Endoscopic Ultrasound and Clinical Features for Differentiating Autoimmune Pancreatitis and Pancreatic Ductal Adenocarcinoma: A Multicenter Cohort Study.

Evaluate suspected pancreatic adenocarcinoma with a dedicated pancreatic-protocol (multiphasic, contrast-enhanced) CT of the abdomen as the preferred imaging for diagnosis and staging (MRI/MRCP is an acceptable alternative); PET/CT may be added after, never as a substitute for, protocol CT/MRI in higher-risk situations. Obtain tissue confirmation, preferably by EUS-guided FNA/FNB with core biopsy where feasible; biopsy is generally required before neoadjuvant or palliative therapy, whereas patients with clearly resectable disease may proceed to surgery without preoperative biopsy. Measure baseline CA 19-9 (interpret after biliary decompression / with normal bilirubin; it can be falsely low in Lewis-antigen-negative patients and falsely elevated with cholestasis). Offer GERMLINE testing for inherited susceptibility to EVERY patient with confirmed pancreatic adenocarcinoma regardless of family history, using a comprehensive multi-gene panel; separately, for patients with locally advanced or metastatic disease who are candidates for anti-cancer therapy, obtain TUMOR/SOMATIC molecular profiling (broad NGS; RNA-based assays improve fusion detection; cell-free/liquid biopsy if tissue is insufficient). Assign resectability, resectable, borderline resectable, locally advanced (unresectable), or metastatic, by multidisciplinary review, ideally at a high-volume center. RESECTABLE disease: upfront resection (pancreaticoduodenectomy for head/uncinate; distal pancreatectomy ± splenectomy for body/tail) followed by adjuvant therapy, or neoadjuvant therapy in selected high-risk patients; preferred adjuvant regimen is modified FOLFIRINOX in patients able to tolerate it, ideally begun within 12 weeks of surgery, for a total of ~6 months of perioperative systemic therapy. BORDERLINE RESECTABLE and LOCALLY ADVANCED disease: neoadjuvant systemic therapy, with or without subsequent chemoradiation/RT, then restaging and reassessment for resection. METASTATIC disease by performance status: good PS (ECOG 0-1, adequate organ function), first-line FOLFIRINOX/modified FOLFIRINOX, NALIRIFOX, or gemcitabine + nab-paclitaxel, with clinical trial preferred; after ~4-6 months without progression, transition to a maintenance strategy (including olaparib for germline BRCA1/2 carriers who have NOT progressed on first-line platinum-based therapy), a clinical trial, or a treatment break; intermediate PS (ECOG 2), clinical trial preferred, otherwise less-intensive first-line therapy (preferred gemcitabine + nab-paclitaxel [category 1], or single-agent gemcitabine or capecitabine, or FOLFOX/FOLFIRI/CapeOx), since the intensive triplets (FOLFIRINOX/modified FOLFIRINOX and NALIRIFOX) are limited to ECOG 0-1 and are generally not appropriate at ECOG 2, with the same maintenance-versus-progression reassessment applied after ~4-6 months without progression; poor PS (ECOG 3-4), palliative/best supportive care, with single-agent chemotherapy or a biomarker-directed agent only if clinically appropriate. Treat by molecular target wherever an actionable alteration is present, across lines: pembrolizumab (or dostarlimab) for MSI-H/dMMR and pembrolizumab for TMB-H, olaparib for germline BRCA1/2 (maintenance after platinum), larotrectinib/entrectinib for NTRK fusions, selpercatinib for RET fusions, dabrafenib + trametinib for BRAF V600E, erdafitinib for FGFR2 alterations, fam-trastuzumab deruxtecan for HER2-positive disease, zenocutuzumab for NRG1 fusion-positive disease, and (in recent NCCN versions) KRAS G12C inhibitors (adagrasib/sotorasib), several of these after prior systemic therapy. Integrate supportive care throughout: relieve obstructive jaundice with an endoscopic self-expanding metal stent in non-operative or neoadjuvant pathways, but do NOT perform routine preoperative biliary drainage before planned upfront resection; treat exocrine insufficiency with pancreatic enzyme replacement titrated to symptoms (common starting dose ~40,000-50,000 units of lipase with main meals, roughly half with snacks, increased as needed); manage refractory pain with celiac plexus neurolysis or palliative RT; relieve gastric outlet obstruction with surgical or EUS-guided gastrojejunostomy (or enteral stenting); and provide VTE prophylaxis, nutritional support, and early palliative care.