Fate of Patients With Intraductal Papillary Mucinous Neoplasms of Pancreas After Resection According to the Pathology and Margin Status: Continuously Increasing Risk of Recurrence Even After Curative Resection Suggesting Necessity of Lifetime Surveillance.

OBJECTIVE: This study evaluated the associated factors and prognosis according to pathology and margin after surgical resection of intraductal papillary mucinous neoplasms (IPMN).

BACKGROUND: There is limited information on recurrence patterns according to pathology and margin in IPMN.

METHODS: Total 577 patients who underwent operation for IPMN at a tertiary center were included. Factors associated with recurrence, survival and recurrence outcomes according to pathology and margin were analyzed.

RESULTS: Among 548 patients analyzed, 353 had low-grade dysplasia (LGD); 78, high-grade dysplasia (HGD); and 117, invasive IPMN. Total 50 patients developed recurrences, with four resection margins, eight remnant pancreas, 11 locoregional, and 35 distant recurrences. Invasive IPMN showed worse 5-year cumulative recurrence risk (LGD vs HGD vs invasive: 0.7% vs 4.3% vs 37.6%, p < 0.001) and 5-year survival rate (89.0% vs 84.0% vs 48.4%, p < 0.001). Recurrence risk increased after 5 years, even in LGD and HGD. Malignant margin (HGD and invasive) had worse 5-year cumulative recurrence rate (R0 vs LGD vs malignant: 8.3% vs 5.9% vs 50.6%, p < 0.001) and 5-year survival rate (80.7% vs 83.0% vs 30.8%, p < 0.001). CA19-9 > 37 (p = 0.003), invasive IPMN (p < 0.001), and malignant margin (p = 0.036) were associated with recurrence.

CONCLUSIONS: Invasive IPMN developed more recurrences and had worse survival than LGD or HGD, indicating the need for more efficient postoperative treatment strategies. Patients with LGD and HGD also need regular follow-up for recurrence after 5 years. Malignant margins need additional resection to achieve negative or at least LGD margin.