Is multidisciplinary treatment effective for invasive intraductal papillary mucinous carcinoma?

Background Surgical resection is standard treatment for invasive intraductal papillary mucinous carcinoma (IPMC); however, impact of multidisciplinary treatment on survival including postoperative adjuvant therapy (AT), neoadjuvant therapy (NAT), and treatment for recurrent lesions is unclear. We investigated the effectiveness of multidisciplinary treatment in prolonging survival of patients with invasive IPMC. Methods This retrospective multi‐institutional study included 1183 patients with invasive IPMC undergoing surgery at 40 academic institutions. We analyzed the effects of AT, NAT, and treatment for recurrence on survival of patients with invasive IPMC. Results Completion of the planned postoperative AT for 6 months improved the overall survival (OS), disease‐specific survival (DSS), and recurrence‐free survival (RFS) of patients with stage IIB and stage III resected invasive IPMC, elevated preoperative carbohydrate antigen 19–9 level, lymphovascular invasion, perineural invasion, serosal invasion, and lymph node metastasis on un‐matched and matched analyses. Of the patients with borderline resectable (BR) invasive IPMC, the OS (p = 0.001), DSS (p = 0.001), and RFS (p = 0.001) of patients undergoing NAT was longer than that of those without on the matched analysis. Of the 484 invasive IPMC patients (40.9%) who developed recurrence after surgery, the OS of 365 patients who received any treatment for recurrence was longer than that of those without treatment (40.6 vs. 22.4 months, p