Bile duct regeneration is hypothesised to prevent biliary strictures, a leading cause of morbidity after liver transplantation. Assessing the capacity for biliary regeneration may identify grafts as suitable for transplantation that are currently declined, but has been unfeasible until now. This study used Long-Term Ex-Situ Normothermic Machine Perfusion (LT-NMP) to assess biliary regeneration. Human livers that were declined for transplantation were perfused at 36°C for up to 13.5 days. Bile duct biopsies, bile and perfusate were collected throughout perfusion, which were examined for features of injury and regeneration. Biliary regeneration was defined as new Ki-67 positive biliary epithelium following severe injury. Ten livers were perfused for a median duration of 7.5 days. Severe bile duct injury occurred in all grafts, and biliary regeneration occurred in 70% of grafts. Traditional biomarkers of biliary viability such as bile glucose improved during perfusion but this was not associated with biliary regeneration (p>0.05). In contrast, the maintenance of IL-6 and VEGF-A levels in bile were associated with biliary regeneration (p=0.017 for both cytokines). This is the first study to demonstrate biliary regeneration during LT-NMP and identify a cytokine signature in bile as a novel biomarker for biliary regeneration during LT-NMP.

The optimal treatment approach in very-early and early-stage hepatocellular carcinoma (HCC) is not precisely defined, and there is ambiguity in the literature around the comparative efficacy of surgical resection versus ablation as curative therapies for limited disease. We performed this real-world propensity-matched, multi-centre cohort study to assess for differences in survival outcomes between those undergoing resection and those receiving ablation. Patients with Barcelona Clinic Liver Cancer (BCLC) 0/A HCC first diagnosed between 1 January 2016 and 31 December 2020 who received ablation or resection as initial treatment were included in the study. A total of 450 patients were included in the study from 10 major liver centres including two transplant centres. Following propensity score matching using key covariates, 156 patients were available for analysis with 78 in each group. Patients who underwent resection had significantly improved overall survival (log-rank test p = 0.023) and local recurrence-free survival (log rank test p = 0.027) compared to those who received ablation. Based on real-world data, our study supports the use of surgical resection in preference to ablation as first-line curative therapy in appropriately selected BCLC 0/A HCC patients.

The management of early-stage hepatocellular carcinoma (HCC) is complex, with multiple treatment strategies available. There is a paucity of literature regarding variations in the patterns of care and outcomes between transplant and non-transplant centres. We conducted this real-world multi-centre cohort study in two liver cancer referral centres with an integrated liver transplant program and an additional eight non-transplant HCC referral centres across Australia to identify variation in patterns of care and key survival outcomes. Patients with stage Barcelona Clinic Liver Cancer (BCLC) 0/A HCC, first diagnosed between 1 January 2016 and 31 December 2020, who were managed at a participating site, were included in the study. Patients were excluded if they had a history of prior HCC or if they received upfront liver transplantation. A total of 887 patients were included in the study, with 433 patients managed at a liver cancer centre with a transplant program (LTC) and 454 patients managed at a non-transplant centre (NTC). Management at an LTC did not significantly predict allocation to resection (adjusted OR 0.75, 95% CI 0.50 to 1.11, p = 0.148). However, in those not receiving resection, LTC and NTC patients were systematically managed differently, with LTC patients five times less likely to receive upfront ablation than NTC patients (adjusted OR 0.19, 95% CI 0.13 to 0.28, p < 0.001), even after adjusting for tumour burden, as well as for age, gender, liver disease aetiology, liver disease severity, and medical comorbidities. LTCs exhibited significantly higher proportions of patients undergoing TACE for every tumour burden category, including those with a single tumour measuring 2 cm or less (p < 0.001). Using multivariable Cox proportional hazards analysis, management at a transplant centre was associated with reduced all-cause mortality (adjusted HR 0.71, 95% CI 0.51 to 0.98, p = 0.036), and competing-risk regression analysis, considering liver transplant as a competing event, demonstrated a similar reduction in risk (adjusted HR 0.70, 95% CI 0.50 to 0.99, p = 0.041), suggesting that the reduced risk of death is not fully explained by higher rates of transplantation. Our study highlights systematic differences in HCC care between large volume liver transplant centres and other sites, which has not previously been well-described. Further work is needed to better define the reasons for differences in treatment allocation and to aim to minimise unwarranted treatment variation to maximise patient outcomes across Australia.

Percutaneous ablation is recommended in Barcelona Clinic Liver Cancer (BCLC) stage 0/A patients with HCC ≤3 cm as a curative treatment modality alongside surgical resection and liver transplantation. However, trans-arterial chemo-embolisation (TACE) is commonly used in the real-world as an initial treatment in patients with single small HCC in contrast to widely accepted clinical practice guidelines which typically describe TACE as a treatment for intermediate-stage HCC. We performed this real-world propensity-matched multi-centre cohort study in patients with single HCC ≤ 3 cm to assess for differences in survival outcomes between those undergoing initial TACE and those receiving upfront ablation. Patients with a new diagnosis of BCLC 0/A HCC with a single tumour ≤3 cm first diagnosed between 1 January 2016 and 31 December 2020 who received initial TACE or ablation were included in the study. A total of 348 patients were included in the study, with 147 patients receiving initial TACE and 201 patients undergoing upfront ablation. After propensity score matching using key covariates, 230 patients were available for analysis with 115 in each group. There were no significant differences in overall survival (log-rank test p = 0.652) or liver-related survival (log-rank test p = 0.495) over a median follow-up of 43 months. While rates of CR were superior after ablation compared to TACE as a first treatment (74% vs. 56%, p < 0.004), there was no significant difference in CR rates when allowing for further subsequent treatments (86% vs. 80% p = 0.219). In those who achieved CR, recurrence-free survival and local recurrence-free survival were similar (log rank test p = 0.355 and p = 0.390, respectively). Our study provides valuable real-world evidence that TACE when offered with appropriate follow-up treatment is a reasonable initial management strategy in very early/early-stage HCC, with similar survival outcomes as compared to those managed with upfront ablation. Further work is needed to better define the role for TACE in BCLC 0/A HCC.

Precision medicine is a likely future for all cancer treatment but may have its greatest impact on less common, high-mortality, and molecularly heterogeneous cancers. TFCP2-rearranged rhabdomyosarcoma (RMS) is a rare, aggressive cancer with poor survival due to the lack of effective therapies and relevant models to facilitate research. In this study, we establish the first matched patient-derived xenograft and cell line model for TFCP2-rearranged intraosseous RMS, coupled with comprehensive multiomic and functional analyses, to discover and preclinically validate novel actionable molecular targets for this malignancy. Sequencing analyses of matched patient tumor and xenograft material revealed alterations in gene networks associated with the oncogenic, potentially targetable PI3K/AKT pathway. Preclinical assessments revealed that targeting the pathway with a small-molecule PI3K/mTOR inhibitor dactolisib presents a promising treatment approach for this rare cancer, decreasing cancer cell viability in vitro and significantly reducing tumor growth in vivo. Parallel identification of the codeletion of adjacent genes cyclin-dependent kinase inhibitor 2A and methylthioadenosine phosphorylase in these tumors led us to further explore protein arginine methyltransferase 5 inhibition as a potential therapeutic approach. Strikingly, combined inhibition of protein arginine methyltransferase 5 and PI3K/mTOR signaling synergistically enhanced antitumor response and significantly improved survival in vivo. This study highlights the importance of new patient-derived models for the elucidation of the biology of rare cancers and identification of new therapeutic entry points, with clear implications for the future treatment of TFCP2-rearranged intraosseous RMS.

Precision medicine is a likely future for all cancer treatment but may have its greatest impact on less common, high-mortality, and molecularly heterogeneous cancers. TFCP2-rearranged rhabdomyosarcoma (RMS) is a rare, aggressive cancer with poor survival due to the lack of effective therapies and relevant models to facilitate research. In this study, we establish the first matched patient-derived xenograft and cell line model for TFCP2-rearranged intraosseous RMS, coupled with comprehensive multiomic and functional analyses, to discover and preclinically validate novel actionable molecular targets for this malignancy. Sequencing analyses of matched patient tumor and xenograft material revealed alterations in gene networks associated with the oncogenic, potentially targetable PI3K/AKT pathway. Preclinical assessments revealed that targeting the pathway with a small-molecule PI3K/mTOR inhibitor dactolisib presents a promising treatment approach for this rare cancer, decreasing cancer cell viability in vitro and significantly reducing tumor growth in vivo. Parallel identification of the codeletion of adjacent genes cyclin-dependent kinase inhibitor 2A and methylthioadenosine phosphorylase in these tumors led us to further explore protein arginine methyltransferase 5 inhibition as a potential therapeutic approach. Strikingly, combined inhibition of protein arginine methyltransferase 5 and PI3K/mTOR signaling synergistically enhanced antitumor response and significantly improved survival in vivo. This study highlights the importance of new patient-derived models for the elucidation of the biology of rare cancers and identification of new therapeutic entry points, with clear implications for the future treatment of TFCP2-rearranged intraosseous RMS.