The study aimed to evaluate the role of adjuvant chemotherapy in intraductal papillary mucinous neoplasm (IPMN)-derived pancreatic ductal adenocarcinoma (PDAC), a topic with limited evidence. Conducted as an international multicenter retrospective cohort study from 2005 to 2018, it involved 1,031 patients from 16 centers. The research utilized Cox regressions to identify risk-adjusted hazard ratios (HR) associated with overall survival (OS), alongside Kaplan-Meier curves and log-rank tests for survival analysis. Logistic regression was also performed to identify factors influencing adjuvant chemotherapy administration.
Key findings include that nodal disease and elevated or markedly elevated carbohydrate antigen 19-9 (CA19-9) levels were associated with worse OS. Specifically, node-positive patients with elevated CA19-9 levels experienced a 34.4-month improvement in median OS after adjuvant chemotherapy, while those with markedly elevated CA19-9 levels had a 12.6-month survival benefit. However, node-negative patients, regardless of CA19-9 levels, did not benefit significantly from adjuvant chemotherapy.
The study also proposed a decision tree categorizing patients into overtreated, undertreated, and optimally treated cohorts, revealing that 18.1% of patients were undertreated and 61.2% were overtreated. Factors associated with chemotherapy administration included younger age, R1-margin, poorer differentiation, and nodal disease. This research underscores the need for more tailored approaches to adjuvant chemotherapy in IPMN-derived PDAC, highlighting the importance of considering nodal status and CA19-9 levels in treatment decisions.