Adjuvant radiotherapy versus early salvage radiotherapy plus short-term androgen deprivation therapy in men with localised prostate cancer after radical prostatectomy (GETUG-AFU 17): a randomised, phase 3 trial

Delayed definitive management of localized prostate cancer: what do we know?

Delays in the work-up and definitive management of patients with prostate cancer are common, with logistics of additional work-up after initial prostate biopsy, specialist referrals, and psychological reasons being the most common causes of delays. During the COVID-19 pandemic and the subsequent surges, timing of definitive care delivery with surgery or radiotherapy has become a topic of significant concern for patients with prostate cancer and their providers alike. In response, recommendations for the timing of definitive management of prostate cancer with radiotherapy and radical prostatectomy were published but without a detailed rationale for these recommendations. While the COVID-19 pandemic is behind us, patients are always asking the question: "When should I start radiation or undergo surgery?" In the absence of level I evidence specifically addressing this question, we will hereby present a narrative review to summarize the available data on the effect of treatment delays on oncologic outcomes for patients with localized prostate cancer from prospective and retrospective studies.

Overview of Radiation Therapy in the Management of Localized and Metastatic Prostate Cancer

PURPOSE OF REVIEW

The goal is to describe the evolution of radiation therapy (RT) utilization in the management of localized and metastatic prostate cancer.

RECENT FINDINGS

Long term data for a variety of hypofractionated definitive RT dose-fractionation schemes has matured, allowing patients and providers many standard-of-care options to choose from. Post-prostatectomy, adjuvant RT has largely been replaced by an early salvage approach. Multiparametric MRI and PSMA PET have enabled increasingly targeted RT delivery to the prostate and oligometastatic tumors. Areas of active investigation include determining the value of proton beam therapy and perirectal spacers, and optimally incorporate genomic tumor profiling and next generation hormonal therapies with RT in the curative setting. The use of radiation therapy to treat prostate cancer is rapidly evolving. In the coming years, there will be continued improvements in a variety of areas to enhance the value of RT in multidisciplinary prostate cancer management.

EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer. Part II-2024 Update: Treatment of Relapsing and Metastatic Prostate Cancer

BACKGROUND AND OBJECTIVE

The European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy and Oncology (ESTRO)-European Society of Urogenital Radiology (ESUR)-International Society of Urological Pathology (ISUP)-International Society of Geriatric Oncology (SIOG) guidelines on the treatment of relapsing, metastatic, and castration-resistant prostate cancer (PCa) have been updated. Here we provide a summary of the 2024 guidelines.

METHODS

The panel performed a literature review of new data, covering the time frame between 2020 and 2023. The guidelines were updated and a strength rating for each recommendation was added on the basis of a systematic review of the evidence.

KEY FINDINGS AND LIMITATIONS

Risk stratification for relapsing PCa after primary therapy may guide salvage therapy decisions. New treatment options, such as androgen receptor-targeted agents (ARTAs), ARTA + chemotherapy combinations, PARP inhibitors and their combinations, and prostate-specific membrane antigen-based therapy have become available for men with metastatic PCa.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Evidence for relapsing, metastatic, and castration-resistant PCa is evolving rapidly. These guidelines reflect the multidisciplinary nature of PCa management. The full version is available online (http://uroweb.org/guideline/ prostate-cancer/).

PATIENT SUMMARY

This article summarises the 2024 guidelines for the treatment of relapsing, metastatic, and castration-resistant prostate cancer. These guidelines are based on evidence and guide doctors in discussing treatment decisions with their patients. The guidelines are updated every year.

Pragmatic clinical trials for localized prostate cancer: lessons learned and "three sins"

In "Explanatory and Pragmatic Attitudes in Therapeutic Trials", Schwatrz and Lelouch describe two approaches to the design of trials, "… the first "explanatory", the second "pragmatic". They explained "… the biologist may be interested to know whether the drugs differ in their effects … the explanatory approach". Biologically endpoints might determine whether it was better to give androgen deprivation therapy (ADT) before or after external beam radiation (EBRT) (i.e., does the sequence of treatments matter). Alternatively, if the arms focus on a clinical endpoint, this is considered … "the pragmatic approach". An example of a clinically relevant endpoint is overall survival (OS). A real-world example of this are the two randomized controlled trials (RCTs) evaluating the role of prophylactic whole pelvic radiotherapy (WPRT) conducted by the Radiation Therapy Oncology Group (RTOG). RTOG 9413 evaluated possible interactions between the sequence of drugs and volume irradiated, while RTOG/NRG 0924 focuses on OS. There appears to be a common pattern of "what not to do", or "design errors" made by a number of investigators, that I call the "three sins". I posit that the prospects for a well-designed pragmatic RCT are likely to be high if these "three sins" are avoided/minimized. The "three sins" alluded to are: 1. You can't prove something doesn't work by treating people who don't need the treatment. 2. You can't prove something does not work if the treatment is not done properly. 3. You can't prove something does not work with an underpowered study.

A randomised trial of short- vs long-term androgen deprivation with salvage radiotherapy for biochemical failure following radical prostatectomy: URONCOR 06-24

BACKGROUND

Salvage radiotherapy (SRT) and androgen-deprivation therapy (ADT) are widely used in routine clinical practice to treat patients with prostate cancer who develop biochemical recurrence (BCR) after radical prostatectomy (RP). However, there is no standard-of-care consensus on optimal duration ADT. Investigators propose three distinct risk groups in patients with prostate cancer treated with SRT in order to better define the indications and duration of ADT combined with SRT.

STUDY DESIGN

The URONCOR 06-24 trial (ClinicalTrials.gov identifier NCT05781217) is a prospective, multicentre, randomised, open-label, phase III, clinical trial. The aim of the trial is to determine the impact of short-term (6 months) vs long-term (24 months) ADT in combination with SRT on distant metastasis-free survival (MFS) in patients with prostate cancer with BCR after RP (intermediate and high risk).

ENDPOINTS

The primary endpoint is 5-year MFS rates in patients with prostate cancer treated with long- vs short-term ADT in combination with SRT. Secondary objectives are biochemical-relapse free interval, pelvic progression-free survival, time to start of systemic treatment, time to castration resistance, cancer-specific survival, overall survival, acute and late toxicity, and quality of life.

METHODS AND ANALYSIS

Total of 534 patients will be randomised 1:1 to ADT 6 months or ADT 24 months with a luteinizing hormone-releasing hormone analogue in combination with SRT, stratified by risk group and pathological lymph node status.

ETHICS AND DISSEMINATION

The study is conducted under the guiding principles of the World Medical Association Declaration of Helsinki. The results will be disseminated at research conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

EudraCT number 2021-006975-41.

Image-Guided Stereotactic Body Radiotherapy on Detectable Prostate Bed Recurrence after Prostatectomy in RT-Naïve Patients

Purpose or Objective-The aim of the study is to evaluate the efficacy and safety of SBRT on detectable prostate bed recurrence in RT-naïve prostate cancer patients.

MATERIALS AND METHODS

Eighty-six patients who underwent SBRT for macroscopic bed recurrence after prostatectomy were retrospectively included. Patients were treated based on mpMRI or choline/PSMA PET.

RESULTS

The median time to biochemical relapse (BCR) after RP was 46 months, with a median PSA at restaging of 1.04 ng/mL. Forty-six patients were staged with mpMRI and choline/PSMA PET, while ten and thirty were treated based on PET and MRI only, respectively. Only one late G ≥ 2 GI toxicity was observed. With a median BCR follow-up of 14 months, twenty-nine patients experienced a BCR with a median PSA at recurrence of 1.66 ng/mL and a median survival free from the event of 40.1 months. The median time to BCR was 17.9 months. Twenty-seven patients had clinical relapse (CR), with a median CR follow-up of 16.27 months and a median time to CR of 23.0 months. Biochemical recurrence-free survival at one and two years was 88% and 66%, respectively, while clinical recurrence-free survival at one and two years was 92% and 82%, respectively. Regarding local relapses, seven were in the field of treatment, while eight of them were outside the field of treatment.

CONCLUSIONS

Data showed that SBRT targeting only the macroscopic bed recurrence instead of the whole prostate bed is safe and effective. Additional data and longer follow-ups will provide a clearer indication of the appropriate treatment and staging methodology for these patients.

Prognosis based on postoperative PSA levels and treatment in prostate cancer with lymph node involvement

BACKGROUND

The therapeutic role of pelvic lymph node dissection (PLND) during radical prostatectomy (RP) for prostate cancer is not established. In clinical practice, PLND is primarily performed in cases of high-risk prostate cancer. The detection of lymph node metastasis plays a crucial role in determining the need for subsequent treatments. This study aims to evaluate the prognosis of prostate cancer patients with lymph node involvement (LNI) by stratifying them based on postoperative prostate-specific antigen (PSA) levels to identify biomarkers that can guide postoperative treatment strategies.

METHODS

Analysis was conducted on 383 patients, selected from 572 initially eligible, who underwent RP with LNI across 33 Japanese Urological Oncology Group institutions from 2006 to 2019. Patients were grouped according to postoperative PSA levels and salvage treatments received. Follow-up focused on castration resistance-free survival (CRFS), metastasis-free survival (MFS), and overall survival (OS).

RESULTS

In the persistent PSA group (PSA ≥ 0.1 ng/mL), CRFS and MFS were significantly shorter compared to the non-persistent PSA group (PSA < 0.1 ng/mL), and there was a tendency for shorter OS. In the persistent PSA group, patients with postoperative PSA values above the median (PSA ≥ 0.52 ng/mL) showed shorter CRFS and MFS. Furthermore, in the PSA ≥ 0.52 group, androgen deprivation therapy (ADT) plus radiotherapy (RT) combination had prolonged CRFS and MFS compared with ADT alone.

CONCLUSIONS

This study provides valuable insights into stratifying patients based on postoperative PSA levels to tailor postoperative treatment strategies, potentially improving the prognosis of prostate cancer patients with LNI.

Treatment and Staging Intensification Strategies Associated with Radical Prostatectomy for High-Risk Prostate Cancer: Efficacy Evaluation and Exploration of Novel Approaches

The management of high-risk prostate cancer (PCa) presents a significant clinical challenge, often necessitating treatment intensification due to the potential presence of micrometastases. While radical prostatectomy (RP) constitutes one of the primary treatment modalities, the integration of neoadjuvant and adjuvant therapies suggests a paradigm shift towards more aggressive treatment strategies, also guided by new imaging modalities like positron emission tomography using prostate-specific membrane antigen (PSMA-PET). Despite the benefits, treatment intensification raises concerns regarding increased side effects. This review synthesizes the latest evidence on perioperative treatment intensification and de-escalation for high-risk localized and locally advanced PCa patients eligible for surgery. Through a non-systematic literature review conducted via PubMed, Scopus, Web of Science, and ClinicalTrials.gov, we explored various dimensions of perioperative treatments, including neoadjuvant systemic therapies, adjuvant therapies, and the role of novel diagnostic technologies. Emerging evidence provides more support for neoadjuvant systemic therapies. Preliminary results from studies suggest the potential for treatments traditionally reserved for metastatic PCa to show apparent benefit in a non-metastatic setting. The role of adjuvant treatments remains debated, particularly the use of androgen deprivation therapy (ADT) and adjuvant radiotherapy in patients at higher risk of biochemical recurrence. The potential role of radio-guided PSMA lymph node dissection emerges as a cutting-edge approach, offering a targeted method for eradicating disease with greater precision. Innovations such as artificial intelligence and machine learning are potential game-changers, offering new avenues for personalized treatment and improved prognostication. The intensification of surgical treatment in high-risk PCa patients is a dynamic and evolving field, underscored by the integration of traditional and novel therapeutic approaches. As evidence continues to emerge, these strategies will refine patient selection, enhance treatment efficacy, and mitigate the risk of progression, although with an attentive consideration of the associated side effects.

PTEN Loss Is Associated with Adverse Outcomes in the Setting of Salvage Radiation Therapy

BACKGROUND

Salvage radiation therapy (SRT) is a mainstay of treatment for biochemical relapse following radical prostatectomy; however, few studies have examined genomic biomarkers in this context.

OBJECTIVE

We characterized the prognostic impact of previously identified deleterious molecular phenotypes-loss of PTEN, ERG expression, and TP53 mutation-for patients undergoing SRT.

DESIGN, SETTING, AND PARTICIPANTS

We leveraged an institutional database of 320 SRT patients with available tissue and follow-up. Tissue microarrays were used for genetically validated immunohistochemistry assays.

INTERVENTION

All men underwent SRT with or without androgen deprivation therapy OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Univariable and multivariable Cox-proportional hazard models assessed the association of molecular phenotypes with biochemical recurrence-free (bRFS) and metastasis-free (MFS) survival after SRT.

RESULTS AND LIMITATIONS

Loss of PTEN (n = 123, 43%) and ERG expression (n = 118, 39%) were common in this cohort, while p53 overexpression (signifying TP53 missense mutation) was infrequent (n = 21, 7%). In univariable analyses, any loss of PTEN portended worse bRFS (hazard ratio [HR] 1.86; 95% confidence interval 1.36-2.57) and MFS (HR 1.89; 1.21-2.94), with homogeneous PTEN loss being associated with the highest risk of MFS (HR 2.47; 1.54-3.95). Similarly, p53 overexpression predicted worse bRFS (HR 1.95; 1.14-3.32) and MFS (HR 2.79; 1.50-5.19). ERG expression was associated with worse MFS only (HR 1.6; 1.03-2.48). On the multivariable analysis adjusting for known prognostic features, homogeneous PTEN loss remained predictive of adverse bRFS (HR 1.82; 1.12-2.96) and MFS (HR 2.08; 1.06-4.86). The study is limited by its retrospective and single-institution design.

CONCLUSIONS

PTEN loss by immunohistochemistry is an independent adverse prognostic factor for bRFS and MFS in prostate cancer patients treated with SRT. Future trials will determine the optimal approach to treating SRT patients with adverse molecular prognostic features.

PATIENT SUMMARY

Loss of the PTEN tumor suppressor protein is associated with worse outcomes after salvage radiotherapy, independent of other clinical or pathologic patient characteristics.

Association of Genomic Prostate Score at positive margin with recurrence after radical prostatectomy

OBJECTIVES

To evaluate the utility of the 17-gene Genomic Prostate Score® (GPS; MDxHealth, Irvine, CA, USA) performed on prostate cancer at the positive margin of the radical prostatectomy (RP) for its association with risk of subsequent biochemical recurrence (BCR).

PATIENTS AND METHODS

We designed a case-cohort for the outcome of BCR, selecting 223 from a cohort of 813 RP patients treated at Johns Hopkins from 2008 to 2017 with positive margins and available clinical data; of these, 213 had available tissue and clinical data. RNA was isolated from formalin-fixed paraffin-embedded tumour tissue adjacent to the positive surgical margin and the GPS was evaluable in 203 of these patients with a score ranging from 0 to 100, with higher scores indicating higher risk. All patients underwent RP with or without adjuvant radiation therapy (ART). The statistical analysis employed Cox proportional hazards regression models for outcome of BCR weighted for case-cohort design.

RESULTS

In univariable analysis, every 20-unit increase in the GPS was associated with a nearly threefold increase in risk of BCR (hazard ratio [HR] per 20 units 2.82, P < 0.001). In a multivariable Cox model adjusted for age, race, Cancer of the Prostate Risk Assessment Postsurgical score, Grade Group at the positive margin, and ART, the GPS was significantly associated with BCR (HR 1.56 per 20 units; 95% confidence interval 1.11-2.19; P = 0.011). The study is limited by its retrospective and single institution design.

CONCLUSIONS

The GPS at the positive surgical margin could help stratify prognosis and inform clinical decision-making regarding adjuvant therapy after RP.

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.

Timing of radiotherapy (RT) after radical prostatectomy (RP): long-term outcomes in the RADICALS-RT trial (NCT00541047)

BACKGROUND

The optimal timing of radiotherapy (RT) after radical prostatectomy for prostate cancer has been uncertain. RADICALS-RT compared efficacy and safety of adjuvant RT versus an observation policy with salvage RT for prostate-specific antigen (PSA) failure.

PATIENTS AND METHODS

RADICALS-RT was a randomised controlled trial enrolling patients with ≥1 risk factor (pT3/4, Gleason 7-10, positive margins, preoperative PSA≥10 ng/ml) for recurrence after radical prostatectomy. Patients were randomised 1:1 to adjuvant RT ('Adjuvant-RT') or an observation policy with salvage RT for PSA failure ('Salvage-RT') defined as PSA≥0.1 ng/ml or three consecutive rises. Stratification factors were Gleason score, margin status, planned RT schedule (52.5 Gy/20 fractions or 66 Gy/33 fractions) and treatment centre. The primary outcome measure was freedom-from-distant-metastasis (FFDM), designed with 80% power to detect an improvement from 90% with Salvage-RT (control) to 95% at 10 years with Adjuvant-RT. Secondary outcome measures were biochemical progression-free survival, freedom from non-protocol hormone therapy, safety and patient-reported outcomes. Standard survival analysis methods were used; hazard ratio (HR)<1 favours Adjuvant-RT.

RESULTS

Between October 2007 and December 2016, 1396 participants from UK, Denmark, Canada and Ireland were randomised: 699 Salvage-RT, 697 Adjuvant-RT. Allocated groups were balanced with a median age of 65 years. Ninety-three percent (649/697) Adjuvant-RT reported RT within 6 months after randomisation; 39% (270/699) Salvage-RT reported RT during follow-up. Median follow-up was 7.8 years. With 80 distant metastasis events, 10-year FFDM was 93% for Adjuvant-RT and 90% for Salvage-RT: HR=0.68 [95% confidence interval (CI) 0.43-1.07, P=0.095]. Of 109 deaths, 17 were due to prostate cancer. Overall survival was not improved (HR=0.980, 95% CI 0.667-1.440, P=0.917). Adjuvant-RT reported worse urinary and faecal incontinence 1 year after randomisation (P=0.001); faecal incontinence remained significant after 10 years (P=0.017).

CONCLUSION

Long-term results from RADICALS-RT confirm adjuvant RT after radical prostatectomy increases the risk of urinary and bowel morbidity, but does not meaningfully improve disease control. An observation policy with salvage RT for PSA failure should be the current standard after radical prostatectomy.

TRIAL IDENTIFICATION

RADICALS, RADICALS-RT, ISRCTN40814031, NCT00541047.

Moderate hypofractionated radiotherapy to the prostate bed with or without pelvic lymph nodes: a prospective trial

Background

Hypofractionated radiotherapy in the treatment of prostate cancer has been widely studied. However, in the postoperative setting it has been less explored. The objective of this prospective study is to evaluate the safety and efficacy of hypofractionated radiotherapy in postoperative prostate cancer.

Materials and methods

A prospective study was designed to include patients with prostate cancer with an indication of postoperative radiotherapy as adjuvant or salvage. A hypofractionated radiotherapy scheme of 51 Gy in 17 fractions was performed with the possibility of treating the pelvis at a dose of 36 Gy in 12 fractions sequentially. Safety was evaluated based on acute and late toxicity [according to the Radiation Therapy Oncology Group (RTOG) scale and Common Terminology Criteria Adverse Events (CTCAE) v4.03], International Prognostic Scoring System (IPSS) over time, and quality of life.

Results

From August 2020 to June 2022, 31 patients completed treatment and were included in this report. 35.5% of patients received elective treatment of the pelvic nodal areas. Most patients reported minimal or low acute toxicity, with an acute gastrointestinal (GI) and genitourinary (GU) grade 3 or greater toxicity of 3.2% and 0%, respectively. The evolution in time of the IPSS remained without significant differences (p = 0.42). With the exception of a significant improvement in the domains of hormonal and sexual symptoms of the Expanded Prostate Cancer Index Composite (EPIC) questionnaire, the rest of the domains [EPIC, European Organization for Research and Treatment of Cancer (EORTC) Core quality of life questionnaire (C-30) and Prostate Cancer module (PR-25)] were maintained without significant differences over time. With a follow-up of 15.4 months, late GI and GU grade 2 toxicity was reported greater than 0% and 9.6%, respectively.

Conclusions

Hypofractionated radiotherapy in postoperative prostate cancer appears to be safe with low reports of relevant acute or late toxicity. Further follow-up is required to confirm these results.

Trial registration

The protocol was approved by the accredited Medical Ethical Committee of Pontificia Universidad Católica de Chile. All participants accepted and wrote informed consent.

Impact of 68Ga-PSMA PET/CT on radiation treatment planning of prostate cancer patients

AIM

This study aimed to assess the impact of 68Ga-PSMA PET/CT on radiation treatment (RT) planning in prostate cancer patients with salvage (sRT) or definitive (dRT) radiotherapy.

METHODS

38 patients (27 sRT, median PSA 0.79 ng/ml (range 0.06-12.1); 11 dRT, median PSA 4.35 ng/ml (range 1.55-55.5) underwent 68Ga-PSMA PET/CT before RT. Influence of 68Ga-PSMA PET/CT on the extent of planning target volume (PTV) and addition of PET-based boosts were assessed. Median follow up was 12 months (range 3-24).

RESULTS

68Ga-PSMA PET/CT showed positive findings in 23/38 patients (8/23: local recurrence (LR), 11/23: nodal metastasis, 1/23: LR and nodal, 2/23: solitary bone metastasis, 1/23: oligometastatic nodal/ bone metastases). In sRT primary PTV was changed in 16/27 patients extending the PTV to the lymphatic drainage (10/16), PSMA-positive LR (3/16), bone metastases (2/16) and both nodal/bone metastases (1/16). PET-based increase of primary PTV was 116%. PET-based boosts were administered in 19/27 patients (8/19: local, 10/19: nodal, 1/19: both), median boost volume was 31.3 cm3 (range 17.2-80.2) (local) and 19.7 cm3 (range 3.0-109.3) (nodal). PTV was changed in 1/11 (9%) of dRT patients (extension of primary PTV to the lymphatic drainage (RT volume of 644.5 cm3), additional nodal boost (volume of 2.7 cm3, 23.1 Gy)). All patients showed biochemical response (mean PSA decrease 88.8 +/- 14.0%). Nadir PSA was reached 10 months (range 1-17) after end of RT (median 0.07 ng/ml, range 0.002-3.96). Within a median 12 months follow-up (range 3-22/8-24 in sRT/dRT), median PSA was 0.05 ng/ml (range 0.002-8.5) (sRT) and 0.26 ng/ml (range 0.02-2.68) (dRT).

CONCLUSIONS

68Ga-PSMA PET/CT influenced sRT planning in almost 63% and dRT in 9% of patients by change of PTV and additional boosts.

Association between preradiation therapy prostate-specific antigen levels and radiation therapy failure after prostatectomy: a propensity score matched analysis

Purpose

We sought to determine the association between the pre-radiation therapy prostate-specific antigen (pre-RT PSA) 0.5 and RT failure in post-radical prostatectomy (post-RP) patients. Our study also investigated the prognostic factors for the failure of RT given concurrently with hormone therapy (HT) after RP.

Materials and methods

We retrospectively reviewed our institutional RP data from July 2004 to November 2021. Patients without concurrent hormone therapy were excluded. Propensity score matching was performed. Kaplan-Meier (KM) curve analysis was employed for RT failure-free survival, overall survival (OS), and cancer-specific survival (CSS). Cox regression analysis was used for the RT failure hazard ratio (HR).

Results

After propensity score matching, 193 patients were assigned to the pre-RT PSA ≥0.5 (high-P) arm, and 193 patients were assigned to the pre-RT PSA <0.5 (low-P) arm. There were no significant differences between the two arms after propensity score matching in terms of baseline characteristics and pathologic outcomes. High-P was associated with RT failure-free survival (P = 0.004), OS (P = 0.046), and CSS (P = 0.027). In a multi-variable Cox proportional hazards regression analysis, seminal vesicle invasion, lymph node invasion, the absence of prostatic intraepithelial neoplasia (PIN), and high-P were identified as significant risk factors for RT failure.

Conclusion

High-P was significantly unfavorable with RT failure-free survival, OS, and CSS in patients who underwent RT after radical prostatectomy with concurrent HT. Seminal vesicle invasion, lymph node invasion, and the absence of PIN were identified as significant prognostic factors for RT failure.

Biochemical recurrence in patients with prostate cancer after primary definitive therapy: treatment based on risk stratification

BACKGROUND

Nearly one-third of patients with prostate cancer (PCa) experience biochemical recurrence (BCR) after primary definitive treatment. BCR increases the risk of distant metastasis and mortality in patients with prognostically unfavorable features. These patients are best managed with a tailored treatment strategy incorporating risk stratification using clinicopathological factors, next-generation imaging, and genomic testing.

OBJECTIVE

This narrative review examines the utility of risk stratification for the management of patients with BCR in the context of clinical trial data, referencing the latest recommendations by European and US medical societies.

METHODS

PubMed was searched for relevant studies published through May 21 2023 on treatment of patients with BCR after radical prostatectomy (RP) or external beam radiotherapy (EBRT).

RESULTS

European and US guidelines support the risk-stratified management of BCR. Post-RP, salvage EBRT (with or without androgen deprivation therapy [ADT]) is an accepted treatment option for patients with BCR. Post-EBRT, local salvage therapies (RP, cryotherapy, high-intensity focused ultrasound, stereotactic body radiotherapy, and low-dose-rate and high-dose-rate brachytherapy) have demonstrated comparable relapse-free survival rates but differing adverse event profiles, short and long term. Local salvage therapies should be used for local-only relapses while ADT should be considered for regional or distant relapses. In practice, patients often receive ADT, with varying guidance for intermittent ADT vs. continuous ADT, due to consideration of quality-of-life effects.

CONCLUSIONS

Despite a lack of consensus for BCR treatment among guideline associations and medical societies, risk stratification of patients is essential for personalized treatment approaches, as it allows for an informed selection of therapeutic strategies and estimation of adverse events. In lower-risk disease, observation is recommended while in higher-risk disease, after failed repeat local therapy, ADT and/or clinical trial enrollment may be appropriate. Results from ongoing clinical studies of patients with BCR should provide consensus for management.

Risk Stratification of Patients with Recurrence After Primary Treatment for Prostate Cancer: A Systematic Review

BACKGROUND AND OBJECTIVE

Biochemical recurrence (BCR) after primary definitive treatment for prostate cancer (PCa) is a heterogeneous disease state. While BCR is associated with worse oncologic outcomes, risk factors that impact outcomes can vary significantly, necessitating avenues for risk stratification. We sought to identify prognostic risk factors at the time of recurrence after primary radical prostatectomy or radiotherapy, and prior to salvage treatment(s), associated with adverse oncologic outcomes.

METHODS

We performed a systematic review of prospective studies in EMBASE, MEDLINE, and ClinicalTrials.gov (from January 1, 2000 to October 16, 2023) according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines (CRD42023466330). We reviewed the factors associated with oncologic outcomes among patients with BCR after primary definitive treatment.

KEY FINDINGS AND LIMITATIONS

A total of 37 studies were included (total n = 10 632), 25 after prostatectomy (total n = 9010) and 12 after radiotherapy (total n = 1622). Following recurrence after prostatectomy, factors associated with adverse outcomes include higher pathologic T stage and grade group, negative surgical margins, shorter prostate-specific antigen doubling time (PSADT), higher prostate-specific antigen (PSA) prior to salvage treatment, shorter time to recurrence, the 22-gene tumor RNA signature, and recurrence location on molecular imaging. After recurrence following radiotherapy, factors associated with adverse outcomes include a shorter time to recurrence, and shorter PSADT or higher PSA velocity. Grade group, T stage, and prior short-term hormone therapy (4-6 mo) were not clearly associated with adverse outcomes, although sample size and follow-up were generally limited compared with postprostatectomy data.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This work highlights the recommendations and level of evidence for risk stratifying patients with PCa recurrence, and can be used as a benchmark for personalizing salvage treatment based on prognostics.

PATIENT SUMMARY

We summarize the data from previously reported clinical trials on the topic of which factors predict worse cancer outcomes for patients who recur with prostate cancer after their initial treatment.

Biochemical Response of <0.1 ng/ml Predicts Therapy-free Survival of Prostate Cancer Patients following Prostate-specific Membrane Antigen-targeted Salvage Surgery

BACKGROUND

In a subset of patients with oligorecurrent prostate cancer (PCa), salvage surgery with prostate-specific membrane antigen (PSMA) radioguided surgery (PSMA-RGS) seems to be of value.

OBJECTIVE

To evaluate whether a lower level of postoperative prostate-specific antigen (PSA; <0.1 ng/ml) is predictive of therapy-free survival (TFS) following salvage PSMA-RGS.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study evaluated patients with biochemical recurrence after radical prostatectomy and oligorecurrent PCa on PSMA positron emission tomography treated with PSMA-RGS in three tertiary care centers (2014-2022).

INTERVENTION

PSMA-RGS.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Postsalvage surgery PSA response was categorized as <0.1, 0.1-<0.2, or >0.2 ng/ml. Kaplan-Meier and multivariable Cox regression models evaluated TFS according to PSA response.

RESULTS AND LIMITATIONS

Among 553 patients assessed, 522 (94%) had metastatic soft tissue lesions removed during PSMA-RGS. At 2-16 wk after PSMA-RGS, 192, 62, and 190 patients achieved PSA levels of <0.1, 0.1-<0.2, and >0.2 ng/ml, respectively. At 2 yr of follow-up, TFS rate was 81.1% versus 56.1% versus 43.1% (p < 0.001) for patients with PSA <0.1 versus 0.1-<0.2 versus >0.2 ng/ml. In multivariable analyses, PSA levels of 0.1-0.2 ng/ml (hazard ratio [HR]: 1.9, confidence interval [CI]: 1.1-3.1) and ≥0.2 ng/ml (HR: 3.2, CI: 2.2-4.6, p < 0.001) independently predicted the need for additional therapy after PSMA-RGS. The main limitation is the lack of a control group.

CONCLUSIONS

For patients after salvage PSMA-RGS, a lower biochemical response (PSA <0.1 ng/ml) seems to predict longer TFS. This insight may help in counseling patients postoperatively as well as guiding the timely selection of additional therapy.

PATIENT SUMMARY

We studied what happened to prostate cancer patients in three European centers who had salvage surgery using a special method called prostate-specific membrane antigen-targeted radioguidance. We found that patients who had low prostate-specific antigen levels soon after surgery were less likely to need further treatment for a longer time.

A simple risk stratification model for prostate cancer using histopathologic findings of radical prostatectomy

OBJECTIVES

To develop a simple postoperative risk stratification based on histopathologic findings from radical prostatectomy specimens.

METHODS

This study included 3 cohorts of patients with a preoperative diagnosis of clinically localized prostate cancer: 1 derivation cohort (n = 432) and 2 validation cohorts (n = 506 and n = 720). First, a postoperative risk stratification model was developed in the derivation cohort using the factors extraprostatic extension, surgical margin status, seminal vesicle invasion, and lymph node involvement. Each of the first 3 factors was assigned 0 or 1 point for negative or positive results, respectively, and the sum of the points, ranging from 0 to 3, was scored. pN1 was not scored but was analyzed separately. Validation cohorts were then used to evaluate the predictive accuracy of the model. Additionally, we compared the model with the Cancer of the Prostate Risk Assessment (CAPRA) score.

RESULTS

Because the log-rank test showed no statistically significant differences between scores 1 vs 2 or score 3 vs pN1 in the derivation cohort, the following 3-level risk stratification was created: low risk (score 0), intermediate risk (score 1-2), and high risk (score 3 or pN1). There were statistically significant differences in recurrence-free survival between any of 2 groups of 3-level risk stratification. This model similarly worked in both validation cohorts. The C indexes for the model were higher than those for the CAPRA score.

CONCLUSIONS

This simple postoperative risk stratification model, based on radical prostatectomy findings, has a prognostic impact that has been validated in a multicenter population.

Differences in the expression of the phosphatase PTP-1B in patients with localized prostate cancer with and without adverse pathological features

Introduction

Patients with adverse pathological features (APF) at radical prostatectomy (RP) for prostate cancer (PC) are candidates for adjuvant treatment. Clinicians lack reliable markers to predict these APF preoperatively. Protein tyrosine phosphatase 1B (PTP-1B) is involved in migration and invasion of PC, and its expression could predict presence of APF. Our aim was to compare PTP-1B expression in patients with and without APF, and to explore PTP-1B expression as an independent prognostic factor.

Methods

Tissue microarrays (TMAs) were constructed using RP archival specimens for immunohistochemical staining of PTP-1B; expression was reported with a standardized score (0-9). We compared median PTP-1B score between cases with and without APF. We constructed two logistic regression models, one to identify the independence of PTP-1B score from biologically associated variables (metformin use and type 2 diabetes mellitus [T2DM]) and the second to seek independence of known risk factors (Gleason score and prostate specific antigen [PSA]).

Results

A total of 73 specimens were suitable for TMA construction. Forty-four (60%) patients had APF. The median PTP-1B score was higher in those with APF: 8 (5-9) vs 5 (3-8) (p=0.026). In the logistic regression model including T2DM and metformin use, the PTP-1B score maintained statistical significance (OR 1.21, 95% CI 1.01-1.45, p=0.037). In the model including PSA and Gleason score; the PTP-1B score showed no independence (OR 1.68, 95% CI 0.97-1.41, p=0.11). The area under the curve to predict APF for the PTP-1B score was 0.65 (95% CI 0.52-0.78, p=0.03), for PSA+Gleason 0.71 (95% CI 0.59-0.82, p=0.03), and for PSA+Gleason+PTP-1B score 0.73 (95% CI 0.61-0.84, p=0.001).

Discussion

Patients with APF after RP have a higher expression of PTP-1B than those without APF, even after adjusting for T2DM and metformin exposure. PTP-1B has a good accuracy for predicting APF but does not add to known prognostic factors.

Pelvic Irradiation for Node-Positive Prostate Cancer After Prostatectomy: Long-Term Results of the Prospective PLATIN-4 and PLATIN-5 Trials

PURPOSE

After radical prostatectomy (RP), adjuvant or salvage radiation treatment in node-positive prostate cancer is offered to prevent systemic disease. Prospective long-term survival and toxicity data on patients with radiation for nodal disease are still scarce. This study evaluates safety and feasibility of salvage radiation therapy to the pelvic lymph nodes in node-positive prostate cancer after RP.

METHODS AND MATERIALS

Between 2009 and 2018, 78 patients with lymph node recurrence after RP (PLATIN-4 trial) or after RP and prostate bed radiation therapy (PLATIN-5 trial) were treated with salvage pelvic lymph node radiation therapy with boost to the involved nodes as field abutment (PLATIN-5) and boost to the prostate bed (PLATIN-4). Androgen deprivation therapy was started 2 months before radiation and recommended for 24 months. The primary endpoint was safety and feasibility of the intensity modulated radiation therapy-image guided radiation therapy technique based on the rate of treatment discontinuations and incidence of Common Terminology Criteria for Adverse Events grade 3+ toxicity. Secondary endpoints were progression-free survival and overall survival.

RESULTS

No treatment discontinuations were reported in either trial. Median overall survival was not reached in PLATIN-4 and was 117 months in PLATIN-5. Median progression-free survival was 66 months in PLATIN-4 and 39 months in PLATIN-5. Late grade 3+ genitourinary and gastrointestinal toxicities were observed in 4% of patients at 24 months of follow-up.

CONCLUSIONS

Salvage radiation therapy to the prostate bed and pelvic lymphatic drainage combined with long-term androgen deprivation therapy is a curative treatment option for patients with node-positive prostate cancer after RP, with excellent in-field disease control. Pelvic lymph node radiation therapy as field abutment after prostate bed radiation therapy is feasible with long-term survival and no high-grade toxicity.

Development and Internal Validation of a Novel Nomogram Predicting the Outcome of Salvage Radiation Therapy for Biochemical Recurrence after Radical Prostatectomy in Patients without Metastases on Restaging Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography

Background and objective

Owing to the greater use of prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) in patients with biochemical recurrence (BCR) of prostate cancer (PCa) after robot-assisted radical prostatectomy (RARP), patient selection for local salvage radiation therapy (sRT) has changed. Our objective was to determine the short-term efficacy of sRT in patients with BCR after RARP, and to develop a novel nomogram predicting BCR-free survival after sRT in a nationwide contemporary cohort of patients who underwent PSMA PET/CT before sRT for BCR of PCa, without evidence of metastatic disease.

Methods

All 302 eligible patients undergoing PCa sRT in four reference centers between September 2015 and August 2020 were included. We conducted multivariable logistic regression analysis using a backward elimination procedure to develop a nomogram for predicting biochemical progression of PCa, defined as prostate-specific antigen (PSA) ≥0.2 ng/ml above the post-sRT nadir within 1 yr after sRT.

Key findings and limitations

Biochemical progression of disease within 1 yr after sRT was observed for 56/302 (19%) of the study patients. The final predictive model included PSA at sRT initiation, pathological grade group, surgical margin status, PSA doubling time, presence of local recurrence on PSMA PET/CT, and the presence of biochemical persistence (first PSA result ≥0.1 ng/ml) after RARP. The area under the receiver operating characteristic curve for this model was 0.72 (95% confidence interval 0.64-0.79). Using our nomogram, patients with a predicted risk of >20% had a 30.8% chance of developing biochemical progression within 1 yr after sRT.

Conclusions

Our novel nomogram may facilitate better patient counseling regarding early oncological outcome after sRT. Patients with high risk of biochemical progression may be candidates for more extensive treatment.

Patient summary

We developed a new tool for predicting cancer control outcomes of radiotherapy for patients with recurrence of prostate cancer after surgical removal of their prostate. This tool may help in better counseling of these patients with recurrent cancer regarding their early expected outcome after radiotherapy.

Adjuvant and salvage radiotherapy after neoadjuvant therapy and radical prostatectomy for high-risk localized prostate cancer

BACKGROUND

We sought to describe patterns of delivery of adjuvant (aRT) and salvage RT (sRT) in patients who underwent RP after receiving neoadjuvant androgen receptor pathway inhibitor (ARPI) before radical prostatectomy (RP) for high-risk localized prostate cancer (HRLPC).

METHODS

Two hundred eighteen patients treated on phase 2 neoadjuvant trials between 2006 and 2018 at two academic centers were evaluated. aRT and sRT were defined as receipt of RT with a PSA of ≤0.1 or >0.1 ng/mL, respectively. Primary outcomes were biochemical recurrence (BCR), defined as time from aRT/sRT to a PSA rising to >0.1 ng/mL, and metastasis-free survival (MFS) after RT.

RESULTS

Twenty-three (11%) and 55 (25%) patients received aRT and sRT respectively. Median PSA at start of aRT and sRT was 0.01 and 0.16 ng/mL, and median duration from RP to RT was 5 and 14 months, respectively. All aRT patients had NCCN high-risk disease, 30% were pN1 and 43% had positive surgical margins; 52% had prostate bed RT. Fifty-one percent of sRT patients had biopsy Gleason 9-10, 29% were pT2 and 9% had positive surgical margins; 63% had RT to the prostate bed/pelvis. At a median follow-up of 5.3 and 3.0 years after aRT and sRT, 3-year freedom from BCR was 55% and 47%, and 3-year MFS was 56% and 53%, respectively.

CONCLUSIONS

aRT was infrequently used in patients who received neoadjuvant ARPI before RP for HRLPC. Outcomes of aRT and sRT were similar but generally poor. Studies evaluating intensified systemic therapy approaches with postoperative RT in this high-risk population are needed.

Immediate radiotherapy versus observation in patients with node-positive prostate cancer after radical prostatectomy

BACKGROUND

The optimal management of node-positive (pN1) prostate cancer following radical prostatectomy (RP) remains uncertain. Despite randomized evidence, utilization of immediate, life-long androgen deprivation therapy (ADT) remains poor, and recent trials of early salvage radiotherapy included only a minority of pN1 patients. We therefore emulated a hypothetical pragmatic trial of adjuvant radiotherapy versus observation in men with pN1 prostate cancer.

METHODS

Using the RADICALS-RT trial to inform the design of a hypothetical trial, we identified men aged 50-69 years with pT2-3 Rany pN1 M0, pre-treatment PSA < 50 ng/mL prostate cancer in the NCDB from 2006 to 2015 treated with 60-72 Gy of adjuvant RT (aRT) ± ADT within 26 weeks of RP or observation. After estimating a propensity score for receipt of aRT, we estimated absolute and relative treatment effects using stabilized inverse probability of treatment (sIPW) re-weighting.

RESULTS

In total, 3510 patients were included in the study, of whom 587 (17%) received aRT (73% with concurrent ADT). Median follow-up was 40.0 -months, during which 333 deaths occurred. After sIPW re-weighting, baseline characteristics were well-balanced. Adjusted overall survival (OS) was 93% versus 89% at 5-years and 82% versus 79% at 7-years for aRT versus observation (p = 0.11). In IPW-reweighted Cox regression, aRT was associated with a lower risk of all-cause mortality (ACM) than observation, but this did not reach statistical significance (HR 0.70 p = 0.06). In analyses examining heterogeneity of treatment effects, aRT was associated with improved ACM only for men with Gleason 8-10 disease (HR 0.59, p = 0.01), ≥2 positive LNs (HR 0.49, p = 0.04 for 2 positive LNs; HR 0.42, p = 0.01 for ≥3 positive LNs), or negative surgical margins (HR 0.50, p = 0.02).

CONCLUSIONS

In observational analyses designed to emulate a hypothetical target trial of aRT versus observation in pN1 prostate cancer, aRT was associated with improved OS only for men with Gleason 8-10 disease, ≥2 positive LNs, or negative surgical margins.

Updates on Management of Biochemical Recurrent Prostate Cancer

OPINION STATEMENT

Patients with biochemical recurrent prostate cancer (BCR) are a heterogeneous group, whereby a personalized approach to management is critical. Patients with high-risk features such as PSA doubling time (PSADT) ≤ 9-12 months warrant earlier imaging for metastasis detection and consideration for intensified therapy (beyond intermittent androgen deprivation alone) during this phase of BCR-only disease. The BCR phase represents a unique opportunity to impact disease survival and delay metastasis progression. There is compelling evidence from the EMBARK trial that ADT monotherapy is no longer the optimal consideration for high-risk BCR patients.

Why Do Men Reject Adjuvant Radiotherapy following Radical Prostatectomy? A Systematic Survey

INTRODUCTION

The aim of this study was to investigate non-adherence rates to adjuvant radiotherapy (aRT) after radical prostatectomy (RP) and to obtain patient reported reasons for rejecting aRT despite recommendation by a multidisciplinary team discussion (MTD).

METHODS

In a retrospective monocentric analysis, we identified 1,197 prostate cancer patients who underwent RP between 2014 and 2022 at our institution, of which 735 received a postoperative MTD recommendation. Patients with a recommendation for aRT underwent a structured phone interview with predefined standardised qualitative and quantitative questions and were stratified into "adherent" (aRT performed) and "non-adherent" groups (aRT not performed).

RESULTS

Of 55 patients receiving a recommendation for aRT (7.5% of all RP patients), 24 (44%) were non-adherent. Baseline tumour characteristics were comparable among the groups. "Fear of radiation damage" was the most common reason for rejection, followed by "lack of information," "feeling that the treating physician does not support the recommendation" and "the impression that aRT is not associated with improved oncological outcome." Salvage radiotherapy was performed in 25% of non-adherent patients.

CONCLUSION

High rates of non-adherence to aRT after RP were observed, and reasons for this phenomenon are most likely multifactorial. Multidisciplinary and individualized patient counselling might be a key for increasing adherence rates.

The Impact of Positron Emission Tomography Imaging and Tumor Molecular Profiling on Risk Stratification, Treatment Choice, and Oncological Outcomes of Patients with Primary or Relapsed Prostate Cancer: An International Collaborative Review of the Existing Literature

CONTEXT

The clinical introduction of next-generation imaging methods and molecular biomarkers ("radiogenomics") has revolutionized the field of prostate cancer (PCa). While the clinical validity of these tests has thoroughly been vetted, their clinical utility remains a matter of investigation.

OBJECTIVE

To systematically review the evidence to date on the impact of positron emission tomography (PET) imaging and tissue-based prognostic biomarkers, including Decipher, Prolaris, and Oncotype Dx, on the risk stratification, treatment choice, and oncological outcomes of men with newly diagnosed PCa or those with biochemical failure (BCF).

EVIDENCE ACQUISITION

We performed a quantitative systematic review of the literature using the MEDLINE, EMBASE, and Web of Science databases (2010-2022) following the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guidelines. The validated Quality Assessment of Diagnostic Accuracy Studies 2 scoring system was used to assess the risk of bias.

EVIDENCE SYNTHESIS

A total of 148 studies (130 on PET and 18 on biomarkers) were included. In the primary PCa setting, prostate-specific membrane antigen (PSMA) PET imaging was not useful in improving T staging, moderately useful in improving N staging, but consistently useful in improving M staging in patients with National Comprehensive Cancer Network (NCCN) unfavorable intermediate- to very-high-risk PCa. Its use led to a management change in 20-30% of patients. However, the effect of these treatment changes on survival outcomes was not clear. Similarly, biomarkers in the pretherapy primary PCa setting increased and decreased the risk, respectively, in 7-30% and 32-36% of NCCN low-risk and 31-65% and 4-15% of NCCN favorable intermediate-risk patients being considered for active surveillance. A change in management was noted in up to 65% of patients, with the change being in line with the molecular risk-based reclassification, but again, the impact of these changes on survival outcomes remained unclear. Notably, in the postsurgical primary PCa setting, biomarker-guided adjuvant radiation therapy (RT) was associated with improved oncological control: Δ↓ 2-yr BCF by 22% (level 2b). In the BCF setting, the data were more mature. PSMA PET was consistently useful in improving disease localization-Δ↑ detection for T, N, and M staging was 13-32%, 19-58%, and 9-29%, respectively. Between 29% and 73% of patients had a change in management. Most importantly, these management changes were associated with improved survival outcomes in three trials: Δ↑ 4-yr disease-free survival by 24.3%, Δ↑ 6-mo metastasis-free survival (MFS) by 46.7%, and Δ↑ androgen deprivation therapy-free survival by 8 mo in patients who received PET-concordant RT (level 1b-2b). Biomarker testing in these patients also appeared to be helpful in risk stratifying and guiding the use of early salvage RT (sRT) and concomitant hormonal therapy. Patients with high-genomic-risk scores benefitted from treatment intensification: Δ↑ 8-yr MFS by 20% with the use of early sRT and Δ↑ 12-yr MFS by 11.2% with the use of hormonal therapy alongside early sRT, while low-genomic-risk score patients did equally well with initial conservative management (level 3).

CONCLUSIONS

Both PSMA PET imaging and tumor molecular profiling provide actionable information in the management of men with primary PCa and those with BCF. Emerging data suggest that radiogenomics-guided treatments translate into direct survival benefits for patients, however, additional prospective data are awaited.

PATIENT SUMMARY

In this review, we evaluated the utility of prostate-specific membrane antigen positron emission tomography and tumor molecular profiling in guiding the care of men with prostate cancer (PCa). We found that these tests augmented risk stratification, altered management, and improved cancer control in men with a new diagnosis of PCa or for those experiencing a relapse.

HypoFocal SRT Trial: Ultra-hypofractionated focal salvage radiotherapy for isolated prostate bed recurrence after radical prostatectomy; single-arm phase II study; clinical trial protocol

INTRODUCTION

Despite radical prostatectomy (RP) and radiotherapy (RT) being established treatments for localised prostate cancer, a significant number of patients experience recurrent disease. While conventionally fractionated RT is still being used as a standard treatment in the postoperative setting, ultra-hypofractionated RT has emerged as a viable option with encouraging results in patients with localised disease in the primary setting. In addition, recent technological advancements in RT delivery and precise definition of isolated macroscopic recurrence within the prostate bed using prostate-specific membrane antigen-positron emission tomography (PSMA-PET) and multiparametric MRI (mpMRI) allow the exploration of ultra-hypofractionated schedules in the salvage setting using five fractions.

METHODS AND ANALYSIS

In this single-arm prospective phase II multicentre trial, 36 patients with node-negative prostate adenocarcinoma treated with RP at least 6 months before trial registration, tumour stage pT2a-3b, R0-1, pN0 or cN0 according to the UICC TNM 2009 and evidence of measurable local recurrence within the prostate bed detected by PSMA PET/CT and mpMRI within the last 3 months, will be included. The patients will undergo focal ultra-hypofractionated salvage RT with 34 Gy in five fractions every other day to the site of local recurrence in combination with 6 months of androgen deprivation therapy. The primary outcome of this study is biochemical relapse-free survival at 2 years. Secondary outcomes include acute side effects (until 90 days after the end of RT) of grade 3 or higher based on Common Terminology Criteria for Adverse Events V.5, progression-free survival, metastasis-free survival, late side effects and the quality of life (based on European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30, QLQ-PR25).

ETHICS AND DISSEMINATION

The study has received ethical approval from the Ethics Commission of the Canton of Bern (KEK-BE 2022-01026). Academic dissemination will occur through publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05746806.

Application of Advanced Imaging to Prostate Cancer Diagnosis and Management: A Narrative Review of Current Practice and Unanswered Questions

Major advances in prostate cancer diagnosis, staging, and management have occurred over the past decade, largely due to our improved understanding of the technical aspects and clinical applications of advanced imaging, specifically magnetic resonance imaging (MRI) and prostate-cancer-specific positron emission tomography (PET). Herein, we review the established utility of these important and exciting technologies, as well as areas of controversy and uncertainty that remain important areas for future study. There is strong evidence supporting the utility of MRI in guiding initial biopsy and assessing local disease. There is debate, however, regarding how to best use the imaging modality in risk stratification, treatment planning, and assessment of biochemical failure. Prostate-cancer-specific PET is a relatively new technology that provides great value to the evaluation of newly diagnosed, treated, and recurrent prostate cancer. However, its ideal use in treatment decision making, staging, recurrence detection, and surveillance necessitates further research. Continued study of both imaging modalities will allow for an improved understanding of their best utilization in improving cancer care.

Surgical Management and Considerations for Patients with Localized High-Risk Prostate Cancer

OPINION STATEMENT

Localized high-risk (HR) prostate cancer (PCa) is a heterogenous disease state with a wide range of presentations and outcomes. Historically, non-surgical management with radiotherapy and androgen deprivation therapy was the treatment option of choice. However, surgical resection with radical prostatectomy (RP) and pelvic lymph node dissection (PLND) is increasingly utilized as a primary treatment modality for patients with HRPCa. Recent studies have demonstrated that surgery is an equivalent treatment option in select patients with the potential to avoid the side effects from androgen deprivation therapy and radiotherapy combined. Advances in imaging techniques and biomarkers have also improved staging and patient selection for surgical resection. Advances in robotic surgical technology grant surgeons various techniques to perform RP, even in patients with HR disease, which can reduce the morbidity of the procedure without sacrificing oncologic outcomes. Clinical trials are not only being performed to assess the safety and oncologic outcomes of these surgical techniques, but to also evaluate the role of surgical resection as a part of a multimodal treatment plan. Further research is needed to determine the ideal role of surgery to potentially provide a more personalized and tailored treatment plan for patients with localized HR PCa.

De-Escalation of Therapy for Prostate Cancer

Prostate cancer (PCa) is the second most commonly diagnosed cancer in men with around 1.4 million new cases every year. In patients with localized disease, management options include active surveillance (AS), radical prostatectomy (RP; with or without pelvic lymph node dissection), or radiotherapy to the prostate (with or without pelvic irradiation) with or without hormonotherapy. In advanced disease, treatment options include systemic treatment(s) and/or treatment to primary tumour and/or metastasis-directed therapies (MDTs). Specifically, in advanced stage, the current trend is earlier intensification of treatment such as dual or triple combination systemic treatments or adding treatment to primary and MDT to systemic treatment. However, earlier treatment intensification comes with the cost of increased morbidity and mortality resulting from drug-/treatment-related side effects. The main goal is and should be to provide the best possible care and oncologic outcomes with minimum possible side effects. This chapter will explore emerging possibilities to de-escalate treatment in PCa driven by enhanced insights into disease biology and the natural course of PCa such as AS in intermediate-risk disease or salvage versus adjuvant radiotherapy in post-RP patients. Considerations arising from advancements in PCa imaging and technological advancements in surgical and radiation therapy techniques including omitting pelvic lymph node dissection in the era of prostate-specific membrane antigen positron emitting tomography, the potential of MDT to delay/omit systemic treatment in metachronous oligorecurrence, and the efficacy of hypofractionation schemes compared with conventional fractionated radiotherapy will be discussed.

Radiation Therapy Summary of the AUA/ASTRO Guideline on Clinically Localized Prostate Cancer

PURPOSE

Our purpose was to develop a summary of recommendations regarding the management of patients with clinically localized prostate cancer based on the American Urologic Association/ ASTRO Guideline on Clinically Localized Prostate Cancer.

METHODS

The American Urologic Association and ASTRO convened a multidisciplinary, expert panel to develop recommendations based on a systematic literature review using an a priori defined consensus-building methodology. The topics covered were risk assessment, staging, risk-based management, principles of management including active surveillance, surgery, radiation, and follow-up after treatment. Presented are recommendations from the guideline most pertinent to radiation oncologists with an additional statement on health equity, diversity, and inclusion related to guideline panel composition and the topic of clinically localized prostate cancer.

SUMMARY

Staging, risk assessment, and management options in prostate cancer have advanced over the last decade and significantly affect shared decision-making for treatment management. Current advancements and controversies discussed to guide staging, risk assessment, and treatment recommendations include the use of advanced imaging and tumor genomic profiling. An essential active surveillance strategy includes prostate-specific antigen monitoring and periodic digital rectal examination with changes triggering magnetic resonance imaging and possible biopsy thereafter and histologic progression or greater tumor volume prompting consideration of definitive local treatment. The panel recommends against routine use of adjuvant radiation therapy (RT) for patients with prostate cancer after prostatectomy with negative nodes and an undetectable prostate-specific antigen, while acknowledging that patients at highest risk of recurrence were relatively poorly represented in the 3 largest randomized trials comparing adjuvant RT to early salvage and that a role may exist for adjuvant RT in selected patients at highest risk. RT for clinically localized prostate cancer has evolved rapidly, with new trial results, therapeutic combinations, and technological advances. The recommendation of moderately hypofractionated RT has not changed, and the updated guideline incorporates a conditional recommendation for the use of ultrahypofractionated treatment. Health disparities and inequities exist in the management of clinically localized prostate cancer across the continuum of care that can influence guideline concordance.

The prognostic significance of a negative PSMA-PET scan prior to salvage radiotherapy following radical prostatectomy

AIM

The optimal management for early recurrent prostate cancer following radical prostatectomy (RP) in patients with negative prostate-specific membrane antigen positron-emission tomography (PSMA-PET) scan is an ongoing subject of debate. The aim of this study was to evaluate the outcome of salvage radiotherapy (SRT) in patients with biochemical recurrence with negative PSMA PET finding.

METHODS

This retrospective, multicenter (11 centers, 5 countries) analysis included patients who underwent SRT following biochemical recurrence (BR) of PC after RP without evidence of disease on PSMA-PET staging. Biochemical recurrence-free survival (bRFS), metastatic-free survival (MFS) and overall survival (OS) were assessed using Kaplan-Meier method. Multivariable Cox proportional hazards regression assessed predefined predictors of survival outcomes.

RESULTS

Three hundred patients were included, 253 (84.3%) received SRT to the prostate bed only, 46 (15.3%) additional elective pelvic nodal irradiation, respectively. Only 41 patients (13.7%) received concomitant androgen deprivation therapy (ADT). Median follow-up after SRT was 33 months (IQR: 20-46 months). Three-year bRFS, MFS, and OS following SRT were 73.9%, 87.8%, and 99.1%, respectively. Three-year bRFS was 77.5% and 48.3% for patients with PSA levels before PSMA-PET ≤ 0.5 ng/ml and > 0.5 ng/ml, respectively. Using univariate analysis, the International Society of Urological Pathology (ISUP) grade > 2 (p = 0.006), metastatic pelvic lymph nodes at surgery (p = 0.032), seminal vesicle involvement (p < 0.001), pre-SRT PSA level of > 0.5 ng/ml (p = 0.004), and lack of concomitant ADT (p = 0.023) were significantly associated with worse bRFS. On multivariate Cox proportional hazards, seminal vesicle infiltration (p = 0.007), ISUP score >2 (p = 0.048), and pre SRT PSA level > 0.5 ng/ml (p = 0.013) remained significantly associated with worse bRFS.

CONCLUSION

Favorable bRFS after SRT in patients with BR and negative PSMA-PET following RP was achieved. These data support the usage of early SRT for patients with negative PSMA-PET findings.

Unraveling the safety of adjuvant radiotherapy in prostate cancer: impact of older age and hypofractionated regimens on acute and late toxicity - a multicenter comprehensive analysis

Background

The objective of this study was to assess the impact of age and other patient and treatment characteristics on toxicity in prostate cancer patients receiving adjuvant radiotherapy (RT).

Materials and methods

This observational study (ICAROS-1) evaluated both acute (RTOG) and late (RTOG/EORTC) toxicity. Patient- (age; Charlson's comorbidity index) and treatment-related characteristics (nodal irradiation; previous TURP; use, type, and duration of ADT, RT fractionation and technique, image-guidance systems, EQD2 delivered to the prostate bed and pelvic nodes) were recorded and analyzed.

Results

A total of 381 patients were enrolled. The median EQD2 to the prostate bed (α/β=1.5) was 71.4 Gy. The majority of patients (75.4%) were treated with intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT). Acute G3 gastrointestinal (GI) and genitourinary (GU) toxicity rates were 0.5% and 1.3%, respectively. No patients experienced >G3 acute toxicity. The multivariable analysis of acute toxicity (binomial logistic regression) showed a statistically significant association between older age (> 65) and decreased odds of G≥2 GI acute toxicity (OR: 0.569; 95%CI: 0.329-0.973; p: 0.040) and decreased odds of G≥2 GU acute toxicity (OR: 0.956; 95%CI: 0.918-0.996; p: 0.031). The 5-year late toxicity-free survival rates for G≥3 GI and GU toxicity were 98.1% and 94.5%, respectively. The only significant correlation found (Cox's regression model) was a reduced risk of late GI toxicity in patients undergoing hypofractionation (HR: 0.38; 95% CI: 0.18-0.78; p: 0.008).

Conclusions

The unexpected results of this analysis could be explained by a "response shift bias" concerning the protective effect of older age and by treatment in later periods (using IMRT/VMAT) concerning the favorable effect of hypofractionation. However, overall, the study suggests that age should not be a reason to avoid adjuvant RT and that the latter is well-tolerated even with moderately hypofractionated regimens.

Radiotherapy after radical prostatectomy for prostate cancer: clinical outcomes and factors influencing biochemical recurrence

BACKGROUND

Radiotherapy (RT) after radical prostatectomy (RP) includes adjuvant radiotherapy (ART) and salvage radiotherapy (SRT), which can prevent or cure biochemical recurrence.

AIMS

To evaluate long-term outcomes of RT after RP and to examine factors affecting biochemical recurrence-free survival (bRFS).

METHODS

Sixty-six received ART and 73 received SRT between 2005 and 2012 were included. The clinical outcomes and late toxicities were evaluated. Univariate and multivariate analyses were performed to examine factors affecting bRFS.

RESULTS

Median follow-up from RP was 111 months. Five-year bRFS and 10-year distant metastasis-free survival from RP were 82.8% and 84.5% in ART, and 74.6% and 92.4% in SRT, respectively. The most frequent late toxicity was hematuria, which was higher in ART (p = .01). No recurrence within RT field was occurred. On univariate analysis, pelvic RT was associated with favorable bRFS in ART (p = .048). In SRT, post-RP prostate-specific antigen (PSA) level (< 0.05 ng/mL), PSA nadir after RT (≤ 0.01 ng/mL), and time to PSA nadir (≥ 10 months) were associated with favorable bRFS (p = .03, p < .001, and p = .002, respectively). On multivariate analysis, post-RP PSA level and time to PSA nadir were independent predictive factors for bRFS in SRT (p = .04 and p = .005).

CONCLUSIONS

ART and SRT had favorable outcomes with no recurrence within RT field. In SRT, the time to PSA nadir after RT (≥ 10 months) was found to be a new predictor for favorable bRFS and useful in assessing treatment efficacy.

Rectum and Bladder Toxicity in Postoperative Prostate Bed Irradiation: Dose-Volume Parameters Analysis

Although prostate cancer treatment is increasingly effective, its toxicities pose a major concern. The aim of our study was to assess the rate of adverse events (AEs) and the prognostic value of dose-volume histogram (DVH) parameters for the occurrence of treatment toxicity in patients treated with post-prostatectomy prostate bed radiotherapy (RT). The AEs were scored according to the CTCAE v.5.0. The rectum and bladder were contoured according to the RTOG Guidelines. The DVH parameters were assessed using data exported from the ECLIPSE treatment-planning system. Genitourinary (GU) and gastrointestinal (GI) toxicity were analysed using consecutive dose thresholds for the percentage of an organ at risk (OAR) receiving a given dose and the QUANTEC dose constraints. A total of 213 patients were included in the final analysis. Acute grade 2 or higher (≥G2) GU AEs occurred in 18.7% and late in 21.3% of patients. Acute ≥G2 GI toxicity occurred in 11.7% and late ≥G2 in 11.2% of the patients. Five patients experienced grade 4 AEs. The most common adverse effects were diarrhoea, proctitis, cystitis, and dysuria. The most significant predictors of acute ≥G2 GI toxicity were rectum V47 and V46 (p < 0.001 and p < 0.001) and rectum wall V46 (p = 0.001), whereas the most significant predictors of late ≥G2 GI AEs were rectum wall V47 and V48 (p = 0.019 and p = 0.021). None of the bladder or bladder wall parameters was significantly associated with the risk of acute toxicity. The minimum doses to bladder wall (p = 0.004) and bladder (p = 0.005) were the most significant predictors of late ≥G2 GU toxicity. Postoperative radiotherapy is associated with a clinically relevant risk of AEs, which is associated with DVH parameters, and remains even in patients who fulfil commonly accepted dose constraints. Considering the lack of survival benefit of postoperative adjuvant RT, our results support delaying treatment through an early salvage approach to avoid or defer toxicity.

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

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

Salvage prostate bed plus elective pelvic node radiation without androgen deprivation therapy

BACKGROUND AND PURPOSE

In men with biochemical recurrence (BCR) of prostate cancer (PCA) after radical prostatectomy (RP), there is limited data on the effectiveness of adding elective pelvic nodal radiation (EPNI) to salvage prostate bed radiation (PBRT) without androgen deprivation therapy (ADT) to prevent progression.

MATERIALS AND METHODS

Retrospective chart review of 326 patients treated for BCR of PCA from a single institution was performed to capture baseline pre-operative PSA, pathologic details, post-operative PSA, treatment details (radiation and ADT), subsequent failure (rising PSA), response to radiation, and subsequent outcomes after radiation.

RESULTS

Between 2004 through 2017, 326 patients received PBRT. Majority (n = 253; 78%) did not receive ADT. Majority received EPNI (n = 227; 90%) with salvage PBRT (n = 213; 94%). The median pre-PBRT PSA was 0.50 ng/ml (0.10-75.60 ng/ml). Of the patients that did not receive ADT, 83% (210/253) achieved an undetectable (< 0.2 ng/ml) PSA after salvage PBRT. After a median follow-up of 87 months, 172 (53%) patients were without a rising PSA and 50 (15%) developed metastatic disease.

CONCLUSION

Outcomes with salvage PBRT plus EPNI without ADT appear comparable to salvage PBRT plus EPNI plus ADT. These results need confirmation in a randomized setting.

Salvage Radiation Therapy After Radical Prostatectomy: Analysis of Toxicity by Dose-Fractionation in the RADICALS-RT Trial

PURPOSE

Emerging data indicate comparable disease control and toxicity of normal postoperative fractionation and moderate hypofractionation radiation therapy (RT) in prostate cancer. In RADICALS-RT, patients were planned for treatment with either 66 Gy in 33 fractions (f) over 6.5 weeks or 52.5 Gy in 20f over 4 weeks. This non-randomized, exploratory analysis explored the toxicity of these 2 schedules in patients who had adjuvant RT.

METHODS AND MATERIALS

Information on RT dose was collected in all patients. The Radiation Therapy Oncology Group toxicity score was recorded every 4 months for 2 years, every 6 months until 5 years, then annually until 15 years. Patient-reported data were collected at baseline and at 1, 5, and 10 years using standard measures, including the Vaizey fecal incontinence score (bowel) and the International Continence Society Male Short-Form questionnaire (urinary incontinence). The highest event grade was recorded within the first 2 years and beyond 2 years and compared between treatment groups using the χ² test.

RESULTS

Of 634 patients, 217 (34%) were planned for 52.5 Gy/20f and 417 (66%) for 66 Gy/33f. In the first 2 years, grade 1 to 2 cystitis was reported more frequently among the 66 Gy/33f group (52.5 Gy/20f: 20% vs 66 Gy/33f: 30%; P = .04). After 2 years, grade 1 to 2 cystitis was reported in 16% in the 66-Gy group and 9% in the 52.5-Gy group (P = .08). Other toxic effects were similar in the 2 groups, and very few patients had any grade 3 to 4 toxic effects. Patients reported slightly higher urinary and fecal incontinence scores at 1 year than at baseline, but no clinically meaningful differences were reported between the 52.5 Gy/20f and 66 Gy/33f groups. Patient-reported health was similar at baseline and at 1 year and similar between the 52.5 Gy/20f and 66 Gy/33f groups.

CONCLUSIONS

Severe toxic effects were rare after prostate bed radiation therapy with either 52.5 Gy/20f or 66 Gy/33f. Only modest differences were recorded in toxic effects or in patient-reported outcomes between these 2 schedules.

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.

Long-term complications and health-related quality of life outcomes after radical prostatectomy with or without subsequent radiation treatment for prostate cancer

BACKGROUND

To report objective long-term complications and health related quality of life (HRQOL) outcomes after radical prostatectomy (RP) with and without radiation therapy (RT) for prostate cancer (CaP).

METHODS

We analyzed patients diagnosed with CaP who underwent RP from the UCSF Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) registry between 1995 and 2020. Cox proportional hazards were used to assess risk of postoperative complications which included cystitis, gastrointestinal (GI) toxicity, incontinence requiring a surgical procedure, ureteral injury and urinary stricture. Repeated measures mixed models were used to assess the effects of radiation and complications on patient-reported urinary, bowel, and sexual function after surgery.

RESULTS

Of 6,258 men who underwent RP, cumulative incidence of EBRT was 9.1% at 5 years after surgery. Patients who received postoperative radiation were at increased risk for onset of cystitis (HR 5.60, 95% CI 3.40-9.22, P < 0.01). Receipt of RT was not associated with other complications. In repeated measures analysis, postoperative RT was associated with worsening general health scores, adjusting for complications of incontinence, urinary stricture, GI toxicity or ureteral injury, independent of whether patients had those complications.

CONCLUSIONS

RT after RP was associated with an increase in the risk of cystitis and worse general health in the long term. Other complications and HRQOL outcomes did not demonstrate differences by whether patients had RT or not. While post-operative RT is the only curative option for CaP after RP, patients and providers should be aware of the increased risks when making treatment decisions.

Timing of Early Salvage Therapy for Patients With Biochemical Relapse of Prostate Carcinoma

Between 25% and 33% of patients after radical prostatectomy experience a relapse of the disease. The risk of relapse increases in patients with risk factors up to 50%-80%. For a long time, adjuvant radiotherapy has been considered the standard of care. Four large prospective trials, that compared adjuvant and salvage radiotherapy in patients with biochemical relapse, showed the superiority of the adjuvant approach in biochemical and local relapse-free survival, but no consistent benefit in long-term endpoints (i.e., metastasis-free survival, overall survival, or carcinoma-specific survival) at the expense of increased urinary and bowel toxicity. Three large international studies comparing adjuvant and salvage radiotherapy paved the way toward early salvage radiotherapy. However, the optimal threshold of the PSA level (range of 0.2-0.5 ng/mL) for initiating early salvage radiotherapy remains unresolved and still poses a challenge in everyday clinical practice when balancing the need for early radiotherapy and the associated toxicity. Imprecise stratification of biochemical relaps patients according to the risk of clinical relapse drives efforts to find additional molecular biomarkers that would improve the timing of the salvage therapy.

Predictive factors for disease progression after salvage radiation therapy in biochemical recurrent patients treated by radical prostatectomy

Objective

Salvage radiation therapy (SRT) is standard treatment for patients after radical prostatectomy (RP). However, the optimal timing of SRT remains to be elucidated.

Material and methods

We retrospectively reviewed 133 prostate cancer (PCa) patients who underwent SRT for biochemical recurrence after RP. Disease progression was defined as repeated prostate-specific antigen (PSA) level more than 0.2 ng/mL, greater than the post-SRT nadir or radiographic progression. A receiver operating characteristic curve analysis was used to identify the optimal pre-SRT PSA level for predicting progression after SRT. Cox regression analyses were performed to elucidate the association between clinicopathologic characteristics and disease progression.

Results

Fifty-one PCa patients (38.4%) experienced disease progression after SRT. The optimal cutoff value of the pre-SRT PSA for predicting disease progression was 0.44 ng/mL. In multivariable analysis, pre-SRT PSA >0.44 ng/mL was a significant independent predictor of post-SRT disease progression [hazard ratio (HR): 2.02, P = 0.02]. Although the pre-SRT PSA >0.44 ng/mL did not maintain its independent association with disease progression in the multivariable analysis of patients with adverse pathology (HR: 1.63, P = 0.22), PSA within 4 weeks after RP as a continuous variable was significantly associated with disease progression (HR: 1.19, P = 0.04).

Conclusions

Our results highlight that in PCa patients who undergo RP, SRT should be performed before their PSA reaches 0.44 ng/mL. In patients with adverse pathology disease, a high PSA level within the 4 weeks after RP might identify those who are likely to have disease progression, and these patients might require systemic therapy.

Urinary Continence Recovery after Retzius-Sparing Robot Assisted Radical Prostatectomy and Adjuvant Radiation Therapy

Retzius-sparing robot-assisted radical prostatectomy (RS-RARP) allows the preservation of the structures advocated to play a crucial role in the continence mechanism. This study aims to evaluate the association between adjuvant radiation therapy (aRT) and urinary continence (UC) recovery after RS-RARP. For the purpose of the current study, all patients submitted to RS-RARP for prostate cancer (PCa) at a single high-volume European institution between January 2010 and December 2021 were identified. Only patients that harbored pT2 stage with positive surgical margins or pT3/pN1 stage with or without positive surgical margins were included in the analyses. Two groups of patients were identified as follows: patients who had undergone aRT and patients submitted to observation (no-aRT patients). As per definition, aRT was delivered within 1-6 months after surgery. After 1:1 propensity score matching, 124 aRT patients were compared with 124 no-aRT patients who continued standard follow-up protocol after surgery. UC recovery was 81 vs. 84% in aRT vs. no-aRT patients (p = 0.7). In multivariable Cox regression analyses, aRT did not reach the independent predictor status for UC recovery at 12 months. In the subgroup analysis including only aRT patients, only the nerve-sparing technique was independently associated with UC recovery at 12 months. Conversely, the type of aRT (IMRT/VMAT vs. 3D-CRT) did not reach the independent predictor status for UC recovery at 12 months. The current study is the first to address the association between aRT and UC recovery in patients treated with RS-RARP for PCa. Based on our data, aRT is not associated with worse UC recovery. In the cohort of patients treated with aRT, the nerve-sparing technique independently predicted UC recovery.

Randomized phase II trial of MRI-guided salvage radiotherapy for prostate cancer in 4 weeks versus 2 weeks (SHORTER)

BACKGROUND

Ultra-hypofractionated image-guided stereotactic body radiotherapy (SBRT) is increasingly used for definitive treatment of localized prostate cancer. Magnetic resonance imaging-guided radiotherapy (MRgRT) facilitates improved visualization, real-time tracking of targets and/or organs-at-risk (OAR), and capacity for adaptive planning which may translate to improved targeting and reduced toxicity to surrounding tissues. Given promising results from NRG-GU003 comparing conventional and moderate hypofractionation in the post-operative setting, there is growing interest in exploring ultra-hypofractionated post-operative regimens. It remains unclear whether this can be done safely and whether MRgRT may help mitigate potential toxicity. SHORTER (NCT04422132) is a phase II randomized trial prospectively evaluating whether salvage MRgRT delivered in 5 fractions versus 20 fractions is non-inferior with respect to gastrointestinal (GI) and genitourinary (GU) toxicities at 2-years post-treatment.

METHODS

A total of 136 patients will be randomized in a 1:1 ratio to salvage MRgRT in 5 fractions or 20 fractions using permuted block randomization. Patients will be stratified according to baseline Expanded Prostate Cancer Index Composite (EPIC) bowel and urinary domain scores as well as nodal treatment and androgen deprivation therapy (ADT). Patients undergoing 5 fractions will receive a total of 32.5 Gy over 2 weeks and patients undergoing 20 fractions will receive a total of 55 Gy over 4 weeks, with or without nodal coverage (25.5 Gy over 2 weeks and 42 Gy over 4 weeks) and ADT as per the investigator's discretion. The co-primary endpoints are change scores in the bowel and the urinary domains of the EPIC. The change scores will reflect the 2-year score minus the pre-treatment (baseline) score. The secondary endpoints include safety endpoints, including change in GI and GU symptoms at 3, 6, 12 and 60 months from completion of treatment, and efficacy endpoints, including time to progression, prostate cancer specific survival and overall survival.

DISCUSSION

The SHORTER trial is the first randomized phase II trial comparing toxicity of ultra-hypofractionated and hypofractionated MRgRT in the salvage setting. The primary hypothesis is that salvage MRgRT delivered in 5 fractions will not significantly increase GI and GU toxicities when compared to salvage MRgRT delivered in 20 fractions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04422132. Date of registration: June 9, 2020.

Can We Predict Prostate Cancer Metastasis Based on Biomarkers? Where Are We Now?

The incidence of prostate cancer (PC) has risen annually. PC mortality is explained by the metastatic disease (mPC). There is an intermediate scenario in which patients have non-mPC but have initiated a metastatic cascade through epithelial-mesenchymal transition. There is indeed a need for more and better tools to predict which patients will progress in the future to non-localized clinical disease or already have micrometastatic disease and, therefore, will clinically progress after primary treatment. Biomarkers for the prediction of mPC are still under development; there are few studies and not much evidence of their usefulness. This review is focused on tissue-based genomic biomarkers (TBGB) for the prediction of metastatic disease. We develop four main research questions that we attempt to answer according to the current evidence. Why is it important to predict metastatic disease? Which tests are available to predict metastatic disease? What impact should there be on clinical guidelines and clinical practice in predicting metastatic disease? What are the current prostate cancer treatments? The importance of predicting metastasis is fundamental given that, once metastasis is diagnosed, quality of life (QoL) and survival drop dramatically. There is still a need and space for more cost-effective TBGB tests that predict mPC disease.

Patterns of practice regarding use of radiation therapy following radical prostatectomy: A survey of Radiation Oncologists and Urologists in Australia and New Zealand

INTRODUCTION

This study aimed to investigate the patterns of practices of radiation oncologists (ROs) and urologists in Australia and New Zealand with respect to the utilisation of post-prostatectomy radiation therapy (RT) and help guide the development of an update to the existing Faculty of Radiation Oncology Genito-Urinary Group post-prostatectomy guidelines.

METHODS

ROs and urologists with subspecialty practice in prostate cancer from Australia and New Zealand were invited to participate in an online survey comprised of clinical scenarios regarding post-prostatectomy RT.

RESULTS

Sixty-five ROs and 28 urologists responded to the survey. In the setting of low-risk biochemical relapse, the threshold for initiating RT was lower for ROs than urologists. ROs were more likely than urologists to recommend adjuvant RT for node-positive disease. When salvage RT was advised for a pT3N0R1 recurrence, there was no consensus amongst ROs on whether to add either ADT or nodal treatment over prostate bed RT alone. For a solitary PSMA-avid pelvic lymph node recurrence, whole pelvis RT with androgen deprivation therapy was the preferred treatment option (72% ROs, 43% urologists). Most ROs (92%) recommended conventionally fractionated RT to 66-70 Gy, with a boost to any PSMA PET avid recurrent disease.

CONCLUSION

This survey highlights the marked discordance in practice for the management of prostate cancer relapse post-prostatectomy. This is seen not only between specialties but also within the radiation oncology community. This emphasises the need for an updated evidence-based guideline to be produced.

Hypofractionated Post-Prostatectomy Radiotherapy in 16 Fractions: A Single-Institution Outcome

BACKGROUND

The optimal hypofractionated schedule of post-prostatectomy radiotherapy remains to be established. We evaluated treatment outcomes and toxicity of moderately hypofractionated post-prostatectomy radiotherapy in 16 daily fractions delivered with intensity-modulated radiotherapy. The treatment schedule selection was motivated by limited technology resources and was radiobiologically dose-escalated.

METHODS

One hundred consecutive M0 patients with post-prostatectomy radiotherapy were evaluated. Radiotherapy indication was adjuvant (ART) in 19%, early-salvage (eSRT) in 46% and salvage (SRT) in 35%. The dose prescription for prostate bed planning target volume was 52.8 Gy in 16 fractions of 3.3 Gy. The Common Terminology Criteria v. 4 for Adverse Events scale was used for toxicity grading.

RESULTS

The median follow-up was 61 months. Five-year biochemical recurrence-free survival (bRFS) was 78.6%, distant metastases-free survival (DMFS) was 95.7% and overall survival was 98.8%. Treatment indication (ART or eSRT vs. SRT) was the only significant factor for bRFS (HR 0.15, 95% CI 0.05-0.47, p = 0.001) and DMFS (HR 0.16, 95% CI 0.03-0.90; p = 0.038). Acute gastrointestinal (GI) toxicity grade 2 was recorded in 24%, grade 3 in 2%, acute genitourinary (GU) toxicity grade 2 in 10% of patients, and no grade 3. A cumulative rate of late GI toxicity grade ≥ 2 was observed in 9% and late GU toxicity grade ≥ 2 in 16% of patients.

CONCLUSIONS

The observed results confirmed efficacy and showed a higher than anticipated rate of early GI, late GI, and GU toxicity of post-prostatectomy radiobiologically dose-escalated hypofractionated radiotherapy in 16 daily fractions.

ERG Status at the Margin Is Associated With Biochemical Recurrence After Radical Prostatectomy With Positive Surgical Margins

Positive surgical margins at radical prostatectomy are associated with an increased risk of biochemical recurrence (BCR). However, there is considerable variability in outcomes, suggesting that molecular biomarkers-when assessed specifically at the margin tumor tissue-may be useful to stratify prognosis in this group. We used a case-cohort design for the outcome of BCR, selecting 215 patients from a cohort of 813 patients undergoing prostatectomy treated at the Johns Hopkins from 2008 to 2017 with positive margins and available clinical data. Tissue microarrays were created from the tumor adjacent to the positive margin and stained for PTEN, ERG, and Ki-67. Cases were scored dichotomously (PTEN and ERG) or by the Ki-67 staining index using previously validated protocols. The analysis used Cox proportional hazards models weighted for the case-cohort design. Overall, 20% (37/185) of evaluable cases had PTEN loss and 38% (71/185) had ERG expression, and the median Ki-67 expression was 0.42%. In multivariable analysis adjusting for the CAPRA-S score, adjuvant radiation, and grade group at the positive margin, ERG-positive tumors were associated with a higher risk of BCR compared to those that were ERGnegative (hazard ratio [HR], 2.4; 95% CI, 1.2-4.9; P = .012) regardless of PTEN status at the margin, and adding ERG to clinicopathologic variables increased the concordance index from 0.827 to 0.847. PTEN loss was associated with an increased risk of BCR on univariable analysis (HR, 3.19; 95% CI, 1.72-5.92; P = .0002), but this association did not remain after adjusting for clinicopathologic variables (HR, 1.06; 95% CI, 0.49-2.29; P = .890). Thus, in the setting of prostate tumors with positive surgical margins after prostatectomy, ERG-positive tumors with or without PTEN loss at the positive margin are associated with a significantly higher risk of BCR after adjusting for clinicopathologic variables. If validated, ERG status may be helpful in decision-making surrounding adjuvant therapy after prostatectomy.

Histology Specific Molecular Biomarkers: Ushering in a New Era of Precision Radiation Oncology

Histopathology and clinical staging have historically formed the backbone for allocation of treatment decisions in oncology. Although this has provided an extremely practical and fruitful approach for decades, it has long been evident that these data alone do not adequately capture the heterogeneity and breadth of disease trajectories experienced by patients. As efficient and affordable DNA and RNA sequencing have become available, the ability to provide precision therapy has become within grasp. This has been realized with systemic oncologic therapy, as targeted therapies have demonstrated immense promise for subsets of patients with oncogene-driver mutations. Further, several studies have evaluated predictive biomarkers for response to systemic therapy within a variety of malignancies. Within radiation oncology, the use of genomics/transcriptomics to guide the use, dose, and fractionation of radiation therapy is rapidly evolving but still in its infancy. The genomic adjusted radiation dose/radiation sensitivity index is one such early and exciting effort to provide genomically guided radiation dosing with a pan-cancer approach. In addition to this broad method, a histology specific approach to precision radiation therapy is also underway. Herein we review select literature surrounding the use of histology specific, molecular biomarkers to allow for precision radiotherapy with the greatest emphasis on commercially available and prospectively validated biomarkers.