Background: We tested the hypothesis that in patients with T1 extrahepatic cholangiocarcinoma (EHC), prognosis postresection is significantly different for those with tumors that are limited to the mucosa than for those with tumors that have invaded (but not penetrated) the fibromuscular layer.
Methods: A retrospective analysis was conducted of 33 consecutive patients with pathologic T1 (pT1) EHC tumors. According to the depth of invasion, the pT1 tumors were divided into 2 groups: Group 1, tumors that were limited to the mucosa (mucosal tumors); and Group 2, tumors that had invaded (but not penetrated) the fibromuscular layer (fibromuscular layer-invasive tumors). Long-term outcomes after resection were compared between the 2 groups for a median follow-up time of 175 months.
Results: Eighteen patients had mucosal tumors and 15 patients had tumors that had invaded the fibromuscular layer. None of the patients with mucosal tumors had lymphovascular invasion, whereas 3 of the patients with fibromuscular layer-invasive tumors had lymphovascular invasion (P = .083). Overall survival after resection was better in Group 1 than in Group 2 (cumulative 10-year survival rate, 100% vs 52%; P = .024). The rate of disease-free survival after resection was higher in Group 1 than in Group 2 (cumulative disease-free 10-year survival rate, 100% vs 56%; P = .022).
Conclusions: The long-term outcome after resection for EHC is significantly better for patients with mucosal tumors than for patients with fibromuscular layer-invasive tumors. This suggests that the depth of tumor invasion affects the postresection prognosis for patients with pT1 EHC.