Bloomston, Mark

Objective: This study aims to present a full spectrum of individual patient presentations of pancreatic fistula risk, and to define the utility of mitigation strategies amongst some of the most prevalent, and vulnerable scenarios surgeons encounter. Background: The FRS has been utilized to identify technical strategies associated with reduced CR-POPF incidence across various risk strata. However, risk-stratification using the FRS has never been investigated with greater granularity. By deriving all possible combinations of FRS elements, individualized risk assessment could be utilized for precision medicine purposes. Methods: FRS profiles and outcomes of 5533 PDs were accrued from 17 international institutions (2003–2019). The FRS was used to derive 80 unique combinations of patient “scenarios.” Risk-matched analyses were conducted using a Bonferroni adjustment to identify scenarios with increased vulnerability for CR-POPF occurrence. Subsequently, these scenarios were analyzed using multivariable regression to explore optimal mitigation approaches. Results: The overall CR-POPF rate was 13.6%. All 80 possible scenarios were encountered, with the most frequent being scenario #1 (8.1%) – the only negligible-risk scenario (CR-POPF rate = 0.7%). The moderate-risk zone had the most scenarios (50), patients (N = 3246), CR-POPFs (65.2%), and greatest non-zero discrepancy in CR-POPF rates between scenarios (18-fold). In the risk-matched analysis, 2 scenarios (#59 and 60) displayed increased vulnerability for CR-POPF relative to the moderate-risk zone (both P < 0.001). Multivariable analysis revealed factors associated with CR-POPF in these scenarios: pancreaticogastrostomy reconstruction [odds ratio (OR) 4.67], omission of drain placement (OR 5.51), and prophylactic octreotide (OR 3.09). When comparing the utilization of best practice strategies to patients who did not have these conjointly utilized, there was a significant decrease in CR-POPF (10.7% vs 35.5%, P < 0.001; OR 0.20, 95% confidence interval 0.12–0.33). Conclusion: Through this data, a comprehensive fistula risk catalog has been created and the most clinically-impactful scenarios have been discerned. Focusing on individual scenarios provides a practical way to approach precision medicine, allowing for more directed and efficient management of CR-POPF.

Objective Limited efficacy of immune checkpoint inhibitors in pancreatic ductal adenocarcinoma (PDAC) has prompted investigation into combination therapy. We hypothesised that interleukin 6 (IL-6) blockade would modulate immunological features of PDAC and enhance the efficacy of anti-programmed death-1-ligand 1 (PD-L1) checkpoint inhibitor therapy. Design Transcription profiles and IL-6 secretion from primary patient-derived pancreatic stellate cells (PSCs) were analyzed via Nanostring and immunohistochemistry, respectively. In vivo efficacy and mechanistic studies were conducted with antibodies (Abs) targeting IL-6, PD-L1, CD4 or CD8 in subcutaneous or orthotopic models using Panc02, MT5 or KPC-luc cell lines; and the aggressive, genetically engineered PDAC model (Kras LSL−G12D , Trp53 LSL−R270H , Pdx1-cre, Brca2 F/F (KPC-Brca2 mice)). Systemic and local changes in immunophenotype were measured by flow cytometry or immunohistochemical analysis. Results PSCs (n=12) demonstrated prominent IL-6 expression, which was localised to stroma of tumours. Combined IL-6 and PD-L1 blockade elicited efficacy in mice bearing subcutaneous MT5 (p<0.02) and Panc02 tumours (p=0.046), which was accompanied by increased intratumoural effector T lymphocytes (CD62L − CD44 − ). CD8-depleting but not CD4-depleting Abs abrogated the efficacy of combined IL-6 and PD-L1 blockade in mice bearing Panc02 tumours (p=0.0016). This treatment combination also elicited significant antitumour activity in mice bearing orthotopic KPC-luc tumours and limited tumour progression in KPC-Brca2 mice (p<0.001). Histological analysis revealed increased T-cell infiltration and reduced α-smooth muscle actin cells in tumours from multiple models. Finally, IL-6 and PD-L1 blockade increased overall survival in KPC-Brca2 mice compared with isotype controls (p=0.0012). Conclusions These preclinical results indicate that targeted inhibition of IL-6 may enhance the efficacy of anti-PD-L1 in PDAC.