(P051) Intraductal Papillary Neoplasm of the Bile Duct: Prognostic Factors in SEER Outcomes of Benign and Malignant Cases

April 30, 2015

Both benign and malignant cases had outcomes dependent upon the location and extent of surgical resection. In malignant cases that are not amenable to surgery, radiation offers a survival benefit. Given the cohort in this analysis, selection bias likely plays a significant role. Further study is required to define the optimal management of IPNB.

Sean Szeja, MD, Todd Swanson, MD, PhD; UT Medical Branch

INTRODUCTION: Intraductal papillary neoplasm of the bile duct (IPNB) may be invasive or noninvasive. Given its rarity, there are limited data on the management and clinical outcomes. The purpose of this study is to use the Surveillance, Epidemiology, and End Results (SEER) database to evaluate prognostic factors: stage, anatomical location, extent of surgery, and the use of radiation therapy (RT).

METHODS: Cases diagnosed from 1978–2011 were downloaded from the SEER database. Inclusion criteria were first primary, known status of surgery, and RT history. Analysis of malignant diagnoses from 2004–2011 incorporated TNM staging. Kaplan-Meier curves calculated overall survival (OS) and disease-specific survival (DSS) in months. Log-rank tests were performed to compare survival.

RESULTS: There were 31 benign cases, with an OS of 92 months; surgery was used in 26 cases, definitive RT was used in 1 case, and adjuvant RT was used in another. Ampulla of Vater (AoV) and other extrahepatic ductal (EHD) locations had statistically similar OS (120 vs 79 mo, respectively; P = .93). For EHD, trends suggested that subtotal resection had the best OS (P = .157), and for AoV locations, radical resection trended toward worse OS (P = .128), with statistical power limited by having eight patients with defined surgical extent at each location. There were 1,309 malignant cases; 542 of these patients did not have surgery, and of this group 77 received RT alone that extended median OS from 3 to 7 months (P = .026) and DSS from 4 to 8 months (P = .074). There were 323 malignant cases diagnosed from 2004–2011: 54% with N0M0 and 20% being T1N0M0. Analysis of all stages combined by location showed, in decreasing order, significantly different median survival times (P < .01): AoV: OS 48 mo, DSS 57 mo; EHD: OS 12 mo, DSS 15 mo; and intrahepatic ductal (IHD): OS 5 mo, DSS 5 mo. Analysis by treatment modality showed that, with regard to OS and DSS, surgery alone was better than surgery and radiation (P < .01), which was better than radiation alone (P < .01), which was similar to results with no treatment. Analysis of T1N0M0 cases showed that smaller extent of resection of primary location correlated with better OS and DSS (P < .05, P < .02, respectively) at EHD but not AoV locations.

CONCLUSIONS: Both benign and malignant cases had outcomes dependent upon the location and extent of surgical resection. In malignant cases that are not amenable to surgery, radiation offers a survival benefit. Given the cohort in this analysis, selection bias likely plays a significant role. Further study is required to define the optimal management of IPNB.

Proceedings of the 97th Annual Meeting of the American Radium Society- americanradiumsociety.org