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Objectives: Primary objective was to evaluate the correlation between immune marker expression in baseline tumor biopsies and their respective surgical specimens in squamous cell carcinoma of the oral cavity (OCSCC). Secondary objective was to assess the impact of these markers on overall (OS) and disease-free survival (DFS)., Materials and Methods: Patients with a histological diagnosis of oral squamous cell carcinoma treated surgically between 2012 and 2020 were included in this retrospective, translational monocentric study. The expression of PD-L1, T-cells markers and an OCSCC-adapted immunoscore were evaluated by multiplex immunohistochemistry., Results: One hundred and four patients (mean: 58 years) were included. Seventy patients had paired samples available. Poor correlation was highlighted for PD-L1-positive surface expression (r = 0.29) and combined positive score (CPS). For CPS ≥ 20 and CPS ≥ 1, correlation coefficient r was 0.24 and 0.46 respectively. T-cells density showed also poor correlation with a r of 0.57 and 0.31 for CD3 and CD8 T-cells, respectively. Univariate survival analyses showed significant better OS and DFS (P < 0.05) for patients with stage III-IV OCSCC with a high compared to a low immunoscore, based on surgical samples only., Conclusion: Our study showed poor correlation in PD-L1 expression, CPS, T-cells density and immunoscore between baseline tumor biopsies and surgical resection specimens. In addition, the immunoscore may emerge as a potential prognostic factor in advanced squamous cell carcinoma of the oral cavity. If surgical specimens are available, they may be of interest for clinical practice decision., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: JPM reports grants from Boehringer-Ingelheim, Pfizer, Roche, AstraZeneca, Bayer, Innate, Merck Serono, Boehringer, BMS, Novartis, Janssen, Incyte, Cue Biopharma, ALX oncology, iTEOS, eTheRNA, NEKTAR, F-star, Seagen, Genmab, Astellas, CureVac, MSD, Gilead, and Sanofi outside the submitted work. No disclosures were reported by the other authors., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Only 15-20% of recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) patients derive long-term benefit from nivolumab or pembrolizumab. We developed a circulating tumour DNA (ctDNA) tumour-agnostic assay aimed at the early prediction of single agent programmed cell death 1 (PD1) inhibitor efficacy in R/M SCCHN., Patients and Methods: Our tumour-agnostic assay included 37 genes frequently mutated in R/M SCCHN and two HPV16 genes. Primary endpoint was the concordance between ctDNA kinetics (ΔctDNA) and the best overall response according to Response Evaluation Criteria in Solid Tumors version 1.1. ΔctDNA was defined as the difference in mean variant allele frequency (VAF) between the on-treatment sample harvested 6-10 weeks (FU1) after PD1 inhibitor initiation and the pre-treatment plasma sample (ΔctDNA = mean FU1 VAF - mean pre-treatment VAF)., Results: ctDNA was detected in 35/44 (80%) of the pre-treatment plasma samples. The concordance between ΔctDNA and imaging response was observed in 74%. Median progression-free survival was 8.6 months in the favourable ΔctDNA group and 2.5 months in the unfavourable ΔctDNA group (p = 0.057). Median overall survival (OS) was 18.1 and 8.2 months in the favourable and unfavourable ΔctDNA groups, respectively (p = 0.13). In patients with PD-L1 expressing SCCHN (Combined Positive Score ≥1), OS was significantly better in patients with favourable ΔctDNA compared with patients with unfavourable ΔctDNA: median OS was 41.5 and 8.4 months (p = 0.033), respectively., Conclusions: Tumour-agnostic ctDNA analysis for human papillomavirus (HPV)-negative and HPV-positive R/M SCCHN is feasible. ctDNA kinetics show promising results in predicting the efficacy of PD1 inhibitors in R/M SCCHN., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Forty to fifty percent of patients with locally advanced squamous cell carcinoma of the head and neck (LA SCCHN) relapse despite multimodal treatment. Circulating tumor DNA (ctDNA) has the potential to detect minimal residual disease (MRD) after curative-intent therapy and to identify earlier which patients will progress. We developed a tumor-agnostic plasma ctDNA assay to detect MRD in unselected LA SCCHN with the aim of predicting progression-free survival (PFS) and overall survival without the need for tumor sequencing., Patients and Methods: A 26-gene next-generation sequencing panel was constructed that included the most frequently mutated genes in SCCHN and two HPV-16 genes. MRD was assessed in each patient through an in-house informatic workflow informed by somatic mutations identified in the corresponding pre-treatment plasma sample. The presence of MRD was defined as the detection of ctDNA in one plasma sample collected within 1-12 weeks of the end of curative treatment. The primary endpoint was the PFS rate at 2 years. At least 32 patients were planned for inclusion with the hypothesis that PFS at 2 years was >80% in MRD-negative patients and <30% in MRD-positive patients (α = 0.05, β = 0.9)., Results: We sequenced DNA from 116 plasma samples derived from 53 LA SCCHN patients who underwent curative-intent treatment. ctDNA was detected in 41/53 (77%) patients in the pre-treatment samples. Out of these 41 patients, 17 (41%) were MRD positive after treatment. The 2-year PFS rate was 23.53% (9.9% to 55.4%) and 86.6% (73.4% to 100%) in MRD-positive and MRD-negative patients, respectively (P < 0.05). Median survival was 28.37 months (14.30 months-not estimable) for MRD-positive patients and was not reached for the MRD-negative cohort (P = 0.011)., Conclusions: Our ctDNA assay detects MRD in LA SCCHN and predicts disease progression and survival without the need for tumor sequencing, making this approach easily applicable in daily practice., (Copyright © 2023 European Society for Medical Oncology. Published by Elsevier Ltd. All rights reserved.)

Pancreatitis, an inflammation of the pancreas, appears to be a main driver of pancreatic cancer when combined with Kras mutations. In this context, the exact redox mechanisms are not clearly elucidated. Herein, we treated mice expressing a Kras G12D mutation in pancreatic acinar cells with cerulein to induce acute pancreatitis. In the presence of Kras G12D , pancreatitis triggered significantly greater redox unbalance and oxidative damages compared to control mice expressing wild-type &nbsp; Kras alleles. Further analyses identified the disruption in glutathione metabolism as the main redox event occurring during pancreatitis. Compared to the wild-type background, Kras G12D -bearing mice showed a greater responsiveness to treatment with a thiol-containing compound, N-acetylcysteine (NAC). Notably, NAC treatment increased the pancreatic glutathione pool, reduced systemic markers related to pancreatic and liver damages, limited the extent of pancreatic edema and fibrosis as well as reduced systemic and pancreatic oxidative damages. The protective effects of NAC were, at least, partly due to a decrease in the production of tumor necrosis factor-α (TNF-α) by acinar cells, which was concomitant with the inhibition of NF-κB(p65) nuclear translocation. Our data provide a rationale to use thiol-containing compounds as an adjuvant therapy to alleviate the severity of inflammation during pancreatitis and pancreatic tumorigenesis.

Pancreatic acinar cells are a cell type of origin for pancreatic cancer that become progressively less sensitive to tumorigenesis induced by oncogenic Kras mutations after birth. This sensitivity is increased when Kras mutations are combined with pancreatitis. Molecular mechanisms underlying these observations are still largely unknown. To identify these mechanisms, we generated the first CRISPR-edited mouse models that enable detection of wild-type and mutant KRAS proteins in vivo . Analysis of these mouse models revealed that more than 75% of adult acinar cells are devoid of detectable KRAS protein. In the 25% of acinar cells expressing KRAS protein, transcriptomic analysis highlighted a slight upregulation of the RAS and MAPK pathways. However, at the protein level, only marginal pancreatic expression of essential KRAS effectors, including C-RAF, was observed. The expression of KRAS and its effectors gradually decreased after birth. The low sensitivity of adult acinar cells to Kras mutations resulted from low expression of KRAS and its effectors and the subsequent lack of activation of RAS/MAPK pathways. Pancreatitis triggered expression of KRAS and its effectors as well as subsequent activation of downstream signaling; this induction required the activity of EGFR. Finally, expression of C-RAF in adult pancreas was required for pancreatic tumorigenesis. In conclusion, our study reveals that control of the expression of KRAS and its effectors regulates the sensitivity of acinar cells to transformation by oncogenic Kras mutations. SIGNIFICANCE: This study generates new mouse models to study regulation of KRAS during pancreatic tumorigenesis and highlights a novel mechanism through which pancreatitis sensitizes acinar cells to Kras mutations., (©2021 American Association for Cancer Research.)

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with few therapeutic options. The identification of new promising targets is, therefore, an urgent need. Using available transcriptomic datasets, we first found that Peroxiredoxin-1 gene ( PRDX1 ) expression was significantly increased in human pancreatic tumors, but not in the other gastrointestinal cancers; its high expression correlated with shortened patient survival. We confirmed by immunostaining on mouse pancreata the increased Peroxiredoxin-I protein (PRX-I) expression in pancreatic neoplastic lesions and PDAC. To question the role of PRX-I in pancreatic cancer, we genetically inactivated its expression in multiple human PDAC cell lines, using siRNA and CRISPR/Cas9. In both strategies, PRX-I ablation led to reduced survival of PDAC cells. This was mainly due to an increase in the production of reactive oxygen species (ROS), accumulation of oxidative DNA damage (i.e., 8-oxoguanine), and cell cycle blockade at G2/M. Finally, we found that PRX-I ablation disrupts the autophagic flux in PDAC cells, which is essential for their survival. This proof-of-concept study supports a pro-oncogenic role for PRX-I in PDAC.