Prognostic factors for rapid progression in metastatic pancreatic adenocarcinoma: Clinical, histopathological, and laboratory analysis.

681 Background: Metastatic pancreatic adenocarcinoma (mPAC) remains highly lethal despite modern chemotherapy. Outcome heterogeneity underscores the need for pragmatic prognostic markers. Rapid progression (RP)—progression within six months of first-line therapy—may reflect primary resistance but is under-characterized in real-world Brazilian cohorts. We evaluated clinical, histopathologic, and laboratory factors associated with RP and their impact on survival. Methods: We performed a single-center retrospective cohort at AC Camargo Cancer Center including 164 adults with histologically confirmed mPAC who initiated first-line chemotherapy between January 2021 and January 2024. Baseline variables included demographics, Charlson index, BMI, ECOG, primary tumor site, metastatic burden and sites, ascites (at diagnosis and during follow-up), histologic grade, neutrophil-to-lymphocyte ratio (NLR), albumin, and C-reactive protein (CRP). First-line regimens were FOLFIRINOX, gemcitabine+nab-paclitaxel, or gemcitabine-based. RP was defined as clinical/radiologic progression