Invasive intraductal papillary mucinous carcinomas of the pancreas: predictors of survival and the role of lymph node ratio

Introduction: Intraductal papillary mucinous neoplasms (IPMNs) are being increasingly recognized, and often harbor cancer. Lymph node metastases are an important prognostic factor for patients with invasive intraductal papillary carcinoma (I-IPMC), but the role of lymph node ratio (LNR) in predicting survival after surgery for I-IPMC is unknown. Methods: The combined databases from the Surgical Department of Massachusetts General Hospital of Boston and the University of Verona were queried. We retrospectively reviewed clinical and pathologic data of all patients with resected, pathologically confirmed, I-IPMC between 1990 and 2007. Univariate and multivariate analysis were performed. Results: I-IPMCs were diagnosed in 104 patients (55 males and 49 females), median age was 69 years. Recurrent disease was identified in 49 patients (47.1%) and the median 5-year disease specific survival (DSS) was 60.1%. The median number of resected/ evaluated nodes was 15 (range, 5-60). There were 60 (57.7%) patients who had negative lymph nodes (N0), whereas 44 (42.3%) had lymph node metastases (N1). Patients with lymph node metastases had a shorter 5-year DSS (28.9%) compared with patients with negative lymph nodes (80.3%; P < 0.05) As the LNR increased, 5-year DSS decreased (LNR = 0, 86.5%; LNR >0 to 0.2, 34.4%; LNR >0.2, 11.1%; P < 0.05). On multivariate analysis, LNR, the presence of a family history of pancreatic cancer and a preoperative value of Ca 19.9 > 37 U/L were significant predictors of survival (P < 0.05). Conclusions: Lymph node ratio is a strong predictor of survival after resection for invasive intraductal papillary mucinous carcinoma.