Background: Ampullary carcinoma is often considered to have a better prognosis than distal extrahepatic cholangiocarcinoma. However, studies that directly compare the recurrence and histopathological features between the two groups are rare.
Methods: Clinicopathologic factors and the long-term outcomes of 163 patients with ampullary carcinoma after radical resection were retrospectively evaluated and compared with those of 91 patients with distal extrahepatic cholangiocarcinoma.
Results: Among the 163 ampullary carcinomas, T1 stage, well-differentiated tumors and perineural invasion were 45 (28%), 73 (45%), and 23 (14%), respectively, whereas, only five (6%) were T1 stage, 15 (17%) were well differentiated, and 63 (69%) showed perineural invasion (p < 0.001, for all) in distal extrahepatic cholangiocarcinomas. More patients with distal extrahepatic cholangiocarcinoma had liver metastasis than ampullary carcinoma (24% vs. 10%, p = 0.004). Multivariate analysis identified venous invasion and perineural invasion as risk factors for recurrence of ampullary carcinoma after radical resection. Only lymph node involvement was identified as a risk factor for recurrence of distal extrahepatic cholangiocarcinoma by multivariate analysis. Overall five-year survival of patients with ampullary cancer was higher than that of patients with distal extrahepatic cholangiocarcinoma (68% vs. 54%; p = 0.033). In patients without lymph node metastasis, a significant difference in survival was also observed between the two groups (p = 0.049).
Conclusion: Earlier diagnosis and the less frequent occurrence of pathological factors associated with tumor invasiveness in ampullary carcinoma than in distal extrahepatic cholangiocarcinoma may explain its association with a better prognosis.