Adjuvant radiotherapy versus wait-and-see after radical prostatectomy: 10-year follow-up of the ARO 96-02/AUO AP 09/95 trial

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.

Prostate Cancer Radioligand Therapy: Beta-labeled Radiopharmaceuticals

Prostate cancer is the most common malignancy in men worldwide, with an estimated 174,650 new cases per year in the United States, and the second cancer-related cause of death, after lung cancer, with 31,620 deaths per year. While the 5 year survival rate for prostate cancer in patients without metastatic spread is nearly 100%, those with distant metastases have 5 year survival rates of approximately 30%. Initial diagnosis and assessment are based on PSA levels, Gleason score (derived from prostate biopsy), and advanced imaging modalities, including prostate MR imaging and PSMA-PET/computed tomography in patients with high-risk features.

[Does radiation therapy for prostate cancer increase the risk of second cancers?]

PURPOSE

The increased risk of second cancer after prostate radiotherapy is a debated clinical concern. The objective of the study was to assess the risk of occurrence of second cancers after prostate radiation therapy based on the analysis the literature, and to identify potential factors explaining the discrepancies in results between studies.

MATERIALS AND METHODS

A review of the literature was carried out, comparing the occurrence of second cancers in patients all presenting with prostate cancer, treated or not by radiation.

RESULTS

This review included 30 studies reporting the occurrence of second cancers in 2,112,000 patients treated or monitored for localized prostate cancer, including 1,111,000 by external radiation therapy and 103,000 by brachytherapy. Regarding external radiation therapy, the average follow-up was 7.3years. The majority of studies (80%) involving external radiation therapy, compared to no external radiation therapy, showed an increased risk of second cancers with a hazard ratio ranging from 1.13 to 4.9, depending on the duration of the follow-up. The median time to the occurrence of these second cancers after external radiotherapy ranged from 4 to 6years. An increased risk of second rectal and bladder cancer was observed in 52% and 85% of the studies, respectively. Considering a censoring period of more than 10 years after irradiation, 57% and 100% of the studies found an increased risk of rectal and bladder cancer, without any impact in overall survival. Studies of brachytherapy did not show an increased risk of second cancer. However, these comparative studies, most often old and retrospective, had many methodological biases.

CONCLUSION

Despite numerous methodological biases, prostate external radiation therapy appears associated with a moderate increase in the risk of second pelvic cancer, in particular bladder cancer, without impacting survival. Brachytherapy does not increase the risk of a second cancer.

Noninferiority of Hypofractionated vs Conventional Postprostatectomy Radiotherapy for Genitourinary and Gastrointestinal Symptoms: The NRG-GU003 Phase 3 Randomized Clinical Trial

Importance

No prior trial has compared hypofractionated postprostatectomy radiotherapy (HYPORT) to conventionally fractionated postprostatectomy (COPORT) in patients primarily treated with prostatectomy.

Objective

To determine if HYPORT is noninferior to COPORT for patient-reported genitourinary (GU) and gastrointestinal (GI) symptoms at 2 years.

Design, Setting, and Participants

In this phase 3 randomized clinical trial, patients with a detectable prostate-specific antigen (PSA; ≥0.1 ng/mL) postprostatectomy with pT2/3pNX/0 disease or an undetectable PSA (<0.1 ng/mL) with either pT3 disease or pT2 disease with a positive surgical margin were recruited from 93 academic, community-based, and tertiary medical sites in the US and Canada. Between June 2017 and July 2018, a total of 296 patients were randomized. Data were analyzed in December 2020, with additional analyses occurring after as needed.

Intervention

Patients were randomized to receive 62.5 Gy in 25 fractions (HYPORT) or 66.6 Gy in 37 fractions (COPORT).

Main Outcomes and Measures

The coprimary end points were the 2-year change in score from baseline for the bowel and urinary domains of the Expanded Prostate Cancer Composite Index questionnaire. Secondary objectives were to compare between arms freedom from biochemical failure, time to progression, local failure, regional failure, salvage therapy, distant metastasis, prostate cancer-specific survival, overall survival, and adverse events.

Results

Of the 296 patients randomized (median [range] age, 65 [44-81] years; 100% male), 144 received HYPORT and 152 received COPORT. At the end of RT, the mean GU change scores among those in the HYPORT and COPORT arms were neither clinically significant nor different in statistical significance and remained so at 6 and 12 months. The mean (SD) GI change scores for HYPORT and COPORT were both clinically significant and different in statistical significance at the end of RT (-15.52 [18.43] and -7.06 [12.78], respectively; P < .001). However, the clinically and statistically significant differences in HYPORT and COPORT mean GI change scores were resolved at 6 and 12 months. The 24-month differences in mean GU and GI change scores for HYPORT were noninferior to COPORT using noninferiority margins of -5 and -6, respectively, rejecting the null hypothesis of inferiority (mean [SD] GU score: HYPORT, -5.01 [15.10] and COPORT, -4.07 [14.67]; P = .005; mean [SD] GI score: HYPORT, -4.17 [10.97] and COPORT, -1.41 [8.32]; P = .02). With a median follow-up for censored patients of 2.1 years, there was no difference between HYPORT vs COPORT for biochemical failure, defined as a PSA of 0.4 ng/mL or higher and rising (2-year rate, 12% vs 8%; P = .28).

Conclusions and Relevance

In this randomized clinical trial, HYPORT was associated with greater patient-reported GI toxic effects compared with COPORT at the completion of RT, but both groups recovered to baseline levels within 6 months. At 2 years, HYPORT was noninferior to COPORT in terms of patient-reported GU or GI toxic effects. HYPORT is a new acceptable practice standard for patients receiving postprostatectomy radiotherapy.

Trial Registration

ClinicalTrials.gov Identifier: NCT03274687.

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.

Intra-fractional geometric and dose/volume metric variations of magnetic resonance imaging-guided stereotactic radiotherapy of prostate bed after radical prostatectomy

Background and purpose

Magnetic Resonance Imaging (MRI)-guided Stereotactic body radiotherapy (SBRT) treatment to prostate bed after radical prostatectomy has garnered growing interests. The aim of this study is to evaluate intra-fractional anatomic and dose/volume metric variations for patients receiving this treatment.

Materials and methods

Nineteen patients who received 30-34 Gy in 5 fractions on a 0.35T MR-Linac were included. Pre- and post-treatment MRIs were acquired for each fraction (total of 75 fractions). The Clinical Target Volume (CTV), bladder, rectum, and rectal wall were contoured on all images. Volumetric changes, Hausdorff distance, Mean Distance to Agreement (MDA), and Dice similarity coefficient (DSC) for each structure were calculated. Median value and Interquartile range (IQR) were recorded. Changes in target coverage and Organ at Risk (OAR) constraints were compared and evaluated using Wilcoxon rank sum tests at a significant level of 0.05.

Results

Bladder had the largest volumetric changes, with a median volume increase of 48.9 % (IQR 28.9-76.8 %) and a median MDA of 5.1 mm (IQR 3.4-7.1 mm). Intra-fractional CTV volume remained stable with a median volume change of 1.2 % (0.0-4.8 %). DSC was 0.97 (IQR 0.94-0.99). For the dose/volume metrics, there were no statistically significant changes observed except for an increase in bladder hotspot and a decrease of bladder V32.5 Gy and mean dose. The CTV V95% changed from 99.9 % (IQR 98.8-100 %) to 99.6 % (IQR 93.9-100 %).

Conclusion

Despite intra-fractional variations of OARs, CTV coverage remained stable during MRI-guided SBRT treatments for the prostate bed.

Dose-Intensified Postoperative Radiation Therapy for Prostate Cancer: Long-Term Results From the PKUFH Randomized Phase 3 Trial

PURPOSE

In the randomized, single-center, PKUFH phase 3 trial, dose-intensified (72 Gy) radiation therapy was compared with conventional (66 Gy) radiation therapy. In a previous study, we found no significant difference in biochemical progression-free survival (bPFS) between the 2 cohorts at 4 years. In the current analysis, we provide 7-year outcomes.

METHODS AND MATERIALS

Patients with stage pT3-4, positive surgical margins, or a prostate-specific antigen increase ≥0.2 ng/mL after radical prostatectomy were randomly assigned 1:1 to receive either 72 Gy in 36 fractions or 66 Gy in 33 fractions. All the patients underwent image guided intensity modulated radiation therapy. The primary endpoint was bPFS. Secondary endpoints were distant metastasis-free survival (DMFS), cancer-specific survival (CSS), and overall survival (OS) as estimated using the Kaplan-Meier method.

RESULTS

Between September 2011 and November 2016, 144 patients were enrolled with 73 and 71 in the 72- and 66-Gy cohorts, respectively. At a median follow-up of 89.5 months (range, 73-97 months), there was no difference in 7-year bPFS between the 72- and 66-Gy cohorts (70.3% vs 61.2%; hazard ratio [HR], 0.73; 95% CI, 0.41-1.29; P = .274). However, in patients with a higher Gleason score (8-10), the 72-Gy cohort had statistically significant improvement in 7-year bPFS compared with the 66-Gy cohort (66.5% vs 30.2%; HR, 0.37; 95% CI, 0.17-0.82; P = .012). In addition, in patients with multiple positive surgical margins, the 72-Gy cohort had statistically significant improvement in 7-year bPFS compared with single positive surgical margin (82.5% vs 57.5%; HR, 0.36; 95% CI, 0.13-0.99; P = .037). The 7-year DMFS (88.4% vs 84.9%; HR, 0.93; 95% CI, 0.39-2.23; P = .867), CSS (94.1% vs 95.5%; HR, 1.19; 95% CI, 0.42-3.39; P = .745), and OS (92.8% vs 94.1%; HR, 1.29; 95% CI, 0.51-3.24; P = .594) had no statistical differences between the 72- and 66-Gy cohorts.

CONCLUSIONS

The current 7-year bPFS results confirmed our previous findings that dose escalation (72 Gy) demonstrated no improvement in 7-year bPFS, DMFS, CSS, or OS compared with the 66-Gy regimen. However, patients with a higher Gleason score (8-10) or multiple positive surgical margins might benefit from the 72-Gy regimen, but this requires further prospective research.

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.

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.

Prediction of T staging in PI-RADS 4-5 prostate cancer by combination of multiparametric MRI and 68Ga-PSMA-11 PET/CT

BACKGROUND

In this study, we explored the diagnostic performances of multiparametric magnetic resonance imaging (mpMRI), 68 Ga-PSMA-11 PET/CT and combination of 68 Ga-PSMA-11 PET/CT and mpMRI (mpMRI + PET/CT) for extracapsular extension (ECE). Based on the analyses above, we tested the feasibility of using mpMRI + PET/CT results to predict T staging in prostate cancer patients.

METHODS

By enrolling 75 patients of prostate cancer with mpMRI and 68 Ga-PSMA-11 PET/CT before radical prostatectomy, we analyzed the detection performances of ECE in mpMRI, 68 Ga-PSMA-11 PET/CT and mpMRI + PET/CT on their lesion images matched with their pathological sample images layer by layer through receiver operating characteristics (ROC) analysis. By inputting the lesion data into Prostate Imaging Reporting and Data System (PI-RADS), we divided the lesions into different PI-RADS scores. The improvement of detecting ECE was analyzed by net reclassification improvement (NRI). The predictors for T staging were evaluated by using univariate and multivariable analysis. The Kappa test was used to evaluate the prediction ability.

RESULTS

One hundred three regions of lesion were identified from 75 patients. 50 of 103 regions were positive for ECE. The ECE diagnosis AUC of mpMRI + PET/CT is higher than that of mpMRI alone (ΔAUC = 0.101; 95% CI, 0.0148 to 0.1860; p < 0.05, respectively). Compared to mpMRI, mpMRI + PET/CT has a significant improvement in detecting ECE in PI-RADS 4-5 (NRI 36.1%, p < 0.01). The diagnosis power of mpMRI + PET/CT was an independent predictor for T staging (p < 0.001) in logistic regression analysis. In patients with PI-RADS 4-5 lesions, 40 of 46 (87.0%) patients have correct T staging prediction from mpMRI + PET/CT (κ 0.70, p < 0.01).

CONCLUSION

The prediction of T staging in PI-RADS 4-5 prostate cancer patients by mpMRI + PET/CT had a quite good performance.

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.

Development and Validation of Nomograms Based on Nutritional Risk Index for Predicting Extracapsular Extension and Seminal Vesicle Invasion in Patients Undergoing Radical Prostatectomy

Background

The aim of the study was to investigate the predictive value of the nutritional risk index (NRI) for extracapsular extension (ECE) and seminal vesicle invasion (SVI) in prostate cancer (PCa) patients undergoing radical prostatectomy (RP), and further develop and validate predictive nomograms for ECE and SVI based on the NRI.

Methods

We retrospectively analyzed 734 PCa patients who underwent RP between 2010 and 2020 in the Department of Urology at Peking University Third Hospital. The enrolled patients were randomly divided into a primary cohort (n = 489) and a validation cohort (n = 245) in a 2:1 manner. The baseline NRI of patients was calculated using serum albumin level and body mass index, and a malnutrition status was defined as NRI ≤ 98. Univariate and multivariate logistic regression analyses were conducted to identify predictors for ECE and SVI. Nomograms for predicting ECE and SVI were established based on the results of the multivariate logistic regression analysis. The performance of the nomograms was estimated using Harrell's concordance index (C-index), the area under curve (AUC) of receiver operating characteristic (ROC) curves and the calibration curves.

Results

In the primary cohort, 70 (14.3%) patients with NRI ≤ 98 were classified as malnutrition, while the remaining 419 (85.7%) patients with NRI > 98 were considered to have normal nutrition. The nomograms for predicting ECE and SVI shared common factors including NRI, percentage of positive biopsy cores (PPC) and biopsy Gleason score, while prostate-specific antigen (PSA) levels and PSA density (PSAD) were only incorporated in ECE nomogram. The C-indexes of the nomograms for predicting ECE and SVI were 0.785 (95% confidence interval (CI): 0.745 - 0.826) and 0.852 (95% CI: 0.806 - 0.898), respectively. The calibration curves demonstrated excellent agreement between the predictions by the nomograms and the actual observations. The results remained reproducible when the nomograms were applied to the validation cohort.

Conclusions

The NRI is significantly associated with ECE and SVI in PCa patients. The nomogram established based on the NRI in our study can provide individualized risk estimation for ECE and SVI in PCa patients, and may be valuable for clinicians in making well-informed decisions regarding treatment strategies and patient management.

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.

Evaluating the geometric and dosimetric impact of applying anisotropic CTV to PTV margins in image-guided post-prostatectomy radiation therapy

INTRODUCTION

Guidelines for clinical target volume (CTV) to planning target volume (PTV) margins in post-prostatectomy radiation therapy (PPRT) are varied and often not clearly defined. Assessment of appropriateness of margins is commonly measured on prevalence of geographic miss.

METHODS

Cone-beam CT (CBCT) images (n = 92) for 10 PPRT patients were incorporated to provide on-treatment information on the appropriateness of six different CTV expansion margins in terms of geographic miss and change in dose-volume statistics for CTV, rectum and bladder. Uniform margins included 10 mm, 5 mm, 10 mm + 5 mm posteriorly and 5 mm + 3 mm posteriorly. In addition, two anisotropic margins were evaluated by separating the superior and inferior portions of the CTV before expansion. Treatment plans were created for each PTV retrospectively.

RESULTS

The frequency of geographic miss was the smallest for the large uniform expansions but resulted in the highest organ-at-risk (OAR) doses. Geographic miss in the smaller uniform and anisotropic PTVs was more prevalent but commonly to a small volume < 1% of CTV. When averaged over all CBCT fractions, V95% dose for all CTV margins remained > 99%. The anisotropic expansions generated smaller irradiated target volumes and consequently saw up to 7.3% reduction in bladder dose when compared with similar uniform expansion margins.

CONCLUSION

Supplementing the incidence of geographic miss with dosimetric information on target coverage and OAR doses provides more informed assessment of the appropriateness of different CTV expansion margins. Our study extends the evaluation of anisotropic margins for PPRT.

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.

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.

Development of PSMA-PET-guided CT-based radiomic signature to predict biochemical recurrence after salvage radiotherapy

PURPOSE

To develop a CT-based radiomic signature to predict biochemical recurrence (BCR) in prostate cancer patients after sRT guided by positron-emission tomography targeting prostate-specific membrane antigen (PSMA-PET).

MATERIAL AND METHODS

Consecutive patients, who underwent 68Ga-PSMA11-PET/CT-guided sRT from three high-volume centers in Germany, were included in this retrospective multicenter study. Patients had PET-positive local recurrences and were treated with intensity-modulated sRT. Radiomic features were extracted from volumes of interests on CT guided by focal PSMA-PET uptakes. After preprocessing, clinical, radiomics, and combined clinical-radiomic models were developed combining different feature reduction techniques and Cox proportional hazard models within a nested cross validation approach.

RESULTS

Among 99 patients, median interval until BCR was the radiomic models outperformed clinical models and combined clinical-radiomic models for prediction of BCR with a C-index of 0.71 compared to 0.53 and 0.63 in the test sets, respectively. In contrast to the other models, the radiomic model achieved significantly improved patient stratification in Kaplan-Meier analysis. The radiomic and clinical-radiomic model achieved a significantly better time-dependent net reclassification improvement index (0.392 and 0.762, respectively) compared to the clinical model. Decision curve analysis demonstrated a clinical net benefit for both models. Mean intensity was the most predictive radiomic feature.

CONCLUSION

This is the first study to develop a PSMA-PET-guided CT-based radiomic model to predict BCR after sRT. The radiomic models outperformed clinical models and might contribute to guide personalized treatment decisions.

Radiation therapy after radical surgery in prostate cancer

Radiation therapy plays a key role in the treatment of prostate cancer on its own. For higher risk diseases, the risk of recurrence following single modality therapy increases and a combination of treatment modalities may be necessary to achieve optimal results. We review clinical outcomes of adjuvant and salvage radiotherapy following radical prostatectomy, including disease-free survival, cancer-specific survival and overall survival. We also discuss when best to intervene with post-prostatectomy radiotherapy.

Adverse risk factors for salvage radiotherapy outcomes after radical prostatectomy in prostate cancer patients

PURPOSE

To investigate salvage treatment approaches and treatment outcomes in high-risk prostate cancer after radical prostatectomy (RP).

METHODS

In this retrospective, multicenter study, 272 patients who underwent salvage radiotherapy (RT) ± androgen deprivation therapy (ADT) for recurrent prostate cancer after RP between 2007 and 2021 were analysed. Univariate analyses of time to biochemical and clinical relapse after salvage therapies were conducted using Kaplan-Meier plots and log-rank tests. Multivariate analyses were performed using a Cox proportional hazards model to determine the risk factors for disease relapse.

RESULTS

Median age was 65 (48-82) years. All patients underwent salvage prostate bed RT. Pelvic lymphatic RT was performed in 66 patients (24.3%) and ADT was included in 158 (58.1%) patients. The median PSA value before RT was 0.35 ng/mL. The median follow-up time was 64 (12-180) months. 5-years bRFS, cRFS, and OS were 75.1%, 84.8%, and 94.9% respectively. In multivariate cox regression analysis; seminal vesicle invasion (HR 8.64, 95% CI 3.47-21.48, p < 0.001), pre-RT PSA higher than 0.14 ng/mL (HR 3.79, 95% CI 1.47-9.78, p = 0.006), and ≥ 2 positive pelvic lymph nodes (HR 2.50, 95% CI 1.11-5.62, p = 0.027) were found to be unfavorable prognostic factors for bRFS.

CONCLUSION

Salvage RT ± ADT provided 5-years biochemical disease control in 75.1% of patients. Seminal vesicle invasion, ≥ 2 positive pelvic nodes and delayed administration of salvage RT (PSA levels higher than 0.14 ng/mL) were found to be adverse risk factors for relapse. Such factors should be taken into account during the decision process on salvage treatment.

The pathway of isolated seminal vesicle invasion has a different impact on biochemical recurrence after radical prostatectomy and pelvic lymphadenectomy

OBJECTIVE

Prostate cancer with seminal vesicle invasion (SVI) has been considered an aggressive cancer. To evaluate the prognostic significance of different patterns of isolated SVI in patients undergoing radical prostatectomy (RP) and pelvic lymphadenectomy.

METHODS AND MATERIALS

We retrospectively analyzed all patients who underwent RP between 2007 and 2019. Inclusion criteria were localized prostate adenocarcinoma, SVI at RP, at least 24-months follow-up, and no adjuvant treatment. Patterns of SVI were following Ohori's classification: type 1: direct spread along the ejaculatory duct from inside; type 2: seminal vesicle invasion outside the prostate, through the capsule; type 3: the presence of cancer island(s) in the seminal vesicle with no continuity from the primary tumor (discontinuous metastases). Patients with type 3 SVI (isolated or in association) were included in the same group. Biochemical recurrence (BCR) was defined as any postoperative PSA ≥0.2 ng/ml. A logistic regression analysis was performed to assess predictors of BCR. Time to BCR was investigated using the Kaplan-Meier analysis with the log-rank test.

RESULTS

Sixty-one out of 1,356 patients were included. Median age was 67(7.2) years. Median PSA was 9.4(8.92) ng/ml. Mean follow-up was 85.28 ± 45.27 months. BCR occurred in 28(45.9%) patients. Logistic regression showed that a positive surgical margin (OR 19.964, 95%CI:1.172-29.322, P = 0.038) was predictor of BCR. Kaplan-Meier analysis demonstrated that patients with pattern 3 had a significantly shorter time to BCR compared to other groups (log-rank, P = 0.016). The estimated time to BCR was 48.7 months in type 3, 60.9 months in pattern 1 + 2, 74.8, and 100.8 months in isolated patterns 1 and 2, respectively. In patients with negative surgical margins, pattern 3 confirmed a shorter time to BCR compared to other types of invasions, with an estimated time to BCR of 30.8 months.

CONCLUSIONS

Patients with type 3 SVI demonstrated a shorter time to BCR compared to other patterns.

Treatment-related toxicity using prostate bed versus prostate bed and pelvic lymph node radiation therapy following radical prostatectomy: A national population-based study

Purpose There is debate about the effectiveness and toxicity of pelvic lymph node (PLN) irradiation in addition to prostate bed radiotherapy when used to treat disease recurrence following radical prostatectomy. We compared toxicity from radiation therapy (RT) to the prostate bed and pelvic lymph nodes (PBPLN-RT) with prostatebed only radiation therapy (PBO-RT) following radical prostatectomy. Methods and Materials Patients with prostate cancer who underwent post-prostatectomy RT between 2010 and 2016 were identified by using the National Prostate Cancer Audit (NPCA) database. Follow-up data was available up to December 31, 2018. Validated outcome measures, based on a framework of procedural and diagnostic codes, were used to capture ≥Grade 2 gastrointestinal (GI) and genitourinary (GU) toxicity. An adjusted competing-risks regression analysis estimated subdistribution hazard ratios (sHR). A sHR > 1 indicated a higher incidence of toxicity with PBPLN-RT than with PBO-RT. Results 5-year cumulative incidences in the PBO-RT (n = 5,087) and PBPLNRT (n = 593) groups was 18.2% and 15.9% for GI toxicity, respectively. For GU toxicity it was 19.1% and 20.7%, respectively. There was no evidence of difference in GI or GU toxicity after adjustment between PBO-RT and PBPLN-RT (GI: adjusted sHR, 0.90, 95% CI, 0.67-1.19; P = 0.45); (GU: adjusted sHR, 1.19, 95% CI, 0.99-1.44; P = 0.09). Conclusions This national population-based study found that including PLNs in the radiation field following radical prostatectomy is not associated with a significant increase in rates of ≥Grade 2 GI or GU toxicity at 5 years.

Management of high-risk and post-operative non-metastatic prostate cancer in Catalonia: an expert Delphi consensus

BACKGROUND

To reach a consensus on recommendations for the management of high-risk and post-operative non-metastatic prostate cancer by a group of Radiation Oncologists in Catalonia dedicated to prostate cancer.

METHODS

A modified Delphi approach was employed to reach consensus on controversial topics in Radiation Oncology on high-risk non-metastatic (eight questions) and post-operative (eight questions) prostate cancer. An agreement of at least 75% was considered as consensus. The survey was electronically sent 6 weeks before an expert meeting where topics were reviewed and discussed. A second-round survey for the controversial questions only was sent and answered by participants after the meeting.

RESULTS

After the first round of the survey, 19 experienced Radiation Oncologists attended the meeting and 74% fulfilled the second-round online questionnaire. An agreement of 9 of the 16 questions was accounted for the first round. After the meeting, an additional agreement was reached in 3 questions leading to a final consensus on 12 of the 16 questions. There are still controversial topics like the use of PET for staging of high-risk and post-operative non-metastatic prostate cancer and the optimal dose to the prostate bed in the salvage setting.

CONCLUSION

This consensus contributes to establish recommendations and a framework to help in prostate cancer radiation therapy and pharmacological management in daily clinical practice of high-risk and post-operative non-metastatic prostate cancer.

Utilizing clinical, pathological and radiological information to guide postoperative radiotherapy in prostate cancer

INTRODUCTION

A detectable and rising PSA following radical prostatectomy is indicative of recurrent prostate cancer. Salvage radiotherapy (SRT) with/without androgen deprivation therapy represents the main treatment option for these patients and has been historically associated with a biochemical control rate of ~70%. To determine the optimal timing, diagnostic workup, radiotherapy dosefractionation, treatment volume, and use of systemic therapy, several informative studies have been conducted in the last decade.

AREAS COVERED

This review examines the recent evidence to guide radiotherapy decision making in the SRT setting. Key topics include adjuvant vs salvage RT, utilization of molecular imaging and genomic classifiers, length of androgen deprivation therapy, inclusion of elective pelvic volume, and emerging role for hypofractionation.

EXPERT OPINION

Recently reported trials, conducted in an era prior to the routine use of molecular imaging and genomic classifiers, have been pivotal in establishing the current standard of care for SRT in prostate cancer. However, decisions about radiation treatment and systemic therapy may be tailored based on available prognostic and predictive biomarkers. Data from contemporary clinical trials are awaited to define and establish individualized, biomarker-driven approaches for SRT.

Management of Patients with Advanced Prostate Cancer. Part I: Intermediate-/High-risk and Locally Advanced Disease, Biochemical Relapse, and Side Effects of Hormonal Treatment: Report of the Advanced Prostate Cancer Consensus Conference 2022

BACKGROUND

Innovations in imaging and molecular characterisation and the evolution of new therapies have improved outcomes in advanced prostate cancer. Nonetheless, we continue to lack high-level evidence on a variety of clinical topics that greatly impact daily practice. To supplement evidence-based guidelines, the 2022 Advanced Prostate Cancer Consensus Conference (APCCC 2022) surveyed experts about key dilemmas in clinical management.

OBJECTIVE

To present consensus voting results for select questions from APCCC 2022.

DESIGN, SETTING, AND PARTICIPANTS

Before the conference, a panel of 117 international prostate cancer experts used a modified Delphi process to develop 198 multiple-choice consensus questions on (1) intermediate- and high-risk and locally advanced prostate cancer, (2) biochemical recurrence after local treatment, (3) side effects from hormonal therapies, (4) metastatic hormone-sensitive prostate cancer, (5) nonmetastatic castration-resistant prostate cancer, (6) metastatic castration-resistant prostate cancer, and (7) oligometastatic and oligoprogressive prostate cancer. Before the conference, these questions were administered via a web-based survey to the 105 physician panel members ("panellists") who directly engage in prostate cancer treatment decision-making. Herein, we present results for the 82 questions on topics 1-3.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Consensus was defined as ≥75% agreement, with strong consensus defined as ≥90% agreement.

RESULTS AND LIMITATIONS

The voting results reveal varying degrees of consensus, as is discussed in this article and shown in the detailed results in the Supplementary material. The findings reflect the opinions of an international panel of experts and did not incorporate a formal literature review and meta-analysis.

CONCLUSIONS

These voting results by a panel of international experts in advanced prostate cancer can help physicians and patients navigate controversial areas of clinical management for which high-level evidence is scant or conflicting. The findings can also help funders and policymakers prioritise areas for future research. Diagnostic and treatment decisions should always be individualised based on patient and cancer characteristics (disease extent and location, treatment history, comorbidities, and patient preferences) and should incorporate current and emerging clinical evidence, therapeutic guidelines, and logistic and economic factors. Enrolment in clinical trials is always strongly encouraged. Importantly, APCCC 2022 once again identified important gaps (areas of nonconsensus) that merit evaluation in specifically designed trials.

PATIENT SUMMARY

The Advanced Prostate Cancer Consensus Conference (APCCC) provides a forum to discuss and debate current diagnostic and treatment options for patients with advanced prostate cancer. The conference aims to share the knowledge of international experts in prostate cancer with health care providers and patients worldwide. At each APCCC, a panel of physician experts vote in response to multiple-choice questions about their clinical opinions and approaches to managing advanced prostate cancer. This report presents voting results for the subset of questions pertaining to intermediate- and high-risk and locally advanced prostate cancer, biochemical relapse after definitive treatment, advanced (next-generation) imaging, and management of side effects caused by hormonal therapies. The results provide a practical guide to help clinicians and patients discuss treatment options as part of shared multidisciplinary decision-making. The findings may be especially useful when there is little or no high-level evidence to guide treatment decisions.

Multimodality Therapies for Localized Prostate Cancer

PURPOSE OF REVIEW

Multimodality therapy including radical prostatectomy, radiation therapy, and hormone therapy are frequently deployed in the management of localized prostate cancer. We sought to perform a critical appraisal of the most contemporary literature focusing on the multimodality management of localized prostate cancer.

RECENT FINDINGS

Men who are ideal candidates for multimodality therapy include those with unfavorable intermediate-risk disease, high-risk disease, and very high-risk disease. Enhancements in both systemic agents (including second-generation antiandrogens) as well as localized therapies (such as stereotactic body radiotherapy and brachytherapy) are refining the optimal balance between the use of systemic and local therapies for localized prostate cancer. Genomic predictors are emerging as critical tools for more precisely allocating treatment intensification with multimodality therapies as well as treatment de-intensification. Close collaboration among medical oncologists, surgeons, and radiation oncologists will be critical for coordinating evidence-based multimodality therapies when clearly indicated and for supporting shared decision-making in areas where the evidence is mixed.

Prognostic value of estrogen receptors in patients who underwent prostatectomy for non‑metastatic prostate cancer

Estrogen receptors in prostate cancer (PCa) are a subject of debate. The aim of the present study was to investigate whether estrogen receptor-α (ERα) and estrogen receptor-β (ERβ) impact the biochemical recurrence (BCR) of non-metastatic PCa after surgery. Following the application of the exclusion criteria, data from 108 patients who underwent laparoscopic radical prostatectomy between January 2011 and December 2019 were retrospectively evaluated. A total of 36 patients with BCR constituted the BCR group. The control group was formed using the Propensity Score Matching (PSM) method with a 1:2 ratio, including parameters with well-studied effects on BCR. The median follow-up time was 74.3 (range, 30-127.5) months in the BCR group and 66.6 (range, 31.5-130) months in the control group. Pathology specimens from the two groups were immunohistochemically stained with ERα and ERβ antibodies. Logistic regression analysis and survival analysis were performed. No differences in clinicopathological characteristics were detected between the two groups. The patients with ERα(-)/ERβ(+) staining results had a significantly fewer BCRs than other patients (P=0.024). In the logistic regression analysis, patients with ERα(-)/ERβ(+) PCa also had a significantly lower risk of recurrence (P=0.048). In the survival analysis, the 5-year BCR-free survival rate of patients with ERα(-)/ERβ(+) PCa was higher than that of other patients (85.7 vs. 66.1%; P=0.031). Excluding the effects of well-studied risk factors for recurrence by the PSM method, the present study showed that ERα and ERβ have prognostic value for non-metastatic PCa. The 5-year BCR-free survival rate is significantly higher in patients whose PCa tissue has ERα(-)/ERβ(+) staining results.

Treatment outcomes of postoperative ultra-hypofractionated stereotactic body radiotherapy in prostate cancer

BACKGROUND

This study aimed to evaluate the safety and efficacy of ultra-hypofractionated stereotactic body radiation therapy (SBRT) to prostate bed.

METHODS

Sixty-six prostate cancer patients treated with postoperative ultra-hypofractionated SBRT between 2018 and 2020 were retrospectively reviewed. All patients received a total dose of 35 Gy to prostate bed in 5 fractions. Biochemical complete response (BCR), biochemical failure (BF), acute and late toxicities were assessed.

RESULTS

After a median follow-up of 24.2 months (range, 6.4-37.2), seven patients (10.6%) developed BF, and the 2-year freedom from BF (FFBF) rate was 88.4%. BCR was observed in 57 patients (86.4%). The 2-year FFBF in patients with pre-SBRT PSA value of <0.2 ng/mL was higher than those with pre-SBRT PSA of ≥0.2 ng/mL (100% vs. 81.4%; P = 0.04). The 2-year FFBF in patients with BCR was significantly higher than in those without BCR (94.5% vs. 58.3%; P < 0.001). In multivariate analysis, pre-SBRT PSA and post-SBRT PSA values were prognostic factors for FFBF (P = 0.009 and P = 0.01, respectively). Nine patients (13.6 %) developed acute and late grade 2 genitourinary (GU) toxicities. There was no acute or late grade ≥3 GU toxicity. Acute and late grade ≥2 gastrointestinal (GI) toxicity was observed in 9 (13.6%) and 2 (3%) patients, respectively.

CONCLUSION

Postoperative ultra-fractionated SBRT showed no severe acute toxicity and late toxicity rates of about 15%, in addition to excellent biochemical control rates. Pre- and post-SBRT PSA levels may be a predictor of BCR in patients receiving post-operative ultra-fractionated SBRT.

Quality-of-Life Outcomes and Toxicity Profile Among Patients With Localized Prostate Cancer After Radical Prostatectomy Treated With Stereotactic Body Radiation: The SCIMITAR Multicenter Phase 2 Trial

PURPOSE

Postoperative radiation therapy (RT) is an underused standard-of-care intervention for patients with prostate cancer and recurrence/adverse pathologic features after radical prostatectomy. Although stereotactic body RT (SBRT) is a well-studied and convenient option for definitive treatment, data on the postprostatectomy setting are extremely limited. The purpose of this study was to evaluate short-term physician-scored genitourinary (GU) and gastrointestinal (GI) toxicities and patient-reported outcomes after postprostatectomy SBRT.

METHODS AND MATERIALS

The SCIMITAR trial was a phase 2, dual-center, open-label, single-arm trial that enrolled patients with postoperative prostate-specific antigen >0.03 ng/mL or adverse pathologic features. Coprimary endpoints were 4-year biochemical recurrence-free survival, physician-scored acute and late GU and GI toxicities by the Common Terminology Criteria for Adverse Events (version 4.03) scale, and patient-reported quality-of-life (QOL) outcomes, as represented by the Expanded Prostate Cancer Index-26 and the International Prostate Symptom Score. Patients received SBRT 30 to 34 Gy/5 fractions to the prostate bed ± bed boost ± pelvic nodes with computed tomography (CTgRT) or magnetic resonance imaging guidance (MRgRT) in a nonrandomized fashion. Physician-scored toxicities and patient-reported QOL outcomes were collected at baseline and at 1, 3, and 6 months of follow-up. Univariable and multivariable analyses were performed to evaluate predictors of toxicities and QOL outcomes.

RESULTS

One hundred participants were enrolled (CTgRT, n = 69; MRgRT, n = 31). The median follow-up was 29.5 months (CTgRT: 33.3 months, MRgRT: 22.6 months). The median (range) prostate bed dose was 32 (30-34) Gy. Acute and late grade 2 GU toxicities were both 9% while acute and late grade 2 GI toxicities were 5% and 0%, respectively. Three patients had grade 3 toxicity (n = 1 GU, n = 2 GI). No patient receiving MRgRT had grade 3 GU or grade ≥2 GI toxicity. Compared with CTgRT, MRgRT was associated with a 30.5% (95% confidence interval, 11.6%-49.5%) reduction in any-grade acute GI toxicity (P = .006). MRgRT was independently associated with improved any-grade GI toxicity and improved bowel QOL.

CONCLUSIONS

Postprostatectomy SBRT was well tolerated at short-term follow-up. MRgRT may decrease GI toxicity. Longer toxicity and/or efficacy follow-up and randomized studies are needed.

Using PSMA imaging for prognostication in localized and advanced prostate cancer

The use of prostate-specific membrane antigen (PSMA)-directed applications in modern prostate cancer management has evolved rapidly over the past few years, helping to establish new treatment pathways and provide further insights into prostate cancer biology. However, the prognostic implications of PSMA-PET have not been studied systematically, owing to rapid clinical implementation without long follow-up periods to determine intermediate-term and long-term oncological outcomes. Currently available data suggest that traditional prognostic factors and survival outcomes are associated with high PSMA expression (both according to immunohistochemistry and PET uptake) in men with localized and biochemically recurrent disease. Treatment with curative intent (primary and/or salvage) often fails when PSMA-positive metastases are present; however, the sensitivity of PSMA-PET in detecting all metastases is poor. Low PSMA-PET uptake in recurrent disease is a favourable prognostic factor; however, it can be associated with poor prognosis in conjunction with high ¹⁸F-fluorodeoxyglucose uptake in metastatic castration-resistant prostate cancer. Clinical trials embedding PSMA-PET for guiding management with reliable oncological outcomes are needed to support ongoing clinical use.

Identification of ZDHHC1 as a Pyroptosis Inducer and Potential Target in the Establishment of Pyroptosis-Related Signature in Localized Prostate Cancer

Pyroptosis or cellular inflammatory necrosis is a programmed cell death kind. Accumulating evidence shows that pyroptosis plays a crucial role in the invasion, metastasis, and proliferation of tumor cells, thus affecting the prognosis of tumors and therapeutic effects. Prostate cancer (PCa), a common malignancy among men, is associated with inflammation. Pathophysiological effects of pyroptosis on tumor development and progression, as well as the mediation of PCa, are known, but its effects on the potential prognosis for PCa warrant in-depth investigation. Herein, we built a risk model of six pyroptosis-related genes and verified their predictive abilities for prognostic and therapeutic effects. Higher risk scores indicated a higher probability of biochemical recurrence (BCR), higher immune infiltration, and worsened clinicopathological features. To derive scientific and reliable predictions for BCR in patients having PCa, the findings of the current study were verified in the Gene Expression Omnibus (GEO) cohort following evaluation in The Cancer Genome Atlas (TCGA) dataset. Additionally, after evaluating the six genes in the model, ZDHHC1 was found to be an important component. Its antitumor role was further assessed through in vivo and in vitro experiments, and its promoting effect on pyroptosis was further evaluated and verified. The above results provided a new perspective for further studies on pyroptosis and its clinical utility for PCa.

Single tertiary cancer center experience on the management of pT3b prostate cancer after robotic-assisted laparoscopic prostatectomy

Background

Pathological involvement of the seminal vesicle poses a treatment dilemma following robotic prostatectomy. Margin status plays an important role in deciding further management. A wide range of treatment options are available, including active monitoring, adjuvant radiotherapy, salvage radiotherapy, and occasionally androgen deprivation therapy. Patients undergoing postoperative radiotherapy tend to have higher risk of urinary and bowel morbidities. The recent RADICALS-RT concluded that adjuvant radiotherapy did not have any benefit compared with salvage radiotherapy. We aim to audit the incidence, margin status, and management of T3b cancer cases at our center.

Materials and methods

A retrospective analysis was conducted of all patients diagnosed with pathological T3b (pT3b) prostate cancer following robotic-assisted laparoscopic prostatectomy from January 2012 to July 2020. Preoperative parameters analyzed included prostate-specific antigen (PSA), T stage, and age. A chi-square test and 2-tailed t test were used to determine the relationship between categorical and continuous variables, respectively. Kaplan-Meier survival curves were generated to assess overall survival in patients with pT3b prostate cancer and used to compare unadjusted progression-free survival among those who underwent adjuvant and salvage radiotherapy.

Results

A total of 83 (5%) of 1665 patients who underwent robotic prostatectomy were diagnosed with pT3b prostate cancer between January 2012 and July 2020. Among these, 36 patients (44%) did not receive any radiotherapy during follow-up, compared with 26 patients (31%) who received adjuvant radiotherapy and 21 (25%) who received salvage radiotherapy. The median age of our cohort was 64 (SD, 6.4) years. Mean PSA at presentation was 12.7 μg/L. Positive margins were seen in 36 patients (43%); however, there was no statistically significant difference between treatment groups (p = 0.49). The median overall survival was 96%. There was no significant difference between the adjuvant and salvage groups in terms of biochemical progression-free survival (p = 0.66). Five-year biochemical progression-free survival was 94% for those in the adjuvant radiotherapy group and 97% for those in the salvage radiotherapy group.

Conclusions

Our audit corroborates with the recently concluded RADICALS-RT study, although we had fewer patients with positive margins. Radiotherapy can be avoided in patients with T3b prostate cancer, even if margin is positive, until there is definitive evidence of PSA recurrence. In keeping with the conclusion of RADICALS-RT, salvage radiotherapy may be preferable to adjuvant radiotherapy.

Failure Patterns by PSMA PET for Recurrent Prostate Cancer after Prostatectomy and Salvage Radiation

OBJECTIVE

To characterize patterns of failure using prostate-specific membrane antigen positron emission tomography (PSMA PET) after radical prostatectomy (RP) and salvage radiotherapy (SRT).

METHODS

Patients with rising PSA post-RP+SRT underwent 68Ga-HBED-iPSMA PET/CT on a single-arm, prospective imaging trial (NCT03204123). Scans were centrally reviewed with pattern-of-failure analysis by involved site. Positive scans were classified using 3 failure categories: pelvic nodal, extra-pelvic nodal or distant non-nodal. Associations with failure categories were analyzed using cumulative incidence and generalized logits regression.

RESULTS

We included 133 men who received SRT a median of 20 months post-RP; 56% received SRT to the prostatic fossa alone, while 44% received pelvic SRT. PSMA PET/CT was performed a median of 48 months post-SRT. Overall, 31% of PSMA PET/CT scans were negative, 2% equivocal and 67% had at least 1 positive site. Scan detection was significantly associated with PSA level prior to PSMA PET/CT. Analysis of 89 positive scans demonstrated pelvic nodal (53%) was the most common relapse and fossa relapse was low (9%). Overall, positive scans were pelvic (n = 35, 26%), extra-pelvic nodal (n = 26, 20%) or distant non-nodal failure (n = 28, 21%), and 70% of positive scans were oligorecurrent. We observed similar cumulative incidence for all failure categories and relatively few clinicodemographic associations. Men treated with pelvic SRT had reduced odds of pelvic failure versus exclusive fossa treatment.

CONCLUSION

Pelvic, extra-pelvic nodal, and distant non-nodal failures occur with similar incidence post-SRT. Regional nodal relapse is relatively common, especially with fossa-only SRT. A high oligorecurrence rate suggests a potentially important role for PSMA-guided focal therapies.

How can we best manage biochemical failure after radical prostatectomy?

Biochemical recurrence (BCR) is common after radical prostatectomy, but effective treatment options for men with BCR after curative treatment remain controversial. Although prostate-specific antigen is widely used as a surrogate marker for prostate cancer survival, it cannot fully differentiate between prostate-cancer-specific survival and overall survival. Thus, it is challenging for physicians to determine the timing of treatment to halt or slow the clinical progression of disease in patients with BCR while avoiding overtreatment for patients whose disease may not progress beyond BCR. Adjuvant therapy for radical prostatectomy or radiotherapy in intermediate- or high-risk localized prostate cancer has a benefit in terms of disease progression and survival but is not recommended in low-risk prostate cancer because of the significant adverse effects related to radiotherapy and androgen-deprivation therapy (ADT). Salvage radiotherapy (SRT) is also recommended for patients with BCR after radical prostatectomy. Several options for management of BCR after radical prostatectomy include SRT to the prostatic bed and/or pelvis, continuous or intermittent ADT, or observation. Patients' comorbidity, preferences, and cancer-related factors must be considered when deciding the best management strategy. Modern imaging technology such as positron emission tomography imaging of prostate-specific membrane antigen-positive regions enables earlier detection of disease progression, thus enhancing decision making for future disease management.

Postoperative Radiotherapy of Prostate Cancer: Adjuvant versus Early Salvage

Results of three randomized clinical trials (RCTs) comparing adjuvant radiotherapy (ART) and early salvage radiotherapy (eSRT) of prostate carcinoma and a subsequent meta-analysis of the individual patient data from these RCTs were recently published. The results suggest that early eSRT is as effective and potentially less toxic than ART. Therefore, eSRT should be considered the standard of care. However, due to limitations in the RCTs, ART remains a valid treatment option in patients with the combination of high-risk features such as Gleason Score (GS) 8–10, positive surgical margins (R1) and pathological T-stage 3 or 4 (pT3/4). This article provides a critical appraisal of the RCTs and the rationale for recommendations adopted in the current national guidelines regarding patients with high-risk features after radical prostatectomy (RP): ART should be offered in case of pT3/pT4 and R1 and Gleason Score 8–10; ART can be offered in case of pT3/pT4 and R0 and Gleason Score 8–10 as well as in case of multifocal R1 (including pT2) and Gleason Score 8–10. In any case, the alternative treatment option of eSRT in case of rising PSA should be discussed with the patient.

The maximum standardized uptake value in patients with recurrent or persistent prostate cancer after radical prostatectomy and PSMA-PET-guided salvage radiotherapy-a multicenter retrospective analysis

Purpose

This study aims to evaluate the association of the maximum standardized uptake value (SUVmax) in positron-emission tomography targeting prostate-specific membrane antigen (PSMA-PET) prior to salvage radiotherapy (sRT) on biochemical recurrence free survival (BRFS) in a large multicenter cohort.

Methods

Patients who underwent ⁶⁸ Ga-PSMA11-PET prior to sRT were enrolled in four high-volume centers in this retrospective multicenter study. Only patients with PET-positive local recurrence (LR) and/or nodal recurrence (NR) within the pelvis were included. Patients were treated with intensity-modulated-sRT to the prostatic fossa and elective lymphatics in case of nodal disease. Dose escalation was delivered to PET-positive LR and NR. Androgen deprivation therapy was administered at the discretion of the treating physician. LR and NR were manually delineated and SUVmax was extracted for LR and NR. Cox-regression was performed to analyze the impact of clinical parameters and the SUVmax-derived values on BRFS.

Results

Two hundred thirty-five patients with a median follow-up (FU) of 24 months were included in the final cohort. Two-year and 4-year BRFS for all patients were 68% and 56%. The presence of LR was associated with favorable BRFS (p = 0.016). Presence of NR was associated with unfavorable BRFS (p = 0.007). While there was a trend for SUVmax values ≥ median (p = 0.071), SUVmax values ≥ 75% quartile in LR were significantly associated with unfavorable BRFS (p = 0.022, HR: 2.1, 95%CI 1.1–4.6). SUVmax value in NR was not significantly associated with BRFS. SUVmax in LR stayed significant in multivariate analysis (p = 0.030). Sensitivity analysis with patients for who had a FU of > 12 months (n = 197) confirmed these results.

Conclusion

The non-invasive biomarker SUVmax can prognosticate outcome in patients undergoing sRT and recurrence confined to the prostatic fossa in PSMA-PET. Its addition might contribute to improve risk stratification of patients with recurrent PCa and to guide personalized treatment decisions in terms of treatment intensification or de-intensification.

This article is part of the Topical Collection on Oncology—Genitourinary.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-022-05931-5.

Bilateral Seminal Vesicle Invasion Is Not Associated with Worse Outcomes in Locally Advanced Prostate Carcinoma

Background and Objectives: Patients with seminal vesicle invasion (SVI) are a highly heterogeneous group. Prognosis can be affected by many clinical and pathological characteristics. Our aim was to study whether bilateral SVI (bi-SVI) is associated with worse oncological outcomes. Materials and Methods: This is an observational retrospective study that included 146 pT3b patients treated with radical prostatectomy (RP). We compared the results between unilateral SVI (uni-SVI) and bi-SVI. The log-rank test and Kaplan–Meier curves were used to compare biochemical recurrence-free survival (BCR), metastasis-free survival (MFS), and additional treatment-free survival. Cox proportional hazard models were used to identify predictors of BCR-free survival, MFS, and additional treatment-free survival. Results: 34.93% of patients had bi-SVI. The median follow-up was 46.84 months. No significant differences were seen between the uni-SVI and bi-SVI groups. BCR-free survival at 5 years was 33.31% and 25.65% (p = 0.44) for uni-SVI and bi-SVI. MFS at 5 years was 86.03% vs. 75.63% (p = 0.1), and additional treatment-free survival was 36.85% vs. 21.93% (p = 0.09), respectively. In the multivariate analysis, PSA was related to the development of BCR [HR 1.34 (95%CI: 1.01–1.77); p = 0.03] and metastasis [HR 1.83 (95%CI: 1.13–2.98); p = 0.02]. BCR was also influenced by lymph node infiltration [HR 2.74 (95%CI: 1.41–5.32); p = 0.003]. Additional treatment was performed more frequently in patients with positive margins [HR: 3.50 (95%CI: 1.65–7.44); p = 0.001]. Conclusions: SVI invasion is an adverse pathology feature, with a widely variable prognosis. In our study, bilateral seminal vesicle invasion did not predict worse outcomes in pT3b patients despite being associated with more undifferentiated tumors.

Immediate Versus Salvage Postoperative Radiotherapy in High-Risk Prostate Cancer Patients: A Critical Review

Radical prostatectomy in high-risk prostate cancer patients has long been followed by immediate adjuvant radiotherapy (IART) to increase biochemical relapse-free survival. However, the increased urinary and digestive radio-induced toxicities have raised questions about the safety of delaying radiotherapy until the occurrence of biochemical or clinical relapse. Recently, early salvage radiotherapy (ESRT) has been compared to IART, and results found equivalence in terms of efficiency outcomes, but increased toxicity was noted in patients receiving IART, leading to the proposal of ESRT as the new standard of care in high-risk patients after surgery. However, several confounding points are discussed in the present review regarding the methodology and results of these recent trials. Further follow-up is necessary to detect possible long-term advantages of one radiotherapy timing over the other.

Randomized Trial of Conventional Versus Conventional Plus Fluciclovine (18F) Positron Emission Tomography/Computed Tomography-Guided Postprostatectomy Radiation Therapy for Prostate Cancer: Volumetric and Patient-Reported Analyses of Toxic Effects

PURPOSE

Postprostatectomy radiation therapy planning with fluciclovine (¹⁸F) positron emission tomography (PET)/computed tomography has demonstrated improved disease-free survival over conventional only (computed tomography- or magnetic resonance imaging-based) treatment planning. We hypothesized that incorporating PET would result in larger clinical target volumes (CTVs) without increasing patient-reported toxic effects.

METHODS AND MATERIALS

From 2012 to 2019, 165 postprostatectomy patients with detectable prostate-specific antigen were randomized (arm 1 [no PET]: 82; arm 2 [PET]: 83). Prostate bed target volumes with (CTV1: 45.0-50.4 Gy/1.8 Gy) or without (CTV2/CTV: 64.8-70.2 Gy/1.8 Gy) pelvic nodes, as well as organ-at-risk doses, were compared pre- versus post-PET (arm 2) using the paired t test and between arms using the t test. Patient-reported outcomes used International Prostate Symptom Score and Expanded Prostate Cancer Index Composite for Clinical Practice (EPIC-CP). Univariate and multivariable analyses were performed and linear mixed models were fitted.

RESULTS

Median follow-up of the whole cohort was 3.52 years. All patients had baseline patient-reported outcomes, 1 patient in arm 1 and 3 patients in arm 2 withdrew, and 4 arm 2 patients had extrapelvic uptake on PET with radiotherapy aborted, leaving 81 (arm 1) and 76 patients (arm 2) for analysis of toxic effects. Mean CTV1 (427.6 vs 452.2 mL; P = .462, arm 1 vs arm 2) and CTV2/CTV (137.18 vs 134.2 mL; P = .669) were similar before PET incorporation. CTV1 (454.57 vs 461.33 mL; P = .003) and CTV2/CTV (134.14 vs 135.61 mL; P < .001) were modestly larger after PET incorporation. Although V40 Gy (P = .402 and P = .522 for rectum and bladder, respectively) and V65 Gy (P = .157 and P = .182 for rectum and bladder, respectively) were not significantly different pre- versus post-PET, penile bulb dose significantly increased post-PET (P < .001 for both V40 Gy and V65 Gy). On univariate and multivariable analyses, arm was not significant for any EPIC-CP subdomain. International Prostate Symptom Score and EPIC-CP linear mixed models were not significantly different between arms.

CONCLUSIONS

Despite larger CTVs after incorporation of fluciclovine (¹⁸F) PET, we found no significant difference in patient-reported toxic effects with long-term follow-up.

Defining Prostatic Vascular Pedicle Recurrence and the Anatomy of Local Recurrence of Prostate Cancer on Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography

Background

The term local recurrence in prostate cancer is considered to mean persistent local disease in the prostatic bed, most commonly at the site of the vesicourethral anastomosis (VUA). Since the introduction of prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging for assessment of early biochemical recurrence (BCR), we have found histologically confirmed prostate cancer in the prostatic vascular pedicle (PVP). If a significant proportion of local recurrences are distant to the VUA, it may be possible to alter adjuvant and salvage radiation fields in order to reduce the potential morbidity of radiation in selected patients.

Objective

To describe PVP local recurrence and to map the anatomic pattern of prostate bed recurrence on PSMA PET/CT.

Design, setting, and participants

This was a retrospective multicentre study of 185 patients imaged with PSMA PET/CT following radical prostatectomy (RP) between January 2016 and November 2018. All patient data and clinical outcomes were prospectively collected. Recurrences were documented according to anatomic location. For patients presenting with local recurrence, the precise location of the recurrence within the prostate bed was documented.

Intervention

PSMA PET/CT for BCR following RP.

Results and limitations

A total of 43 local recurrences in 41/185 patients (22%) were identified. Tumour recurrence at the PVP was found in 26 (63%), VUA in 15 (37%), and within a retained seminal vesicle and along the anterior rectal wall in the region of the neurovascular bundle in one (2.4%) each. Histological and surgical evidence of PVP recurrence was acquired in two patients. The study is limited by its retrospective nature with inherent selection bias. This is an observational study reporting on the anatomy of local recurrence and does not include follow-up for patient outcomes.

Conclusions

Our study showed that prostate cancer can recur in the PVP and is distant to the VUA more commonly than previously thought. This may have implications for RP technique and for the treatment of selected patients in the local recurrence setting.

Patient summary

We investigated more precise identification of the location of tumour recurrence after removal of the prostate for prostate cancer. We describe a new definition of local recurrence in an area called the prostatic vascular pedicle. This new concept may alter the treatment recommended for recurrent disease.

Construction and validation of N6-methyladenosine long non-coding RNAs signature of prognostic value for early biochemical recurrence of prostate cancer

PURPOSE

Early biochemical recurrence (eBCR) indicated a high risk for potential recurrence and metastasis in prostate cancer. The N6-methyladenosine (m6A) methylation modification played an important role in prostate cancer progression. This study aimed to develop a m6A lncRNA signature to accurately predict eBCR in prostate cancer.

METHODS

Pearson correlation analysis was first conducted to explore m6A lncRNAs and univariate Cox regression analysis was further performed to identify m6A lncRNAs of prognostic roles for predicting eBCR in prostate cancer. The m6A lncRNA signature was constructed by least absolute shrinkage and selection operator analysis (LASSO) in training cohort and further validated in test cohort. Furthermore, half maximal inhibitory concentration (IC50) values were utilized to explore potential effective drugs for high-risk group in this study.

RESULTS

Five hundred and thirty-eighth m6A lncRNAs were searched out through Pearson correlation analysis and 25 out of 538 m6A lncRNAs were identified to pose prediction roles for eBCR in prostate cancers. An m6A lncRNA signature including 5 lncRNAs was successfully built in training cohort. The high-risk group derived from m6A lncRNA signature could efficiently predict eBCR occurrence in both training (p < 0.001) and test cohort (p = 0.002). ROC analysis also confirmed that lncRNA signature in this study posed more accurate prediction roles for eBCR occurrence when compared with PSA, TNM stages and Gleason scores. Drug sensitivity analysis further discovered that various drugs could be potentially utilized to treat high-risk samples in this study.

CONCLUSIONS

The m6A lncRNA signature in this study could be utilized to efficiently predict eBCR occurrence, various clinical characteristic and immune microenvironment for prostate cancer.

A meta-analysis on the use of radiotherapy after prostatectomy: adjuvant versus early salvage radiation

To determine which method of radiotherapy proves more effective after prostatectomy: Adjuvant (ART) or early salvage (ESRT), we observed the pathologic and adverse risk factors of patients and their results from both treatments, looking specifically at biochemical-free survival rates, metastasis-free survival rates, and overall survival rates. Peer review articles containing their own data collected between 1986 and 2022 were reviewed. We reviewed 67 peer review articles and included 33 that met criteria. Studies focused on the adverse risk factors and the results of patients either before/after receiving adjuvant or early salvage/salvage radiotherapy were included in the analysis. Patient characteristics had an effect on what treatment a patient would receive; if a patient had more than one adverse risk factor such as a high Gleason score, prostate-specific antigen (PSA) level, T-stage, or positive margins, they would receive immediate radiation after prostatectomy, which would classify as ART. If the patient had no adverse risk factors after surgery, they would be placed in an observation period to follow their PSA and overall health, and only if necessary, undergo ESRT. Of the 33 studies, ART was proven to be only slightly more beneficial when relating to biochemical recurrence-free survival while ART and ESRT results were similar in metastasis-free survival and overall survival. ART and ESRT are overall comparable in their patient outcomes, despite their own unique pros and cons. The use of ESRT reduces overtreatment in men who may not experience biochemical recurrence. However, in those with very high-risk pathologic features, a multi-disciplinary approach should be utilized to best determine which mode of radiation therapy after surgery is recommended.

The addition of androgen deprivation therapy and pelvic lymph node treatment to prostate bed salvage radiotherapy (NRG Oncology/RTOG 0534 SPPORT): an international, multicentre, randomised phase 3 trial

BACKGROUND

In men with a detectable prostate-specific antigen (PSA) level after prostatectomy for prostate cancer, salvage prostate bed radiotherapy (PBRT) results in about 70% of patients being free of progression at 5 years. A three-group randomised trial was designed to determine whether incremental gains in patient outcomes can be achieved by adding either 4-6 months of short-term androgen deprivation therapy (ADT) to PBRT, or both short-term ADT and pelvic lymph node radiotherapy (PLNRT) to PBRT.

METHODS

The international, multicentre, randomised, controlled SPPORT trial was done at 283 radiation oncology cancer treatment centres in the USA, Canada, and Israel. Eligible patients (aged ≥18 years) were those who after prostatectomy for adenocarcinoma of the prostate had a persistently detectable or an initially undetectable and rising PSA of between 0·1 and 2·0 ng/mL. Patients with and without lymphadenectomy (N0/Nx) were eligible if there was no clinical or pathological evidence of lymph node involvement. Other eligibility criteria included pT2 or pT3 disease, prostatectomy Gleason score of 9 or less, and a Zubrod performance status of 0-1. Eligible patients were randomly assigned to receive PBRT alone at a dose of 64·8-70·2 Gy at 1·8 Gy per fraction daily (group 1), PBRT plus short-term ADT (group 2), or PLNRT (45 Gy at 1·8 Gy per fraction, and then a volume reduction made to the planning target volume for the remaining 19·8-25 ·2 Gy) plus PBRT plus short-term ADT (group 3). The primary endpoint was freedom from progression, in which progression was defined as biochemical failure according to the Phoenix definition (PSA ≥2 ng/mL over the nadir PSA), clinical failure (local, regional, or distant), or death from any cause. A planned interim analysis of 1191 patents with minimum potential follow-up time of 5 years applied a Haybittle-Peto boundary of p<0·001 (one sided) for comparison of 5-year freedom from progression rates between the treatment groups. This trial is registered with ClinicalTrials.gov, NCT00567580. The primary objectives of the trial have been completed, although long-term follow-up is continuing.

FINDINGS

Between March 31, 2008, and March 30, 2015, 1792 eligible patients were enrolled and randomly assigned to the three treatment groups (592 to group 1 [PBRT alone], 602 to group 2 [PBRT plus short-term ADT], and 598 to group 3 [PLNRT plus PBRT plus short-term ADT]). 76 patients subsequently found to be ineligible were excluded from the analyses; thus, the evaluable patient population comprised 1716 patients. At the interim analysis (n=1191 patients; data cutoff May 23, 2018), the Haybittle-Peto boundary for 5-year freedom from progression was exceeded when group 1 was compared with group 3 (difference 17·9%, SE 2·9%; p<0·0001). The difference between groups 2 and 3 did not exceed the boundary (p=0·0063). With additional follow-up beyond the interim analysis (the final planned analysis; data cutoff May 26, 2021), at a median follow-up among survivors of 8·2 years (IQR 6·6-9·4), the 5-year freedom from progression rates in all 1716 eligible patients were 70·9% (95% CI 67·0-74·9) in group 1, 81·3% (78·0-84·6) in group 2, and 87·4% (84·7-90·2) in group 3. Per protocol criteria, freedom from progression in group 3 was superior to groups 1 and 2. Acute (≤3 months after radiotherapy) grade 2 or worse adverse events were significantly more common in group 3 (246 [44%] of 563 patients) than in group 2 (201 [36%] of 563; p=0·0034), which, in turn, were more common than in group 1 (98 [18%] of 547; p<0·0001). Similar findings were observed for grade 3 or worse adverse events. However, late toxicity (>3 months after radiotherapy) did not differ significantly between the groups, apart from more late grade 2 or worse blood or bone marrow events in group 3 versus group 2 (one-sided p=0·0060) attributable to the addition of PLNRT in this group.

INTERPRETATION

The results of this randomised trial establish the benefit of adding short-term ADT to PBRT to prevent progression in prostate cancer. To our knowledge, these are the first such findings to show that extending salvage radiotherapy to treat the pelvic lymph nodes when combined with short-term ADT results in meaningful reductions in progression after prostatectomy in patients with prostate cancer.

FUNDING

National Cancer Institute.

Risk of severe late toxicity after radiotherapy following radical prostatectomy - a nationwide study

BACKGROUND

Severe side-effects are rare but may occur years after radiation therapy following radical prostatectomy. We sought to estimate the long-term risks of severe late toxicities in an unselected, nationwide, cohort.

METHODS

The study population comprised all men undergoing radical prostatectomy between 1997-2016 in the Prostate Cancer database Sweden (PCBaSe) (n=40,962). By (1:2) matching, two cohorts were created: 2789 men exposed to postoperative radiation and 5578 nonexposed men with comparable age, comorbidities and year of surgery. Cumulative incidences and rate ratios were calculated for the following outcomes: symptoms and interventions of the urinary or intestinal tract demanding inpatient care, secondary malignancies and non-prostate cancer mortality.

RESULTS

The largest differences were seen for late toxicities affecting the urinary tract. The 10-year cumulative incidences among those exposed to postoperative radiation versus the surgery only group were: 17.8% versus 10.5% for procedures of the urinary tract (difference 7.3%, 95% confidence interval [CI] 4.4 to 10.3; relative risk [RR] 1.74, 95% CI 1.47 to 2.05); 6.0% versus 1.2% for hematuria (difference 4.8%, 95% CI 3.1 to 6.5; RR 6.50 95% CI 4.31 to 10.10); and 2.4% versus 1.1% for bladder cancer (difference 1.4%, 95% CI 0.4 to 2.3; RR 2.71 95% CI 1.72 to 4.33). The groups were similar regarding intestinal toxicity, other secondary malignancies, and non-prostate cancer mortality. Adjustments for preoperative tumor risk factors did not importantly affect the rate ratios.

CONCLUSION

Severe late toxicity after postoperative radiation following radical prostatectomy predominately affects the bladder and can appear many years after radiotherapy.

Radiation therapy after radical prostatectomy is associated with higher other-cause mortality

PURPOSE

To test the association between external beam radiotherapy (EBRT) after radical prostatectomy (RP) vs RP only on rates of other-cause mortality (OCM) in men with prostate cancer (PCa).

PATIENTS AND METHODS

Within the 2004-2016 Surveillance, Epidemiology, and End Results database, we identified 181,849 localized PCa patients, of whom 168,041 received RP only vs 13,808 who received RP + EBRT. Cumulative incidence plots displayed OCM between RP vs RP + EBRT after propensity score matching for age, PSA, clinical T- and N-stages, and biopsy Gleason scores. Multivariable competing risks regression models addressed OCM, accounting prostate cancer-specific mortality (CSM) as a competing event. Stratifications were made according to low- vs intermediate- vs high-risk groups and additionally according to age groups of ≤ 60, 61-70, and ≥ 71 years, within each risk group.

RESULTS

In low-, intermediate-, and high-risk patients, RP + EBRT rates were 2.7, 5.4 and 17.0%, respectively. After matching, 10-year OCM rates between RP and RP + EBRT were 7.7 vs 16.2% in low-, 9.4 vs 13.6% in intermediate-, and 11.4 vs 13.5% in high-risk patients (all p < 0.001), which, respectively, resulted in multivariable HR of 2.1, 1.3, and 1.2 (all p < 0.001). In subgroup analyses, excess OCM was recorded in low-risk RP + EBRT patients of all age groups (all p ≤ 0.03), but only in the older age group in intermediate-risk patients (61-70 years, p = 0.03) and finally, only in the oldest age group in high-risk patients (≥ 71 years, p = 0.02).

CONCLUSION

Excess OCM was recorded in patients exposed to RT after RP. Its extent was most pronounced in low-risk patients, decreased in intermediate-risk patients, and was lowest in high-risk patients.

Interim analysis of companion, prospective, phase II, clinical trials assessing the efficacy and safety of multi-modal total eradication therapy in men with synchronous oligometastatic prostate cancer

Multimodal therapies were combined to eradicate the primary site, metastatic, and micrometastatic disease in men with newly diagnosed, synchronous, oligometastatic prostate cancer. The investigation included companion, phase II studies: total eradication therapy-1 (TET-1) for those treatment-naïve and total eradication therapy-2 (TET-2) for those post-prostatectomy. The treatment-naive protocol included androgen deprivation and docetaxel (with concurrent abiraterone added in a protocol amendment), followed by a prostatectomy, adjuvant radiation (if positive margins, T3/4, or detectable PSA), and metastasis-directed therapy. The post-prostatectomy protocol assigned the same therapies (omitting the prostatectomy). The primary endpoint was an undetectable PSA with recovered testosterone. The safety boundaries were ≤ 50% for grade 3/4 neutropenic and ≤ 20% for grade 3/4 surgical- and radiation-related toxicities. Enrollment was planned for 60 patients per protocol, to detect a PSA progression-free survival ≥ 32%, as compared to 15% in a historic control. Enrollment closed early. An interim analysis was conducted once > 50% of patients were evaluable for the primary endpoint. The primary endpoint duration was assessed by median progression-free survival. 52 patients were enrolled (n = 26 per protocol). Medium follow-up was 30.3 months. 80% (24/30) of evaluable patients achieved the primary endpoint; the duration was not reached. Of those not evaluable, 77% (17/22) had not reached the endpoint and 23% (5/22) had exited. There were 8% (4/52) grade 3/4 neutropenic and 2% (1/48) grade 3/4 surgical or radiation-induced toxicities. Interim findings suggest the trials' endpoints were met, advancing the concept of total eradication therapy in men with oligometastatic prostate cancer.

Characterization of a Pyroptosis-Related Signature for Prognosis Prediction and Immune Microenvironment Infiltration in Prostate Cancer

This study was aimed at constructing a pyroptosis-related signature for prostate cancer (PCa) and elucidating the prognosis and immune landscape and the sensitivity of immune checkpoint blockade (ICB) therapy in signature-define subgroups of PCa. We identified 22 differentially expressed pyroptosis-related genes in PCa from The Cancer Genome Atlas (TCGA) database. The pyroptosis-related genes could divide PCa patients into two clusters with differences in survival. Seven genes were determined to construct a signature that was confirmed by qRT-PCR to be closely associated with the biological characteristics of malignant PCa. The signature could effectively and independently predict the biochemical recurrence (BCR) of PCa, which was validated in the GSE116918 and GSE21034. We found that patients in the high-risk group were more prone to BCR and closely associated with high-grade and advanced-stage disease progression. Outperforming clinical characteristics and nine published articles, our signature demonstrated excellent predictive performance. The patients in the low-risk group were strongly related to the high infiltration of various immune cells including CD8+ T cells and plasma B cells. Furthermore, the high-risk group with higher TMB levels and expression of immune checkpoints was more likely to benefit from immune checkpoint therapy such as PD-1 and CTLA-4 inhibitors. The sensitivity to chemotherapy, endocrine, and targeted therapy showed significant differences in the two risk groups. Our signature was a novel therapeutic strategy to distinguish the prognosis and guide treatment strategies.