원위부 담도암의 T1 병기에서의 췌장 침범에 대한 임상적 의미 및 장기 생존율과 연관된 예후인자 분석을 위한 국내 다기관 연구

Abstract

Introduction: Distal bile duct cancer (DBC) staging is revised from adjacent organ invasion of AJCC 7th edition to depth of invasion of AJCC 8th edition. Adequacy of recent staging system of DBC is controversial in that the invasion of organ around the distal bile duct is clinically meaningful and has an impact on prognosis of DBC. This study aimed to evaluate the pancreatic invasion of DBC in T1 stage and analyze the prognostic factors associated with long-term survival of DBC with pT1. Methods: This study is a multicenter retrospective analysis from 6 tertiary center in Korea. We identified patients with DBC who underwent pancreaticoduodenectomy with pT1 stage of AJCC 8th edition in 6 centers from 2009 to 2019. The 5-year recurrence-free survival (RFS) and overall survival (OS) were analyzed and multivariate analysis for prognosis of pT1 DBC was performed. Results: 287 patients were included in this study. 5-year OS of DBC with pT1 was 63.9% (95% confidence interval [CI]: 0.582-0.702) and 5-year RFS of that was 56.2% (95% CI: 0.502-0.629). There was no significant difference according to pancreatic invasion in 5-year OS (without pancreatic invasion group, 69.9% vs. with pancreatic invasion group, 54.1, p=0.25) and 5-year RFS (without pancreatic invasion group, 56.3% vs. with pancreatic invasion group, 55.4%, p=0.97). In multivariate analysis, the factors associated with OS was male (hazard ratio [HR]: 1.92, CI 1.23-3.01, p=0.004), age (HR: 1.03, CI 1.01-1.06, p=0.007), invasion of ampulla of Vater (HR: 0.49, CI 0.27-0.90, p=0.20), lymphovascular invasion (HR: 2.15, CI 1.43-3.23, p<0.001), R1 resection (HR: 2.09, CI 1.07-4.10, p=0.031) and N stage (N1; HR: 2.09 CI 1.28-3.42, p=0.003, N2; HR: 4.94, CI 2.14-11.4, p<0.001). Among the factors for OS, male (HR: 1.87, CI 1.20-2.92, p=0.005), invasion of ampulla of Vater (HR: 0.50, CI 0.29-0.87, p=0.015), lymphovascular invasion (HR: 2.07, CI 1.39-3.06, p<0.001) and N1 stage (HR: 2.23, CI 1.39-3.56, p<0.001) were also significantly associated with RFS. Conclusion: The impact of pancreatic involvement on long-term prognosis in DBC with pT1 was not observed, which is in line with the depth-based system of AJCC 8th staging.