Clinical and molecular features of early onset pancreatic adenocarcinoma

Abstract Pancreatic adenocarcinoma (PDAC) is a major health burden and may become the second cause of death by cancer in developed countries. The incidence of early‐onset pancreatic cancer (EOPC, defined by an age at diagnosis 50). Eight hundred and seventy eight patients were included, of which 113 EOPC, exhibiting a comparable performance status. EOPC were more often diagnosed at the metastatic stage (70.0% vs 58.3%) and liver metastases were more prevalent at diagnosis (60.2% vs. 43.9%). The median overall survival (OS) from diagnosis was 18.1 months, similar between EOPC and nEOPC. Among patients who underwent surgery, recurrence‐free survival was similar between age groups. Among metastatic patients, first line progression free survival was similar but EOPC received more treatment lines (72.3% vs. 58.1% received ≥2 lines). Regarding molecular alterations, the mean tumor mutational burden (TMB) was lower in EOPC (1.42 vs. 2.95 mut/Mb). The prevalence of KRAS and BRCA1/2 mutations was similar, but EOPC displayed fewer alterations in CNKN2A/B. Fifty eight patients (18.6%) had actionable alterations (ESCAT I‐III) and 31 of them received molecularly matched treatments. On the transcriptomic level, despite its clinical aggressiveness, EOPC was less likely to display a basal‐like phenotype. To conclude, EOPC were diagnosed more frequently at the metastatic stage. OS and 1st line PFS were similar to nEOPC. EOPC displayed specific molecular features, such as a lower TMB and fewer alterations in CDKN2A/B.