Eggener, Scott E.

208 Background: In the Phase 3 PRESTO study, intensified androgen deprivation therapy (ADT) with apalutamide (APA) with or without abiraterone acetate plus prednisone (AAP), administered for a finite treatment period of 52 weeks, prolonged prostate-specific antigen progression-free survival (PSA PFS) in pts with high-risk biochemically relapsed prostate cancer (BRPC). We evaluated baseline factors associated with PSA PFS in this study. Methods: PRESTO is a randomized phase 3, open-label trial in pts with BRPC following radical prostatectomy (RP) and PSA doubling time (PSADT) ≤ 9 months (mo), without distant metastases on conventional imaging (NCT03009981). Pts were randomized 1:1:1 to receive a finite 52-week treatment course with ADT, ADT + APA, or ADT + APA + AAP, stratified by PSADT (< 3 vs 3–9 mo), with post-treatment follow-up. Baseline factors associated with PSA PFS including Gleason sum at RP (6-7, 8, ≥ 9) were analyzed in a post hoc fashion. Results: 504 pts were randomized to ADT alone (N = 167), ADT + APA (N = 168) or ADT + APA + AAP (N = 169). Baseline patient characteristics including Gleason sum at diagnosis, serum PSA and PSADT at study entry, time interval from radical prostatectomy, and receipt of prior radiation (none, adjuvant, salvage) were well balanced across the three treatment arms. At the first planned interim analysis, both experimental arms significantly prolonged PSA PFS compared to the control arm (median 24.9 mo for ADT + APA vs 20.3 mo for ADT, HR = 0.52 (95% CI: 0.35–0.77); median 26.0 mo for ADT + APA + AAP vs 20.0 mo for ADT, HR = 0.48 (95% CI: 0.32–0.71)). Across the study cohort, Gleason sum ≥ 9 at diagnosis was associated with shorter PSA PFS (median 21.9 mo for Gleason ≥ 9 vs. 31.1 mo for Gleason 8 vs. 25.2 mo for Gleason 6-7, log-rank p-value = 0.0409). In addition, within each treatment arm, a shorter observed median PSA PFS was detected for patients with Gleason ≥ 9 prostate cancer. Serum PSA and PSADT at study entry, time from prior radical prostatectomy, and prior radiation were not associated with PSA PFS in the overall study cohort or in individual study arms. Conclusions: Gleason sum ≥ 9 prostate cancer at diagnosis was associated with shorter time to PSA progression following subsequent intensified ADT administered for a finite treatment interval in BRPC. Follow-up is ongoing to integrate genomic profiling of primary prostate cancer tissue with these results and validate with longer term endpoints including metastasis-free survival. Clinical trial information: NCT03009981 .

PURPOSE The long-term toxicities of chemotherapy and radiotherapy can represent a significant burden to testicular cancer survivors. Retroperitoneal lymph node dissection (RPLND) is an established treatment for testicular germ cell tumors with minimal late morbidity although little data exist on its efficacy in early metastatic seminoma. Surgery in early metastatic seminoma is a prospective phase II single-arm, multi-institutional trial of RPLND as first-line treatment for testicular seminoma with clinically low-volume retroperitoneal lymphadenopathy. PATIENTS AND METHODS Twelve sites in the United States and Canada prospectively enrolled adult patients with testicular seminoma and isolated retroperitoneal lymphadenopathy (1-3 cm). Open RPLND was performed by certified surgeons with a primary end point of 2-year recurrence-free survival (RFS). Complication rates, pathologic up/downstaging, recurrence patterns, adjuvant therapies, and treatment-free survival were assessed. RESULTS A total of 55 patients were enrolled, with a median (IQR) largest clinical lymph node size of 1.6 cm (1.3-1.9). RPLND pathology demonstrated a median (IQR) largest lymph node size of 2.3 cm (0.9-3.5); nine patients (16%) were pN0, 12 (22%) pN1, 31 (56%) pN2, and 3 (5%) pN3. One patient received adjuvant chemotherapy. With a median (IQR) follow-up of 33 months (12.0-61.6), 12 patients experienced recurrence, with a 2-year RFS of 81% and a recurrence rate of 22%. Of the patients who experienced recurrence, 10 were treated with chemotherapy and two underwent additional surgery. At last follow-up, all patients who experienced a recurrence were disease-free and the 2-year overall survival was 100%. Four patients (7%) experienced short-term complications, and four patients experienced long-term complications including incisional hernia (1) and anejaculation (3). CONCLUSION RPLND is a treatment option for testicular seminoma with clinically low-volume retroperitoneal lymphadenopathy and is associated with low long-term morbidity.

375 Background: Chemotherapy or radiotherapy are standard treatments for stage II seminoma, though they are associated with significant long-term treatment-related toxicities. Retroperitoneal lymph node dissection (RPLND) is an established treatment for testicular germ cell tumors but little data exists on its efficacy as a front-line treatment in early metastatic (stage II) seminoma. This is a single-arm, multi-institutional (NCT02537548), phase II study of retroperitoneal lymph node dissection (RLND) as first-line treatment for testicular seminoma with isolated retroperitoneal disease. Methods: Twelve sites in the United States and Canada prospectively enrolled patients (16 years of age) with testicular seminoma and isolated retroperitoneal lymphadenopathy between 1-3 cm in size. Patients were excluded if they received prior therapy (except orchiectomy) for testicular cancer. Open, modified-template RPLND was performed by qualified surgeons with a primary endpoint of 2-year recurrence-free survival. Data on complication rates (short and long-term), pathologic up/downstaging, recurrence patterns, adjuvant therapies, and treatment-free survival were assessed. Results: A total of 55 patients were enrolled and underwent RPLND. Fourteen patients had initial stage I disease who developed isolated retroperitoneal relapse while 41 patients had clinical stage IIA-B at presentation. With a median follow-up of 24 months (8-52 months), there were a total of 10 recurrences. The overall recurrence rate was 18% with a median time to recurrence of 8 months. Of the recurrences, 8 underwent chemotherapy (6 BEP X 3, 1 EP X 4, 1 carbo/etoposide) and 2 underwent additional surgery. The two-year recurrence free survival was 87% and the overall survival was 100%. There were 7 (13%) patients who experienced short-term complications within 1 year of RPLND. Of these, 5 (9%) were classified as Clavien Dindo I-II and 2 (3.6%) were classified as Clavien Dindo III. No patients have reported long-term complications. Conclusions: This trial establishes RPLND as a therapeutic option as a first-line treatment in early metastatic seminoma. The surgery offers cancer control rates similar to those seen in non-seminomatous germ cell tumors. Clinical trial information: NCT02537548.

PURPOSE Germline testing (GT) is a central feature of prostate cancer (PCA) treatment, management, and hereditary cancer assessment. Critical needs include optimized multigene testing strategies that incorporate evolving genetic data, consistency in GT indications and management, and alternate genetic evaluation models that address the rising demand for genetic services. METHODS A multidisciplinary consensus conference that included experts, stakeholders, and national organization leaders was convened in response to current practice challenges and to develop a genetic implementation framework. Evidence review informed questions using the modified Delphi model. The final framework included criteria with strong (> 75%) agreement (Recommend) or moderate (50% to 74%) agreement (Consider). RESULTS Large germline panels and somatic testing were recommended for metastatic PCA. Reflex testing—initial testing of priority genes followed by expanded testing—was suggested for multiple scenarios. Metastatic disease or family history suggestive of hereditary PCA was recommended for GT. Additional family history and pathologic criteria garnered moderate consensus. Priority genes to test for metastatic disease treatment included BRCA2, BRCA1, and mismatch repair genes, with broader testing, such as ATM, for clinical trial eligibility. BRCA2 was recommended for active surveillance discussions. Screening starting at age 40 years or 10 years before the youngest PCA diagnosis in a family was recommended for BRCA2 carriers, with consideration in HOXB13, BRCA1, ATM, and mismatch repair carriers. Collaborative (point-of-care) evaluation models between health care and genetic providers was endorsed to address the genetic counseling shortage. The genetic evaluation framework included optimal pretest informed consent, post-test discussion, cascade testing, and technology-based approaches. CONCLUSION This multidisciplinary, consensus-driven PCA genetic implementation framework provides novel guidance to clinicians and patients tailored to the precision era. Multiple research, education, and policy needs remain of importance.

Abstract Background Immunosuppressive regimens associated with organ transplantation increase the risk of developing cancer. Transplant candidates and recipients with prostate cancer are often treated, even if low-risk features would ordinarily justify active surveillance. Methods Using SEER-Medicare, we identified 163 676 men aged 66 years and older diagnosed with nonmetastatic prostate cancer. History of solid organ transplant was identified using diagnosis or procedure codes. A propensity score-matched cohort was identified by matching transplanted men to nontransplanted controls by age, race, region, year, T-stage, grade, comorbidity, and cancer therapy. Fine-Gray competing risk models assessed associations between transplant status and prostate cancer-specific mortality (PCSM) and overall mortality (OM). Results We identified 620 men (0.4%) with transplant up to 10 years before (n = 320) or 5 years after (n = 300) prostate cancer diagnosis and matched them to 3100 men. At 10 years, OM was 55.7% and PCSM was 6.0% in the transplant cohort compared with 42.4% (P &lt; .001) and 7.6% (P = .70) in the nontransplant cohort, respectively. Adjusted models showed no difference in PCSM for transplanted men (hazard ratio = 0.88, 95% confidence interval = 0.61 to 1.27, P = .70) or differences by prostate cancer therapy. Among 334 transplanted men with T1-2N0, well or moderately differentiated “low-risk” prostate cancer, PCSM was similar for treated and untreated men (hazard ratio = 0.92, 95% confidence interval = 0.47 to 1.81). Conclusions Among men aged 66 years and older with prostate cancer, an organ transplant is associated with higher OM but no observable difference in PCSM. These findings suggest men with prostate cancer and previous or future organ transplantation should be managed per usual standards of care, including consideration of active surveillance for low-risk cancer characteristics.