Koontz, Bridget F.

TPS283 Background: There is no clear standard of care for biochemically recurrent prostate cancer (PCa) with positron emission tomography (PET)-detected oligometastases and normal conventional imaging (CIM). Phase II trials show that stereotactic ablative body radiotherapy (SABR) to oligometastases may delay cancer progression and initiation of androgen deprivation therapy (ADT) and its untoward effects. ADT with radiation prolongs survival in locally advanced PCa and in CIM metastatic PCa. However, there is a knowledge gap about timing and benefit vs toxicity of ADT with SABR in early oligometastatic PCa. NRG GU011 (PROMETHEAN) is a randomized phase II trial of SABR with or without relugolix for early PET-detected recurrent oligometastatic PCa. This study aims to evaluate the impact of relugolix, a novel oral gonadotropin-releasing hormone receptor antagonist, when combined with SABR to oligometastases. Relugolix allows for rapid testosterone recovery and is associated with fewer cardiovascular events when compared to leuprolide and is hypothesized to have low late ADT toxicity. GU011 will provide patients and their physicians data on the relative risks and benefits of early or delayed ADT in this setting. Methods: NRG-GU011 NCT# 05053152 is a randomized phase II double-blinded, placebo-controlled trial with randomization to SABR + 6 months placebo vs SABR + 6 months relugolix. Eligible patients have biochemical recurrence after prior curative intent radiation or surgery for localized PCa, PSA < 10 ng/mL, negative CIM and 1-5 PET-evident metastases (≥1 extrapelvic). SABR is delivered in 1-5 fractions to BED >100 Gy1.5, followed by placebo or relugolix 120mg daily for 6 months. Patients will then be followed with imaging at time of biochemical recurrence. The planned sample size of 260 patients (130 per arm) will provide 85% power to detect a hazard ratio of 0.65 for radiographic progression-free survival (rPFS), based on a one-sided test at alpha 0.10. Planned enrollment is predicted at 8 patients per month with an estimated study completion date of late 2026. The primary endpoint is CIM rPFS. Secondary endpoints include PET-based rPFS, sexual and hormonal quality of life (QoL) assessed by EPIC-26, other QoL measures from EQ5D-5L, EORTC QLQ-30 and PROMIS Fatigue, and between-group comparisons of time to salvage therapy, castration-resistance, local progression (SABR-targeted lesion), biochemical progression, distant metastases, prostate cancer-specific mortality, metastasis-free survival, and overall survival. We also aim to determine adverse event rates for both treatment arms and evaluate genomic and blood markers of treatment response. This study opened in December 2021. Clinical trial information: NCT05053152 .

AbstractBackgroundPatients with prostate cancer suffer significant sexual dysfunction after treatment which negatively affects them and their partners psychologically, and strain their relationships.AimWe convened an international panel with the aim of developing guidelines that will inform clinicians, patients and partners about the impact of prostate cancer therapies (PCT) on patients’ and partners’ sexual health, their relationships, and about biopsychosocial rehabilitation in prostate cancer (PC) survivorship.MethodsThe guidelines panel included international expert researchers and clinicians, and a guideline methodologist. A systematic review of the literature, using the Ovid MEDLINE, Scopus, CINAHL, PsychINFO, LGBT Life, and Embase databases was conducted (1995–2022) according to the Cochrane Handbook for Systematic Reviews of Interventions. Study selection was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Each statement was assigned an evidence strength (A-C) and a recommendation level (strong, moderate, conditional) based on benefit/risk assessment, according to the nomenclature of the American Urological Association (AUA). Data synthesis included meta-analyses of studies deemed of sufficient quality (3), using A Measurement Tool to Assess Systematic Reviews (AMSTAR).OutcomesGuidelines for sexual health care for patients with prostate cancer were developed, based on available evidence and the expertise of the international panel.ResultsThe guidelines account for patients’ cultural, ethnic, and racial diversity. They attend to the unique needs of individuals with diverse sexual orientations and gender identities. The guidelines are based on literature review, a theoretical model of sexual recovery after PCT, and 6 principles that promote clinician-initiated discussion of realistic expectations of sexual outcomes and mitigation of sexual side-effects through biopsychosocial rehabilitation. Forty-seven statements address the psychosexual, relationship, and functional domains in addition to statements on lifestyle modification, assessment, provider education, and systemic challenges to providing sexual health care in PC survivorship.Clinical ImplicationsThe guidelines provide clinicians with a comprehensive approach to sexual health care for patients with prostate cancer.Strengths & LimitationsThe strength of the study is the comprehensive evaluation of existing evidence on sexual dysfunction and rehabilitation in prostate cancer that can, along with available expert knowledge, best undergird clinical practice. Limitation is the variation in the evidence supporting interventions and the lack of research on issues facing patients with prostate cancer in low and middle-income countries.ConclusionThe guidelines document the distressing sexual sequelae of PCT, provide evidence-based recommendations for sexual rehabilitation and outline areas for future research.

ABSTRACTBackgroundProstatic radiation therapy (RT) leads to erectile dysfunction by damaging peri-prostatic pro-erectile nerves of the pelvic ganglion. Schwann cells (SC) facilitate neuronal repair after mechanical injury, however, their role in repair of pelvic neurons post-radiation hasn’t been explored.AimTo determine if SCs cocultured with primary pelvic neurons can rescue neuronal survival and growth after ex vivo RT.MethodsMajor pelvic ganglia (MPG) were collected from adult male Sprague-Dawley rats (n = 12) to isolate SCs. SCs received RT (0 or 8 Gy), were plated on coated coverslips and grown to confluence before the addition of neurons. Additional MPGs were irradiated (0 or 8 Gy) and digested to isolate pelvic neurons. Dissociated neurons were plated alone or atop SC-coated coverslips to create 6 experimental groups (n = 3/grp): (i) Control (CON) MPG, (ii) RT MPG, (iii) CON SC + CON MPG, (iv) CONSC + RT MPG, (v) RT SC + CON MPG, and (iv) RT SC + RT MPG. After 72 hours, coverslips were fixed and stained for beta-tubulin (neuron marker), S100 (SC marker), neuronal nitric oxide synthase (nitrergic marker), tyrosine hydroxylase (sympathetic marker), and terminal deoxynucleotidyl transferase dUTP nick-end labeling.OutcomesWe measured neurite length, branching, specific neuron populations and apoptosis.ResultsEx vivo RT decreased MPG neuron length, increased apoptosis and decreased nitrergic neurons in monoculture. Compared to all other groups, CON SC + RT MPG cocultures demonstrated increased neurite outgrowth (P &lt; .001). Neurite branching was decreased in the RT MPG + RT SC coculture, but unchanged in other cocultures. Groups containing RT MPG neurons exhibited increased apoptosis, but coculture with CON SC reduced the degree of RT-induced apoptosis (P &lt; .01). The number of tyrosine hydroxylase positive neurons was unchanged while nitrergic neurons were significantly lower in RT neurons and coculture with CON SCs was unable to prevent nitrergic loss.Clinical TranslationThese findings suggest that SCs may be an important target in prostate cancer patients with radiation-induced pelvic neuropathy to promote MPG neuron survival and neuronal repair after RT.Strengths and LimitationsThis is the first study to characterize the ex vivo ability of SCs to rescue pelvic nerve growth and survival. The study is limited by little supporting mechanistic molecular data and the need to confirm the ability of healthy SCs to promote pelvic neuron survival and repair following prostatic RT in vivo.ConclusionUnirradiated SCs partially mitigated RT-induced MPG apoptosis but did not affect the loss of nitrergic neuron populations suggesting that SCs promote irradiated MPG neuron survival and facilitate intrinsic repair functions.

24 Background: The use of radical prostatectomy (RP) as initial treatment of high-risk/locally-advanced prostate cancer is increasing but patients (pts) with adverse pathologic features such as positive surgical margins or T3 disease have up to 70% recurrence risk. These high-risk pts may be managed with adjuvant radiotherapy (ART) or early salvage radiotherapy (ESRT). The optimal timing of post-operative radiotherapy is unclear. Methods: Individual data from 1566 consecutive pts with pT2N0M0/R1 or pT3N0M0/R0-1 disease who underwent post-prostatectomy ART or ESRT (1987-2013) at 10 academic centers were pooled. Post-irradiation freedom from biochemical failure (FFBF), freedom from distant metastases (FFDM), prostate-cancer specific survival (PCSS), and overall survival (OS) were compared using Kaplan-Meier and multivariate competing-risks regression (MVA) analyses. Propensity score (PS) matching was used to account for covariates potentially associated with treatment allocation. All outcomes were measured from the date of surgery to address lead time bias. Results: After PS-matching, median follow-up after surgery was 66 vs. 73 months for the ART and ESRT groups, respectively, and baseline characteristics were well-matched. ART was associated with higher FFBF (12-yr: 69% vs. 43%; log-rank P < 0.0001), FFDM (12-yr: 95% vs. 85%; log-rank P = 0.03), PCSS (12-yr: 99% vs. 94%; log-rank P = 0.048), and OS (12-yr: 91% vs. 79%; log-rank P = 0.01). ART, lower Gleason score, lower T-stage, nodal irradiation, and postoperative androgen deprivation therapy were favorable prognostic features on MVA for BF. Sensitivity analysis demonstrated that the decreased risk of BF associated with ART remained significant unless more than 56% of ART pts were cured by surgery alone. This threshold is greater than the estimated 12-yr FFBF of 46% after RP alone as determined by a contemporary nomogram. Conclusions: To the best of our knowledge, this represents the largest multi-institutional study to date comparing ART to ESRT. ART was associated with reduced biochemical recurrence, distant metastases, and death compared to ESRT for high-risk pts, pending prospective validation.

9 Background: Early salvage radiation therapy (SRT) following radical prostatectomy (RP) has been shown to reduce biochemical recurrence and distant metastases. We aim to identify factors predictive of prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) from a consortium database from 10 academic institutions. Methods: 2,454 node-negative patients (pts) with detectable post-prostatectomy PSA ( ≥ 0.01 ng/mL) treated with SRT ± neoadjuvant/concurrent androgen deprivation therapy (N/C ADT) were included. Cumulative incidence and Kaplan-Meier methods were used to estimate rates of PCSM and ACM, respectively. Univariate and multivariable analyses (MVA) were performed by competing risks regression and Cox proportional hazards methods for PCSM and ACM. Results: Median follow-up was 5 years from SRT completion and 8 years from date of RP; 24% had pathologic Gleason score (GS) of ≤ 6, 56% GS 7, and 19% GS ≥ 8; 56% extraprostatic extension (EPE), 18% seminal vesicle invasion (SVI), 58% positive surgical margins, and 16% received N/C ADT. Median age at RP and SRT were 62 years (IQR 56-66) and 64 years (59-69), respectively. Median SRT dose was 66 Gy (IQR 65-68) and median pre-SRT PSA was 0.5 ng/mL (IQR 0.3-1.1). MVA performed from SRT completion date demonstrated higher pre-SRT PSA (HR = 2.1), higher GS (GS 7 vs. ≤ 6: HR 2.0; GS ≥ 8 vs. 6: HR 3.3) , SVI (HR 2.5), year of SRT (2000-2004, 1995-1999, 1985-1994 vs. 2005-2012; HR 2.9, HR 2.5, HR 3.6, respectively) were significantly associated with higher PCSM. These same variables were all significantly associated with higher PCSM and ACM rates calculated from both SRT completion date and date of RP. Conclusions: Initiation of early SRT at lower post-operative PSA levels following RP is associated with reduced risk of PCSM and ACM, even when calculated from RP date to account for lead time bias. Other factors significantly associated with PCSM include higher GS, SVI, and earlier year of SRT. [Table: see text]

1 Background: To determine whether the efficacy of a hypofractionated (H) schedule is no worse than a conventional (C) schedule in men with low-risk prostate cancer. Methods: From April 2006 to December 2009, one thousand one hundred fifteen men with low-risk prostate cancer (clinical stage T1-2a, Gleason ≤ 6, PSA < 10) were randomly assigned 1:1 to a conventional (C) schedule (73.8 Gy in 41 fractions over 8.2 weeks) or to a hypofractionated (H) schedule (70 Gy in 28 fractions over 5.6 weeks). The trial was designed to establish with 90% power and alpha = 0.05 that (H) results in 5-year disease-free survival (DFS) that is not lower than (C) by more than 7% (hazard ratio (HR) < 1.52). Secondary endpoints include freedom from biochemical recurrence (FFBR) and overall survival. At the third planned interim analysis (July 2015), the NRG Oncology Data Monitoring Committee recommended that the results of the trial be reported. Results: One thousand one hundred and one protocol eligible men were randomized: 547 to C and 554 to H. Median follow-up is 5.9 years. Baseline characteristics are not different according to treatment arm. At the time of analysis 185 DFS events have been observed; 99 in the C arm and 86 in the H arm. The estimated 7-year disease-free survival is 75.6% (95% CI 70.3, 80.1) in the C arm and 81.8% (77.5, 85.3) in the H arm. The DFS HR (C/H) is 0.85 (0.64, 1.14). Comparison of biochemical recurrence (HR = 0.77, (0.51, 1.17)) and overall survival (HR = 0.95, (0.65, 1.41)) also met protocol non-inferiority criteria. Grade ≥ 3 GI toxicity is 3.0% (C) vs. 4.6% (H), Relative risk (RR) for H vs. C 1.53, (95% CI 0.86, 2.83); grade ≥ 3 GU toxicity is 4.5% (C) vs. 6.4% (H), RR = 1.43 (0.86,2.37). Conclusions: In men with low-risk prostate cancer, 70 Gy in 28 fractions over 5.6 weeks is non-inferior to 73.8 Gy in 41 fractions over 8.2 weeks. Clinical trial information: NCT00331773.

Purpose We aimed to update a previously published, multi-institutional nomogram of outcomes for salvage radiotherapy (SRT) following radical prostatectomy (RP) for prostate cancer, including patients treated in the contemporary era. Methods Individual data from node-negative patients with a detectable post-RP prostate-specific antigen (PSA) treated with SRT with or without concurrent androgen-deprivation therapy (ADT) were obtained from 10 academic institutions. Freedom from biochemical failure (FFBF) and distant metastases (DM) rates were estimated, and predictive nomograms were generated. Results Overall, 2,460 patients with a median follow-up of 5 years were included; 599 patients (24%) had a Gleason score (GS) ≤ 6, 1,387 (56%) had a GS of 7, 244 (10%) had a GS of 8, and 230 (9%) had a GS of 9 to 10. There were 1,370 patients (56%) with extraprostatic extension (EPE), 452 (18%) with seminal vesicle invasion (SVI), 1,434 (58%) with positive surgical margins, and 390 (16%) who received ADT (median, 6 months). The median pre-SRT PSA was 0.5 ng/mL (interquartile range, 0.3 to 1.1). The 5-yr FFBF rate was 56% overall, 71% for those with a pre-SRT PSA level of 0.01 to 0.2 ng/mL (n = 441), 63% for those with a PSA of 0.21 to 0.50 ng/mL (n = 822), 54% for those with a PSA of 0.51 to 1.0 ng/mL (n = 533), 43% for those with a PSA of 1.01 to 2.0 ng/mL (n = 341), and 37% for those with a PSA > 2.0 ng/mL (n = 323); P < .001. On multivariable analysis, pre-SRT PSA, GS, EPE, SVI, surgical margins, ADT use, and SRT dose were associated with FFBF. Pre-SRT PSA, GS, SVI, surgical margins, and ADT use were associated with DM, whereas EPE and SRT dose were not. The nomogram concordance indices were 0.68 (FFBF) and 0.74 (DM). Conclusion Early SRT at low PSA levels after RP is associated with improved FFBF and DM rates. Contemporary nomograms can estimate individual patient outcomes after SRT in the modern era.