Supplementary Material for: Factors Influencing Lymph Node Metastasis in Patients with Ampullary Adenocarcinoma

<b><i>Aim:</i></b> In cases of ampullary carcinoma, lymph node involvement affects the selection of treatment strategies. This study aimed to identify clinicopathologic features of ampullary carcinoma with lymph node metastases. <b><i>Methods:</i></b> The records of 74 consecutive patients with ampullary adenocarcinoma who underwent pancreaticoduodenectomy (PD) with regional lymph node dissection were retrospectively analyzed. <b><i>Results:</i></b> Twenty-two patients (30%) with lymph node metastasis had significantly worse survival after resection than those without lymph node metastasis (p = 0.017). Univariate analyses revealed that preoperative biliary drainage; elevated serum carbohydrate antigen 19-9 (≥36 U/ml); moderate-to-poor pathologic grade (G2/3); perineural, vascular, lymphatic, pancreas, and duodenal invasion; and T category were significantly associated with lymph node metastasis. In multivariate analysis, only pathologic grade (G2/3) remained significantly associated with lymph node metastasis (hazard ratio, 6.51; p = 0.035). In sub-classified analysis for T category, lymph node metastasis was found in 5 of 22 cases (22.7%) of T1 tumors. Four of five cases with lymph node metastases had a dominant G2/3 component, whereas only 2 of 17 cases without lymph node metastases had a G2/3 component in T1 tumors (p = 0.0036). <b><i>Conclusions:</i></b> Pathologic grade (G2/3) was significantly and independently associated with lymph node metastasis and was also a significant predictor in T1 tumor cases.