation therapy (STADT or LTADT) in the treatment of prostate cancer are unknown.

OBJECTIVE

To perform a network meta-analysis (NMA) of relevant randomized trials to compare the relative benefits of RT dose escalation ± STADT or LTADT.

DESIGN, SETTING, AND PARTICIPANTS

An NMA of individual patient data from 13 multicenter randomized trials was carried out for a total of 11862 patients. Patients received one of the six permutations of low-dose RT (64 to <74 Gy) ± STADT or LTADT, high-dose RT (≥74 Gy), or high-dose RT ± STADT or LTADT.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

Metastasis-free survival (MFS) was the primary endpoint. Frequentist and Bayesian NMAs were performed to rank the various treatment strategies by MFS and biochemical recurrence-free survival (BCRFS).

RESULTS AND LIMITATIONS

Median follow-up was 8.8 yr (interquartile range 5.7-11.5). The greatest relative improvement in outcomes was seen for addition of LTADT, irrespective of RT dose, followed by addition of STADT, irrespective of RT dose. RT dose escalation did not improve MFS either in the absence of ADT (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.80-1.18) or with STADT (HR 0.99, 95% CI 0.8-1.23) or LTADT (HR 0.94, 95% CI 0.65-1.37). According to P-score ranking and rankogram analysis, high-dose RT + LTADT was the optimal treatment strategy for both BCRFS and longer-term outcomes.

CONCLUSIONS

Conventionally escalated RT up to 79.2 Gy, alone or in the presence of ADT, does not improve MFS, while addition of STADT or LTADT to RT alone, regardless of RT dose, consistently improves MFS. RT dose escalation does provide a high probability of improving BCRFS and, provided it can be delivered without compromising quality of life, may represent the optimal treatment strategy when used in conjunction with ADT.

PATIENT SUMMARY

Using a higher radiotherapy dose when treating prostate cancer does not reduce the chance of developing metastases or death, but it does reduce the chance of having a rise in prostate-specific antigen (PSA) signifying recurrence of cancer. Androgen deprivation therapy improves all outcomes. A safe increase in radiotherapy dose in conjunction with androgen deprivation therapy may be the optimal treatment.

A transcriptomic signature for prostate cancer relapse prediction identified from the differentially expressed genes between TP53 mutant and wild-type tumors

For prostate cancer (PCa) patients, biochemical recurrence (BCR) is the first sign of disease relapse and the subsequent metastasis. TP53 mutations are relatively prevalent in advanced PCa forms. We aimed to utilize this knowledge to identify robust transcriptomic signatures for BCR prediction in patients with Gleason score ≥ 7 cancers, which cause most PCa deaths. Using the TCGA-PRAD dataset and the novel data-driven stochastic approach proposed in this study, we identified a 25-gene signature from the genes whose expression in tumors was associated with TP53 mutation statuses. The predictive strength of the signature was assessed by AUC and Fisher’s exact test p-value according to the output of support vector machine-based cross validation. For the TCGA-PRAD dataset, the AUC and p-value were 0.837 and 5 × 10^–13, respectively. For five external datasets, the AUCs and p-values ranged from 0.632 to 0.794 and 6 × 10^–2 to 5 × 10^–5, respectively. The signature also performed well in predicting relapse-free survival (RFS). The signature-based transcriptomic risk scores (TRS) explained 28.2% of variation in RFS on average. The combination of TRS and clinicopathologic prognostic factors explained 23–72% of variation in RFS, with a median of 54.5%. Our method and findings are useful for developing new prognostic tools in PCa and other cancers.

Metastasis-free survival and patterns of distant metastatic disease after PSMA-PET-guided salvage radiotherapy in recurrent or persistent prostate cancer after prostatectomy

INTRODUCTION

Prostate specific membrane antigen positron-emission tomography (PSMA-PET) is increasingly used to guide salvage radiotherapy (sRT) in prostate cancer (PCa) patients with biochemical recurrence/persistence after prostatectomy. This work examines (i) metastasis-free survival (MFS) following PSMA-PET guided sRT and (ii) the metastatic patterns on PSMA-PET images after sRT.

METHODS

This retrospective, multicenter (9 centers, 5 countries) study included patients referred for PSMA-PET due to recurrent/persistent disease after prostatectomy. Patients with distant metastases (DM) on PSMA-PET prior to sRT were excluded. Cox-regression was performed to assess the impact of clinical parameters on MFS. The distribution of PSMA-PET detected DM following sRT and their respective risk factors were analysed.

RESULTS

All (n=815) patients received intensity-modulated RT to the prostatic fossa. In case of PET-positive pelvic lymph nodes (PLN-PET, n=275, 34%), pelvic lymphatics had been irradiated. Androgen deprivation therapy had been given in 251 (31%) patients. The median follow-up after sRT was 36 months. The 2-/4-year MFS following sRT were 93%/81%. In multivariate analysis the presence of PLN-PET was a strong predictor for MFS (HR=2.39, p<0.001). Following sRT, DM were detected by PSMA-PET in 128/198 (65%) patients and two metastatic patterns were observed: 43% had DM in sub diaphragmatic paraaortic LNs (abdominal-lymphatic) whereas 45% in bones, 9% in supra diaphragmatic LNs and 6% in visceral organs (distant). Two distinct signatures with risk factors for each pattern were identified.

CONCLUSION

MFS in our study is lower compared to previous studies, obviously due to the higher detection rate of DM in PSMA-PET after sRT. Thus, it remains unclear whether MFS is a surrogate endpoint for overall survival in PSMA PET-staged patients in the post sRT setting. PLN-PET may be proposed as a new surrogate parameter predictive of MFS. Analysis of recurrence patterns in PET after sRT revealed risk factor signatures for two metastatic patterns (abdominal-lymphatic and distant), which may allow individualized sRT concepts in the future.

Incremental benefits of novel pharmaceuticals in the UK: a cross-sectional analysis of NICE technology appraisals from 2010 to 2020

OBJECTIVES

To evaluate the incremental value of new drugs across disease areas receiving favourable coverage decisions by the UK's National Institute for Health and Care Excellence (NICE) over the past decade.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study assessed favourable appraisal decisions of drugs between 1 January 2010 and 31 December 2020. Estimates of incremental benefit were extracted from NICE's evidence review groups reports.

PRIMARY OUTCOME MEASURE

Incremental benefit of novel drugs relative to the best alternative therapeutic option, expressed in quality-adjusted life-years (QALYs).

RESULTS

184 appraisals of 129 drugs provided QALYs. The median incremental value was 0.27 QALY (IQR: 0.07-0.73). Benefits varied across drug-indication pairs (range: -0.49 to 5.22 QALY). The highest median benefits were found in haematology (0.70, IQR: 0.55-1.22) and oncology (0.46, IQR: 0.20-0.88), the lowest in ophthalmology (0.09, IQR: 0.04-0.22) and endocrinology (0.02, IQR: 0.01-0.06). Eight appraisals (4.3%) found contributions of more than two QALYs, but one in four (50/184) drug-indication pairs provided less than the equivalent of 1 month in perfect health compared to existing treatments.

CONCLUSIONS

In our review period, the median incremental value of novel drugs approved for use within the English National Health System, relative to the best alternative therapeutic option, was equivalent to 3-4 months of life in perfect health, but data were heterogeneous. Objective evaluations of therapeutic value helps patients and physicians to develop reasonable expectations of drugs and delivers insights into disease areas where medicinal therapeutic progress has had the most and least impact.

The Prognostic Value of PI-RADS Score in CyberKnife Ultra-Hypofractionated Radiotherapy for Localized Prostate Cancer

Prostate Imaging-Reporting and Data System (PI-RADS) has been widely implemented as a diagnostic tool for significant prostate cancer (PCa); less is known about its prognostic value, especially in the setting of primary radiotherapy. We aimed to analyze the association between PI-RADS v. 2.1 classification and risk of metastases, based on a group of 152 patients treated with ultra-hypofractionated stereotactic CyberKnife radiotherapy for localized low or intermediate risk-group prostate cancer. We found that all distant failures (n = 5) occurred in patients diagnosed with a PI-RADS score of 5, and axial measurements of the target lesion were associated with the risk of developing metastases (p < 0.001). The best risk stratification model (based on a combination of greatest dimension, the product of multiplication of PI-RADS target lesion axial measurements, and age) achieved a c-index of 0.903 (bootstrap-validated bias-corrected 95% CI: 0.848−0.901). This creates a hypothesis that PI-RADS 5 and the size of the target lesion are important prognostic factors in early-stage PCa patients and should be considered as an adverse prognostic measure for patients undergoing early treatment such as radiation or focal therapy.

High Keratin-7 Expression in Benign Peri-Tumoral Prostatic Glands Is Predictive of Bone Metastasis Onset and Prostate Cancer-Specific Mortality

BACKGROUND

New predictive biomarkers are needed to accurately predict metastasis-free survival (MFS) and cancer-specific survival (CSS) in localized prostate cancer (PC). Keratin-7 (KRT7) overexpression has been associated with poor prognosis in several cancers and is described as a novel prostate progenitor marker in the mouse prostate.

METHODS

KRT7 expression was evaluated in prostatic cell lines and in human tissue by immunohistochemistry (IHC, on advanced PC, n = 91) and immunofluorescence (IF, on localized PC, n = 285). The KRT7 mean fluorescence intensity (MFI) was quantified in different compartments by digital analysis and correlated to clinical endpoints in the localized PC cohort.

RESULTS

KRT7 is expressed in prostatic cell lines and found in the basal and supra-basal compartment from healthy prostatic glands and benign peri-tumoral glands from localized PC. The KRT7 staining is lost in luminal cells from localized tumors and found as an aberrant sporadic staining (2.2%) in advanced PC. In the localized PC cohort, high KRT7 MFI above the 80th percentile in the basal compartment was significantly and independently correlated with MFS and CSS, and with hypertrophic basal cell phenotype.

CONCLUSION

High KRT7 expression in benign glands is an independent biomarker of MFS and CSS, and its expression is lost in tumoral cells. These results require further validation on larger cohorts.

Automated quality assessment of large digitised histology cohorts by artificial intelligence

Research using whole slide images (WSIs) of histopathology slides has increased exponentially over recent years. Glass slides from retrospective cohorts, some with patient follow-up data are digitised for the development and validation of artificial intelligence (AI) tools. Such resources, therefore, become very important, with the need to ensure that their quality is of the standard necessary for downstream AI development. However, manual quality control of large cohorts of WSIs by visual assessment is unfeasible, and whilst quality control AI algorithms exist, these focus on bespoke aspects of image quality, e.g. focus, or use traditional machine-learning methods, which are unable to classify the range of potential image artefacts that should be considered. In this study, we have trained and validated a multi-task deep neural network to automate the process of quality control of a large retrospective cohort of prostate cases from which glass slides have been scanned several years after production, to determine both the usability of the images at the diagnostic level (considered in this study to be the minimal standard for research) and the common image artefacts present. Using a two-layer approach, quality overlays of WSIs were generated from a quality assessment (QA) undertaken at patch-level at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$5\times$$\end{document}5× magnification. From these quality overlays the slide-level quality scores were predicted and then compared to those generated by three specialist urological pathologists, with a Pearson correlation of 0.89 for overall ‘usability’ (at a diagnostic level), and 0.87 and 0.82 for focus and H&E staining quality scores respectively. To demonstrate its wider potential utility, we subsequently applied our QA pipeline to the TCGA prostate cancer cohort and to a colorectal cancer cohort, for comparison. Our model, designated as PathProfiler, indicates comparable predicted usability of images from the cohorts assessed (86–90% of WSIs predicted to be usable), and perhaps more significantly is able to predict WSIs that could benefit from an intervention such as re-scanning or re-staining for quality improvement. We have shown in this study that AI can be used to automate the process of quality control of large retrospective WSI cohorts to maximise their utility for research.