Concurrent prognostic utility of lymph node count and lymph node density for men with pathological node-positive prostate cancer

BACKGROUND

While both the number (+LN) and density (LND) of metastatic lymph nodes on radical prostatectomy lymphadenectomy predict mortality in prostate cancer, the independent impact of each on overall mortality (OM) is unknown.

METHODS

We sampled men who underwent radical prostatectomy and lymphadenectomy between 2004 and 2013 from the National Cancer Database. Multivariable Cox proportional hazards analysis with restricted cubic spline was used to assess the non-linear association of +LN count and LND with OM.

RESULTS

Of 229,547 men in our sample, 3% (n = 7507) had +LNs, of which 89% had 1-3 +LN and 11% had ≥4 +LN. In multivariable Cox analysis across all patients, OM increased with each additional +LN up to four (HR 1.14, 95%CI 1.06-1.23 per node), with no increase beyond 4 +LN. LND was an independent predictor of OM (HR 1.09, 95%CI 1.06-1.12 per 10% increase). However, after excluding patients with inadequate nodal sampling (<5 LN examined), the variation in OM explained by LND was negligible for patients with ≤3 +LN. In men with 1, 2, and 3 +LN, there was a 0.28%, 0.02%, and 0.50% increase in OM for each 10% increase in LND, compared with 1.9% and 1.6% for men with 4 or 5+ LNs.

CONCLUSIONS

While +LN count and LND independently predict OM, the impact of LND is negligible in men with ≤3 +LN, who comprise the vast majority of men with +LN. Pathological nodal staging should primarily rely on LN count rather than LND.

Refining Risk Stratification of High-risk and Locoregional Prostate Cancer: A Pooled Analysis of Randomized Trials

BACKGROUND AND OBJECTIVE

Radiotherapy (RT) and long-term androgen deprivation therapy (ltADT; 18-36 mo) is a standard of care in the treatment of high-risk localized/locoregional prostate cancer (HRLPC). We evaluated the outcomes in patients treated with RT + ltADT to identify which patients have poorer prognosis with standard therapy.

METHODS

Individual patient data from patients with HRLPC (as defined by any of the following three risk factors [RFs] in the context of cN0 disease-Gleason score ≥8, cT3-4, and prostate-specific antigen [PSA] >20 ng/ml, or cN1 disease) treated with RT and ltADT in randomized controlled trials collated by the Intermediate Clinical Endpoints in Cancer of the Prostate group. The outcome measures of interest were metastasis-free survival (MFS), overall survival (OS), time to metastasis, and prostate cancer-specific mortality. Multivariable Cox and Fine-Gray regression estimated hazard ratios (HRs) for the three RFs and cN1 disease.

KEY FINDINGS AND LIMITATIONS

A total of 3604 patients from ten trials were evaluated, with a median PSA value of 24 ng/ml. Gleason score ≥8 (MFS HR = 1.45; OS HR = 1.42), cN1 disease (MFS HR = 1.86; OS HR = 1.77), cT3-4 disease (MFS HR = 1.28; OS HR = 1.22), and PSA >20 ng/ml (MFS HR = 1.30; OS HR = 1.21) were associated with poorer outcomes. Adjusted 5-yr MFS rates were 83% and 78%, and 10-yr MFS rates were 63% and 53% for patients with one and two to three RFs, respectively; corresponding 10-yr adjusted OS rates were 67% and 60%, respectively. In cN1 patients, adjusted 5- and 10-yr MFS rates were 67% and 36%, respectively, and 10-yr OS was 47%.

CONCLUSIONS AND CLINICAL IMPLICATIONS

HRLPC patients with two to three RFs (and cN0) or cN1 disease had the poorest outcomes on RT and ltADT. This will help in counseling patients treated in routine practice and in guiding adjuvant trials in HRLPC.

PATIENT SUMMARY

Radiotherapy and long-term hormone therapy are standard treatments for high-risk and locoregional prostate cancer. In this report, we defined prognostic groups within high-risk/locoregional prostate cancer and showed that outcomes to standard therapy are poorest in those with two or more "high-risk" factors or evidence of lymph node involvement. Such patients may therefore be the best candidates for intensification of treatment.

Use of Persuasive Language in Communication of Risk during Prostate Cancer Treatment Consultations

BACKGROUND

Physician treatment preference may influence how risks are communicated in prostate cancer consultations. We identified persuasive language used when describing cancer prognosis, life expectancy, and side effects in relation to a physician's recommendation for aggressive (surgery/radiation) or nonaggressive (active surveillance/watchful waiting) treatment.

METHODS

A qualitative analysis was performed on transcribed treatment consultations of 40 men with low- and intermediate-risk prostate cancer across 10 multidisciplinary providers. Quotes pertaining to cancer prognosis, life expectancy, and side effects were randomized. Coders predicted physician treatment recommendations from isolated blinded quotes. Testing characteristics of consensus predictions against the physician's treatment recommendation were reported. Coders then identified persuasive strategies favoring aggressive/nonaggressive treatment for each quote. Frequencies of persuasive strategies favoring aggressive/nonaggressive treatment were reported. Logistic regression quantified associations between persuasive strategies and physician treatment recommendations.

RESULTS

A total of 496 quotes about cancer prognosis (n = 127), life expectancy (n = 51), and side effects (n = 318) were identified. The accuracy of predicting treatment recommendation based on individual quotes containing persuasive language (n = 256/496, 52%) was 91%. When favoring aggressive treatment, persuasive language downplayed side effect risks and amplified cancer risk (recurrence, progression, or mortality). Significant predictors (P < 0.05) of aggressive treatment recommendation included favorable side effect interpretation, downplaying side effects, and long time horizon for cancer risk due to longevity. When favoring nonaggressive treatment, persuasive language amplified side effect risks and downplayed cancer risk. Significant predictors of nonaggressive treatment recommendation included unfavorable side effect interpretation, favorable interpretation of cancer risk, and short time horizon for cancer risk due to longevity.

CONCLUSIONS

Physicians use persuasive language favoring their preferred treatment, regardless of whether their recommendation is appropriate.

IMPLICATIONS

Clinicians should quantify risk so patients can judge potential harm without solely relying on persuasive language.

HIGHLIGHTS

Physicians use persuasive language favoring their treatment recommendation when communicating risks of prostate cancer treatment, which may influence a patient's treatment choice.Coders predicted physician treatment recommendations based on isolated, randomized quotes about cancer prognosis, life expectancy, and side effects with 91% accuracy.Qualitative analysis revealed that when favoring nonaggressive treatment, physicians used persuasive language that amplified side effect risks and downplayed cancer risk. When favoring aggressive treatment, physicians did the opposite.Providers should be cognizant of using persuasive strategies and aim to provide quantified assessments of risk that are jointly interpreted with the patient so that patients can make evidence-based conclusions regarding risks without solely relying on persuasive language.

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.

Variation in communication of side effects in prostate cancer treatment consultations

BACKGROUND

Effective communication of treatment side effects (SE) is critical for shared decision-making (SDM) in localized prostate cancer. We sought to qualitatively characterize how physicians communicate SE in consultations.

METHODS

We transcribed 50 initial prostate cancer treatment consultations across nine multidisciplinary providers (Urologists, Radiation Oncologists, Medical Oncologists) at our tertiary referral, academic center. Coders identified quotes describing SE and used an inductive approach to establish a hierarchy for granularity of communication: (1) not mentioned, (2) name only, (3) generalization("high"), (4) average incidence without timepoint, (5) average incidence with timepoint, and (6) precision estimate. We reported the most granular mode of communication for each SE throughout the consultation overall and across specialty and tumor risk.

RESULTS

Among consultations discussing surgery (n = 40), erectile dysfunction (ED) and urinary incontinence (UI) were omitted in 15% and 12%, not quantified (name only or generalization) in 47% and 30%, and noted as average incidence without timeline in 8% and 8%, respectively. In only 30% and 49% were ED and UI quantified with timeline (average incidence with timeline or precision estimate), respectively. Among consultations discussing radiation (n = 36), irritative urinary symptoms, ED, and other post-radiotherapy SE were omitted in 22%, 42%, and 64-67%, not quantified in 61%, 33%, and 23-28%, and noted as average incidence without timeline in 8%, 22%, and 6-8%, respectively. In only 3-8% were post-radiotherapy SE quantified with timeline. Specialty concordance (but not tumor risk) was associated with higher granularity of communication, though physicians frequently failed to quantify specialty-concordant SE.

CONCLUSIONS

SE was often omitted, not quantified, and/or lacked a timeline in treatment consultations in our sample. Physicians should articulate, quantify, and assign a timeline for SE to optimize SDM.

Disparities With Systemic Therapies for Black Men Having Advanced Prostate Cancer: Where Do We Stand?

PURPOSE

Prostate cancer represents the most common cancer diagnosis in Black men and is the second leading cause of cancer death in this population. Multilevel disparities have been well-documented in Black men with prostate cancer and play a role in poorer survival outcomes when compared with White men with prostate cancer. In this review, we highlight the changing trend in disparities for systemic therapy outcomes in Black men diagnosed with metastatic prostate cancer.

METHODS

We reviewed data from real-world registries and prospective clinical trials with a particular focus on equal access settings to compare outcomes to systemic therapies between Black and White men with metastatic prostate cancer.

RESULTS

In metastatic prostate cancer, there is growing evidence to suggest that Black men may have similar, if not better, outcomes to systemic therapies than White men with advanced disease, as corroborated by prospective studies and clinical trials where health care delivery and follow-up are more likely to be standardized.

CONCLUSION

This review illustrates the importance of nonbiological drivers of racial disparities in Black men with advanced prostate cancer. Mitigating barriers to health care access and delivery as well as including participation in clinical trials will be pivotal to ongoing efforts to address disparities in systemic therapy outcomes for Black men with metastatic prostate cancer.

Early Endpoints in High-risk Localized Prostate Cancer: Exploratory Analysis of Three Radiation Therapy Oncology Group Phase 3 Studies

BACKGROUND

Early endpoints in clinical trials of high-risk localized prostate cancer (HRLPC) that resemble those monitored in real-world practice could expedite clinical development.

OBJECTIVE

To assess the association of prostate-specific antigen (PSA) recurrence (PSA-R)-based early endpoints with metastasis-free survival (MFS), overall survival (OS), and prostate cancer (PC)-specific survival (PCSS), and to identify clinically undetectable disease.

DESIGN, SETTING, AND PARTICIPANTS

A post hoc analysis of patients with HRLPC from Radiation Therapy Oncology Group studies 9202, 9902, and 0521 was performed.

INTERVENTION

Long-term adjuvant androgen-deprivation therapy (ADT) and post-primary definitive radiotherapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Event-free survival (EFS; PSA-R, locoregional recurrence [LRR], distant metastasis [DM], or death), biochemical failure (PSA-R), general clinical failure (PSA-R, LRR, DM, ADT initiation, or death), and no evidence of disease (NED; alive patients without PSA-R, LRR, DM, and subsequent PC therapy, and with testosterone recovery) were assessed for association with MFS, OS, and PCSS using correlation and landmark analyses, Kaplan-Meier method, and Cox proportional-hazard model. PSA-R was defined as PSA nadir + 2 ng/ml; PSA nadir + 2 ng/ml and rising; PSA >5, 10, and 25 ng/ml; or PSA doubling time (PSADT) <6 mo.

RESULTS AND LIMITATIONS

Among assessed early endpoints, EFS with PSA nadir + 2 ng/ml and rising, or with PSA >5 ng/ml was associated with MFS, OS, and PCSS. No development of EFS with PSADT <6 mo or ADT initiation event or achievement of NED at 3 yr was associated with prolonged OS, MFS, and PCSS (hazard ratio [95% confidence interval], 0.53 [0.45-0.64], 0.63 [0.52-0.76], and 0.26 [0.18-0.36], or 0.56 [0.48-0.66], 0.62 [0.52-0.74], and 0.26 [0.19-0.37]) after the landmark time. Older studies performed before the current guidance should be interpreted with caution.

CONCLUSIONS

We identified EFS with PSA nadir + 2 ng/ml and rising, PSA >5 ng/ml, or PSADT <6 mo ± ADT initiation and NED as potentially promising early endpoints in HRLPC that should be validated further.

PATIENT SUMMARY

We identified novel clinical measures that may expedite the development of new medicines for patients with localized prostate cancer at a high risk of progression. These measures, which took into account prostate-specific antigen assessments and other clinical characteristics, should be confirmed in future studies. We also defined a novel measure of no evidence of disease that can help treating physicians identify patients with clinically undetectable disease.

The American Society for Radiation Oncology Workforce Taskforce Review of the United States Radiation Oncology Workforce Analysis

Over the past decade, concerns have arisen in radiation oncology regarding potential workforce supply and demand imbalance. The American Society for Radiation Oncology commissioned an independent analysis in 2022, looking at supply and demand in the United States radiation oncology workforce and projecting future trends for 2025 and 2030. The final report entitled, "Projected Supply and Demand for Radiation Oncologists in the U.S. in 2025 and 2030" is now available. The analysis included evaluating radiation oncologist supply (new graduates, exits from the specialty), potential changes in demand (growth of Medicare beneficiaries, hypofractionation, loss of indications, new indications) as well as radiation oncologist productivity (growth of work RVUs produced) and demand per beneficiary. The results demonstrated a relative balance between radiation oncology supply and demand for radiation services; the growth in radiation oncologists was balanced by the rapid growth of Medicare beneficiaries over the same time period. The primary factors driving the model were found to be growth of Medicare beneficiaries, and change in work RVU productivity with hypofractionation and loss of indication having only a moderate impact; while the most likely scenario was a balance of workforce supply and demand, scenarios did demonstrate the possibility of over and under supply. Oversupply may become a concern if radiation oncologist wRVU productivity reaches the highest region; beyond 2030, this is also possible if growth in radiation oncologist supply does not parallel Medicare beneficiary growth. Limitations of the analysis included the lack of inclusion of most technical reimbursement and its impact as well as failing to account for SBRT. A modeling tool is available to allow individuals to evaluate different scenarios. Moving forward, continued study will be needed to evaluate trends (particularly work RVU productivity and Medicare beneficiary growth) to allow for continued assessment of workforce supply and demand in radiation oncology.

Consensus Quality Measures and Dose Constraints for Prostate Cancer From the Veterans Affairs Radiation Oncology Quality Surveillance Program and American Society for Radiation Oncology Expert Panel

PURPOSE

There are no agreed upon measures to comprehensively determine the quality of radiation oncology (RO) care delivered for prostate cancer. Consequently, it is difficult to assess the implementation of scientific advances and adherence to best practices in routine clinical practice. To address this need, the US Department of Veterans Affairs (VA) National Radiation Oncology Program established the VA Radiation Oncology Quality Surveillance (VA ROQS) Program to develop clinical quality measures to assess the quality of RO care delivered to Veterans with cancer. This article reports the prostate cancer consensus measures.

METHODS AND MATERIALS

The VA ROQS Program contracted with the American Society for Radiation Oncology to commission a Blue Ribbon Panel of prostate cancer experts to develop a set of evidence-based measures and performance expectations. From February to June 2021, the panel developed quality, aspirational, and surveillance measures for (1) initial consultation and workup, (2) simulation, treatment planning, and delivery, and (3) follow-up. Dose-volume histogram (DVH) constraints to be used as quality measures for definitive and post-prostatectomy radiation therapy were selected. The panel also identified the optimal Common Terminology Criteria for Adverse Events, version 5.0 (CTCAE V5.0), toxicity terms to assess in follow-up.

RESULTS

Eighteen prostate-specific measures were developed (13 quality, 2 aspirational, and 3 surveillance). DVH metrics tailored to conventional, moderately hypofractionated, and ultrahypofractionated regimens were identified. Decision trees to determine performance for each measure were developed. Eighteen CTCAE V5.0 terms were selected in the sexual, urinary, and gastrointestinal domains as highest priority for assessment during follow-up.

CONCLUSIONS

This set of measures and DVH constraints serves as a tool for assessing the comprehensive quality of RO care for prostate cancer. These measures will be used for ongoing quality surveillance and improvement among veterans receiving care across VA and community sites. These measures can also be applied to clinical settings outside of those serving veterans.

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.

Variation in Communication of Competing Risks of Mortality in Prostate Cancer Treatment Consultations

PURPOSE

Men with prostate cancer prefer patient-specific, quantitative assessments of longevity in shared decision making. We sought to characterize how physicians communicate the 3 components of competing risks-life expectancy (LE), cancer prognosis and treatment-related survival benefit-in treatment consultations.

MATERIALS AND METHODS

Conversation related to LE, cancer prognosis and treatment-related survival benefit was identified in transcripts from treatment consultations of 42 men with low- and intermediate-risk disease across 10 multidisciplinary providers. Consensus of qualitative coding by multiple reviewers noted the most detailed mode of communication used to describe each throughout the consultation.

RESULTS

Physicians frequently failed to provide patient-specific, quantitative estimates of LE and cancer mortality. LE was omitted in 17% of consultations, expressed as a generalization (eg "long"/"short") in 17%, rough number of years in 31%, probability of mortality/survival at an arbitrary timepoint in 17% and in only 19% as a specific number of years. Cancer mortality was omitted in 24% of consultations, expressed as a generalization in 7%, years of expected life in 2%, probability at no/arbitrary timepoint in 40% and in only 26% as the probability at LE. Treatment-related survival benefit was often omitted; cancer mortality was reported without treatment in 38%, with treatment in 10% and in only 29% both with and without treatment. Physicians achieved "trifecta"-1) quantifying probability of cancer mortality 2) with and without treatment 3) at the patient's LE-in only 14% of consultations.

CONCLUSIONS

Physicians often fail to adequately quantify competing risks. We recommend the "trifecta" approach, reporting 1) probability of cancer mortality 2) with and without treatment 3) at the patient's LE.

Veterans Affairs Radiation Oncology Quality Surveillance Program and American Society for Radiation Oncology Quality Measures Initiative

INTRODUCTION

Ensuring high quality, evidence-based radiation therapy for patients is of the upmost importance. As a part of the largest integrated health system in America, the Department of Veterans Affairs National Radiation Oncology Program (VA-NROP) established a quality surveillance initiative to address the challenge and necessity of providing the highest quality of care for veterans treated for cancer.

METHODS

As part of this initiative, the VA-NROP contracted with the American Society for Radiation Oncology (ASTRO) to commission five Blue-Ribbon Panels for lung, prostate, rectal, breast, and head & neck cancers experts. This group worked collaboratively with the VA-NROP to develop consensus quality measures. In addition to the site-specific measures, an additional Blue-Ribbon Panel comprised of the chairs and other members of the disease sites was formed to create 18 harmonized quality measures for all five sites (13 quality, 4 surveillance, and 1 aspirational).

CONCLUSION

The VA-NROP and ASTRO collaboration have created quality measures spanning five disease sites to help improve patient outcomes. These will be used for the ongoing quality surveillance of veterans receiving radiation therapy through the VA and its community partners.

ETHICS BOARD APPROVAL

N/A - No human subjects were required.

Salvage Low Dose Rate Prostate Brachytherapy: Clinical Outcomes of a Phase II Trial for Local Recurrence after External Beam Radiotherapy (NRG Oncology/xxxx)

PURPOSE

We report efficacy of a prospective Phase II trial (YYYY) of salvage low dose rate (LDR) prostate brachytherapy (BT) for local failure (LF) after prior external beam radiotherapy (EBRT) with minimum 5- years' follow up.

MATERIALS/METHODS

Eligible patients had low/intermediate risk prostate cancer (PCa) prior to EBRT and biopsy-proven LF > 30 months after EBRT, with PSA < 10 ng/mL and no regional/distant disease. The primary endpoint, late GI/GU Adverse Events (AEs) (CTCAE V3.0 ≥ Grade 3) was 14%. With minimum 5-year follow up after salvage BT, secondary clinical outcomes including disease-free (DFS; includes death from any cause), disease-specific (DSS), and overall survival (OS) were estimated using the Kaplan-Meier method and modelled using Cox proportional hazards regression. Local tumor progression (LF), distant and biochemical failure (DF/BF) were estimated using cumulative incidence. Time to LF, DF and BF were modeled by cause-specific Cox proportional hazards regression.

RESULTS

From 05/2007 -01/2014, 20 centers registered 100 patients (92 analyzable). Median follow up is 6.7 years (range: 0.3-11.2); median age 70 years (range: 55-82); median prior EBRT dose 74 Gy (IQR: 70-76) at a median of 85 months prior(IQR: 60-119). Androgen deprivation was combined with salvage BT in 16%. 10-year OS is 70% (95% confidence interval [CI]: 58 -83). 19 patients died (5 PCa, 10 other, 4 unknown). 10-year failure rates are local 5% (95% CI:1-11), distant 19% (95% CI:10-29) and biochemical 46% (95% CI:34-57). DFS is 61% at 5 years; 33% at 10 years. No baseline characteristic was significantly associated with any clinical outcome.

CONCLUSION

This is the first prospective multicenter trial reporting outcomes of salvage LDR BT for LF after EBRT. Five-year freedom from BF is 68%, comparable to other salvage modalities. Although further LF is rare (5%), BF climbs to 46% by10-years.

Outcomes with brachytherapy based dose escalation for gleason 8 versus 9-10 prostate cancer: An NCDB analysis

INTRODUCTION

The addition of brachytherapy (BT) in high risk prostate cancer is supported by Level 1 evidence. Whether all high risk patients benefit from BT to the same extent is unknown. The National Cancer Database (NCDB) was used to investigate overall survival (OS) differences between GS 8 and 9-10 treated with external beam radiation (EBRT) only or BT +/- EBRT.

MATERIALS AND METHODS

We included localized prostate adenocarcinoma definitively treated with radiation between 2004-2014. Patients were stratified into various radiation treatment groups: EBRT 7560 - 8640 cGy, EBRT 5940 - 7540 cGy, and BT +/- EBRT. All EBRT only and BT +/- EBRT patients received ADT. A multivariable Cox proportional hazard model was used to assess OS. Propensity score matching was used to account for differences between groups. Median survival was determined based on Kaplan-Meier survival curves.

RESULTS

30,698 patients were included. On multivariable analysis among GS 8 patients, BT was associated with improved OS compared to 7560 - 8640 cGy (HR-0.80 (95% CI 0.70-0.92, P = 0.002). In Gleason 9-10 BT did not result in improved OS compared to 7560 - 8640 cGy (HR- 0.91 (95% CI 0.79 - 1.05, P = 0.212). Results remained significant with propensity score matching and removing patients with medical comorbidities.

CONCLUSION

BT was associated with improved OS when compared to 7560 - 8640 cGy in GS 8, but not in Gleason 9-10 disease. This hypothesis generating study suggests there may be variable benefit with BT in high risk prostate cancer patients on OS. Future prospective studies are needed to investigate whether the benefit of BT is similar across all high risk prostate cancer patients.

Integrating PARP Inhibitors Into Advanced Prostate Cancer Therapeutics

DNA-damage repair (DDR) pathway mutations can sensitize cancer cells to a class of cancer therapeutics known as PARP inhibitors. Given that DDR alterations can be found in up to one-third of advanced prostate cancers, PARP inhibitors have recently been established in treatment-refractory settings. We provide an updated review of the clinical data supporting the 4 PARP inhibitors that have undergone the most investigation thus far in metastatic castrate-resistant prostate cancer (mCRPC). Two of these agents are currently approved for the treatment of DDR-altered mCRPC. We end with a discussion on integration of approved PARP inhibitors into advanced prostate cancer clinical practice.

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

BACKGROUND

The international Intermediate Clinical Endpoints in Cancer of the Prostate working group has established metastasis-free survival as a surrogate for overall survival in localised prostate cancer based on the findings of 19 predominantly radiotherapy-based trials. We sought to comprehensively assess aggregate trial-level performance of commonly reported intermediate clinical endpoints across all randomised trials in localised prostate cancer.

METHODS

For this meta-analysis, we searched PubMed for all trials in localised or biochemically recurrent prostate cancer published between Jan 1, 1970, and Jan 15, 2020. Eligible trials had to be randomised, therapeutic, reporting overall survival and at least one intermediate clinical endpoint, and with a sample size of at least 70 participants. Trials of metastatic disease were excluded. Intermediate clinical endpoints included biochemical failure, local failure, distant metastases, biochemical failure-free survival, progression-free survival, and metastasis-free survival. Candidacy for surrogacy was assessed using the second condition of the meta-analytical approach (ie, correlation of the treatment effect of the intermediate clinical endpoint and overall survival), using R2 weighted by the inverse variance of the log intermediate clinical endpoint hazard ratio. The intermediate clinical endpoint was deemed to be a surrogate for overall survival if R2 was 0·7 or greater.

FINDINGS

75 trials (53 631 patients) were included in our analysis. Median follow-up was 9·1 years (IQR 5·7-10·6). Biochemical failure (R2 0·38 [95% CI 0·11-0·64]), biochemical failure-free survival (R2 0·12 [0·0030-0·33]), biochemical failure and clinical failure (R2 0·28 [0·0045-0·65]), and local failure (R2 0·085 [0·00-0·37]) correlated poorly with overall survival. Progression-free survival (R2 0·46 [95% CI 0·22-0·67]) showed moderate correlation with overall survival, and metastasis-free survival (R2 0·78 [0·59-0·89]) correlated strongly.

INTERPRETATION

Intermediate clinical endpoints based on biochemical and local failure did not meet the second condition of the meta-analytical approach and are not surrogate endpoints for overall survival in localised prostate cancer. Our findings validate metastasis-free survival as the only identified surrogate endpoint for overall survival to date.

FUNDING

Prostate Cancer Foundation and National Institutes of Health.

Assessment of Postprostatectomy Radiotherapy as Adjuvant or Salvage Therapy in Patients With Prostate Cancer: A Systematic Review

Importance

After radical prostatectomy, adverse pathologic features and postoperative prostate-specific antigen (PSA) levels can herald disease recurrence or progression. Postoperative radiotherapy (RT) remains beneficial in this setting.

Objective

To examine the evidence supporting the use of postoperative RT as well as recent advances that help determine timing, scope, and use in combination with androgen deprivation therapy (ADT) with or without lymphatic irradiation.

Evidence Review

A search was conducted of MEDLINE (Ovid), Embase (Elsevier), and the Cochrane Library (Wiley) databases, in addition to clinical trial registries. The reference list of included studies was reviewed for relevant articles. The search was limited to studies published between January 1, 2014, and December 31, 2019.

Findings

After 548 citations were screened, 27 articles were selected for inclusion. In addition to conventional imaging, positron-emission tomographic (PET)-based radiotracers can aid in disease localization. While PET imaging may influence management with RT, studies are underway examining this issue, and several limitations must be considered, such as limited detectability at lower PSA levels and regional sensitivity. Available genomic classifiers can risk stratify patients or assess potential added benefit of RT. Prospective validation is underway with cooperative group trials. Adjuvant RT, on the basis of adverse pathologic features (such as extraprostatic extension or positive margins) is beneficial in terms of disease control, but it is unclear whether this therapy translates into more meaningful clinical benefit (eg, improved overall survival and a reduction in metastasis), which has been demonstrated by only 1 older, prospective randomized study. Preliminary data suggest that for a relatively favorable-risk population (low Gleason score but with positive margins), PSA monitoring may be a reasonable alternative in some men. Use of androgen deprivation therapy and lymphatic irradiation should be considered in higher-risk cohorts (those with high PSA, high Gleason score, seminal vesicle invasion or node positivity) in conjunction with postoperative RT.

Conclusions and Relevance

The findings of this review suggest that postprostatectomy RT should be considered for men with prostate cancer in the setting of adverse pathologic features; in carefully selected patients with favorable characteristics, close PSA monitoring is an option. Androgen deprivation therapy and pelvic lymphatic irradiation should be considered for higher risk cohorts (eg, higher PSA values, higher Gleason score). PET imaging and molecular studies remain unproven as decision tools.

Implementation of Germline Testing for Prostate Cancer: Philadelphia Prostate Cancer Consensus Conference 2019

PURPOSE

Germline testing (GT) is a central feature of prostate cancer (PCA) treatment, management, and hereditary cancer assessment. Critical needs include optimized multigene testing strategies that incorporate evolving genetic data, consistency in GT indications and management, and alternate genetic evaluation models that address the rising demand for genetic services.

METHODS

A multidisciplinary consensus conference that included experts, stakeholders, and national organization leaders was convened in response to current practice challenges and to develop a genetic implementation framework. Evidence review informed questions using the modified Delphi model. The final framework included criteria with strong (> 75%) agreement (Recommend) or moderate (50% to 74%) agreement (Consider).

RESULTS

Large germline panels and somatic testing were recommended for metastatic PCA. Reflex testing-initial testing of priority genes followed by expanded testing-was suggested for multiple scenarios. Metastatic disease or family history suggestive of hereditary PCA was recommended for GT. Additional family history and pathologic criteria garnered moderate consensus. Priority genes to test for metastatic disease treatment included BRCA2, BRCA1, and mismatch repair genes, with broader testing, such as ATM, for clinical trial eligibility. BRCA2 was recommended for active surveillance discussions. Screening starting at age 40 years or 10 years before the youngest PCA diagnosis in a family was recommended for BRCA2 carriers, with consideration in HOXB13, BRCA1, ATM, and mismatch repair carriers. Collaborative (point-of-care) evaluation models between health care and genetic providers was endorsed to address the genetic counseling shortage. The genetic evaluation framework included optimal pretest informed consent, post-test discussion, cascade testing, and technology-based approaches.

CONCLUSION

This multidisciplinary, consensus-driven PCA genetic implementation framework provides novel guidance to clinicians and patients tailored to the precision era. Multiple research, education, and policy needs remain of importance.

Event-Free Survival, a Prostate-Specific Antigen-Based Composite End Point, Is Not a Surrogate for Overall Survival in Men With Localized Prostate Cancer Treated With Radiation

PURPOSE

Recently, we have shown that metastasis-free survival is a strong surrogate for overall survival (OS) in men with intermediate- and high-risk localized prostate cancer and can accelerate the evaluation of new (neo)adjuvant therapies. Event-free survival (EFS), an earlier prostate-specific antigen (PSA)-based composite end point, may further expedite trial completion.

METHODS

EFS was defined as the time from random assignment to the date of first evidence of disease recurrence, including biochemical failure, local or regional recurrence, distant metastasis, or death from any cause, or was censored at the date of last PSA assessment. Individual patient data from trials within the Intermediate Clinical Endpoints in Cancer of the Prostate-ICECaP-database with evaluable PSA and disease follow-up data were analyzed. We evaluated the surrogacy of EFS for OS using a 2-stage meta-analytic validation model by determining the correlation of EFS with OS (patient level) and the correlation of treatment effects (hazard ratios [HRs]) on both EFS and OS (trial level). A clinically relevant surrogacy was defined a priori as an R² ≥ 0.7.

RESULTS

Data for 10,350 patients were analyzed from 15 radiation therapy-based trials enrolled from 1987 to 2011 with a median follow-up of 10 years. At the patient level, the correlation of EFS with OS was 0.43 (95% CI, 0.42 to 0.44) as measured by Kendall's tau from a copula model. At the trial level, the R² was 0.35 (95% CI, 0.01 to 0.60) from the weighted linear regression of log(HR)-OS on log(HR)-EFS.

CONCLUSION

EFS is a weak surrogate for OS and is not suitable for use as an intermediate clinical end point to substitute for OS to accelerate phase III (neo)adjuvant trials of prostate cancer therapies for primary radiation therapy-based trials.

VA-Radiation Oncology Quality Surveillance Program

PURPOSE

We sought to develop a quality surveillance program for approximately 15,000 US veterans treated at the 40 radiation oncology facilities at the Veterans Affairs (VA) hospitals each year.

METHODS AND MATERIALS

State-of-the-art technologies were used with the goal to improve clinical outcomes while providing the best possible care to veterans. To measure quality of care and service rendered to veterans, the Veterans Health Administration established the VA Radiation Oncology Quality Surveillance program. The program carries forward the American College of Radiology Quality Research in Radiation Oncology project methodology of assessing the wide variation in practice pattern and quality of care in radiation therapy by developing clinical quality measures (QM) used as quality indices. These QM data provide feedback to physicians by identifying areas for improvement in the process of care and identifying the adoption of evidence-based recommendations for radiation therapy.

RESULTS

Disease-site expert panels organized by the American Society for Radiation Oncology (ASTRO) defined quality measures and established scoring criteria for prostate cancer (intermediate and high risk), non-small cell lung cancer (IIIA/B stage), and small cell lung cancer (limited stage) case presentations. Data elements for 1567 patients from the 40 VA radiation oncology practices were abstracted from the electronic medical records and treatment management and planning systems. Overall, the 1567 assessed cases passed 82.4% of all QM. Pass rates for QM for the 773 lung and 794 prostate cases were 78.0% and 87.2%, respectively. Marked variations, however, were noted in the pass rates for QM when tumor site, clinical pathway, or performing centers were separately examined.

CONCLUSIONS

The peer-review protected VA-Radiation Oncology Surveillance program based on clinical quality measures allows providers to compare their clinical practice to peers and to make meaningful adjustments in their personal patterns of care unobtrusively.