Cell kinetics of colorectal liver metastases

Abstract

PURPOSE: Liver metastases are the main cause of death in patients with colorectal cancer. We defined the proliferative activity of a metastatic liver cell population to investigate its potential role as an indicator of clinical outcome in patients with metastatic disease of the colorectum. METHODS: The S-phase cell fraction, evaluated asin vitro [³H]thymidine-labeling index, was determined on liver metastases of primary colorectal cancers from 75 patients. RESULTS: Cell proliferation was not related to the degree of liver involvement, the site of the primary cancer, or the time of presentation of liver metastases. Survival at 2 years was statistically different for patients with slowly proliferating (78 percent) or rapidly proliferating liver metastases (47 percent) (P=0.024). The risk of death for patients with high [³H]thymidine-labeling index lesions was consistently threefold that of patients with low [³H]thymidine-labeling index lesions throughout the observation period. Bivariate analysis showed that cell proliferation was a further prognostic discriminant within the subsets characterized by a different degree of liver involvement. CONCLUSIONS: These results indicate that cell proliferation is a good prognostic marker even in patients with liver metastases from colorectal cancer. The clinical implications of the marker could be further potentiated by considering it in association with some clinical aspects of known prognostic relevance.