Radical Prostatectomy Versus Radiation and Androgen Deprivation Therapy for Clinically Localized Prostate Cancer: How Good Is the Evidence?

Multi-criteria optimization for planning volumetric-modulated arc therapy for prostate cancer

We aimed to compare the volumetric-modulated arc therapy (VMAT) plans with or without multi-criteria optimization (MCO) on commercial treatment-planning systems (Eclipse, Varian Medical System, Palo Alto, CA, USA) for patients with prostate cancer. We selected 25 plans of patients with prostate cancer who were previously treated on the basis of a VMAT plan. All plans were imported into the Eclipse Treatment Planning System version 15.6, and re-calculation and re-optimization were performed. The MCO plan was then generated. The dosimetric quality of the plans was evaluated using dosimetric parameters and dose indices that account for target coverage and sparing of the organs at risk (OARs). We defined the rectum, bladder, and bilateral femoral heads. The VMAT-MCO plan offers an improvement of gross treatment volume coverage with increased minimal dose and reduced maximal dose. In the planning treatment volume, the Dmean and better gradient, homogeneity, and conformity indexes improved despite the increasing hot and cold spots. When implemented through the MCO plan, a steeper fall off the adjacent OARs in the overlap area was achieved to obtain lower dose parameters. MCO generated better sparing of the rectum and bladder through a tradeoff of the increasing dose to the bilateral femoral heads within the tolerable dose constraints. Compared with re-optimization and re-calculation, respectively, significant dose reductions were observed in the bladder (241 cGy and 254 cGy; p<0.001) and rectum (474 cGy and 604 cGy, p<0.001) with the MCO. Planning evaluation and dosimetric measurements showed that the VMAT-MCO plan using visualized navigation can provide sparing of OAR doses without compromising the target coverage in the same OAR dose constraints.

Characterizing Surgical and Radiotherapy Outcomes in Non-metastatic High-Risk Prostate Cancer: A Systematic Review and Meta-Analysis

Background Identifying the optimal management of high-risk non-metastatic prostate cancer (PCa) is an important public health concern, given the large burden of this disease. We performed a meta-analysis of studies comparing PCa-specific mortality (CSM) among men diagnosed with high-risk non-metastatic PCa who were treated with primary radiotherapy (RT) and radical prostatectomy (RP). Methods Medline and Embase were searched for articles between January 1, 2005, and February 11, 2020. After title and abstract screening, two authors independently reviewed full-text articles for inclusion. Data were abstracted, and a modified version of the Newcastle-Ottawa Scale, involving a comprehensive list of confounding variables, was used to assess the risk of bias. Results Fifteen studies involving 131,392 patients were included. No difference in adjusted CSM in RT relative to RP was shown (hazard ratio, 1.02 [95% confidence interval: 0.84, 1.25]). Increased CSM was found in a subgroup analysis comparing external beam radiation therapy (EBRT) with RP (1.35 [1.10, 1.68]), whereas EBRT combined with brachytherapy (BT) versus RP showed lower CSM (0.68 [0.48, 0.95]). All studies demonstrated a high risk of bias as none fully adjusted for all confounding variables. Conclusion We found no difference in CSM between men diagnosed with non-metastatic high-risk PCa and treated with RP or RT; however, this is likely explained by increased CSM in men treated with EBRT and decreased CSM in men treated with EBRT + BT studies relative to RP. High risk of bias in all studies identifies the need for better data collection and confounding control in the PCa research.

Optimizing External Beam Radiotherapy as per the Risk Group of Localized Prostate Cancer: A Nationwide Multi-Institutional Study (KROG 18-15)

Simple Summary

This multi-institutional study analyzed the patterns of care and outcomes of external beam radiotherapy (EBRT) in localized prostate cancer to identify the optimal EBRT strategy for each risk-stratified patient subgroup for clinical practice implementation. In 1573 patients from 17 institutions, EBRT treated prostate cancer effectively. Also, among various risk classification tools, NCCN classification revealed the highest predictive power. The modern RT techniques and dose escalation (≥179 Gy_1.5) enhanced therapeutic effects of RT significantly, especially in the high-risk group. On the other hand, modest doses (≥170 Gy_1.5) was a significant factor in the intermediate-risk group and no significant impact of dose was observed in the low-risk group. IMRT+ ≥179 Gy_1.5+ hypofractionation resulted in higher biochemical failure-free survival in all risk groups, and it translated into survival benefits in the high-risk group. Therefore, risk-adapted RT (more intense RT, high-risk patients; moderate-dose RT, low-risk patients) can be considered, although further prospective studies are warranted.

Abstract

Purpose: This nationwide multi-institutional study analyzed the patterns of care and outcomes of external beam radiotherapy (EBRT) in localized prostate cancer patients. We compared various risk classification tools and assessed the need for refinements in current radiotherapy (RT) schemes. Methods and Materials: We included non-metastatic prostate cancer patients treated with primary EBRT from 2001 to 2015 in this study. Data of 1573 patients from 17 institutions were analyzed and re-grouped using a risk stratification tool with the highest predictive power for biochemical failure-free survival (BCFFS). We evaluated BCFFS, overall survival (OS), and toxicity rates. Results: With a median follow-up of 75 months, 5- and 10-year BCFFS rates were 82% and 60%, and 5- and 10-year OS rates were 95% and 83%, respectively. NCCN risk classification revealed the highest predictive power (AUC = 0.556, 95% CI 0.524–0.588; p < 0.001). Gleason score, iPSA < 12 ng/mL, intensity-modulated RT (IMRT), and ≥179 Gy_1.5 (EQD2, 77 Gy) were independently significant for BCFFS (all p < 0.05). IMRT and ≥179 Gy_1.5 were significant factors in the high-risk group, whereas ≥170 Gy_1.5 (EQD2, 72 Gy) was significant in the intermediate-risk group and no significant impact of dose was observed in the low-risk group. Both BCFFS and OS improved significantly when ≥179 Gy_1.5 was delivered using IMRT and hypofractionation in the high-risk group without increasing toxicities. Conclusions: With NCCN risk classification, dose escalation with modern high-precision techniques might increase survivals in the high-risk group, but not in the low-risk group, although mature results of prospective studies are awaited.

Phase 3 multicenter randomized trial of PSMA PET/CT prior to definitive radiation therapy for unfavorable intermediate-risk or high-risk prostate cancer [PSMA dRT]: study protocol

BACKGROUND

Definitive radiation therapy (dRT) is an effective initial treatment of intermediate-risk (IR) and high-risk (HR) prostate cancer (PCa). PSMA PET/CT is superior to standard of care imaging (CT, MRI, bone scan) for detecting regional and distant metastatic PCa. PSMA PET/CT thus has the potential to guide patient selection and the planning for dRT and improve patient outcomes.

METHODS

This is a multicenter randomized phase 3 trial (NCT04457245). We will randomize 312 patients to proceed with standard dRT (control Arm, n = 150), or undergo a PSMA PET/CT scan at the study site (both 18F-DCFPyL and 68Ga-PSMA-11 can be used) prior to dRT planning (intervention arm, n = 162). dRT will be performed at the treating radiation oncologist facility. In the control arm, dRT will be performed as routinely planned. In the intervention arm, the treating radiation oncologist can incorporate PSMA PET/CT findings into the RT planning. Androgen deprivation therapy (ADT) is administered per discretion of the treating radiation oncologist and may be modified as a result of the PSMA PET/CT results. We assume that approximately 8% of subjects randomized to the PSMA PET arm will be found to have M1 disease and thus will be more appropriate candidates for long-term systemic or multimodal therapy, rather than curative intent dRT. PET M1 patients will thus not be included in the primary endpoint analysis. The primary endpoint is the success rate of patients with unfavorable IR and HR PCa after standard dRT versus PSMA PET-based dRT. Secondary Endpoints (whole cohort) include progression free survival (PFS), metastasis-free survival after initiation of RT, overall survival (OS), % of change in initial treatment intent and Safety.

DISCUSSION

This is the first randomized phase 3 prospective trial designed to determine whether PSMA PET/CT molecular imaging can improve outcomes in patients with PCa who receive dRT. In this trial the incorporation of PSMA PET/CT may improve the success rate of curative intent radiotherapy in two ways: to optimize patient selection as a biomarker and to personalizes the radiotherapy plan.

CLINICAL TRIAL REGISTRATION

UCLA IND#147591 ○ Submission: 02.27.2020 ○ Safe-to-proceed letter issued by FDA: 04.01.2020 UCLA IRB #20-000378 ClinicalTrials.gov Identifier NCT04457245 . Date of Registry: 07.07.2020. Essen EudraCT 2020-003526-23.

Oncologic outcome of radical prostatectomy versus radiotherapy as primary treatment for high and very high risk localized prostate cancer

OBJECTIVE

To compare the oncologic outcomes of radical prostatectomy (RP) versus external beam radiotherapy (EBRT) ± androgen deprivation therapy for primary treatment of high risk localized prostate cancer (CaP).

METHODS

We retrospectively reviewed a prospectively-populated database for cases who underwent primary treatment for high risk localized CaP, had more than 2 years follow-up, and were treated since 2006. A total of 335 cases were studied of whom 291 underwent RP and 44 underwent EBRT. Clinical characteristics, biochemical progression-free survival (BPFS), metastasis-free survival (MFS), cancer-specific survival (CSS) and overall survival (OS) were compared.

RESULTS

EBRT cases were older (p < .01; mean 71 years vs. 61 years) and had longer PSA doubling time (PSADT) (p = .03; median 4.8 years vs. 3.5 years) than RP. Race, pretreatment PSA and biopsy Gleason score were similar. Median follow-up was 5.1 (range: 2.3-12.8) years for RP versus 3.3 (range: 2-12.4) years for EBRT. Three- and 5-year BPFS were 42% and 36% after RP versus 86% and 75% after EBRT (p < .01). The rate of adjuvant/salvage therapy was 58% after RP versus 20% after EBRT (p < .01). Three- and 5-year MFS were 80% and 77% after RP versus 91% and 91% after EBRT (p = .11). Three-year CSS was 98% in both groups and OS was 97% after RP versus 94% after EBRT (p = .73).

CONCLUSIONS

RP had higher rates of biochemical failure and adjuvant or salvage treatment versus EBRT in high risk localized CaP. MFS trended toward benefit after EBRT, but CSS and OS remained high in both groups.

The Impact of Prostate Cancer Treatment on Quality of Life: A Narrative Review with a Focus on Randomized Data

Despite excellent oncologic outcomes, the management of localized prostate cancer remains complex and is dependent on multiple factors, including patient life expectancy, medical comorbidities, tumor characteristics, and genetic risk factors. Decades of iterative clinical trials have improved the optimization and utilization of surgical and radiation-based modalities, as well as their combinatorial use with anti-androgen and systemic therapies. While cure rates are high and converging on equivalent disease control should an upfront surgical or radiotherapeutic approach be optimized, the long-term side effects of surgical and radiation-based treatments can differ significantly in nature. Decisions regarding the selection of therapy are therefore best made in an informed and shared medical decision-making process between clinician and patient with respect to cancer control as well as adverse effects. We outline in this narrative review an understanding regarding implications of surgical and radiation treatment on quality of life after treatment, and how these data may be considered in the context of advising patients regarding the selection of therapy. This narrative review largely focuses on the quality of life data obtained from prospective randomized trials of men treated for prostate cancer. We believe this provides the best assessment of the quality of life and can be used to inform patients when making treatment decisions.

Updated evidence on oncological outcomes of surgery versus external beam radiotherapy for localized prostate cancer

Radical prostatectomy and external beam radiotherapy are recognized as comparable treatment options for localized prostate cancer. Previous studies of oncological outcomes of surgery versus radiotherapy have reported their comparability or possible superiority of surgery. However, the issue of which treatment is better remains controversial. Several factors make fair comparison of their outcomes difficult: different patient backgrounds caused by selection bias, different definitions of biochemical recurrence and different complication profiles between the treatment modalities. In 2016, the first large randomized controlled trial was published, which compared radical prostatectomy, external beam radiotherapy and active monitoring in localized prostate cancer. More recently, another study has reported comparative outcomes of robot-assisted radical prostatectomy and volumetric modulated arc therapy, as the leading surgery and radiotherapy techniques, respectively. Furthermore, there has been a trend toward combining external beam radiotherapy with brachytherapy boost, especially in patients with high-risk prostate cancer. This review summarizes the updated evidence on oncological outcomes of surgery versus external beam radiotherapy for localized prostate cancer.

Intermediate-risk Prostate Cancer: Stratification and Management

CONTEXT

Intermediate-risk prostate cancer consists of a highly heterogeneous group of patients. Owing to this heterogeneity and variable prognoses, it is challenging to provide uniform treatment recommendations for men in this group.

OBJECTIVE

To review the current literature regarding the best available evidence for stratification and treatment of intermediate-risk prostate cancer patients.

EVIDENCE ACQUISITION

We searched Medline and EMBASE, through September 2019 without year or language restriction, supplemented with hand search.

EVIDENCE SYNTHESIS

Different treatment options with good long-term oncological outcomes are available for intermediate-risk prostate cancer patients. Best available evidence with long follow-up exists for radical prostatectomy and dose-escalated radiotherapy with short-term androgen deprivation. In favorable intermediate-risk patients, active surveillance and brachy-monotherapy also represent two valid treatment options. In carefully selected men, partial gland ablation represents a reasonable option. Patient preferences and comorbidities should also be considered.

CONCLUSIONS

Treatment options for intermediate-risk patients range from active surveillance to partial gland ablation, radical prostatectomy, and various radiotherapy methods. The best stratification and the optimal treatment remain controversial. Classification systems, such as the National Cancer Comprehensive Network guidelines, stratify this large cohort into subgroups with favorable or unfavorable disease, which may simplify treatment recommendations but still leave substantial variability within strata. Advanced imaging may further improve current stratification systems of intermediate-risk patients.

PATIENT SUMMARY

In this review, we assessed the current literature regarding the best available evidence for stratification and treatment of intermediate-risk prostate cancer patients.

Clinical Outcomes of Dose-escalated Radiotherapy for Localised Prostate Cancer: A Single-institution Experience

BACKGROUND/AIM

To report the outcomes of patients with prostate cancer treated with dose-escalated radiotherapy over a 15-year period at our Institution.

PATIENTS AND METHODS

Patients with biopsy-proven cT1-4N0M0 disease who received radical external beam radiotherapy (EBRT) were reviewed. The endpoints were 5-year overall survival (OS), freedom from biochemical failure (FFBF) and late treatment toxicities.

RESULTS

A total of 236 patients were eligible. Median follow-up was 70 months. Low-, intermediate- and high-risk disease was found in 9%; 29% and 62% of patients, respectively. The median radiation dose was 73.8 Gy. Overall 42% of patients had dose escalation to >74 Gy. Five-year OS and FFBF were 95.2%/81.6%/75.4% and 95.0%/98.0%/82.0% for low-/intermediate-/high-risk patients, respectively. Dose escalation to >74 Gy did not improve FFBF (hazard ratio=0.97, 95% confidence intervaI=0.43-2.19, p=0.93) and was associated with a 4.3-fold increase in the odds of grade 3 or more rectal bleeding (p<0.01).

CONCLUSION

Dose escalation to >74 Gy did not improve OS or FFBF but was associated with a higher rate of grade 3 or more rectal haemorrhage.

Combined Modality Therapies for High-Risk Prostate Cancer: Narrative Review of Current Understanding and New Directions

Despite the many prospective randomized trials that have been available in the past decade regarding the optimization of radiation, hormonal, and surgical therapies for high-risk prostate cancer (PCa), many questions remain. There is currently a lack of level I evidence regarding the relative efficacy of radical prostatectomy (RP) followed by adjuvant radiation compared to radiation therapy (RT) combined with androgen deprivation therapy (ADT) for high-risk PCa. Current retrospective series have also described an improvement in biochemical outcomes and PCa-specific mortality through the use of augmented radiation strategies incorporating brachytherapy. The relative efficacy of modern augmented RT compared to RP is still incompletely understood. We present a narrative review regarding recent advances in understanding regarding comparisons of overall and PCa-specific mortality measures among patients with high-risk PCa treated with either an RP/adjuvant RT or an RT/ADT approach. We give special consideration to recent trends toward the assembly of multi-institutional series targeted at providing high-quality data to minimize the effects of residual confounding. We also provide a narrative review of recent studies examining brachytherapy boost and systemic therapies, as well as an overview of currently planned and ongoing studies that will further elucidate strategies for treatment optimization over the next decade.

Comparison of Radical Prostatectomy Versus Radiation and Androgen Deprivation Therapy Strategies as Primary Treatment for High-risk Localized Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

There is little level 1 evidence regarding the relative efficacy of radical prostatectomy (RP) compared with radiotherapy (RT) combined with androgen deprivation therapy (ADT) for high-risk prostate cancer.

OBJECTIVE

To conduct a systematic review and meta-analysis comparing overall and prostate cancer-specific mortality (OM and PCM) among patients with high-risk prostate cancer treated with RP or RT/ADT.

EVIDENCE ACQUISITION

We searched PubMed, Scopus, and the Cochrane Library through July 2019 covering a period since 2009. We report the results of our systematic search according to recommendations from the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Adjusted hazard ratios (aHRs) were extracted for each endpoint. The risk of bias was assessed using the Newcastle-Ottawa Scale.

EVIDENCE SYNTHESIS

A total of 23 studies with low to moderate risk of bias were found to meet the inclusion criteria. In keeping with prior studies, external beam radiation therapy (XRT) without specification of ADT was associated with worse OM and PCM (aHR 1.65, 95% confidence interval [CI] 1.42-1.91, p <  0.0001: I² = 53.4%) and (aHR 1.90, 95% CI 1.61-2.23, p <  0.0001: I² = 50.4%). These associations were weaker although not entirely eliminated when comparing RT/ADT versus RP (PCM aHR 1.54, 95% CI 1.16-2.04, p =  0.002: I² = 61.5%). Combination of RT and brachytherapy (MaxRT), on the contrary, was associated with improved PCM compared with RP (aHR 0.48, 95% CI 0.30-0.78, p =  0.003: I² = 23.8%), an effect that was not significant when comparing MaxRT with the combination RP/adjuvant RT (aHR 0.81, 95% CI 0.59-1.11, p =  0.197: I² = 0%).

CONCLUSIONS

Evidence demonstrating definitive superiority of either modality is lacking. Recent studies show improved consideration of ADT, radiation dose, brachytherapy boost, and utilization of postoperative adjuvant radiation. Residual confounding continues to limit the interpretation of observational data.

PATIENT SUMMARY

In the treatment of high-risk prostate cancer, many observational studies reporting higher mortality for radiotherapy demonstrate potential for confounding. More recent studies with current standard of care radiation regimens using androgen deprivation therapy or brachytherapy boost demonstrate approaching equivalence of prostatectomy and radiation modalities. Prospective randomized trials are needed to confirm these findings.

Clinical outcomes of external beam radiotherapy in patients with localized prostate cancer: Does dose escalation matter?

BACKGROUND

To report outcomes of localized prostate cancer treated with radical external beam radiation therapy (EBRT) in our institution over a 14-year period, and to determine the impact of dose escalation of prostate cancer outcomes.

METHODS

Patients with T1-T4 N0 M0 prostate cancer who received radical EBRT between January 2002 and December 2015 were reviewed retrospectively. Clinical data were obtained via the institutional electronic medical records. The primary endpoint was 5-year overall survival (OS). The secondary endpoints were 5-year freedom from biochemical failure (FFBF) and treatment toxicities.

RESULTS

A total of 200 eligible patients were identified. Median follow-up duration was 48 months. 13%, 36% and 51% of patients had low-, intermediate- and high-risk disease. Median dose was 79.2 Gy. The 5-year OS were 90%, 87% and 78% and FFBF were 94%, 100% and 81% for low-, intermediate- and high-risk patients, respectively. Multivariable analysis showed that Eastern Cooperate Oncology Group performance status 2 and Gleason grade group 5 were independent predictors of worse OS. The incidence of grade ≥2 proctitis was 24.5%. Dose escalation was significantly associated with increased incidence of grade ≥2 proctitis (odd ratio, 4.42; 95% confidence interval, 1.95-10.08; P < 0.01).

CONCLUSION

Men with localized prostate cancer treated with EBRT in our population had excellent 5-year OS and biochemical outcomes. Dose escalation did not significantly improve these outcomes but was associated with significantly increased risk of grade ≥2 proctitis in our population. Future studies should be performed to identify patients who will benefit the most from dose-escalated EBRT.

Differences in overall survival and cancer-specific survival in high-risk prostate cancer patients according to the primary treatment

INTRODUCTION AND OBJECTIVES

There is no high-level evidence as to which primary treatment provides an overall survival (OS) or cancer-specific survival (CSS) advantage in high-risk localised prostate cancer (HRLPC). Our aim was to analyse the differences in survival and predictive factors in this group of patients, according to their primary treatment (radical prostatectomy (RP) or radiotherapy and androgen blockade (RT+HT)).

MATERIAL AND METHODS

A retrospective study of 286 HRLPC patients diagnosed between 1996-2008, treated by RP (n=145) or RT+HT(n=141). Survival was assessed using the Kaplan-Meier method. Significant differences between the different variables were analysed using the log-rank test. A uni and multivariate Cox regression analysis was performed to identify risk factors.

RESULTS

the median follow-up was 117.5 (IQR 87-158) months. The OS was longer (p=.04) in the RP patients, while there were no differences (P=.44) in CSS between either group. The type of primary treatment was not related to OS or CSS. Age (P=.002), the onset during follow-up of a 2nd tumour (P=.0001), and stage cT3a (P=.009) behaved as independent predictive variables of OS. None of the variables behaved as an independent predictive variable of CSS, although biochemical recurrence after rescue treatment (P=.058), and the onset of a 2nd tumour during follow-up showed a significant trend to statistical significance, the latter reducing specific cancer mortality (HR .16, 95%CI .02-1.18, P=.07).

CONCLUSIONS

Primary treatment did not relate to OS or CSS in patients with HRPC.

Individual prognosis at diagnosis in nonmetastatic prostate cancer: Development and external validation of the PREDICT Prostate multivariable model

BACKGROUND

Prognostic stratification is the cornerstone of management in nonmetastatic prostate cancer (PCa). However, existing prognostic models are inadequate-often using treatment outcomes rather than survival, stratifying by broad heterogeneous groups and using heavily treated cohorts. To address this unmet need, we developed an individualised prognostic model that contextualises PCa-specific mortality (PCSM) against other cause mortality, and estimates the impact of treatment on survival.

METHODS AND FINDINGS

Using records from the United Kingdom National Cancer Registration and Analysis Service (NCRAS), data were collated for 10,089 men diagnosed with nonmetastatic PCa between 2000 and 2010 in Eastern England. Median follow-up was 9.8 years with 3,829 deaths (1,202 PCa specific). Totals of 19.8%, 14.1%, 34.6%, and 31.5% of men underwent conservative management, prostatectomy, radiotherapy (RT), and androgen deprivation monotherapy, respectively. A total of 2,546 men diagnosed in Singapore over a similar time period represented an external validation cohort. Data were randomly split 70:30 into model development and validation cohorts. Fifteen-year PCSM and non-PCa mortality (NPCM) were explored using separate multivariable Cox models within a competing risks framework. Fractional polynomials (FPs) were utilised to fit continuous variables and baseline hazards. Model accuracy was assessed by discrimination and calibration using the Harrell C-index and chi-squared goodness of fit, respectively, within both validation cohorts. A multivariable model estimating individualised 10- and 15-year survival outcomes was constructed combining age, prostate-specific antigen (PSA), histological grade, biopsy core involvement, stage, and primary treatment, which were each independent prognostic factors for PCSM, and age and comorbidity, which were prognostic for NPCM. The model demonstrated good discrimination, with a C-index of 0.84 (95% CI: 0.82-0.86) and 0.84 (95% CI: 0.80-0.87) for 15-year PCSM in the UK and Singapore validation cohorts, respectively, comparing favourably to international risk-stratification criteria. Discrimination was maintained for overall mortality, with C-index 0.77 (95% CI: 0.75-0.78) and 0.76 (95% CI: 0.73-0.78). The model was well calibrated with no significant difference between predicted and observed PCa-specific (p = 0.19) or overall deaths (p = 0.43) in the UK cohort. Key study limitations were a relatively small external validation cohort, an inability to account for delayed changes to treatment beyond 12 months, and an absence of tumour-stage subclassifications.

CONCLUSIONS

'PREDICT Prostate' is an individualised multivariable PCa prognostic model built from baseline diagnostic information and the first to our knowledge that models potential treatment benefits on overall survival. Prognostic power is high despite using only routinely collected clinicopathological information.

Individual and Population Comparisons of Surgery and Radiotherapy Outcomes in Prostate Cancer Using Bayesian Multistate Models

IMPORTANCE

Whether surgery or radiotherapy is the preferred treatment for patients with localized prostate cancer continues to be debated, and randomized clinical trials cannot yet fully address this question. Furthermore, there may be heterogeneity in responses, and the optimal treatment for a patient will depend on his clinical and tumor characteristics.

OBJECTIVES

To use a unified statistical approach to compare the association of surgery and radiotherapy with both metastatic clinical failure (CF) and survival in localized prostate cancer and to develop an online calculator for individualized, treatment-specific outcome prediction.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study for statistical analysis and development of individualized predictions using Bayesian multistate models that jointly consider both CF and survival and adjust for confounding factors. This study used data from patients treated at the University of Michigan between January 1, 1996, and July 1, 2013, with detailed information on treatment, patient and tumor characteristics, and outcomes. Primary analyses were performed in 2017 and 2018. Participants were a cohort of 4544 patients with localized prostate cancer undergoing primary treatment.

EXPOSURES

Radical prostatectomy and external beam radiotherapy.

MAIN OUTCOMES AND MEASURES

The clinical outcomes were metastatic CF, death after CF, and death from other causes. The adjustment factors were age, prostate gland volume, prostate-specific antigen level, comorbidities, Gleason score, perineural invasion, cT category, race, and treatment year. An online calculator was developed to estimate risks for multiple outcomes for any patient based on 2 treatment choices and on his clinical and tumor characteristics.

RESULTS

Among 4544 men (mean [SD] age, 61.2 [8.0] years), 3769 underwent radical prostatectomy, 775 received external beam radiotherapy, 157 (3.5%) had CF, 90 (2.0%) died after CF, and 378 (8.3%) died of other causes. Across all patients, there was no significant difference in risk of CF for surgery vs radiotherapy (hazard ratio, 0.80; 95% CI, 0.52-1.23). However, using multistate models, in some cases individualized predictions resulted in different expected outcomes between surgery and radiotherapy for a given patient.

CONCLUSIONS AND RELEVANCE

In this study, after adjustment for measured confounders, the hazard of CF was similar between treatments on average. However, these data indicate a greater oncologic benefit for some individual patients if treated with surgery and for other patients if treated with radiotherapy. Individualized predictions provide a novel approach to facilitate treatment decision making.

Comparisons of health-related quality of life among surgery and radiotherapy for localized prostate cancer: a systematic review and meta-analysis

The objective of this study is to compare health-related quality of life (QOL) outcomes between radical prostatectomy (RP) and external beam radiation therapy (EBRT) for localized prostate cancer. PubMed, EMBASE, the Cochrane Library and Web of Science (to July 2017) were searched. Pooled analysis of each domain-specific score was calculated in relevant studies, and its change with follow-up time was explored by sub-group analysis. A total of six studies containing 4423 patients were included. Men underwent RP was associated with worse urinary and sexual domain score than EBRT (standardized mean difference (SMD) = -0.59, -0.58; 95% confidence interval (CI) = -0.73 to -0.45, -0.72 to -0.44). In contrast, EBRT group had lower bowel domain score than RP group (SMD = 0.42, 95% CI = 0.33 to 0.52). The sub-group analysis revealed the most severe urinary and sexual QOL in RP as well as bowel QOL in EBRT group all happened in the first month post operation. The different performance of two treatments in three QOL domains diminished afterwards. Health-related QOL should be considered comprehensively when planning follow-up for men after RP or EBRT for localized prostate cancer.

Improving postoperative radiotherapy following radical prostatectomy

INTRODUCTION

Prostate cancer has one of the highest incidences in the world, with good curative treatment options like radiotherapy and radical prostatectomy. Unfortunately, about 30% of the patients initially treated with curative intent will develop a recurrence and need adjuvant treatment. Five randomized trials covered the role of postoperative radiotherapy after radical prostatectomy, but there is still a lot of debate about which patients should receive postoperative radiotherapy. Areas covered: This review will give an overview on the available literature concerning post-operative radiotherapy following radical prostatectomy with an emphasis on the five randomized trials. Also, new imaging techniques like prostate-specific membrane antigen positron emission tomography (PSMA-PET) and multiparametric magnetic resonance imaging (mp-MRI) and the development of biomarkers like genomic classifiers will be discussed in the search for an improved selection of patients who will benefit from postoperative radiotherapy following radical prostatectomy. With new treatment techniques like Intensity Modulated Radiotherapy, toxicity profiles will be kept low. Expert commentary: Patients with biochemical recurrence following radical prostatectomy with an early rise in prostate-specific antigen (PSA) will benefit most from postoperative radiotherapy. In this way, patients with only high risk pathological features can avoid unnecessary treatment and toxicity, and early intervention in progressing patients would not compromise the outcome.

Toxicity after post-prostatectomy image-guided intensity-modulated radiotherapy using Australian guidelines

INTRODUCTION

We evaluated single institution toxicity outcomes after post-prostatectomy radiotherapy (PPRT) via image-guided intensity-modulated radiation therapy (IG-IMRT) with implanted fiducial markers following national eviQ guidelines, for which late toxicity outcomes have not been published.

METHODS

Prospectively collected toxicity data were retrospectively reviewed for 293 men who underwent 64-66 Gy IG-IMRT to the prostate bed between 2007 and 2015.

RESULTS

Median follow-up after PPRT was 39 months. Baseline grade ≥2 genitourinary (GU), gastrointestinal (GI) and sexual toxicities were 20.5%, 2.7% and 43.7%, respectively, reflecting ongoing toxicity after radical prostatectomy. Incidence of new (compared to baseline) acute grade ≥2 GU and GI toxicity was 5.8% and 10.6%, respectively. New late grade ≥2 GU, GI and sexual toxicity occurred in 19.1%, 4.7% and 20.2%, respectively. However, many patients also experienced improvements in toxicities. For this reason, prevalence of grade ≥2 GU, GI and sexual toxicities 4 years after PPRT was similar to or lower than baseline (21.7%, 2.6% and 17.4%, respectively). There were no grade ≥4 toxicities.

CONCLUSIONS

Post-prostatectomy IG-IMRT using Australian contouring guidelines appears to have tolerable acute and late toxicity. The 4-year prevalence of grade ≥2 GU and GI toxicity was virtually unchanged compared to baseline, and sexual toxicity improved over baseline. This should reassure radiation oncologists following these guidelines. Late toxicity rates of surgery and PPRT are higher than following definitive IG-IMRT, and this should be taken into account if patients are considering surgery and likely to require PPRT.

Survival and Complications Following Surgery and Radiation for Localized Prostate Cancer: An International Collaborative Review

BACKGROUND

Evaluation of treatment options for localized prostate cancer (PCa) remains among the highest priorities for comparative effectiveness research. Surgery and radiotherapy (RT) are the two interventions most commonly used.

OBJECTIVE

To provide a critical narrative review of evidence of the comparative effectiveness and harms of surgery and RT in the treatment of localized PCa.

EVIDENCE ACQUISITION

A collaborative critical narrative review of the literature was conducted.

EVIDENCE SYNTHESIS

Evidence to clearly guide treatment choice in PCa remains insufficient. Randomized trials are underpowered for clinically meaningful endpoints and have demonstrated no difference in overall or PCa-specific survival. Observational studies have consistently demonstrated an absolute survival benefit for men treated with radical prostatectomy, but are limited by selection bias and residual confounding errors. Surgery and RT are associated with comparable health-related quality of life following treatment in three randomized trials. Randomized data regarding urinary, erectile, and bowel function show few long-term (>5 yr) differences, although short-term continence and erectile function were worse following surgery and short-term urinary bother and bowel function were worse following RT. There has been recent recognition of other complications that may significantly affect the life trajectory of those undergoing PCa treatment. Of these, hospitalization, the need for urologic, rectoanal, and other major surgical procedures, and secondary cancers are more common among men treated with RT. Androgen deprivation therapy, frequently co-administered with RT, may additionally contribute to treatment-related morbidity. Technological innovations in surgery and RT have shown inconsistent oncologic and functional benefits.

CONCLUSIONS

Owing to underpowered randomized control studies and the selection biases inherent in observational studies, the question of which treatment provides better PCa control cannot be definitively answered now or in the near future. Complications following PCa treatment are relatively common regardless of treatment approach. These include the commonly identified issues of urinary incontinence and erectile dysfunction, and others including hospitalization and invasive procedures to manage complications and secondary malignancies. Population-based outcome studies, rather than clinical trial data, will be necessary for a comprehensive understanding of the relative benefits and risks of each therapeutic approach.

PATIENT SUMMARY

Surgery and radiotherapy are the most common interventions for men diagnosed with prostate cancer. Comparisons of survival after these treatments are limited by various flaws in the relevant studies. Complications are common regardless of the treatment approach.

Cancer-Specific Mortality Among Korean Men with Localized or Locally Advanced Prostate Cancer Treated with Radical Prostatectomy Versus Radiotherapy: A Multi-Center Study Using Propensity Scoring and Competing Risk Regression Analyses

Purpose

Studies comparing radical prostatectomy (RP) outcomes with those of radiotherapy with or without androgen deprivation therapy (RT±ADT) for prostate cancer (PCa) have yielded conflicting results. Therefore, we used propensity score-matched analysis and competing risk regression analysis to compare cancer-specific mortality (CSM) and other-cause mortality (OCM) between these two treatments.

Materials and Methods

The multi-center, Severance Urological Oncology Group registry was utilized to identify 3,028 patients with clinically localized or locally advanced PCa treated by RP (n=2,521) or RT±ADT (n=507) between 2000 and 2016. RT±ADT cases (n=339) were matched with an equal number of RP cases by propensity scoring based on age, preoperative prostate-specific antigen, clinical tumor stage, biopsy Gleason score, and Charlson Comorbidity Index (CCI). CSM and OCM were co-primary endpoints.

Results

Median follow-up was 65.0 months. Five-year overall survival rates for patients treated with RP and RT±ADT were 94.7% and 92.0%, respectively (p=0.105). Cumulative incidence estimates revealed comparable CSM rates following both treatments within all National Comprehensive Cancer Network risk groups. Gleason score ≥ 8 was associated with higher risk of CSM (p=0.009). OCM rates were comparable between both groups in the low- and intermediate-risk categories (p=0.354 and p=0.643, respectively). For high-risk patients, RT±ADT resulted in higher OCM rates than RP (p=0.011). Predictors of OCM were age ≥ 75 years (p=0.002) and CCI ≥ 2 (p < 0.001).

Conclusion

RP and RT±ADT provide comparable CSM outcomes in patients with localized or locally advanced PCa. The risk of OCM may be higher for older high-risk patients with significant comorbidities.

Astaxanthin Inhibits PC-3 Xenograft Prostate Tumor Growth in Nude Mice

Prostate cancer (PCa), the most common malignancy in men, is a major cause of cancer deaths. A better understanding of the mechanisms that drive tumor initiation and progression may identify actionable targets to improve treatment of this patient group. As a dietary carotenoid, astaxanthin has been demonstrated to exert beneficial effects against inflammation, cardiovascular disease, oxidative damage, or different cancer sites. This study used intragastric administration of astaxanthin to detect its role on tumor proliferation, apoptosis, microRNA (miRNA) overexpression, and microbacteria composition change by establishing androgen-independent PCa cell PC-3 xenograft nude mice. Nude mice were inoculated with androgen-independent prostate cancer PC-3 cells subcutaneously. The intervention was started when tumors reached 0.5–0.6 cm in diameter. Mice were intragastrically administered 100 mg/kg astaxanthin (HA), 25 mg/kg astaxanthin (LA), or olive oil (TC). The results showed that 100 mg/kg astaxanthin significantly inhibited tumor growth compared to the TC group, with an inhibitory rate of 41.7%. A decrease of Ki67 and proliferating cell nuclear antigen (PCNA) as well as an increase of cleaved caspase-3 were observed in HA-treated tumors, along with increasing apoptotic cells, obtained by TUNEL assay. The HA significantly elevated the levels of tumor suppressors miR-375 and miR-487b in tumor tissues and the amount of Lactobacillus sp. and Lachnospiraceae in mice stools, while there was no significant difference between LA and TC groups. These results provide a promising regimen to enhance the therapeutic effect in a dietary supplement manner.

Optimization of the Radiation Management of High-Risk Prostate Cancer

Radiation and androgen-deprivation therapy (ADT) are mainstays of treatment for men with high-risk prostate cancer. High-risk disease is heterogeneous and subcategories of "favorable" high risk and very high risk can identify subgroups with particularly good or poor prognosis to help personalize treatment. Overall, randomized trials show that the combination of radiation and ADT improves survival when compared with either by itself. The optimum duration of ADT remains controversial, but for most healthy men with aggressive disease, approximately 2-3 years of ADT is well supported by the literature. The role of prophylactic pelvic nodal irradiation remains controversial, and there is an ongoing trial testing whether it improves overall survival. The use of brachytherapy boost appears to improve recurrence-free survival without yet improving survival, and may come at the cost of slightly higher toxicity. The addition of docetaxel to radiation and ADT may also improve failure-free survival, but a meta-analysis did not find that it improved overall survival. Retrospective data about the relative value of surgery vs radiation for high-risk disease have yielded varied conclusions and are ultimately hampered by the major issue of selection bias in retrospective series.

Extreme hypofractionation for early prostate cancer: Biology meets technology

The aim of this review is to present the available radiobiological, technical and clinical data about extreme hypofractionation in primary prostate cancer radiotherapy. The interest in this technique is based on the favourable radiobiological characteristics of prostate cancer and supported by advantageous logistic aspects deriving from short overall treatment time. The clinical validity of short-term treatment schedule is proven by a body of non-randomised studies, using both isocentric (LINAC-based) or non-isocentric (CyberKnife^®-based) stereotactic body irradiation techniques. Twenty clinical studies, each enrolling more than 40 patients for a total of 1874 treated patients, were revised in terms of technological setting, toxicity, outcome and quality of life assessment. The implemented strategies for the tracking of the prostate and the sparing of the rectal wall have been investigated with particular attention. The urinary toxicity after prostate stereotactic body irradiation seems slightly more pronounced as compared to rectal adverse events, and this is more evident for late occurring events, but no worse as respect to conventional fractionation schemes. As far as the rate of severe acute toxicity is concerned, in all the available studies the treatment was globally well tolerated. While awaiting long-term data on efficacy and toxicity, the analysed studies suggest that the outcome profile of this approach, alongside the patient convenience and reduced costs, is promising. Forty-eight ongoing clinical trials are also presented as a preview of the expectation from the near future.

Clinical Outcomes for Patients with Gleason Score 9-10 Prostate Adenocarcinoma Treated With Radiotherapy or Radical Prostatectomy: A Multi-institutional Comparative Analysis

BACKGROUND

The long natural history of prostate cancer (CaP) limits comparisons of efficacy between radical prostatectomy (RP) and external beam radiotherapy (EBRT), since patients treated years ago received treatments considered suboptimal by modern standards (particularly with regards to androgen deprivation therapy [ADT] and radiotherapy dose-escalation]. Gleason score (GS) 9-10 CaP is particularly aggressive, and clinically-relevant endpoints occur early, facilitating meaningful comparisons.

OBJECTIVE

To compare outcomes of patients with GS 9-10 CaP following EBRT, extremely-dose escalated radiotherapy (as exemplified by EBRT+brachytherapy [EBRT+BT]), and RP.

DESIGN, SETTING, PARTICIPANTS

Retrospective analysis of 487 patients with biopsy GS 9-10 CaP treated between 2000 and 2013 (230 with EBRT, 87 with EBRT+BT, and 170 with RP). Most radiotherapy patients received ADT and dose-escalated radiotherapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier analysis and multivariate Cox regression estimated and compared 5-yr and 10-yr rates of distant metastasis-free survival, cancer-specific survival (CSS), and overall survival (OS).

RESULTS AND LIMITATIONS

The median follow-up was 4.6 yr. Local salvage and systemic salvage were performed more frequently in RP patients (49.0% and 30.1%) when compared with either EBRT patients (0.9% and 19.7%) or EBRT+BT patients (1.2% and 16.1%, p<0.0001). Five-yr and 10-yr distant metastasis-free survival rates were significantly higher with EBRT+BT (94.6% and 89.8%) than with EBRT (78.7% and 66.7%, p=0.0005) or RP (79.1% and 61.5%, p<0.0001). The 5-yr and 10-yr CSS and OS rates were similar across all three cohorts.

CONCLUSIONS

Radiotherapy and RP provide equivalent CSS and OS. Extremely dose-escalated radiotherapy with ADT in particular offers improved systemic control when compared with either EBRT or RP. These data suggest that extremely dose-escalated radiotherapy with ADT might be the optimal upfront treatment for patients with biopsy GS 9-10 CaP.

PATIENT SUMMARY

While some prostate cancers are slow-growing requiring many years, sometimes decades, of follow-up in order to compare between radiation and surgery, high-risk and very aggressive cancers follow a much shorter time course allowing such comparisons to be made and updated as treatments, especially radiation, rapidly evolve. We showed that radiation-based treatments and surgery, with contemporary standards, offer equivalent survival for patients with very aggressive cancers (defined as Gleason score 9-10). Extremely-dose escalated radiotherapy with short-course androgen deprivation therapy offered the least risk of developing metastases, and equivalent long term survival.