PubMed, the Cochrane Library databases, and Embase were searched for studies evaluating the effect of peri-operative chemotherapy on the survival of patients with CRC after pulmonary metastasectomy. The hazard ratio (HR) was used for analyzing overall survival (OS) and progression-free survival (PFS)/recurrence-free survival (RFS)/disease-free survival (DFS).
Eight studies were included in the final analysis. The outcome showed that peri-operative chemotherapy had a significant favourable effect on OS (HR 0.83, 95% CI 0.75-0.92, p < 0.05) and PFS/RFS/DFS (HR 0.67, 95% CI 0.53-0.86, p < 0.05) in patients who received pulmonary metastasectomy. Multivariate analysis also validated this result (OS: HR 0.56, 95% CI 0.36-0.86, p < 0.05; PFS/RFS/DFS: HR 0.64, 95% CI 0.46-0.87, p < 0.05). There was a significant benefit in peri-operative group on OS and PFS/RFS/DFS in studies with R0 resection of pulmonary metastases (OS: HR 0.72, 95% CI 0.53-0.97, p < 0.05; PFS/RFS/DFS: HR 0.72, 95% CI 0.54-0.95, p < 0.05) and metachronous pulmonary metastases (OS: HR 0.40, 95% CI 0.22-0.75, p < 0.05; PFS/RFS/DFS: HR 0.67, 95% CI 0.49-0.92, p < 0.05).
Our meta-analysis demonstrated a significant difference in favor of peri-operative chemotherapy in CRC patients who underwent resection of pulmonary metastases. More clinical data and studies are needed to validate the findings of our study.