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Disease recurrence is common following prostatectomy in patients with localised prostate cancer with high-risk features. Although androgen deprivation therapy increases the rates of organ-confined disease and negative surgical margins, there is no significant benefit on disease recurrence. Multiple lines of evidence suggest that (Fibroblast Growth Factor/Fibroblast Growth Factor Receptor) FGF/FGFR-signalling is important in supporting prostate epithelial cell survival in hostile conditions, including acute androgen deprivation. Given the recent availability of oral FGFR inhibitors, we investigated whether combination therapy could improve tumour response in the neo-adjuvant setting.We conducted an open label phase II study of the combination of erdafitinib (3 months) and androgen deprivation therapy (4 months) in men with localised prostate cancer with high-risk features prior to prostatectomy using a Simon's 2 stage design. The co-primary endpoints were safety and tolerability and pathological response in the prostatectomy specimen. The effect of treatment on residual tumours was explored by global transcriptional profiling with RNA-sequencing.Nine patients were enrolled in the first stage of the trial. The treatment combination was poorly tolerated. Erdafitinib treatment was discontinued early in six patients, three of whom also required dose interruptions/reductions. Androgen deprivation therapy for 4 months was completed in all patients. The most common adverse events were hyperphosphataemia, taste disturbance, dry mouth and nail changes. No patients achieved a complete pathological response, although patients who tolerated erdafitinib for longer had smaller residual tumours, associated with reduced transcriptional signatures of epithelial cell proliferation.Although there was a possible enhanced anti-tumour effect of androgen deprivation therapy in combination with erdafitnib in treatment naïve prostate cancer, the poor tolerability in this patient population prohibits the use of this combination in this setting.

Despite the rapidly evolving therapeutic landscape, immunotherapy has demonstrated limited activity in prostate cancer. A greater understanding of the molecular landscape, particularly the expression of immune-related pathways, will inform future immunotherapeutic strategies. Consensus nonnegative matrix factorization (cNMF) is a novel model of molecular classification analyzing gene expression data, focusing on biological interpretation of metagenes and selecting meaningful clusters.We aimed to identify molecular subtypes of prostate cancer using cNMF and correlate these with existing biomarkers to inform future immunotherapeutic strategies.A cohort of archival tumor specimens from hormone-sensitive and castration-resistant disease was studied. Whole transcriptomic profiles were generated using TruSeq RNA Access technology and subjected to cNMF. Comprehensive genomic profiling was performed with the FoundationOne assay. NMF subtypes were characterized by gene expression pathways, genomic alterations and correlated with clinical data, then applied to The Cancer Genome Atlas data set.We studied 164 specimens, including 52 castration-resistant and 13 paired primary/metastatic specimens. cNMF identified four distinct subtypes. NMF1 (19%) is enriched for immune-related and stromal-related pathways with transforming growth factor β (TGFβ) signature. NMF2 (36%) is associated with FOXO-mediated transcription signature and AKT signaling, NMF3 (26%) is enriched for ribosomal RNA processing, while NMF4 (19%) is enriched for cell cycle and DNA-repair pathways. The most common gene alterations included TMPRSS22 (42%), TP53 (23%), and DNA-repair genes (19%), occurring across all subtypes. NMF4 is significantly enriched for MYC and Wnt-signaling gene alterations. TMB, CD8 density, and PD-L1 expression were low overall. NMF1 and NMF4 were NMF2 was associated with superior overall survival.Using cNMF, we identified four molecularly distinct subtypes which may inform treatment selection. NMF1 demonstrates the most inflammatory signature with asuppressive TGFβ signature, suggesting potential benefit with immunotherapy combination strategies targeting TGFβ and PD-(L)1. Prospective studies are required to evaluate the use of this novel model to molecularly stratify patients for optimal treatment selection.

Background Immune checkpoint inhibitor monotherapy in metastatic castration-resistant prostate cancer (mCRPC) has produced modest results. High-dose radiotherapy may be synergistic with checkpoint inhibitors. Objective To evaluate the efficacy and safety of the PD-L1 inhibitor avelumab with stereotactic ablative body radiotherapy (SABR) in mCRPC. Design, setting, and participants From November 2017 to July 2019, this prospective phase 2 study enrolled 31 men with progressive mCRPC after at least one prior androgen receptor–directed therapy. Median follow-up was 18.0 mo. Intervention Avelumab 10 mg/kg intravenously every 2 wk for 24 wk (12 cycles). A single fraction of SABR (20 Gy) was administered to one or two disease sites within 5 d before the first and second avelumab treatments. Outcomes measurements and statistical analysis The primary endpoint was the disease control rate (DCR), defined as a confirmed complete or partial response of any duration, or stable disease/non–complete response/non–progressive disease for ≥6 mo (Prostate Cancer Clinical Trials Working Group 3–modified Response Evaluation Criteria in Solid Tumours version 1.1). Secondary endpoints were the objective response rate (ORR), radiographic progression-free survival (rPFS), overall survival (OS), and safety. DCR and ORR were calculated using the Clopper-Pearson exact binomial method. Results and limitations Thirty-one evaluable men were enrolled (median age 71 yr, 71% with ≥2 prior mCRPC therapy lines, 81% with >5 total metastases). The DCR was 48% (15/31; 95% confidence interval [CI] 30–67%) and ORR was 31% (five of 16; 95% CI 11–59%). The ORR in nonirradiated lesions was 33% (four of 12; 95% CI 10–65%). Median rPFS was 8.4 mo (95% CI 4.5–not reached [NR]) and median OS was 14.1 mo (95% CI 8.9–NR). Grade 3–4 treatment-related adverse events occurred in six patients (16%), with three (10%) requiring high-dose corticosteroid therapy. Plasma androgen receptor alterations were associated with lower DCR (22% vs 71%, p = 0.13; Fisher’s exact test). Limitations include the small sample size and the absence of a control arm. Conclusions Avelumab with SABR demonstrated encouraging activity and acceptable toxicity in treatment-refractory mCRPC. This combination warrants further investigation. Patient summary In this study of men with advanced and heavily pretreated prostate cancer, combining stereotactic radiotherapy with avelumab immunotherapy was safe and resulted in nearly half of patients experiencing cancer control for 6 months or longer. Stereotactic radiotherapy may potentially improve the effectiveness of immunotherapy in prostate cancer.

INTRODUCTION: Bone metastases occur frequently in castration-resistant prostate cancer (CRPC) and may lead to skeletal-related events (SREs), including symptomatic skeletal events (SSEs). Bone-modifying agents (BMAs) delay SREs and SSEs. However, the real-world use of BMAs is debated given the absence of demonstrated survival advantage and potential adverse events (AEs). Our retrospective study examined BMA use and SSE rates in Australian patients with CRPC. METHODS: Patients with CRPC and bone metastases were identified from the electronic CRPC Australian Database. Patient characteristics, treatment patterns and AEs were analysed. Descriptive statistics reported baseline characteristics, SSE rates and BMA use. Comparisons between groups used t-tests and Chi-square analyses. Overall survival was calculated by the Kaplan-Meier method. RESULTS: A total of 532 eligible patients were identified with a median age of 73 years (range: 44-97 years). BMAs were prescribed in 232 men (46%), 183 of whom received denosumab. Patients receiving first-line docetaxel for CRPC were more likely to commence BMAs than those receiving abiraterone or enzalutamide (51% vs 31% vs 38%; p = 0.004). SSEs occurred in 148 men (28%), most commonly symptomatic lesions requiring intervention (75%). At the time of initial SSEs, only 28% were receiving BMAs. Patients treated at sites with lower BMA use (

Traditional cancer registries have often been siloed efforts, established by single groups with limited objectives. There is the potential for registry data to support a broad range of research, audit and education initiatives. Here, we describe the establishment of a series of comprehensive cancer registries across the spectrum of common solid cancers. The experience and learnings of each registry team as they develop, implement and then use collected data for a range of purposes, that informs the conduct and output of other registries in a virtuous cycle. Each registry is multi-site, multi-disciplinary and aims to collect data of maximal interest and value to a broad range of enquiry, which would be accessible to any researcher with a high-quality proposal. Lessons learnt include the need for careful and continuous curation of data fields, with regular database updates, and the need for a continued focus on data quality. The registry data as a standalone resource has supported numerous projects, but linkage with external datasets with patients in common has enhanced the audit and research potential. Multiple projects have linked registry data with matched tissue specimens to support prognostic and predictive biomarker studies, both validation and discovery. Registry-based biomarker trials have been successfully supported, generating novel and practice-changing data. Registry-based clinical trials, particularly randomised studies exploring the optimal use of available therapy options are now complementing the research conducted in traditional clinical trials. More recent projects supported by the registries include health economic studies, personalised patient education material, and increased consumer engagement, including consumer entered data.

BackgroundThe development of anti-human epidermal growth factor receptor 2 (HER2) therapies has significantly improved disease outcomes in patients with HER2-positive advanced breast cancer (ABC). However, elderly patients are persistently under-represented in clinical trials, with only 2.4% of patients aged ≥75 years in the pivotal CLEOPATRA study. Despite a lack of research addressing treatment outcomes in elderly patients, advanced age at diagnosis is associated with a greater likelihood of receiving no initial systemic therapy for de novo metastatic breast cancer. Studies have also shown that older women diagnosed with metastatic breast cancer have a poorer prognosis and shorter life expectancy. We examined treatment patterns and outcomes in an elderly (defined as ≥70) ‘real world’ Australian population. MethodsData was extracted from the Treatment of Advanced Breast Cancer in the HER2-positive Australian Patient (TABITHA) multi-site clinical registry, and patients stratified according to age ( ResultsWe identified 319 patients, including 67 patients (21%) aged ≥70 years. Older patients were more likely to have an Eastern Cooperative Oncology Group performance status of ≥2 (16% vs 3%; p ConclusionElderly patients with HER2-positive ABC demonstrated shorter chemotherapy durations, poorer overall survival, and increased rates of adverse events despite having similar disease characteristics and treatment patterns. Prospective studies are required to improve outcomes in the elderly HER2 positive population. Citation Format: Nicole Evans, Angelyn Anton, Rachel Wong, Sheau Wen Lok, Richard De Boer, Laeeq Malik, Sally Greenberg, Belinda Yeo, Louise Nott, Gary Richardson, Ian M Collins, Javier Torres, Frances Barnett, Peter Gibbs, Bianca Devitt. Real world outcomes in elderly women with HER2 positive advanced breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS6-35.

BACKGROUND Distress is common immediately following a diagnosis with testicular cancer, however there is an unmet need to develop instruments to address this important issue. OBJECTIVE We evaluated an online intervention, Nuts & Bolts, designed to provide support and alleviate distress associated with the diagnosis of testicular cancer in individuals with a new diagnosis. METHODS In this trial using a mixed methods design designed to evaluate the acceptability, feasibility and impact of Nuts & Bolts, we randomly assigned 39 participants with recently diagnosed testicular cancer in a 1:1 ratio to access Nuts & Bolts at the time of consent (“early”), or alternatively, one week later (day 8; “delayed”). The primary endpoint was change in distress, measured by the National Comprehensive Cancer Network Distress Thermometer (DT; score range 0-10), between consent/day 8. Secondary endpoints of distress, anxiety and depression were assessed at defined intervals across a four-week follow-up period; semi-structured interviews were thematically analysed. RESULTS Moderate- or high-levels of distress evaluated using DT were reported in 58% of participants at the time of consent. “Early intervention” with Nuts & Bolts did not significantly decrease mean DT score by day eight compared to “delayed intervention” (early: 4.56 to 2.74 versus delayed: 4.47 to 2.74, p=.85), however reduced DT scores were observed by day 8 (early: p CONCLUSIONS Distress is common following diagnosis with testicular cancer; however, reduces over time. Earlier introduction to Nuts & Bolts did not impact change in distress across one-week measured by DT, but utility was widely supported by participants. Nuts & Bolts was considered useful, acceptable, and relevant by individuals diagnosed with testicular cancer. It may have a greater impact on distress if utilised as soon as testicular cancer is suspected. CLINICALTRIAL ACTRN12620000902998

The development of brain metastases occurs commonly in HER2-positive metastatic breast cancer and is associated with a poorer prognosis. The advent of HER2-targeted therapy has improved overall survival, but the benefit in patients with brain metastases is unclear, as these patients are often excluded from clinical trials. This study aimed to explore real-world outcomes in patients with brain metastases in HER2-positive MBC.Data was extracted from the TABITHA registry, which consists of patient data collected prospectively from 16 Australian sites from 24th February 2015 to 31st October 2021. Data analysed included characteristics of brain metastases, treatment received and survival outcomes.A total of 135 (37%) of 361 patients with HER2-positive MBC were diagnosed with brain metastases during their clinical course, including 45 (12%) with brain metastases at time of MBC diagnosis. 61 (45%) had ≥4 brain lesions. The most common local therapy given was whole brain radiation therapy (WBRT) (36%) followed by multi-modality treatment with both surgery and radiation therapy (27%). The majority of patients received first-line HER2-targeted treatment with trastuzumab and pertuzumab followed by second-line trastuzumab emtansine (T-DM1) but third-line therapy was heterogenous. The median overall survival in patients who developed brain metastases was significantly shorter than those who did not develop brain metastases (58.9 vs. 96.1 months, P = .02).Real-world patients diagnosed with brain metastases in HER2-positive MBC have a relatively poor prognosis, despite advances in HER2-targeted treatment. As the range of HER2-targeted treatment expands, it is important to pursue clinical trials that focus on patients with brain metastases.

OBJECTIVES: To investigate the recent real-world use of first-generation antiandrogens (FGAs) in metastatic castration-resistant prostate cancer (mCRPC) using a retrospective multicentre cohort study. PATIENTS AND METHODS: The electronic CRPC Australian Database (ePAD) was interrogated to identify patients with mCRPC. Clinicopathological features, treatment and outcome data, stratified by FGA use, were retrieved and reported through descriptive statistics. Survival analyses were calculated using the Kaplan-Meier method and groups compared using log-rank tests. Factors influencing overall survival (OS) were analysed using Cox proportional hazards regression model. RESULTS: We identified 634 patients with mCRPC, enrolled in ePAD between January 2016 and March 2019, including 322 (51%) who received FGAs. The median follow-up was 21.9 months. Patients treated with FGAs were more likely to have lower International Society of Urological Pathologists (ISUP) grade group (P = 0.04), longer median time to CRPC (25.6 vs 16.0 months, P

Several systemic therapies have demonstrated a survival advantage in metastatic castration resistant prostate cancer (mCRPC). Access to these medications varies significantly worldwide. In Australia until recently, patients must have received docetaxel first, unless unsuitable for chemotherapy, despite no evidence suggesting superiority over androgen receptor signalling inhibitors (ARSIs). Our study investigated real-world systemic treatment patterns in Australian patients with mCRPC.The electronic CRPC Australian Database (ePAD) was interrogated to identify mCRPC patients. Clinicopathological features, treatment and outcome data, stratified by first-line systemic therapies, were extracted. Comparisons between groups utilised Kruskal-Wallis tests and Chi-Square analyses. Time-to-event data were calculated using Kaplan-Meier methods and groups compared using log-rank tests. Factors influencing overall survival (OS) and time to treatment failure (TTF) were analysed through Cox proportional hazards regression models.We identified 578 patients who received first-line systemic therapy for mCRPC. Enzalutamide (ENZ) was most commonly prescribed (In our real-world population, ENZ and AA were common first-line systemic therapy choices, particularly among older patients and those with poorer performance status. Patients receiving ENZ and AA demonstrated superior TTF compared to DOC, while OS was not statistically different. Our findings highlight the important role of ARSIs, given the variability of access worldwide.

Multiple life-prolonging therapies are available for metastatic castration-resistant prostate cancer (mCRPC). However, the optimal treatment strategy following progression through standard treatment with docetaxel, androgen receptor signaling inhibitor (ARSI) and cabazitaxel, remains unclear. We aimed to describe treatment patterns in men with mCRPC following progression on standard treatments and determine whether subsequent treatment choice impacts overall survival.Clinicopathologic and treatment data were extracted from the electronic CRPC Australian Database (ePAD) for patients who had received docetaxel, ARSIs and cabazitaxel in any order. Data were analyzed to compare groups that did versus did not receive subsequent systemic therapy. Treatment sequences, median duration of treatment, and median overall survival (mOS) were reported for each treatment group.Ninety-eight eligible patients were identified, with 51 receiving subsequent systemic therapy. Those who received further treatment were younger (68 vs. 71 years, p .01) but did not have any other differences in clinicopathologic features compared to those who received no further treatment. Patients who received upfront docetaxel were more likely to proceed to subsequent treatment (p = .02). Subsequent systemic therapies varied, the most common being carboplatin-based regimens (n = 13, 25.5%) and many patients were rechallenged with ARSI (n = 10, 19.6%) or docetaxel (n = 6, 11.8%). There was no difference in mOS according to subsequent systemic therapy (p = .09).This retrospective multicenter analysis demonstrates the variation in treatment sequences used for mCRPC in the real-world setting. In the absence of high quality, prospective evidence, our results suggest that subsequent treatment choice does not influence survival outcomes and the optimal choice is guided by individual patient and disease-related factors.

International practice guidelines recommend administration of bone-modifying agents (BMA) in metastatic breast cancer (MBC) patients with bone metastases to reduce skeletal-related events (SRE). Optimal delivery of BMA in routine clinical practice, including agent selection and prescribing intervals, remains unclear.To describe real-world practice of Australian breast oncologists.Prospective data from February 2015 to July 2020 on BMA delivery to MBC patients with bone metastases was analysed from Treatment of Advanced Breast Cancer in the Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Australian Patient (TABITHA), a multi-site Australian HER2+ MBC registry.Of 333 HER2+ MBC patients, 171 (51%) had bone metastases at diagnosis, with a mean age of 58.1 years (range, 32-87). One hundred and thirty (76%) patients received a BMA, with 90 (69%) receiving denosumab and 40 (31%) receiving a bisphosphonate. Patients who received a BMA were more likely to have received concurrent first-line systemic anti-HER2 therapy (95% vs 83%; P = 0.04), to present with bone-only metastases at diagnosis (24% vs 7%; P = 0.02) and less likely to have visceral metastases (51% vs 71%; P = 0.03). Ten of 40 (25%) bisphosphonate patients and 45 of 90 (50%) denosumab patients received their BMA at the recommended 4-weekly interval. Prescribing intervals varied over time. Adverse events reported were consistent with clinical trial data.Three-quarters of Australian HER2+ MBC patients with bone metastases receive a BMA, often at different schedules than guidelines recommend. Further studies, including all MBC subtypes, are warranted to better understand clinicians' prescribing rationale and potential consequences of current prescribing practice on SRE incidence.

5017 Background: The VISION and TheraP trials have established the safety and efficacy of 177Lu-PSMA-617 in mCRPC with a 50% PSA response rate (PSA50-RR) of 46% and 66% and median progression free survival (PFS) of 8.7 and 5.1 months, respectively. More effective treatments are required as disease progression remains universal. Immunotherapy has limited single-agent efficacy in mCRPC. We hypothesise that by potentially inducing immunogenic cell death, 177Lu-PSMA-617 may act synergistically with pembrolizumab, an anti-programmed death 1 inhibitor, to enhance the depth and durability of response. PRINCE is a Phase I trial evaluating the safety and efficacy of this combination. Methods: mCRPC patients with high PSMA expression (SUVmax ≥ 20 in an index lesion, SUVmax > 10 for all lesions ≥ 10mm), and no FDG+ve/PSMA-ve lesions on paired baseline PET/CT screening, received up to 6 cycles of 177Lu-PSMA-617 (starting at 8.5 GBq, reducing by 0.5 GBq with each cycle) every 6 weeks in conjunction with 200mg of pembrolizumab every 3 weeks for up to 2 years. Response evaluation was undertaken as per PCWG3 and RECIST criteria. Co-primary endpoints were safety and PSA50-RR. Secondary endpoints included PSA-PFS, radiographic PFS (rPFS), overall survival (OS), and patient reported outcomes (PROs). This analysis was undertaken after the last patient had 12 months follow-up. Results: 37 patients (median age 72 years; prior docetaxel 73%; prior androgen receptor targeted agent 100%) received a median of 5 cycles (range: 2 to 6) of 177Lu-PSMA-617 and 12 doses (range: 6 to 19) of pembrolizumab. The median follow up was 16 months. PSA50-RR was 76% (28/37 [95% CI 59-88]) and 7/10 (70%) patients with RECIST-measurable disease had a partial response. Median rPFS, PSA-PFS and OS was 11.2 months (95% CI: 5.1-14.1), 8.2 months (95% CI: 5.1-11.2) and 17.8 months (95% CI:13.4-not estimable). 12-month rPFS and OS was 38% (95% CI: 22-54) and 83% (95% CI: 67-92), respectively. Common (≥10%) treatment-related adverse events (TRAE) were mainly Grade (G) 1-2, including xerostomia (78%), fatigue (43%), pruritus (27%), nausea (27%), rash (24%), diarrhoea (14%), anorexia (16%), thrombocytopenia (16%), elevated ALT (11%), arthralgia (11%) and a flare in bone pain (11%). Haematologic TRAEs included G2-3 anaemia (8%), G1-2 thrombocytopenia (16%), and G1 neutropenia (3%). G3 immune-related AEs occurred in 10 (27%) patients with no dominant manifestation. 5 (14%) patients discontinued pembrolizumab due to toxicity. PROs including BPI-SF and FACT-P were stable throughout the study. Conclusions: The combination of 177Lu-PSMA-617 and pembrolizumab had promising activity. Toxicities were generally consistent with those of single-agent 177Lu-PSMA-617 and pembrolizumab and were not clearly augmented by combination use. No new safety concerns were observed. Clinical trial information: NCT03658447.

Clinical trials have strict eligibility criteria, potentially limiting external validity. However, while often discussed this has seldom been explored, particularly across cancer types and at variable time frames posttrial completion. We examined comprehensive registry data (January 2014 to June 2019) for standard first-line treatments for metastatic colorectal cancer (CRC), advanced pancreatic cancer (PC), metastatic HER2-amplified breast cancer (BC) and castrate-resistant prostate cancer (CaP). Registry patient characteristics and outcomes were compared to the practice-changing trial. Registry patients were older than the matched trial cohort by a median of 2-6 years (all P =

Prostate-specific membrane antigen (PSMA) PET/CT imaging is increasingly being utilised in clinical practice, demonstrating greater sensitivity in the detection of metastatic prostate cancer (mPC) compared to conventional imaging [1]. Prior studies have primarily focussed on its use following biochemical recurrence to detect oligometastatic disease potentially amenable to salvage therapies [2-4]. However, the role of PSMA PET/CT in assessing treatment response remains unclear. Standardised criteria for metabolic response have not been established, particularly to account for whole body tumour burden and the effects of systemic therapies on PSMA expression.

Aim Optimal treatment for newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC) has evolved, with many patients deriving benefit from the addition of docetaxel to androgen deprivation therapy (D-ADT). This study sought to define the therapy used and associated activity following D-ADT. Methods Retrospective analysis of patients with mHSPC treated with one or more cycles of D-ADT who were identified from a prospectively maintained multisite prostate cancer database of patients treated in a community or academic center setting in Australia. The primary endpoint of this study was first-line time to treatment failure (1L TTF) for subsequent treatment of metastatic Castrate Resistant Prostate Cancer (mCRPC), with secondary endpoints of prostate-specific antigen (PSA) reduction >50% and time from 1L to second-line (2L) treatment initiation. Results A total of 93 patients received D-ADT for mHSPC, 85 (91%) had subsequent treatment for mCRPC. Median time to mCRPC (biochemical, clinical or radiographic) had been 14.8 months (95% confidence interval [CI], 11.9-16.5). 1L treatment was enzalutamide 47 patients (55%), abiraterone 23 (27%), cabazitaxel 7 (8%), docetaxel 4 (5%) and other therapies 4 (5%). Median 1L TTF was 6.3 months (95% CI, 4.9-7.6), PSA > 50% reduction was achieved in 32 of 89 patients (36%), median time from 1L to second-line treatment was 7.3 months (1.3-27.4), which did not differ significantly between treatment groups. Conclusions Abiraterone, enzalutamide, cabazitaxel and docetaxel all demonstrate activity following progression on D-ADT. No difference in efficacy was detected between treatment options for mCRPC. Prospective trials investigating the optimal treatment sequence for prostate cancer following progression on D-ADT needed.

Testicular seminomas occur in young men and are highly curable. Toxicities following treatment for men with extensive stage II-III seminomas may cause long-term morbidities. However, it is not clear whether the risk of late effects also increases following surgery for testis-confined seminoma. In this systematic review, we examined the available literature regarding the incidence of late effects in our target population of patients with stage I seminoma treated with orchidectomy alone. Publications were identified through an electronic literature search using the MEDLINE, EMBASE and PsychInfo databases, identifying cohorts treated for stage I seminoma. Data on late effects were collected and classified as physical or psychological. Six hundred and four articles were screened to identify 100 studies. In the target population, available evidence suggests no increased risk of cardiovascular disease, metabolic syndrome, or renal dysfunction compared to the general population. Sperm counts were initially lower than an age-matched cohort; however, counts normalised when re-assessed 5 years later. Data were not specifically reported for the target population regarding bone health, second malignancy, hypogonadism, fertility and all psychological domains. Heterogeneity of study design and reporting methods contributed to uncertainty regarding the true incidence and clinical significance of late effects. The curability of stage I seminoma and the wide range of potential late effects of treatment suggest the need for long-term monitoring alongside standard cancer surveillance. Important data are needed on the prevalence of late effects, specifically related to testicular cancer survivors undergoing surveillance following orchidectomy. Awareness and screening for relevant late effects may prevent further morbidity in men treated for stage I seminoma.

86 Background: Studies investigating immune checkpoint inhibitors (ICI) in mCRPC have produced modest results. Radiation therapy may be synergistic with ICIs. We hypothesised that SABR would enhance anti-tumour activity of PD-L1 inhibitor avelumab in patients (pts) with progressive mCRPC. Methods: This phase II, single arm, multicentre study enrolled mCRPC pts following progression on ≥1 novel androgen receptor-directed therapy. Up to two lines of prior taxane chemotherapy were permitted. Pts received avelumab 10mg/kg IV q2weeks for a total of 24 weeks (12 cycles). A single fraction of 20Gy SABR was administered to 1-2 disease sites within five days prior to first and second doses of avelumab. Primary endpoint was disease control rate (DCR); secondary endpoints were PSA response (PSA50), overall response rate (ORR), radiographic progression-free survival (rPFS), overall survival (OS) and safety. Radiographic disease assessment (CT and bone scintigraphy) was performed after cycles 6 and 12 of avelumab treatment. Following enrolment of 14 pts, a protocol amendment allowed avelumab beyond 12 cycles in pts with disease control at 24 weeks. Results: Thirty-one pts were enrolled, with 30 evaluable for the primary endpoint. Median follow-up was 18 months (mo). Pt characteristics: median age 71 years (IQR 64-75), bone-only disease 42%, visceral disease 16%, prior taxane chemotherapy 84%, treatment with both abiraterone and enzalutamide 13%. Seventy metastatic sites received SABR, most frequently to bone (90%) and soft tissue (29%) disease. Avelumab was given as second-line, third-line and fourth- or greater line systemic therapy in 29%, 42% and 29% of pts, respectively. Median cycles of avelumab administered was 9 (IQR 5-13). DCR (95% CI) was 50% (31-69) and 60% (32-84) in all-comers and soft tissue disease subgroup, respectively. Following protocol amendment, 7/17 pts (41%) received avelumab beyond 12 cycles. Incidence of grade 3-4 treatment-related AEs was 16% (no grade 5 events), with three pts requiring oral/IV corticosteroid therapy. Conclusions: Avelumab with SABR demonstrated durable disease control in treatment-refractory mCRPC with an acceptable toxicity profile. This combination warrants further investigation. Clinical trial information: ACTRN12618000954224. [Table: see text]

BACKGROUND: The impact of regulatory approvals of new therapies for castration-resistant prostate cancer (CRPC) in Australia is unclear. AIMS: To determine if changes in novel therapy access in Australia affected how clinicians initially managed men with newly diagnosed CRPC. METHODS: Data from patients diagnosed with CRPC from 2013 to 2016 across three Australian hospitals were retrospectively collected. Baseline clinicopathological factors and initial management decision at the time of CRPC development (early treatment (ET) vs deferred treatment (DT)) were recorded. Categorical variables between cohorts were compared by Chi-squared analysis. Cox regression analysis was performed to assess the impact of CRPC diagnosis year on time to commencing life-prolonging systemic treatment (TTT). RESULTS: Our study identified 137 CRPC patients, with 126 (92%) patients receiving life-prolonging systemic treatment. The median age was 73 years. The initial management decision was DT in 71 (52%) patients and ET in 66 (48%) patients. There was a significant shift from DT to ET during the study period (2013-2014: DT 61% vs ET 33%; 2015-2016: DT 39% vs ET 67%; P = 0.004), with a rise in novel androgen receptor signalling inhibitor use and simultaneous reduction in first-generation antiandrogen use at CRPC development. Each successive CRPC diagnosis year was associated with shorter TTT on univariate analysis (HR: 1.5, 95% CI: 1.3-1.7, P < 0.001). CONCLUSION: Over time, clinicians are favouring earlier introduction of life-prolonging systemic treatment at the development of CRPC. This trend is largely driven by substantial uptake of novel androgen receptor signalling inhibitors as the preferred initial treatment for CRPC patients.

251 Background: Immune checkpoint inhibitors (CPIs) (anti-CTLA4, anti-PD-1/PD-L1 mAbs) have had limited monotherapy activity in prostate cancer (PC) compared to urothelial cancer (UC). Recent biomarker studies revealed molecular features associated w/ better efficacy/resistance to CPIs in UC.1 Here we examined the tumor immune microenvironment (iTME) of hormone naïve/sensitive (HSPC) & castrate resistant prostate (CRPC) specimens from primary & metastatic sites, to determine if parallels to UC molecular correlates exist that will allow us to predict subsets of PC pts who are more likely to benefit from rational combination therapies w/ CPIs. Methods: Tumor FFPE archival tissues (HSPC, n = 98; CRPC, n = 46; Unk, n = 6) were sourced from a Royal Melbourne Hospital cohort of PC patients. Tissues were evaluated by H&E for TILs & IHC performed for PD-L1 (clones SP142 & SP263) & CD8. RNAseq was conducted & Lund bladder molecular subtyping performed during bioinformatics analyses. TCGA PRAD dataset was used for further validation. Results: We first applied Lund molecular subtyping to broadly categorize this cohort into luminal/basal subtypes. CRPC tumors were almost entirely luminal, whereas HSPC tumors were mainly basal. Luminal PC tumors enriched for Wnt gene sets (p = 0.026) & enriched for a genomically unstable (GU) subtype w/ higher expression of DNA damage repair (DDR) & cell cycle gene sets (p = 0.082). Compared to CRPC, HSPCs had higher numbers of infiltrating CD8s (p = 4.37e-004), increased expression of T-effector, MHC-I antigen presentation machinery, immune checkpoints, macrophages & activated stromal biology, including the fibroblast TGFβ response signature. PD-L1 on immune cells by SP142 & SP263 was 30% & 17% respectively & was enriched in HSPC samples (SP142: CRPC 18% vs. HSPC 34%, p = 0.08). Within patients w/ CRPC, differences were minimal between primary & metastatic samples. Conclusions: These analyses on the iTME contexture of PC reveal potentially actionable biological nodes for targeted therapies. These findings could inform future clinical strategies to improve CPI responses in CRPC & HSPC w/ rationale combinations.1. Mariathasan et al. Nature 2018.

Aim To identify biochemical and genetic variation relating to increased risk of developing type 2 diabetes mellitus and cardiovascular disease in young, lean male and female adults of different ethnicities. Method Fasting blood and urine and non-fasting blood following oral glucose intake were analysed in 90 Caucasians, South Asians and South East/East Asians. Results There were no differences in age, birthweight, blood pressure, body mass index, percent body fat, total energy, percentage of macronutrient intake, microalbumin, leptin, cortisol, adrenocorticotropic hormone, nitric oxide metabolites, C-reactive protein, homocysteine, tumor necrosis factor-α, interleukin-6, von Willebrand factor, vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, and tissue plasminogen activator. Fasting total cholesterol (P = .000), triglycerides (P = .050), low density lipoprotein (P = .009) and non-fasting blood glucose (15 min) (P = .024) were elevated in South Asians compared with Caucasians, but there was no significant difference in glucose area under curve (AUC). Non-fasting insulin in South Asians (15–120 min), in South East/East Asians (60–120 min), and insulin AUC in South Asians and South East/East Asians, were elevated compared with Caucasians (P≤0.006). The molar ratio of C-peptide AUC/Insulin AUC (P = .045) and adiponectin (P = .037) were lower in South Asians compared with Caucasians. A significant difference in allele frequency distributions in Caucasians and South Asians was found for rs2166706 (P = 0.022) and rs10830963 (P = 0.009), which are both near the melatonin receptor MTNR1B. Conclusions Elevated non-fasting insulin exists in young South Asians of normal fasting glucose and insulin. Hepatic clearance of insulin may be reduced in South Asians. No current biochemical evidence exists of endothelial dysfunction at this stage of development. MTNR1B signalling may be a useful therapeutic target in Asian populations in the prevention of type 2 diabetes mellitus.