Current status and treatment outcomes of intraductal papillary mucinous carcinoma in Korea: A multi-center cohort study.

812 Background: The spectrum of intraductal papillary mucinous neoplasm (IPMN) varies from benign cysts to intraductal papillary mucinous carcinoma (IPMC). There is a lack of large-scaled data on IPMC and high-grade dysplasia. We aimed to study the real-world status and treatment outcomes of IPMC in South Korea. Methods: This is a retrospective, multicenter study conducted in South Korea. We reviewed the electronic medical records of patients who were histologically diagnosed with IPMC or high-grade (HG) dysplasia between 2011 and 2020, and analyzed the baseline characteristics, treatment patterns, and survival. Results: A total of 388 patients were eligible from six institutes (145 female [37%]; median age 67.8; 259 IPMC [67%] vs 129 HG dysplasia [33%]). The median overall survival for IPMC patients was 75 months, compared to 133 months for HG dysplasia. In IPMC group, 217 (84%) were underwent surgical resection and 42 (16%) did not underwent surgery due to general condition or advanced stage whose median overall survival was 83 months and 49 months respectively. In resected IPMC, 104 (48%) received adjuvant chemotherapy (gemcitabine single 48%, 5FU+leucovorin 33%, others 19%) and 66 (30%) experienced recurrence and median recurrence-free survival (RFS) was 20 months. Among IPMC group, 11 (4.2%) was in advanced stage and eight of those received palliative chemotherapy (FOLFIRINOX 62.5%; gemcitabine single 25%; gemcitabine with erlotinib 12.5%). In HG dysplasia, 108 (84%) patients underwent surgery, and 21 (16%) patients did not undergo surgery whose OS were 171 and 133 months, retrospectively. In patients with resected HG dysplasia, 29 (27%) experienced recurrence and median RFS was 21 months. Conclusions: IPMC generally showed longer survival and a lower recurrence rate than those of historical data in PDAC, with HG dysplasia demonstrating even better outcomes. In real world, similar chemotherapy regimens used for PDAC were applied to IPMN patients. Treatment status of intraductal papillary mucinous carcinoma and high-grade dysplasia. IPMC(259) IPMN-HG(129) Total(388) Median overall survival (month) 75 133 85 Treatment OP 217(84%) 108(84%) 325(84%) Adjuvant chemotherapy 104(48%) 19(18%) 123(38%) Recurrence rate 66(30%) 29(27%) 95(29%) Median recurrence-free survival (month) 20 19 21 Palliative chemotherapy 8(3%) NA Progression rate 5(63%) NA Progression-free survival (month) 13 NA