Impact of age, comorbidities and relevant changes on surveillance strategy of intraductal papillary mucinous neoplasms: a competing risk analysis

Abstract

OBJECTIVE: Cost-effectiveness of surveillance for branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) is debated. We combined different categories of risks of IPMN progression and of IPMN-unrelated mortality to improve surveillance strategies. DESIGN: Retrospective analysis of 926 presumed BD-IPMNs lacking worrisome features (WFs)/high-risk stigmata (HRS) under surveillance. Charlson Comorbidity Index (CACI) defined the severity of comorbidities. IPMN relevant changes included development of WF/HRS, pancreatectomy or death for IPMN or pancreatic cancer. Pancreatic malignancy-unrelated death was recorded. Cumulative incidence of IPMN relevant changes were estimated using the competing risk approach. RESULTS: 5-year cumulative incidence of relevant changes was 17.83% and 1.6% developed pancreatic malignancy. 5-year cumulative incidences for IPMN relevant changes were 13.73%, 19.93% and 25.04% in low-risk, intermediate-risk and high-risk groups, respectively. Age ≥75 (HR: 4.15) and CACI >3 (HR: 3.61) were independent predictors of pancreatic malignancy-unrelated death. 5-year cumulative incidence for death for other causes was 15.93% for age ≥75+CACI >3 group and 1.49% for age <75+CACI ≤3. 5-year cumulative incidence of IPMN relevant changes were 13.94% in patients with age <75+CACI ≤3 compared with 29.60% in those with age ≥75+CACI >3. In this group 5-year rate of malignancy-free patients was 95.56% with a 5-year survival of 79.51%. CONCLUSION: Although it is not uncommon the occurrence of changes considered by current guidelines as relevant during surveillance of low risk BD-IPMNs, malignancy rate is low and survival is significantly affected by competing patients' age and comorbidities. IPMN surveillance strategy should be tailored based on these features and modulated over time.