Yoshiki Hirooka

BACKGROUND: With recent advances in chemotherapy for unresectable pancreatic ductal adenocarcinoma (PDAC) with liver metastasis (LM), attempts have been made to resect the primary tumor in patients showing favorable responses to anti-cancer treatment (so-called "conversion surgery"; CS). This study aimed to clarify the outcomes of CS for PDAC with LM in a nationwide multicenter study. METHODS: This retrospective, multicenter study was conducted as a project study of the Japan Pancreas Society and included patients with PDAC with LM at initial diagnosis, diagnosed radiologically or intraoperatively (occult LM), who underwent CS after at least 4 months of chemotherapy between 2010 and 2022. Survival outcomes and prognostic factors were analyzed. RESULTS: 90 patients were enrolled from 31 Japanese institutions. Median duration of preoperative chemotherapy was 10.4 (range, 4.2-58.5) months, and gemcitabine plus nab-paclitaxel was the most common first-line regimen, followed by folinic acid, 5-fluorouracil, irinotecan, and oxaliplatin. Liver metastasectomy was performed in 27 patients (30%). 82 patients (91.1%) initiated adjuvant chemotherapy, and 41 (45.6%) completed it. Overall survival (OS) from initial treatment was 53.1 (95% CI 41.6-65.7) months; OS after CS was 39.7 (95% CI 24.4-55.9) months, and disease-free survival was 14.7 (95% CI 9.3-23.4) months. Preoperative normalization of carbohydrate antigen 19-9 and pathologic negative lymph node metastasis were independent prognostic factors for OS. CONCLUSION: CS may provide a survival benefit for highly selected patients with PDAC and LM, including those with occult lesions, who respond well to multidisciplinary treatment.

Background & Aims: Age-related variation in the gut microbiota complicates biomarker discovery for pancreatic cancer. This study aimed to identify microbial taxa with minimal age dependence that are associated with pancreatic neoplasia and to develop a practical quantitative PCR (qPCR)-based assay targeting a shared gene involved in butyrate production. Study design: Cross-sectional study. Place and Duration of Study: Department of Gastroenterology and Hepatology, Fujita Health University, Toyoake, Japan, between October 2022 and July 2025. Methodology: Fecal samples from 64 individuals with precursor lesions considered to be at high risk for pancreatic cancer (HR) and 22 patients with pancreatic cancer (PC) were compared with those from healthy controls aged <50 years (Young; n = 71) and ≥50 years (Old; n = 65). Microbiota composition was analyzed by 16S rRNA gene sequencing. A qPCR primer set targeting the but gene, which encodes butyryl-CoA:acetate CoA-transferase, was designed to evaluate the shared genetic potential of the identified minimally age-dependent taxa, namely the Anaerostipes hadrus group and Agathobacter rectalis. Results: The A. hadrus group and A. rectalis showed disease-associated depletion with minimal age dependency. The qPCR assay showed no difference in but gene levels between the Young and Old groups (P = 0.3301). but gene levels in the HR group were comparable to those in the Old group (P > 0.9999), whereas levels in the PC group were significantly lower than those in the Old group (P = 0.0020) and the HR group (P = 0.0136). Conclusion: Targeting the but gene provides a practical approach to assessing the shared butyrate-producing potential of this minimally age-dependent microbial cluster. Within this cross-sectional cohort, but gene levels were preserved in HR individuals, whereas levels in the PC group were reduced, suggesting its potential utility as a non-invasive adjunct for future evaluation in longitudinal monitoring or risk assessment after prospective validation.