[1598] Pathologic Factors Affecting the Recurrence and Survival of Pancreatic Intraductal Papillary Mucinous Neoplasm

SA Kim, E Yu, SC Kim, JH Kim. University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea

Background: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas constitutes a heterogeneous group with several subtypes. The frequency of each subtype has not been fully examined yet in Korean population. In addition, the benefit of clearing resection margin is still controversal.
Design: We reviewed surgically resected 281 cases of IPMN for 13 years in a single institute. Dividing all cases into either noninvasive IPMN or invasive carcinoma group, the recurrence of each group was compared according to the histologic grade (benign or borderline IPMN, carcinoma in situ, invasive carcinoma) and size (PanIN; lesions involving small ducts less than 0.5cm in diameter and IPMN; more than 0.5cm-sized lesions) of the residual lesions in the resection margin.
Results: Sixty cases (21.4%) were invasive carcinoma, and 221 (78.6%) non-invasive cases included 87 cases (31.0%) of benign, 107 (38.1%) cases of borderline and 11 (3.9%) cases of carcinoma in situ. Main duct was involved in 154 (54.8%) cases. According to the type of epithelium, gastric foveolar, intestinal and pancreatobiliary type were 230 (81.9%) cases, 27 (9.6%) cases and 24 (8.5%) cases, respectively. Invasiveness, main duct involvement and large tumor size were associated with decreased patient survival (P<0.001, =0.009, and <0.001) and disease-free survival (P=0.001, 0.011, and <0.001). In noninvasive IPMN, increased recurrence in patients with five or more years of follow-up was related to the involvement of resection margin by carcinoma in situ, but not by PanIN, benign or borderline IPMN. In addition, the recurrence rate of invasive carcinoma was significantly high (27.3%) even when the resection margin was clear, and was not related to the grade or size of residual tumors in resection margin.
Conclusions: The proportion of gastric foveloar type was higher in our series than previously reported. Invasiveness is the strong risk factor for recurrence in IPMN regardless of the status of resection margin. However, in noninvasive IPMN, the histologic grading is more important than the size of residual lesion in the evaluation of pancreatic resection margin.
Category: Liver & Pancreas

Tuesday, March 23, 2010 1:00 PM

Poster Session IV # 201, Tuesday Afternoon

 

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