Comparative Outcome after Treatment for Synchronous vs. Metachronous Colorectal Cancer Liver Metastasis

Purpose: This study was designed to compare outcomes in patients who underwent hepatectomy or radiofrequency thermal ablation (RFA) for synchronous or metachronous colorectal liver metastases (CLM). Methods: One hundred twenty-two patients who underwent hepatectomy or RFA for their first CLM between 2001 and 2004 were enrolled in this study. The patients were divided into two groups (synchronous [N=77] and metachronous [N=45] CLM). Patient characteristics, clinicopathologic features, long-term outcomes, and prognostic factors were analyzed retrospectively. Results: There were no significant differences in the 5-year disease-free and overall survival rates between the synchronous and metachronous CLM groups (36.2% vs. 37.2%, p=0.78; and 53.0% vs. 54.4%, p=0.82, respectively). Patients in the synchronous CLM group underwent more bilobar hepatic resections, intra-operative RFA, or co-modality treatments than the metachronous CLM group (p=0.035). The surgical resection group had a longer disease-free survival, but not overall survival than the RFA group. Greater N stage and female gender were associated with a worse prognosis in overall survival; N0 stage and surgical resection were good prognostic factors for disease-free survival. N stage and surgical resection were also statistically significant prognostic factors based on multivariate analysis. Conclusion: The synchronicity of CLM is not a significant prognostic factor, but the clinicopathologic characteristics that reflect more disseminated disease than metachronous metastasis are significant prognostic factors. Tumor characteristics and aggressiveness may be more important for prognosis than chronology.