Aim: To immunohistochemically examine micrometastasis and VEGF-C expression in hilar bile duct carcinoma (HBDC) and to evaluate the clinical significance of the results.
Methods: A total of 361 regional lymph nodes from 25 patients with node-negative HBDC were immunostained with an antibody against cytokeratins 8 and 18 (CAM 5.2), and immunohistochemical staining of VEGF-C was performed in 34 primary resected tumors.
Results: Lymph node micrometastasis was detected in 6 (24%) of the 25 patients and 10 (2.8%) of the 361 lymph nodes. Patients with micrometastasis showed significantly poorer survival rates than those without (P = 0.025). VEGF-C expression was positive in 17 (50%) of 34 HBDC, and significantly correlated with lymph node metastasis (P = 0.042) and microscopic venous invasion (P = 0.035).
Conclusions: It is suggested that immunohistochemically detected lymph node micrometastasis has an impact on the outcome of HBDC. VEGF-C expression is highly correlated with lymph node metastasis in HBDC and might therefore be a useful predictor.