Simultaneous, Delayed and Liver-First Hepatic Resections for Synchronous Colorectal Liver Metastases: A Systematic Review and Network Meta-Analysis

BACKGROUND: Systematic reviews and meta-analyses that compare simultaneous, delayed and liver-first approach for synchronous colorectal liver metastases have found no significant differences. The aim of this study was to determine the best treatment strategy on the basis of effect sizes and the probabilities of treatment ranking by using a network meta-analysis. Moreover, first-time pairwise and network meta-analyses were used to estimate the existing evidence, and their results were compared to detect any discrepancies between them. METHODS: Systematic review, pairwise meta-analysis and network meta-analysis were performed. The primary and secondary outcomes were 5-year overall survival and postoperative major morbidity, respectively. RESULTS: No significant differences in long-term survival and major morbidity were found amongst the three approaches. The hazard ratios (95% confidence interval) for 5-year overall survival for the simultaneous, delayed and liver-first approaches were 0.93 (0.69 - 1.24, P = 0.613), 0.97 (0.87 - 1.07, P = 0.596) and 0.90 (0.67 - 1.22, P = 0.499), respectively. Moreover, the liver-first approach with a surface under the cumulative ranking area score of 89% was ranked as the potentially best treatment option based on probabilities of treatment ranking. CONCLUSIONS: On the basis of the relative ranking of treatments, the liver-first approach ranked first, followed by the delayed and simultaneous approaches. Therefore, a three-arm randomized controlled trial that compares the liver-first, simultaneous and delayed approaches needs to shed further light as to which is the best treatment option.