Intrahepatic Lymphatic Invasion Independently Predicts Poor Survival and recurrences after Hepatectomy in Patients with Colorectal Carcinoma Liver Metastases

BACKGROUND: D2-40 monoclonal antibody immunoreactivity is specific for lymphatic endothelium and therefore provides a marker of lymphatic invasion. We hypothesized that intrahepatic lymphatic invasion reflects the nodal status of colorectal carcinoma liver metastases and may function as an adverse prognostic factor. METHODS: A retrospective analysis of 105 consecutive patients who underwent resection for colorectal carcinoma liver metastases was conducted. Intrahepatic lymphatic invasion was declared when either single tumor cells or cell clusters were clearly visible within vessels that showed immunoreactivity for D2-40 monoclonal antibody. The median follow-up time was 124 months. RESULTS: Of 105 patients, 13 were classified as having intrahepatic lymphatic invasion. All tumor foci of intrahepatic lymphatic invasion were detected within the portal tracts. Intrahepatic lymphatic invasion was significantly associated with hepatic lymph node involvement (P = 0.039). Survival after resection was significantly worse in patients with intrahepatic lymphatic invasion (median survival time of 13 months; cumulative five-year survival rate of 0%) than in patients without (median survival time of 40 months; cumulative five-year survival rate of 41%; P < 0.0001). Patients with intrahepatic lymphatic invasion also showed decreased disease-free survival rates (P < 0.0001). Intrahepatic lymphatic invasion thus independently affected both survival (relative risk, 7.666; 95% confidence interval, 3.732-15.748; P < 0.001) and disease-free survival (relative risk, 4.112; 95% confidence interval, 2.185-7.738; P < 0.001). CONCLUSIONS: Intrahepatic lymphatic invasion is associated with hepatic lymph node involvement and is an adverse prognostic factor in patients with colorectal carcinoma liver metastases.