Erectile function preservation after salvage radiation therapy for biochemically recurrent prostate cancer after prostatectomy: Five-year results of the SAKK 09/10 randomized phase 3 trial

Objectives

To evaluate effects of dose intensified salvage radiotherapy (sRT) on erectile function in biochemically recurrent prostate cancer (PC) after radical prostatectomy (RP).

Materials and methods

Eligible patients had evidence of biochemical failure after RP and a PSA at randomization of ≤ 2 ng/ml. Erectile dysfunction (ED) was investigated as secondary endpoint within the multicentre randomized trial (February 2011 to April 2014) in patients receiving either 64 Gy or 70 Gy sRT. ED and quality of life (QoL) were assessed using CTCAE v4.0 and the EORTC QoL questionnaires C30 and PR25 at baseline and up to 5 years after sRT.

Results

344 patients were evaluable. After RP 197 (57.3 %) patients had G0-2 ED while G3 ED was recorded in 147 (42.7 %) patients. Subsequently, sexual activity and functioning was impaired. 5 years after sRT, 101 (29.4 %) patients noted G0-2 ED. During follow-up, 44.2 % of patients with baseline G3 ED showed any improvement and 61.4 % of patients with baseline G0-2 ED showed worsening. Shorter time interval between RP and start of sRT (p = 0.007) and older age at randomization (p = 0.005) were significant predictors to more baseline ED and low sexual activity in the long-term. Age (p = 0.010) and RT technique (p = 0.031) had a significant impact on occurrence of long-term ED grade 3 and worse sexual functioning. During follow-up, no differences were found in erectile function, sexual activity, and sexual functioning between the 64 Gy and 70 Gy arm.

Conclusion

ED after RP is a known long-term side effect with significant impact on patients' QoL. ED was further affected by sRT, but dose intensification of sRT showed no significant impact on erectile function recovery or prevalence of de novo ED after sRT. Age, tumor stage, prostatectomy and RT-techniques, nerve-sparing and observation time were associated with long-term erectile function outcome.ClinicalTrials.gov. Identifier: NCT01272050.

Genomic Determinants Associated with Modes of Progression and Patterns of Failure in Metachronous Oligometastatic Castration-sensitive Prostate Cancer

BACKGROUND AND OBJECTIVE

Oligometastatic castration-sensitive prostate cancer (omCSPC) represents an early state in the progression of metastatic disease for which patients experience better outcomes in comparison to those with higher disease burden. Despite the generally more indolent nature, there is still much heterogeneity, with some patients experiencing a more aggressive clinical course unexplained by clinical features alone. Our aim was to investigate correlation of tumor genomics with the mode of progression (MOP) and pattern of failure (POF) following first treatment (metastasis-directed and/or systemic therapy) for omCSPC.

METHODS

We performed an international multi-institutional retrospective study of men treated for metachronous omCSPC who underwent tumor next-generation sequencing with at least 1 yr of follow-up after their first treatment. Descriptive MOP and POF results are reported with respect to the presence of genomic alterations in pathways of interest. MOP was defined as class I, long-term control (LTC; no radiographic progression at last follow-up), class II, oligoprogression (1-3 lesions), or class III, polyprogression (≥4 lesions). POF included the location of lesions at first failure. Genomic pathways of interest included TP53, ATM, RB1, BRCA1/2, SPOP, and WNT (APC, CTNNB1, RNF43). Genomic associations with MOP/POF were compared using χ2 tests. Exploratory analyses revealed that the COSMIC mutational signature and differential gene expression were also correlated with MOP/POF. Overall survival (OS) was calculated via the Kaplan-Meier method from the time of first failure.

KEY FINDINGS AND CLINICAL IMPLICATIONS

We included 267 patients in our analysis; the majority had either one (47%) or two (30%) metastatic lesions at oligometastasis. The 3-yr OS rate was significantly associated with MOP (71% for polyprogression vs 91% for oligoprogression; p = 0.005). TP53 mutation was associated with a significantly lower LTC rate (27.6% vs 42.3%; p = 0.04) and RB1 mutation was associated with a high rate of polyprogression (50% vs 19.9%; p = 0.022). Regarding POF, bone failure was significantly more common with tumors harboring TP53 mutations (44.8% vs25.9%; p = 0.005) and less common with SPOP mutations (7.1% vs 31.4%; p = 0.007). Visceral failure was more common with tumors harboring either WNT pathway mutations (17.2% vs 6.8%, p = 0.05) or SPOP mutations (17.9% vs 6.3%; p = 0.04). Finally, visceral and bone failures were associated with distinct gene-expression profiles.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Tumor genomics provides novel insight into MOP and POF following treatment for metachronous omCSPC. Patients with TP53 and RB1 mutations have a higher likelihood of progression, and TP53, SPOP, and WNT pathway mutations may have a role in metastatic organotropism.

PATIENT SUMMARY

We evaluated cancer progression after a first treatment for metastatic prostate cancer with up to five metastases. We found that mutations in certain genes were associated with the location and extent of further metastasis in these patients.

PEACE V-Salvage Treatment of OligoRecurrent nodal prostate cancer Metastases (STORM): Acute Toxicity of a Randomized Phase 2 Trial

BACKGROUND

Treatment recommendations for patients with limited nodal recurrences are lacking, and different locoregional treatment approaches are currently being used.

OBJECTIVE

The aim of this trial is to compare metastasis-directed therapy (MDT) with or without elective nodal pelvic radiotherapy (ENRT).

DESIGN, SETTING, AND PARTICIPANTS

PEACE V-Salvage Treatment of OligoRecurrent nodal prostate cancer Metastases (STORM) is an international, phase 2, open-label, randomized, superiority trial (ClinicalTrials.gov identifier: NCT03569241). Patients diagnosed with positron emission tomography-detected pelvic nodal oligorecurrence (five or fewer nodes) following radical local treatment for prostate cancer were randomized in a 1:1 ratio between arm A (MDT and 6 mo of androgen deprivation therapy [ADT]) and arm B (ENRT [25 × 1.8 Gy] with MDT and 6 mo of ADT).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We report the secondary endpoint acute toxicity, defined as worst grade ≥2 Common Terminology Criteria for Adverse Events v4.0 gastrointestinal (GI) or genitourinary (GU) toxicity within 3 mo of treatment. The chi-square test was used to compare toxicity between treatment arms. We also compare the quality of life (QoL) using the European Organisation for Research and Treatment of Cancer QLQ C30 and PR25 questionnaires.

RESULTS AND LIMITATIONS

Between June 2018 and April 2021, 196 patients were assigned randomly to MDT or ENRT. Ninety-seven of 99 patients allocated to MDT and 93 of 97 allocated to ENRT received per-protocol treatment. Worst acute GI toxicity proportions were as follows: grade ≥2 events in three (3%) in the MDT group versus four (4%) in the ENRT group (p = 0.11). Worst acute GU toxicity proportions were as follows: grade ≥2 events in eight (8%) in the MDT group versus 12 (13%) in the ENRT group (p = 0.95). We observed no significant difference between the study groups in the proportion of patients with a clinically significant QoL reduction from baseline for any subdomain score area.

CONCLUSIONS

No clinically meaningful differences were observed in worst grade ≥2 acute GI or GU toxicity or in QoL subdomains between MDT and ENRT.

PATIENT SUMMARY

We found no evidence of differential acute bowel or urinary side effects using metastasis-directed therapy and elective nodal radiotherapy for the treatment of patients with a pelvic lymph node recurrence.

Cancer-specific dose and fractionation schedules in stereotactic body radiotherapy for oligometastatic disease: An interim analysis of the EORTC-ESTRO E2-RADIatE OligoCare study

BACKGROUND AND INTRODUCTION

Optimal dose and fractionation in stereotactic body radiotherapy (SBRT) for oligometastatic cancer patients remain unknown. In this interim analysis of OligoCare, we analyzed factors associated with SBRT dose and fractionation.

MATERIALS AND METHODS

Analysis was based on the first 1,099 registered patients. SBRT doses were converted to biological effective doses (BED) using α/β of 10 Gy for all primaries, and cancer-specific α/β of 10 Gy for non-small cell lung and colorectal cancer (NSCLC, CRC), 2.5 Gy for breast cancer (BC), or 1.5 Gy for prostate cancer (PC).

RESULTS

Of the interim analysis population of 1,099 patients, 999 (99.5 %) fulfilled inclusion criteria and received metastasis-directed SBRT for NSCLC (n = 195; 19.5 %), BC (n = 163; 16.3 %), CRC (n = 184; 18.4 %), or PC (n = 457; 47.5 %). Two thirds of patients were treated for single metastasis. Median number of fractions was 5 (IQR, 3-5) and median dose per fraction was 9.7 (IQR, 7.7-12.4) Gy. The most frequently treated sites were non-vertebral bone (22.8 %), lung (21.0 %), and distant lymph node metastases (19.0 %). On multivariate analysis, the dose varied significantly for primary cancer type (BC: 237.3 Gy BED, PC 300.6 Gy BED, and CRC 84.3 Gy BED), and metastatic sites, with higher doses for lung and liver lesions.

CONCLUSION

This real-world analysis suggests that SBRT doses are adjusted to the primary cancers and oligometastasis location. Future analysis will address safety and efficacy of this site- and disease-adapted SBRT fractionation approach (NCT03818503).

Delphi consensus on stereotactic ablative radiotherapy for oligometastatic and oligoprogressive renal cell carcinoma-a European Society for Radiotherapy and Oncology study endorsed by the European Association of Urology

The purpose of this European Society for Radiotherapy and Oncology (ESTRO) project, endorsed by the European Association of Urology, is to explore expert opinion on the management of patients with oligometastatic and oligoprogressive renal cell carcinoma by means of stereotactic ablative radiotherapy (SABR) on extracranial metastases, with the aim of developing consensus recommendations for patient selection, treatment doses, and concurrent systemic therapy. A questionnaire on SABR in oligometastatic renal cell carcinoma was prepared by a core group and reviewed by a panel of ten prominent experts in the field. The Delphi consensus methodology was applied, sending three rounds of questionnaires to clinicians identified as key opinion leaders in the field. At the end of the third round, participants were able to find consensus on eight of the 37 questions. Specifically, panellists agreed to apply no restrictions regarding age (25 [100%) of 25) and primary renal cell carcinoma histology (23 [92%] of 25) for SABR candidates, on the upper threshold of three lesions to offer ablative treatment in patients with oligoprogression, and on the concomitant administration of immune checkpoint inhibitor. SABR was indicated as the treatment modality of choice for renal cell carcinoma bone oligometatasis (20 [80%] of 25) and for adrenal oligometastases 22 (88%). No consensus or major agreement was reached regarding the appropriate schedule, but the majority of the poll (54%-58%) retained the every-other-day schedule as the optimal choice for all the investigated sites. The current ESTRO Delphi consensus might provide useful direction for the application of SABR in oligometastatic renal cell carcinoma and highlight the key areas of ongoing debate, perhaps directing future research efforts to close knowledge gaps.

Multi-institutional Analysis of Metastasis-directed Therapy with or Without Androgen Deprivation Therapy in Oligometastatic Castration-sensitive Prostate Cancer

BACKGROUND

Metastasis-directed therapy (MDT) is increasingly being used in oligometastatic castration-sensitive prostate cancer (omCSPC). However, it is currently unclear how to optimally integrate MDT with the standard of care of systemic hormonal therapy.

OBJECTIVE

To report long-term outcomes of MDT alone versus MDT and a defined course of androgen deprivation therapy (ADT) in omCSPC.

DESIGN, SETTING, AND PARTICIPANTS

Here, a multicenter, international retrospective cohort of omCSPC as defined by conventional imaging was reported.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Biochemical progression-free survival (bPFS), distant progression-free survival (dPFS), and combined biochemical or distant progression-free survival (cPFS) were evaluated with Kaplan-Meier and multivariable Cox proportional hazard regression models.

RESULTS AND LIMITATIONS

A total of 263 patients were included, 105 with MDT + ADT and 158 with MDT alone. The majority of patients had metachronous disease (90.5%). Five-year bPFS, dPFS, and cPFS were, respectively, 24%, 41%, and 19% in patients treated with MDT + ADT and 11% (hazard ratio [HR] 0.48, 95% confidence interval [CI] 0.36-0.64), 29% (HR 0.56, 95% CI 0.40-0.78), and 9% (HR 0.50, 95% CI 0.38-0.67) in patients treated with MDT alone. On a multivariable analysis adjusting for pretreatment variables, the use of ADT was associated with improved bPFS (HR 0.43, p < 0.001), dPFS (HR 0.45, p = 0.002), and cPFS (HR 0.44, p < 0.001).

CONCLUSIONS

In this large multi-institutional report, the addition of concurrent ADT to MDT appears to improve time to prostate-specific antigen progression and distant recurrence, noting that about 10% patients had durable control with MDT alone. Ongoing phase 3 studies will help further define treatment options for omCSPC.

PATIENT SUMMARY

Here, we report a large retrospective review evaluating the outcomes of metastasis-directed therapy with or without a limited course of androgen deprivation for patients with oligometastatic castration-sensitive prostate cancer. This international multi-institutional review demonstrates that the addition of androgen deprivation therapy to metastasis-directed therapy (MDT) improves progression-free survival. While a proportion of patients appear to have long-term disease control with MDT alone, further work in biomarker discovery is required to better identify which patients would be appropriate for de-escalated therapy.

Moderate hypofractionated radiotherapy for prostate cancer: 3-year toxicity results of a multicentre randomized phase 3, non-inferiority trial

BACKGROUND AND PURPOSE

Moderate hypofractionated radiotherapy (HFRT) is a standard treatment for prostate cancer patients. We compared 2 moderate HFRT regimens, with a biologically equivalent dose of 80 Gy in 2 Gy fractions, with a modest simultaneous integrated boost to the dominant intraprostatic lesion.

MATERIAL AND METHODS

This is a multicenter, non-inferiority, randomized phase 3 trial with acute toxicity as the primary endpoint, comparing: 56 Gy in 4 weeks (16x3.5 Gy, 4 days/week, Arm A) with 67 Gy in 5 weeks (25x2.68 Gy, 5 days/week, Arm B). The H0 hypothesis is that both regimens are equivalent in terms of acute grade ≥ 2 gastro-intestinal toxicity, defined as a difference in acute grade ≥ 2 gastro-intestinal toxicity of ≤ 10 %. Here we report on acute and late toxicity.

RESULTS

We included 170 patients in Arm A and 172 patients in Arm B. The median follow-up time for all patients was 42 months. Acute grade ≥ 2 gastrointestinal toxicity was reported by 24 % of patients in both groups. Acute grade 2 and 3 urinary toxicity was observed in 52 % and 9 % of patients in Arm A and 53 % and 7 % in Arm B. Late grade 2 and grade ≥ 3 gastrointestinal toxicity occurred in 19 % and 4 % of patients in Arm A compared with 15 % and 4 % in Arm B. Late grade 2 and grade ≥ 3 urinary toxicity was observed in 37 % and 10 % of patients in Arm A and 36 % and 6 % in Arm B.

CONCLUSION

This analysis confirms that both HFRT regimens are safe and equivalent in terms of acute grade ≥ 2 gastrointestinal toxicity.

Long-Term Results of a Phase 1 Dose Escalation Trial of Ablative Stereotactic Body Radiation Therapy

PURPOSE

Stereotactic body radiation therapy is increasingly used for oligometastatic disease as well as palliation, but treatment protocols for nonspine bone and nodal metastases are lacking, with a wide variety of schedules applied.

METHODS AND MATERIALS

A prospective dose-escalation trial was initiated, involving 90 patients, among whom 52 (58%) had primary prostate tumors, 13 had breast tumors (14%), and 25 (28%) had other primary tumor types. All visible lymph node or nonspine bone oligometastases were treated in 3 consecutive cohorts: 5 × 7.0 Gy, 3 × 10.0 Gy, or 1 × 20.0 Gy.

RESULTS

Initial results revealed no dose-limiting toxicity after a median follow-up of 17.2 months. This update provides information on long-term toxicity, local failure (LF), and progression-free survival (PFS). After a median follow-up of 50 months, no new safety signals were observed. Grade 2 toxicity was 13%, 7% and 10% in the respective cohorts (P = .9), without grade 3 to 5 toxicities. LF rates were 9%, 3%, and 6% (P = .5) for the respective treatment groups, with an overall cumulative risk of LF of 7% (95% CI, 2-12) at 4 years. Median PFS was 16.5 months (95% CI, 9.8-21.5), and 4-year PFS was 21% (95% CI, 14-32). Median overall survival across groups was not reached (95% CI, 52.8 - not reached), 4-year OS was 68% (95% CI, 59-78). A subset of patients (23%) remained long-term disease-free, 37% had oligoprogressive disease at first recurrence and 40% developed polymetastatic relapse.

CONCLUSIONS

The safe and effective use of dose-escalated single-fraction stereotactic body radiation therapy for bone and lymph node metastases is supported by this trial, especially considering patient-convenience and cost-effectiveness. Caution is needed when generalizing these outcomes beyond breast and prostate cancer, given their underrepresentation in our study.

Health-related quality of life in men with oligometastatic prostate cancer following metastases-directed stereotactic body radiotherapy: Real-world data from the E2-RADIatE OligoCare cohort

Objective

To evaluate the impact of metastases-directed stereotactic body radiotherapy (SBRT) on health-related quality of life (HRQoL) in men with oligometastatic prostate cancer (PCa) using real-world data from the OligoCare cohort.

Materials and methods

OligoCare is a pragmatic, observational cohort designed to assess the impact of metastases-directed SBRT on patients with oligometastatic disease (OMD). We report an interim analyses of the secondary endpoint HRQoL, assessed using the EORTC QLQ-C30, within six months of metastases-directed SBRT for oligometastatic disease in men with PCa among the first 1600 registered patients. HRQoL data collection was optional within the OligoCare cohort. To compare HRQoL between baseline and first follow-up assessment, a Wilcoxon signed-rank test was used. A multiple linear regression model was used to explore the HRQoL associations with predefined factors.

Results

Out of the 1600 registered patients, 658 were treated for oligometastatic PCa, of which 233 had baseline QoL data and 132 patients had both baseline and follow-up HRQoL data. At baseline, most patients had a WHO performance status of 0 or 1 (87 %), were de-novo oligometastatic (79 %), had one metastasis (90 %), and had a good overall global health status (mean 80.81, SD16.11, IQR 75-92). 51 % received hormonal therapy as concomitant systemic treatment. Patients with comorbidities as assessed by the Charlson Comorbidity index had a worse global health status at baseline (-4.88, 95 % CI:-9.35, -0.42). No clinically meaningful significant difference in global health status was observed at first assessment following SBRT (median 3.0 months) compared with baseline (mean difference 2.27, 95 % CI:-1.54, 6.08). Upon evaluating the proportions, meaningful clinically important differences (a 10-point or more difference) was observed in, 17 % and 11 % of the patients reporting deterioration and improvement of global health status, respectively.

Conclusion

Metastases-directed stereotactic body radiotherapy had no negative impact on global HRQoL within the first six months after treatment.

Stereotactic Body and Conventional Radiotherapy for Painful Bone Metastases: A Systematic Review and Meta-Analysis

Importance

Conventional external beam radiotherapy (cEBRT) and stereotactic body radiotherapy (SBRT) are commonly used treatment options for relieving metastatic bone pain. The effectiveness of SBRT compared with cEBRT in pain relief has been a subject of debate, and conflicting results have been reported.

Objective

To compare the effectiveness associated with SBRT vs cEBRT for relieving metastatic bone pain.

Data Sources

A structured search was performed in the PubMed, Embase, and Cochrane databases on June 5, 2023. Additionally, results were added from a new randomized clinical trial (RCT) and additional unpublished data from an already published RCT.

Study Selection

Comparative studies reporting pain response after SBRT vs cEBRT in patients with painful bone metastases.

Data Extraction and Synthesis

Two independent reviewers extracted data from eligible studies. Data were extracted for the intention-to-treat (ITT) and per-protocol (PP) populations. The study is reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

Main Outcomes and Measures

Overall and complete pain response at 1, 3, and 6 months after radiotherapy, according to the study's definition. Relative risk ratios (RRs) with 95% CIs were calculated for each study. A random-effects model using a restricted maximum likelihood estimator was applied for meta-analysis.

Results

There were 18 studies with 1685 patients included in the systematic review and 8 RCTs with 1090 patients were included in the meta-analysis. In 7 RCTs, overall pain response was defined according to the International Consensus on Palliative Radiotherapy Endpoints in clinical trials (ICPRE). The complete pain response was reported in 6 RCTs, all defined according to the ICPRE. The ITT meta-analyses showed that the overall pain response rates did not differ between cEBRT and SBRT at 1 (RR, 1.14; 95% CI, 0.99-1.30), 3 (RR, 1.19; 95% CI, 0.96-1.47), or 6 (RR, 1.22; 95% CI, 0.96-1.54) months. However, SBRT was associated with a higher complete pain response at 1 (RR, 1.43; 95% CI, 1.02-2.01), 3 (RR, 1.80; 95% CI, 1.16-2.78), and 6 (RR, 2.47; 95% CI, 1.24-4.91) months after radiotherapy. The PP meta-analyses showed comparable results.

Conclusions and Relevance

In this systematic review and meta-analysis, patients with painful bone metastases experienced similar overall pain response after SBRT compared with cEBRT. More patients had complete pain alleviation after SBRT, suggesting that selected subgroups will benefit from SBRT.

The Efficacy and Safety of Metastasis-directed Therapy in Patients with Prostate Cancer: A Systematic Review and Meta-analysis of Prospective Studies

CONTEXT

Despite the lack of level 1 evidence, metastasis-directed therapy (MDT) is used widely in the management of metastatic prostate cancer (mPCa) patients. Data are continuously emerging from well-designed prospective studies.

OBJECTIVE

To summarise and report the evidence on oncological and safety outcomes of MDT in the management of mPCa patients.

EVIDENCE ACQUISITION

We searched the PubMed, Scopus, and Web of Science databases for prospective studies assessing progression-free survival (PFS), local control (LC), androgen deprivation therapy (ADT)-free survival (ADT-FS), overall survival (OS), and/or adverse events (AEs) in mPCa patients treated with MDT. A meta-analysis was performed for 1- and 2-yr PFS, LC, ADT-FS, OS, and rate of AEs. Meta-regression and sensitivity analysis were performed to account for heterogeneity and identify moderators.

EVIDENCE SYNTHESIS

We identified 22 prospective studies (n = 1137), including two randomised controlled trials (n = 116). Two studies were excluded from the meta-analysis (n = 120). The estimated 2-yr PFS was 46% (95% confidence interval [CI]: 36-56%) or 42% (95% CI: 33-52%) after excluding studies using biochemical or ADT-related endpoints. The estimated 2-yr LC, ADT-FS, and OS were 97% (95% CI: 94-98%), 55% (95% CI: 44-65%), and 97% (95% CI: 95-98%), respectively. Rates of treatment-related grade 2 and ≥3 AEs were 2.4% (95% CI: 0.2-7%) and 0.3% (95% CI: 0-1%), respectively.

CONCLUSIONS

MDT is a promising treatment strategy associated with favourable PFS, excellent LC, and a low toxicity profile that allows oligorecurrent hormone-sensitive patients to avoid or defer ADT-related toxicity. Integration of MDT with other therapies offers a promising research direction, in particular, in conjunction with systemic treatments and as a component of definitive care for oligometastatic PCa. However, in the absence of randomised trials, using MDT for treatment intensification remains an experimental approach, and the impact on OS is uncertain.

PATIENT SUMMARY

Direct treatment of metastases is a promising option for selected prostate cancer patients. It can delay hormone therapy and is being investigated as a way of intensifying treatment at the expense of manageable toxicity.

Docetaxel Provides Oncological Benefits in the Era of New-Generation Androgen Receptor Inhibitors - or Is Three a Crowd?

In recent years, several systemic therapies have been introduced for metastatic hormone-sensitive prostate cancer, including androgen deprivation therapy (ADT) combined with docetaxel (Doc) and/or new-generation androgen receptor signaling inhibitors (ARSI). Trials evaluating ADT + ARSI have consistently demonstrated an overall survival (OS) benefit for doublet therapy over ADT alone. Similarly, the STOPCaP meta-analysis showed an OS benefit in favor of ADT + Doc versus ADT alone. ARSI, Doc, and ADT have different antitumor mechanisms, thus potentiating the effect of combination therapy. Two randomized trials showed that the addition of ARSI to ADT + Doc improves OS, especially for synchronous high-volume disease. However, the real question about triplet therapy remains unanswered: whether combining Doc with ARSI improves outcomes compared to ADT + ARSI. As there are no head-to-head comparisons, this narrative review aims to summarize the current evidence regarding triplet therapy versus doublet therapy including ADT+ ARSI.

Incidence and radiotherapy treatment patterns of complicated bone metastases

Background

Despite the encouraging results of the SCORAD trial, single fraction radiotherapy (SFRT) remains underused for patients with complicated bone metastases with rates as low as 18-39%. We aimed to evaluate the incidence and treatment patterns of these metastases in patients being referred to a tertiary centre for palliative radiotherapy.

Materials and methods

We performed a retrospective review of all bone metastases treated at our centre from January 2013 until December 2017. Lesions were classified as uncomplicated or complicated. Complicated was defined as associated with (impending) fracture, existing spinal cord or cauda equina compression. Our protocol suggests using SFRT for all patients with complicated bone metastases, except for those with symptomatic neuraxial compression and a life expectancy of ≥28 weeks.

Results

Overall, 37 % of all bone metastases were classified as complicated. Most often as a result of an (impending) fracture (56 %) or spinal cord compression (44 %). In 93 % of cases, complicated lesions were located in the spine, most commonly originating from prostate, breast and lung cancer (60 %). Median survival of patients with complicated bone metastases was 4 months. The use of SFRT for complicated bone metastases increased from 51 % to 85 % over the study period, reaching 100 % for patients with the poorest prognosis.

Conclusions

Approximately 37 % of bone metastases are classified as complicated with the majority related to (impending) fracture. Patients with complicated bone metastases have a median survival of 4 months and were mostly treated with SFRT.

A Phase 2 Randomized Open-label Study of Oral Darolutamide Monotherapy Versus Androgen Deprivation Therapy in Men with Hormone-sensitive Prostate Cancer (EORTC-GUCG 1532)

BACKGROUND AND OBJECTIVE

Darolutamide is an androgen receptor inhibitor that increases overall survival in combination with androgen deprivation therapy (ADT) in patients with metastatic hormone-sensitive and nonmetastatic castration-resistant prostate cancer (PCa). This phase 2 study assessed the efficacy and safety of darolutamide as monotherapy without ADT in patients with eugonadal testosterone levels.

METHODS

This was a 24-wk, open-label, randomized study of patients with hormone-sensitive, histologically confirmed PCa requiring gonadotropin-releasing hormone (GnRH); an Eastern Cooperative Oncology Group performance status score of 0/1; and life expectancy >1 yr. All patients received darolutamide 600 mg bid or a commercially available GnRH analog. The primary endpoint is a prostate-specific antigen (PSA) response, defined as a ≥80% decline at week 24 relative to baseline in the darolutamide study arm. The GnRH arm is used as an internal control. The secondary endpoints included changes in T levels, safety/tolerability, and quality of life.

KEY FINDINGS AND LIMITATIONS

Among 61 men enrolled, the median (range) age was 72 yr (53-86 yr); 42.6% of them had metastases. In the darolutamide arm, the evaluable population with available PSA values at baseline and week 24 consisted of 23 patients. Twenty-three (100%) evaluable darolutamide patients achieved a PSA decline of >80% at week 24 (primary endpoint), with a median (range) decrease of -99.1% (-91.9%, -100%). Serum T levels increased by a median (range) of 44.3 (5.7-144.0) at week 24, compared with baseline. In the darolutamide arm, 48.4% of men reported drug-related adverse events (AEs; mostly grade 1 or 2). The most frequent treatment-emergent AEs included gynecomastia (35.5%), fatigue (12.9%), hot flush (12.9%), and hypertension (12.9%). Health-related quality of life measures are descriptive, and GnRH arm results will be presented as an internal reference.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Darolutamide monotherapy was associated with a significant PSA response in nearly all men with hormone-naïve PCa. Testosterone-level changes and most common AEs (gynecomastia, fatigue, hypertension, and hot flush) were consistent with potent androgen receptor inhibition.

PATIENT SUMMARY

In this study, we report the first use of darolutamide, a novel antiandrogen, as monotherapy without androgen deprivation therapy (ADT). The study shows that darolutamide induce a profound suppression of prostate-specific antigen in all patients, with a safety profile different from that of ADT.

Multiregion sampling of de novo metastatic prostate cancer reveals complex polyclonality and augments clinical genotyping

De novo metastatic prostate cancer is highly aggressive, but the paucity of routinely collected tissue has hindered genomic stratification and precision oncology. Here, we leveraged a rare study of surgical intervention in 43 de novo metastatic prostate cancers to assess somatic genotypes across 607 synchronous primary and metastatic tissue regions plus circulating tumor DNA. Intra-prostate heterogeneity was pervasive and impacted clinically relevant genes, resulting in discordant genotypes between select primary restricted regions and synchronous metastases. Additional complexity was driven by polyclonal metastatic seeding from phylogenetically related primary populations. When simulating clinical practice relying on a single tissue region, genomic heterogeneity plus variable tumor fraction across samples caused inaccurate genotyping of dominant disease; however, pooling extracted DNA from multiple biopsy cores before sequencing can rescue misassigned somatic genotypes. Our results define the relationship between synchronous treatment-sensitive primary and metastatic lesions in men with de novo metastatic prostate cancer and provide a framework for implementing genomics-guided patient management.

TP53 structure-function relationships in metastatic castrate-sensitive prostate cancer and the impact of APR-246 treatment

PURPOSE

Despite well-informed work in several malignancies, the phenotypic effects of TP53 mutations in metastatic castration-sensitive prostate cancer (mCSPC) progression and metastasis are not clear. We characterized the structure-function and clinical impact of TP53 mutations in mCSPC.

PATIENTS AND METHODS

We performed an international retrospective review of men with mCSPC who underwent next-generation sequencing and were stratified according to TP53 mutational status and metastatic burden. Clinical outcomes included radiographic progression-free survival (rPFS) and overall survival (OS) evaluated with Kaplan-Meier and multivariable Cox regression. We also utilized isogenic cancer cell lines to assess the effect of TP53 mutations and APR-246 treatment on migration, invasion, colony formation in vitro, and tumor growth in vivo. Preclinical experimental observations were compared using t-tests and ANOVA.

RESULTS

Dominant-negative (DN) TP53 mutations were enriched in patients with synchronous (vs. metachronous) (20.7% vs. 6.3%, p < 0.01) and polymetastatic (vs. oligometastatic) (14.4% vs. 7.9%, p < 0.01) disease. On multivariable analysis, DN mutations were associated with worse rPFS (hazards ratio [HR] = 1.97, 95% confidence interval [CI]: 1.31-2.98) and overall survival [OS] (HR = 2.05, 95% CI: 1.14-3.68) compared to TP53 wild type (WT). In vitro, 22Rv1 TP53 R175H cells possessed stronger migration, invasion, colony formation ability, and cellular movement pathway enrichment in RNA sequencing analysis compared to 22Rv1 TP53 WT cells. Treatment with APR-246 reversed the effects of TP53 mutations in vitro and inhibited 22Rv1 TP53 R175H tumor growth in vivo in a dosage-dependent manner.

CONCLUSIONS

DN TP53 mutations correlated with worse prognosis in prostate cancer patients and higher metastatic potential, which could be counteracted by APR-246 treatment suggesting a potential future therapeutic avenue.

Microbiome and metabolome dynamics during radiotherapy for prostate cancer

BACKGROUND

Prostate cancer patients treated with radiotherapy are susceptible to acute gastrointestinal (GI) toxicity due to substantial overlap of the intestines with the radiation volume. Due to their intimate relationship with GI toxicity, faecal microbiome and metabolome dynamics during radiotherapy were investigated.

MATERIAL & METHODS

This prospective study included 50 prostate cancer patients treated with prostate (bed) only radiotherapy (PBRT) (n = 28) or whole pelvis radiotherapy (WPRT) (n = 22) (NCT04638049). Longitudinal sampling was performed prior to radiotherapy, after 10 fractions, near the end of radiotherapy and at follow-up. Patient symptoms were dichotomized into a single toxicity score. Microbiome and metabolome fingerprints were analyzed by 16S rRNA gene sequencing and ultra-high-performance liquid chromatography hybrid high-resolution mass spectrometry, respectively.

RESULTS

The individual α-diversity did not significantly change over time. Microbiota composition (β-diversity) changed significantly over treatment (PERMANOVA p-value = 0.03), but there was no significant difference in stability when comparing PBRT versus WPRT. Levels of various metabolites were significantly altered during radiotherapy. Baseline α-diversity was not associated with any toxicity outcome. Based on the metabolic fingerprint, no natural clustering according to toxicity profile could be achieved.

CONCLUSIONS

Radiation dose and treatment volume demonstrated limited effects on microbiome and metabolome fingerprints. In addition, no distinctive signature for toxicity status could be established. There is an ongoing need for toxicity risk stratification tools for diagnostic and therapeutic purposes, but the current evidence implies that the translation of metabolic and microbial biomarkers into routine clinical practice remains challenging.

Characterizing prostate cancer risk through multi-ancestry genome-wide discovery of 187 novel risk variants

The transferability and clinical value of genetic risk scores (GRSs) across populations remain limited due to an imbalance in genetic studies across ancestrally diverse populations. Here we conducted a multi-ancestry genome-wide association study of 156,319 prostate cancer cases and 788,443 controls of European, African, Asian and Hispanic men, reflecting a 57% increase in the number of non-European cases over previous prostate cancer genome-wide association studies. We identified 187 novel risk variants for prostate cancer, increasing the total number of risk variants to 451. An externally replicated multi-ancestry GRS was associated with risk that ranged from 1.8 (per standard deviation) in African ancestry men to 2.2 in European ancestry men. The GRS was associated with a greater risk of aggressive versus non-aggressive disease in men of African ancestry (P = 0.03). Our study presents novel prostate cancer susceptibility loci and a GRS with effective risk stratification across ancestry groups.

Clinical and Genomic Differences Between Advanced Molecular Imaging-detected and Conventional Imaging-detected Metachronous Oligometastatic Castration-sensitive Prostate Cancer

In metastatic castration-sensitive prostate cancer (mCSPC), disease volume plays an integral role in guiding treatment recommendations, including selection of docetaxel therapy, metastasis-directed therapy, and radiation to the prostate. Although there are multiple definitions of disease volume, they have commonly been studied in the context of metastases detected via conventional imaging (CIM). One such numeric definition of disease volume, termed oligometastasis, is heavily dependent on the sensitivity of the imaging modality. We performed an international multi-institutional retrospective review of men with metachronous oligometastatic CSPC (omCSPC), detected via either advanced molecular imaging alone (AMIM) or CIM. Patients were compared with respect to clinical and genomic features using the Mann-Whitney U test, Pearson's χ2 test, and Kaplan-Meier overall survival (OS) analyses with a log-rank test. A total of 295 patients were included for analysis. Patients with CIM-omCSPC had significantly higher Gleason grade group (p = 0.032), higher prostate-specific antigen at omCSPC diagnosis (8.0 vs 1.7 ng/ml; p < 0.001), more frequent pathogenic TP53 mutations (28% vs 17%; p = 0.030), and worse 10-yr OS (85% vs 100%; p < 0.001). This is the first report of clinical and biological differences between AMIM-detected and CIM-detected omCSPC. Our findings are particularly important for ongoing and planned clinical trials in omCSPC. PATIENT SUMMARY: Metastatic prostate cancer with just a few metastases only detected via newer scanning methods (called molecular imaging) is associated with fewer high-risk DNA mutations and better survival in comparison to metastatic cancer detected via conventional scan methods.

Elective Nodal Irradiation for Oligorecurrent Nodal Prostate Cancer: Interobserver Variability in the PEACE V-STORM Randomized Phase 2 Trial

Purpose

Consistency in delineation of pelvic lymph node regions for prostate cancer elective nodal radiation therapy is still challenging despite current guidelines. The aim of this study was to evaluate the interobserver variability in elective lymph node delineation in the PEACE V - STORM randomized phase 2 trial for oligorecurrent nodal prostate cancer.

Methods and Materials

Twenty-three centers were asked to delineate the elective pelvic nodal clinical target volume (CTV) of a postoperative oligorecurrent nodal prostate cancer benchmark case using a modified Radiation Therapy Oncology Group (RTOG) 2009 template (upper limit at the L4/L5 interspace). Overall, intersection and overflow volumes, Dice coefficient, Hausdorff distance, and count maps merged with computed tomography images were analyzed.

Results

The mean volume including the 23 nodal CTVs was 430.4 ± 64.1 cm3, larger than the modified RTOG 2009 CTV reference volume (386.1 cm3). The intersection common volume between the modified reference RTOG 2009 and the 23 nodal CTVs was estimated at 83.9%, whereas the overflow volume was 23.4%, mainly located at the level of the presacral and the upper limit of the L4/L5 interspace. The mean Dice coefficient was 0.79 ± 0.02, whereas the mean Hausdorff distance was 27 ± 4.4 mm.

Conclusions

In salvage radiation therapy treatment of oligorecurrent nodal prostate cancer, variations in elective lymph node volume delineation were mainly observed in the presacral and common iliac areas. Routine implementation and diffusion of available contouring guidelines together with a constant evaluation and evidence-based updating are expected to further decrease the existing variability in pelvic node contouring.

Stereotactic body radiation therapy after radical prostatectomy: current status and future directions

PURPOSE

Around 40% of men with intermediate-risk or high-risk prostate cancer will experience a biochemical recurrence after radical prostatectomy (RP). The aim of this review is to describe both toxicity and oncological outcomes following stereotactic body radiation therapy (SBRT) delivered to the prostate bed (PB).

METHOD

In april 2023, we performed a systematic review of studies published in MEDLINE or ClinicalTrials.gov according to Preferred Reporting Items for Systematic Reviews, using the keywords "stereotactic radiotherapy" AND "postoperative" AND "prostate cancer".

RESULTS

A total of 14 studies assessing either adjuvant or salvage SBRT to the whole PB or macroscopic local recurrence (MLR) within the PB, and SBRT on radiorecurrent MLR within the PB were included. Doses delivered to either whole PB or MLR between 30 to 40 Gy are associated with a low rate of late grade ≥ 2 genitourinary (GU) toxicity, ranging from 2.2 to 15.1%. Doses above 40 Gy are associated with increased rate of late GU toxicity, raising up to 38%. Oncological outcomes should be interpreted with caution, due to both short follow-up, heterogeneous populations and androgen deprivation therapy (ADT) use.

CONCLUSION

PB or MLR SBRT delivered at doses up to 40 Gy appears safe with relatively low late severe GU toxicity rates. Caution is needed with dose-escalated RT schedules above 40 Gy. Further prospective trials are eagerly awaited in this disease setting.

The Impact of TP53 Mutations and Use of the TP53-Mutation-Reactivating Agent APR-246 on Metastatic Castrate-Sensitive Prostate Cancer

PURPOSE/OBJECTIVE(S)

TP53 mutations appear to be enriched over the spectrum of metastatic castration-sensitive prostate cancer (mCSPC) and are associated with worse survival outcomes. We chose to further explore the impact of dominant negative (DN) TP53 mutations on mCSPC progression and pro-metastatic behaviors in addition to studying the ability of APR-246, a small molecule targeting TP53 mutants, to blunt pro-metastatic behaviors.

MATERIALS/METHODS

We retrospectively analyzed 531 mCSPC patients who underwent next-generation sequencing. Patients were stratified by metastasis timing (synchronous if metastasis present at diagnosis or metachronous if arising after definitive treatment of localized disease) and the number of metastatic lesions (oligometastatic ≤5 or polymetastatic >5 lesions). Tumors were classified based on TP53 mutation status (missense, truncating, or wild-type [WT]) and dominant negativity, which was defined as the production of a mutant protein that reduces the residual WT protein's transcriptional activity according to the World Health Organization TP53 database. Clinical outcomes were radiographic progression-free survival (rPFS) and overall survival (OS), evaluated with Kaplan-Meier and multivariable Cox regression. To verify the impact of TP53 mutation on metastasis, we created isogenic 22Rv1 prostate cancer cell lines that carried either TP53 WT or TP53 R175H and tested this mutation for migration, invasion, and anchorage-independent growth. APR-246 (25-80 µM) was tested for anti-metastatic properties in vitro and anti-tumor growth in 22Rv1 xenografted nude mice.

RESULTS

In our cohort, 155 (29.2%) had a TP53 mutation, which mostly occurred in the DNA-binding domain (85.16%). DN TP53 mutations were associated with more aggressive disease states: DN TP53 mutations were enriched in patients with synchronous (vs. metachronous: 20.7% vs. 6.3%, p < 0.01) and polymetastatic disease (vs. oligometastatic: 14.4% vs. 7.9%, p < 0.01). On multivariable analysis, DN TP53 mutations were correlated with shorter rPFS (HR = 1.97, 95% CI: 1.31-2.98, p < 0.01) and OS (HR = 2.05, 95% CI: 1.14-3.68, p = 0.02) compared to those with TP53 WT. In vitro, 22Rv1 cells with DN TP53 R175H mutation had increased abilities to migrate, invade, and form colonies compared to TP53 WT. APR-246 treatment of TP53 R175H mutants blunted the pro-metastatic effects of the cell line in vitro (p < 0.01 for all assays by unpaired t-test). Interestingly, APR-246 also inhibited xenograft tumor growth of 22Rv1 TP53 R175H mutants (p < 0.0001 by two-way ANOVA).

CONCLUSION

DN TP53 mutations were associated with poorer survival outcomes for mCSPC patients. DN TP53 mutations also promoted prostate cancer pro-metastatic behaviors in vitro, which was effectively counteracted by APR-246, making it a promising treatment option that should be explored further in early-phase clinical studies.

Definition and Diagnosis of Oligometastatic Bladder Cancer: A Delphi Consensus Study Endorsed by the European Association of Urology, European Society for Radiotherapy and Oncology, and European Society of Medical Oncology Genitourinary Faculty

BACKGROUND

In contrast to other cancers, the concept of oligometastatic disease (OMD) has not been investigated in bladder cancer (BC).

OBJECTIVE

To develop an acceptable definition, classification, and staging recommendations for oligometastatic BC (OMBC) spanning the issues of patient selection and the roles of systemic therapy and ablative local therapy.

DESIGN, SETTING, AND PARTICIPANTS

A European consensus group of 29 experts, led by the European Association of Urology (EAU), the European Society for Radiotherapy and Oncology (ESTRO), and the European Society of Medical Oncology (ESMO), and including members from all other relevant European societies, was established.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

A modified Delphi method was used. A systematic review was used to build consensus questions. Consensus statements were extracted from two consecutive surveys. The statements were formulated during two consensus meetings. Agreement levels were measured to determine if consensus was achieved (≥75% agreement).

RESULTS AND LIMITATIONS

The first survey included 14 questions and the second survey had 12. Owing to a considerable lack of evidence, which was the major limitation, definition was limited in the context of de novo OMBC, which was further classified as synchronous OMD, oligorecurrence, and oligoprogression. A maximum of three metastatic sites, all resectable or amenable to stereotactic therapy, was proposed as the definition of OMBC. Pelvic lymph nodes represented the only "organ" not included in the definition of OMBC. For staging, no consensus on the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography was reached. A favourable response to systemic treatment was proposed as the criterion for selection of patients for metastasis-directed therapy.

CONCLUSIONS

A consensus statement on the definition and staging of OMBC has been formulated. This statement will help to standardise inclusion criteria in future trials, potentiate research on aspects of OMBC for which consensus was not achieved, and hopefully will lead to the development of guidelines on optimal management of OMBC.

PATIENT SUMMARY

As an intermediate state between localised cancer and disease with extensive metastasis, oligometastatic bladder cancer (OMBC) might benefit from a combination of systemic treatment and local therapy. We report the first consensus statements on OMBC drawn up by an international expert group. These statements can provide a basis for standardisation of future research, which will lead to high-quality evidence in the field.