Abstract
Background: Pancreatic ductal adenocarcinoma (PDAC) exhibits variable survival outcomes based on tumor location, with pancreatic head cancer (PHC) and pancreatic body/tail cancer (PBTC) differing in prognosis and treatment response. This study investigates the correlation between tumor location and survival outcomes in PDAC patients treated with standard chemotherapy regimens. Methods: A retrospective analysis of 604 PDAC patients (400 PHC, 204 PBTC) diagnosed between January 2015 and May 2024 at Houston Methodist Neal Cancer Center was conducted. Patients received either mFOLFIRINOX or gemcitabine/nab-paclitaxel as first-line therapy. Clinical data, including demographics, tumor stage, treatment modalities, and molecular profiles, were extracted from electronic records. Overall survival (OS) and progression-free survival (PFS) were assessed using Kaplan-Meier analyses and Cox proportional hazards models. Latent class analysis (LCA) identified patient subgroups based on shared clinical, demographic, and survival characteristics. Results: PHC patients demonstrated superior median OS (12 months) compared to PBTC (9 months, p = 0.012) and PFS (8 months vs. 5 months, p = 0.0008). Across both subtypes, mFOLFIRINOX was associated with significantly longer OS than gem/nab-paclitaxel (PHC: 18.8 vs. 12.7 months, p < 0.0001; PBTC: 14 vs. 6 months, p = 0.011). LCA revealed distinct clusters: in PHC, a curative-intent class (median OS > 24 months) contrasted with a palliative class (<6 months); in PBTC, an aggressive treatment class (median OS > 18 months) differed from a limited treatment class (<6 months). Cluster differences were linked to treatment intensity, stage, and radiation use. Conclusions: PHC is associated with better survival outcomes than PBTC, with mFOLFIRINOX outperforming gem/nab-paclitaxel in both subtypes. LCA highlights heterogeneous patient subgroups, suggesting opportunities for personalized treatment strategies in PDAC management.