Long-Term Survival and Prognostic Factors of Pulmonary Metastasectomy in Liver Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Lung is the most common extrahepatic metastatic organ of liver cancer. Surgical resection is a common local treatment for pulmonary metastasis. But the long-term prognosis of pulmonary metastasectomy varies greatly due to the small sample size and different results of previous studies. Therefore, we conducted this meta-analysis to evaluate the combined 5-year overall survival (OS) rate and prognostic factors after pulmonary metastasectomy in liver cancer.

METHODS: Key words such as liver cancer pulmonary metastasis and metastasectomy were retrieved firstly in PubMed, Cochrane Library, Embase and Chinese Wanfang databases. Eligible studies were identified by manual searches. Each included study should report 5-year OS rate and/or prognostic factors of pulmonary metastasectomy. Newcastle-Ottawa Scale was used for quality assessment, and heterogeneity was estimated by I2 . We calculated the combined 5-year survival rates and determined the prognostic factors for OS by the hazard ratios (HR) and number of events.

RESULTS: Seventeen cohort studies with a total of 513 patients were included in this meta-analysis. The combined 5-year survival rates after pulmonary metastasectomy were 33% [95% confidence interval (95% CI) 29-37%]. The poor prognostic factors were disease-free interval (DFI) < 12 months (HR = 2.421 95% CI 1.384 4.236) and existence of cirrhosis (HR = 1.936 95% CI 1.031 3.636).

CONCLUSION: The 5-year OS rate of patients with pulmonary metastasectomy after resection of primary liver cancer is 33%. DFI < 12 months and existence of cirrhosis are probably poor prognostic factors.