Invasive and Noninvasive Progression After Resection of Noninvasive Intraductal Papillary Mucinous Neoplasms

Area of Science:

• Gastroenterology
• Surgical Oncology
• Pancreatic Pathology

Background:

• Intraductal papillary mucinous neoplasms (IPMNs) are cystic neoplasms of the pancreas.
• A risk of progression exists in the remnant pancreas after IPMN resection.

Purpose of the Study:

• To determine the frequency and patterns of progression (noninvasive vs. invasive) of resected noninvasive IPMNs.
• To identify risk factors associated with IPMN progression after surgical resection.

Main Methods:

• Retrospective analysis of 449 patients with resected IPMNs (1995-2018).
• Exclusion of patients with invasive carcinoma or <6 months follow-up.
• Definition of noninvasive progression (new IPMN, lesion growth) and invasive progression (development of invasive cancer or metastasis).

Main Results:

• Progression occurred in 27.6% of patients (24.1% noninvasive, 3.6% invasive) over a median follow-up of 48.9 months.
• Cumulative 10-year incidence of invasive progression was 12.9%, and noninvasive progression was 41.5%.
• Multifocality (HR 4.53) and high-grade dysplasia (HGD) (HR 3.60) in the original resection were significant risk factors for invasive progression.

Conclusions:

• Progression to invasive carcinoma after noninvasive IPMN resection can be delayed.
• High-grade dysplasia and multifocal cysts are significant risk factors for invasive progression.
• Patients with high-risk features warrant intensive surveillance and may benefit from novel therapeutic strategies.