Abstract
Background: Pancreatic cancer is projected to become the second leading cause of cancer related death in the US. We aim to investigate the demographics, clinical outcomes and survival outcomes of patients diagnosed with early-onset (<40 years) and late-onset (>40 years) pancreatic adenocarcinoma (PAC). Methods: Data on PAC between 1975 and 2016 were extracted from the Surveillance, Epidemiology, and End Results Registry. Results: Within the study period, 136,100 patients were identified which included 1181 patients with early-onset PAC and 134,919 patients with late-onset PAC. Both cohorts tend to present with distant metastasis (70.3% vs 57.9%). Both groups also showed an exponential rise in incidence (early-onset 3.69% annual change vs late-onset 6.25% annual change). When stratified by anatomical location, there was a trend of increasing cancer in the head of the pancreas for patients <40 years (3.63% annual change). While late PAC showed increasing cancer in all anatomical locations, the largest increase was observed in the tail of the pancreas (8.62% annual change). Overall, there was a mild difference in survival for early- and late-onset PAC (7 months vs 6 months, respectively, log rank p = 0.004). Both age groups showed the worse prognosis when cancer occurred in the tail of the pancreas (6 months vs 4 months, respectively). On cox proportion analysis, patients with late-onset PAC had twice the risk of mortality compared to early-onset PAC (HR 2.06, CI: 1.788–2.370, P = 0.001). Conclusions: Our study showed that both early- and late-onset PAC are increasing and while prognosis remains poor. Tumor anatomy showed a growing incidence of early-onset PAC in the head of the pancreas while late-onset PAC showed a rising incidence in the body and tail of the pancreas.