Comparison of clinicopathological characteristics between resected ampullary carcinoma and carcinoma of the second portion of the duodenum

BACKGROUND Few studies compared the oncological and biological characteristics between ampullary carcinoma (AC) and cancer of the second portion of the duodenum (DC-II), although both tumors arise from anatomically close locations. AIM To elucidate differences in clinicopathological characteristics, especially the patterns of lymph node metastasis (LNM), between AC and DC-II. METHODS This was a retrospective cohort study of 80 patients with AC and 27 patients with DC-II who underwent pancreaticoduodenectomy between January 1998 and December 2018 in two institutions. Clinicopathological factors, LNM patterns, and prognosis were compared between the two groups. RESULTS The patients with AC and DC-II did not exhibit significant differences in 5-year overall survival (66.0% and 67.1%, respectively) and 5-year relapse-free survival (63.5% and 62.2%, respectively). Compared to the patients with DC-II, the rate of preoperative biliary drainage was higher (P = 0.042) and the rates of digestive symptoms (P = 0.0158), ulcerative-type cancer (P < 0.0001), large tumor diameter (P < 0.0001), and advanced tumor stage (P = 0.0019) were lower in the patients with AC. The LNM rates were 27.5% and 40.7% in patients with AC and DC-II, respectively, without significant difference (P = 0.23). The rates of LNM to hepatic nodes (N-He) and pyloric nodes (N-Py) were significantly higher in patients with DC-II than in those with AC (metastasis to N-HE: 18.5% and 5% in patients with DC-II and AC, respectively; P = 0.0432; metastasis to N-Py: 11.1% and 0% in patients with DC-II and AC, respectively; P = 0.0186) CONCLUSION Although there were no significant differences in the prognosis and recurrence rates between the two groups, metastases to N-He and N-Py were more frequent in patients with DC-II than in those with AC.