Superior metastasis-free survival for patients with high-risk prostate cancer treated with definitive radiation therapy compared to radical prostatectomy: A propensity score-matched analysis

Japanese clinical practice guidelines for prostate cancer 2023

This fourth edition of the Japanese Clinical Practice Guidelines for Prostate Cancer 2023 is compiled. It was revised under the leadership of the Japanese Urological Association, with members selected from multiple academic societies and related organizations (Japan Radiological Society, Japanese Society for Radiation Oncology, the Department of EBM and guidelines, Japan Council for Quality Health Care (Minds), Japanese Society of Pathology, and the patient group (NPO Prostate Cancer Patients Association)), in accordance with the Minds Manual for Guideline Development (2020 ver. 3.0). The most important feature of this revision is the adoption of systematic reviews (SRs) in determining recommendations for 14 clinical questions (CQs). Qualitative SRs for these questions were conducted, and the final recommendations were made based on the results through the votes of 24 members of the guideline development group. Five algorithms based on these results were also created. Contents not covered by the SRs, which are considered textbook material, have been described in the general statement. In the general statement, a literature search for 14 areas was conducted; then, based on the general statement and CQs of the Japanese Clinical Practice Guidelines for Prostate Cancer 2016, the findings revealed after the 2016 guidelines were mainly described. This article provides an overview of these guidelines.

Use of rectal balloon spacer in patients with localized prostate cancer receiving external beam radiotherapy

Objective

To evaluate the efficacy of the balloon spacer when used to reduce the radiation dose delivered to the rectum in prostate cancer patients undergoing external beam radiotherapy.

Method

A single center retrospective analysis including 75 PC patients with localized T1-T3a disease who received balloon spacer followed by EBRT. Pre- and post-implantation computed tomography (CT) scans were utilized for treatment planning for standard EBRT (78-81 Gy in 1.8-2 Gy fractions). Rectal dosimetry was assessed using DVHs, and toxicities were graded with CTCAE v.4.

Results

A median (IQR) prostate-rectum separation resulted in 1.6 cm (1.4-2.0) post balloon spacer implantation. Overall, 90.6 % (68/75) of patients had a clinically significant 25 % relative reduction in the rectal with a median relative reduction of 91.8 % (71.2-98.6 %) at rV70. Three (4.0 %) patients reported mild procedural adverse events, anal discomfort and dysuria. Within 90 days post-implantation, five patients (6.67 %) and 1 patient (1.33 %) reported grade 1 and grade 2 rectal toxicities (anal pain, constipation, diarrhea and hemorrhoids). Genitourinary (GU) grade 1 toxicity was reported in 37 patients (49.33 %), with only one patient (1.33 %) experiencing grade 2 GU toxicity. No grade ≥ 3 toxicity was reported.

Conclusion

Balloon spacer implantation effectively increased prostate-rectum separation and associated with dosimetric gains EBRT for PC stage T1-T3a. Further controlled studies are required to ascertain whether this spacer allows for radiotherapy dose escalation and minimizes gastrointestinal (GI) toxicity.

Radical prostatectomy versus external beam radiotherapy with androgen deprivation therapy for high-risk prostate cancer: a systematic review

BACKGROUND

To summarize recent evidence in terms of health-related quality of life (HRQoL), functional and oncological outcomes following radical prostatectomy (RP) compared to external beam radiotherapy (EBRT) and androgen deprivation therapy (ADT) for high-risk prostate cancer (PCa).

METHODS

We searched Medline, Embase, Cochrane Database of Systematic Reviews, Cochrane Controlled Trial Register and the International Standard Randomized Controlled Trial Number registry on 29 march 2021. Comparative studies, published since 2016, that reported on treatment with RP versus dose-escalated EBRT and ADT for high-risk non-metastatic PCa were included. The Newcastle-Ottawa Scale was used to appraise quality and risk of bias. A qualitative synthesis was performed.

RESULTS

Nineteen studies, all non-randomized, met the inclusion criteria. Risk of bias assessment indicated low (n = 14) to moderate/high (n = 5) risk of bias. Only three studies reported functional outcomes and/or HRQoL using different measurement instruments and methods. A clinically meaningful difference in HRQoL was not observed. All studies reported oncological outcomes and survival was generally good (5-year survival rates > 90%). In the majority of studies, a statistically significant difference between both treatment groups was not observed, or only differences in biochemical recurrence-free survival were reported.

CONCLUSIONS

Evidence clearly demonstrating superiority in terms of oncological outcomes of either RP or EBRT combined with ADT is lacking. Studies reporting functional outcomes and HRQoL are very scarce and the magnitude of the effect of RP versus dose-escalated EBRT with ADT on HRQoL and functional outcomes remains largely unknown.

Radiation therapy compared to radical prostatectomy as first-line definitive therapy for patients with high-risk localised prostate cancer: An updated systematic review and meta-analysis

Objective

To present an update of the available literature on external beam radiation therapy (EBRT) with or without brachytherapy (BT) compared to radical prostatectomy (RP) for patients with high-risk localised prostate cancer (PCa).

Methods

We conducted a systematic review and meta-analysis of the literature assessing the survival outcomes in patients with high-risk PCa who received EBRT with or without BT compared to RP as the first-line therapy with curative intent. We queried PubMed and Web of Science database in January 2021. Moreover, we used random or fixed-effects meta-analytical models in the presence or absence of heterogeneity per the I² statistic, respectively. We performed six meta-analyses for overall survival (OS) and cancer-specific survival (CSS).

Results

A total of 27 studies were selected with 23 studies being eligible for both OS and CSS. EBRT alone had a significantly worse OS and CSS compared to RP (hazard ratio [HR] 1.38, 95% confidence interval [CI] 1.16–1.65; and HR 1.55, 95% CI 1.25–1.93). However, there was no difference in OS (HR 1.1, 95% CI 0.76–1.34) and CSS (HR 0.69, 95% CI 0.45–1.06) between EBRT plus BT compared to RP.

Conclusion

While cancer control affected by EBRT alone seems inferior to RP in patients with high-risk PCa, BT additive to EBRT was not different from RP. These data support the need for BT in addition to EBRT as part of multimodal RT for high-risk PCa.

Abbreviations: ADT: androgen-deprivation therapy; BT: brachytherapy; CSS: cancer-specific survival; HR: hazard ratio; MFS, metastatic-free survival; MOOSE: Meta-analyses of Observational Studies in Epidemiology; OR: odds ratio; OS: overall survival; PCa: prostate cancer; RR: relative risk; RP: radical prostatectomy; RCT: randomised controlled trials; (EB)RT: (external beam) radiation therapy

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.

The role of radical prostatectomy and definitive external beam radiotherapy in combined treatment for high-risk prostate cancer: a systematic review and meta-analysis

The first-line treatment options for high-risk prostate cancer (PCa) are definitive external beam radiotherapy (EBRT) with or without androgen deprivation therapy (ADT) and radical prostatectomy (RP) with or without adjuvant therapies. However, few randomized trials have compared the survival outcomes of these two treatments. To systematically evaluate the survival outcomes of high-risk PCa patients treated with EBRT- or RP-based therapy, a comprehensive and up-to-date meta-analysis was performed. A systematic online search was conducted for randomized or observational studies that investigated biochemical relapse-free survival (bRFS), cancer-specific survival (CSS), and/or overall survival (OS), in relation to the use of RP or EBRT in patients with high-risk PCa. The summary hazard ratios (HRs) were estimated under the random effects models. We identified heterogeneity between studies using Q tests and measured it using I2 statistics. We evaluated publication bias using funnel plots and Egger's regression asymmetry tests. Seventeen studies (including one randomized controlled trial [RCT]) of low risk of bias were selected and up to 9504 patients were pooled. When comparing EBRT-based treatment with RP-based treatment, the pooled HRs for bRFS, CSS, and OS were 0.40 (95% confidence interval [CI]: 0.24-0.67), 1.36 (95% CI: 0.94-1.97), and 1.39 (95% CI: 1.18-1.62), respectively. Better OS for RP-based treatment and better bRFS for EBRT-based treatment have been identified, and there was no significant difference in CSS between the two treatments. RP-based treatment is recommended for high-risk PCa patients who value long-term survival, and EBRT-based treatment might be a promising alternative for elderly patients.

The efficacy and safety of radical prostatectomy and radiotherapy in high-risk prostate cancer: a systematic review and meta-analysis

Background

The optimal treatment for patients with high-risk prostate cancer (PCa) remains a debate and selection of patients to receive proper therapy is still an unsettled question. This systematic review was conducted to compare the effectiveness of prostatectomy (RP) and radiotherapy (RT) in patients with high-risk PCa and to select candidates for optimal treatment.

Methods

PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were searched for eligible studies. We extracted hazard ratios (HRs) and 95% confidence interval (CI) of all included studies. The primary outcomes were overall survival (OS) and cancer-specific survival (CSS); the secondary outcomes were biochemical recurrence-free survival (BRFS), metastasis-free survival (MFS) and clinical recurrence-free survival (CRFS). The meta-analysis was performed using Review Manager 5.3. Subgroup analyses were conducted according to Gleason score (GS), T stage and RT types. Quality of life (QoL) was compared with these two treatments.

Results

A total of 25 studies were included in this meta-analysis. Overall, RP showed more survival benefits than RT on CSS (P = 0.003) and OS (P = 0.002); while RT was associated with better BRFS (P = 0.002) and MFS (P = 0.004). Subgroup analyses showed RT was associated with similar or even better survival outcomes compared to RP in patients with high GS, high T stage or received external beam radiotherapy plus brachytherapy (EBRT + BT). As for QoL, RP was associated with poorer urinary and sexual function but better performance in the bowel domain.

Conclusion

RP could prolong the survival time of patients with high-risk PCa; however, RT could delay the disease progression, and combined RT (EBRT + BT) even brought preferable CSS and similar OS compared to RP. RT might be the prior choice for patients with high T stage or high GS. RP could lead to poorer urinary and sexual function, while bringing better performance in the bowel domain.

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.