Histological characteristics of tumor cells and stromal cells in vessels and lymph nodes are important prognostic parameters of extrahepatic bile duct carcinoma: a prospective study

Extrahepatic bile duct carcinomas (EHBDCs) consist of primary tumors, tumors in vessels, and tumors in lymph nodes. The purpose of this study was to prospectively investigate whether the histological characteristics of tumor cells and tumor stromal cells in vessels and lymph nodes were significantly associated with the outcomes of 60 EHBDC patients as compared with the histological characteristics of tumor cells and tumor stromal cells in primary tumors. Multivariate analyses, using the Cox proportional hazard regression model, showed that in EHBDCs without nodal metastasis, blood vessel tumor emboli with an angiomatous stroma significantly increased the hazard ratios (HRs) of tumor recurrence and death (P < .05). In EHBDCs with nodal metastasis, the presence of tumor necrosis in the nodal tumors significantly increased the HRs of tumor recurrence and initial distant organ metastasis (P < .05). In EHBDCs located in the distal to middle portion of the extrahepatic bile duct, blood vessel tumor emboli with an angiomatous stroma significantly increased the HRs of tumor recurrence, initial distant organ metastasis, and death (P < .05). Severe nuclear atypia of the tumor cells in lymph vessels significantly increased the HRs of tumor recurrence and initial distant organ metastasis (P < .05). In EHBDCs located in the hilar portion of the extrahepatic bile duct, the presence of nodal tumors with more than 4 mitotic figures significantly increased the HRs of tumor recurrence and initial distant organ metastasis (P < .05). Several histological characteristics of tumor cells and tumor stromal cells in vessels and lymph nodes have significant effects on tumor progression of EHBDCs.