Prognostic relevance of lymph node metastasis in pancreaticoduodenectomy for distal cholangiocarcinoma: Rational extent and number-based nodal classification for regional lymphadenectomy.

Abstract

We investigated the rational extent of regional lymphadenectomy and evaluated the prognostic impact of number-based regional nodal classification in patients with distal cholangiocarcinoma. This study included 191 patients with distal cholangiocarcinoma who underwent pancreaticoduodenectomy. The nos. 8, 12a-b-c-p, 13, 14, and 17 nodes were dissected routinely. The impact of the extent of lymphadenectomy on prognostic stratification performed using number-based nodal classification was evaluated. The incidence of metastasis in the routinely dissected nodes was 1.0-25.7%, with 5-year overall survival of 0-36.4% in patients with metastasis. The incidence of metastasis in the no. 12p nodes, which were not included in regional nodes in the American Joint Committee on Cancer or International Union Against Cancer staging systems, was 5.8% with a 5-year overall survival of 36.4% in patients with metastasis. When our dissected nodes were adopted (P < .001), number-based nodal classification predicted overall survival better than when regional nodes defined by the International Union Against Cancer or American Joint Committee on Cancer staging systems were used (nos. 8, 12a-b, 13, 14, and 17 nodes with or without no. 9 nodes; P = .004 each). The 5-year overall survival in patients with pN0, pN1 (1-3 positive nodes), and pN2 (≥4 positive nodes) disease was 57.4%, 37.3%, and 13.6%, respectively (P < .001). The pN classification was an independent prognostic factor (pN1, P = .009; pN2, P < .001). The nos. 8, 12a-b-c-p, 13, 14, and 17 nodes should be prioritized as the rational extent of regional lymphadenectomy for distal cholangiocarcinoma for accurate staging. Number-based regional nodal classification is suitable for prognostic stratification.