Pancreatic neuroendocrine tumors in French VHL mutation carriers: a multicentric retrospective study.

BACKGROUND: Von Hippel-Lindau disease (VHL) is a rare autosomal dominant hereditary cancer-predisposition syndrome caused by germline pathogenic variants (PV) in VHL gene. It is associated with a high penetrance of benign and malignant vascular tumors in multiples organs, including pancreatic neuroendocrine tumors (PanNETs), whose long-term natural history is ill-known. METHODS: Patients with both documented germline PV in VHL gene and PanNETs included in the French PREDIR database between 1995 and 2022 were included. Primary endpoint was the proportion of patients with PanNET-related metastases and secondary endpoint was overall survival (OS). Genotype/phenotype correlations were studied. RESULTS: We included 121 patients with 259 PanNETs. Median age at diagnosis was 38 years. Median follow-up was 89.5 months. PanNET surgical resection was performed in 51 patients. Overall, 29 patients (24%) had metastases (5 synchronous, 10 metachronous), with a higher risk in case of larger PanNET size (p=0.0089; best threshold 28 mm) and grade 2 PanNET (p=0.048), and a pejorative prognostic impact (p=0.043). Patients with PV in VHL exon 1 had larger PanNETs (p=0.018), more often metastatic disease (48% vs 11.5%; p < 0.001) and a trend toward shorter OS (p=0.16). CONCLUSION: The risk of metastases associated to VHL-related PanNETs remains low (24%) but increases with tumor size >28 mm, higher grade and in case of PV located VHL exon 1. These data might help improving the management of these patients, who should be referred to an expert center.

Diagnosis and treatment of bacterial peritonitis in patients with gastrointestinal cancer: an observational multicenter study.

Background: Bacterial peritonitis (BP) in patients with gastrointestinal (GI) cancer has been poorly described, and its prevalence is unknown. Objectives: This study aimed to evaluate in patients with both GI cancer and ascites the prevalence of BP, associated features, mechanisms, prognosis, and the diagnostic performance of neutrophil count in ascites. Design: A retrospective, multicenter, observational study. Methods: All patients with GI cancer and ascites who underwent at least one paracentesis sample analyzed for bacteriology over a 1-year period were included. BP was defined by a positive ascites culture combined with clinical and/or biological signs compatible with infection. Secondary BP was defined as BP related to a direct intra-abdominal infectious source. Results: Five hundred fifty-seven ascites from 208 patients included were analyzed. Twenty-eight patients had at least one episode of BP and the annual prevalence rate of BP was 14%. Among the 28 patients with BP, 19 (65%) patients had proven secondary BP and 17 (59%) patients had multi-microbial BP, mainly due to Enterobacterales. A neutrophil count greater than 110/mm3 in ascites had negative and positive predictive values of 96% and 39%, respectively, for the diagnosis of BP. The median survival of patients with BP was 10 days (interquartile range 6-40) after the diagnosis. Conclusion: BP is not rare in patients with GI cancer and is associated with a poor short-term prognosis. When a patient with GI cancer is diagnosed with BP, a secondary cause should be sought. Further studies are needed to better define the best management of these patients.

Devimistat (CPI-613) With Modified Fluorouarcil, Oxaliplatin, Irinotecan, and Leucovorin (FFX) Versus FFX for Patients With Metastatic Adenocarcinoma of the Pancreas: The Phase III AVENGER 500 Study.

PURPOSE: Metastatic pancreatic adenocarcinoma (mPC) remains a difficult-to-treat disease. Fluorouarcil, oxaliplatin, irinotecan, and leucovorin (FFX) is a standard first-line therapy for mPC for patients with a favorable performance status and good organ function. In a phase I study, devimistat (CPI-613) in combination with modified FFX (mFFX) was deemed safe and exhibited promising efficacy in mPC. METHODS: The AVENGER 500 trial (ClinicalTrials.gov identifier: NCT03504423) is a global, randomized phase III trial conducted at 74 sites across six countries to investigate the efficacy and safety of devimistat in combination with mFFX (experimental arm) compared with standard-dose FFX (control arm) in treatment-naïve patients with mPC. Treatment, administered in once-every-2-weeks cycles until disease progression or intolerable toxicity, included intravenous devimistat at 500 mg/m2 total per day on days 1 and 3 in the experimental arm. The primary end point of the study was overall survival (OS). RESULTS: Five hundred and twenty-eight patients were randomly assigned (266 in the experimental arm and 262 in the control arm). The median OS was 11.10 months for devimistat plus mFFX versus 11.73 months for FFX (hazard ratio [HR], 0.95 [95% CI, 0.77 to 1.18]; P = .655) and median progression-free survival was 7.8 months versus 8.0 months, respectively (HR, 0.99 [95% CI, 0.76 to 1.29]; P = .94). Grade ≥3 treatment-emergent adverse events with >10% frequency in the devimistat plus mFFX arm versus the FFX arm were neutropenia (29.0% v 34.5%), diarrhea (11.2% v 19.6%), hypokalemia (13.1% v 14.9%), anemia (13.9% v 13.6%), thrombocytopenia (11.6% v 13.6%), and fatigue (10.8% v 11.5%), respectively. CONCLUSION: Devimistat in combination with mFFX did not improve long- and short-term mPC patient outcomes compared with standard FFX. There were no new toxicity signals with the addition of devimistat.

Activation of lysosomal iron triggers ferroptosis in cancer.

Iron catalyses the oxidation of lipids in biological membranes and promotes a form of cell death referred to as ferroptosis1-3. Identifying where this chemistry takes place in the cell can inform the design of drugs capable of inducing or inhibiting ferroptosis in various disease-relevant settings. Whereas genetic approaches have revealed underlying mechanisms of lipid peroxide detoxification1,4,5, small molecules can provide unparalleled spatiotemporal control of the chemistry at work6. Here, we show that the ferroptosis inhibitor liproxstatin-1 (Lip-1) exerts a protective activity by inactivating iron in lysosomes. Based on this, we designed the bifunctional compound fentomycin that targets phospholipids at the plasma membrane and activates iron in lysosomes upon endocytosis, promoting oxidative degradation of phospholipids and ferroptosis. Fentomycin effectively kills primary sarcoma and pancreatic ductal adenocarcinoma cells. It acts as a lipolysis-targeting chimera (LIPTAC), preferentially targeting iron-rich CD44high cell-subpopulations7,8 associated with the metastatic disease and drug resistance9,10. Furthermore, we demonstrate that fentomycin also depletes CD44high cells in vivo and reduces intranodal tumour growth in an immunocompetent murine model of breast cancer metastasis. These data demonstrate that lysosomal iron triggers ferroptosis and that lysosomal iron redox chemistry can be exploited for therapeutic benefits.