Predictors of Safety and Efficacy of 2-Stage Hepatectomy for Bilateral Colorectal Liver Metastases

BackgroundIn patients with bilateral colorectal liver metastases (CLM) not resectable in 1 operation, 2-stage hepatectomy is the standard surgical approach. The objective of this study was to determine factors associated with safety and efficacy of 2-stage hepatectomy.Study DesignThe study included all 109 patients for whom 2-stage hepatectomy for CLM was planned during 2003 to 2014. The RAS mutation status and other clinicopathologic factors were evaluated for association with major complications and survival using multivariate analysis.ResultsTwo-stage hepatectomy was completed in 89 of 109 patients (82%). Reasons for dropout after the first stage were disease progression (n = 12), insufficient liver growth (n = 5), and complications after first stage or portal vein embolization (n = 3). More than 6 cycles of preoperative chemotherapy were associated with failure to proceed to the second stage (p = 0.009). Rates of major complications (26% vs 6%; p < 0.001) and 90-day mortality (7% vs 0%; p = 0.006) were higher after the second stage. The cumulative rate of major complications was 15% (n = 29). Factors independently associated with major complications were rectal primary tumor, metachronous CLM, and more than 1 lesion resected at first stage. At median follow-up of 29.5 months, 3-year (68% vs 6%; p < 0.001) and 5-year overall survival rates (49% vs 0%; p < 0.001) were better after 2-stage hepatectomy completion than noncompletion. Factors independently associated with poor overall survival were rectal primary tumor (p = 0.044), more than 5 CLMs (p = 0.043), need for chemotherapy after first stage (p = 0.046), and RAS mutation (p < 0.001).ConclusionsThe RAS mutation independently predicts the oncologic efficacy of 2-stage hepatectomy and may help guide patient selection for this aggressive surgical strategy.