The assessment of prognostic factors for lung metastasectomy in colorectal cancer patients with previously resected liver metastases

The purpose of this study is to investigate the prognostic factors of lung metastasectomy in patients with previously resected liver metastases. Thirty-three patients underwent complete resection of lung metastases after previous liver metastasectomy from colorectal cancer between January 2004 and December 2013. In univariate analyses, all cumulative survival curves were estimated using the Kaplan-Meier method, and differences in variables were evaluated using the log-rank test. Multivariate analyses were performed using the Cox proportional hazards regression model. The 5-year survival rate of all 33 patients after lung metastasectomy was 31%. Univariate analysis identified 2 significant prognostic factors: preoperative serum carcinoembryonic antigen level (P ¼ 0.035) and maximum tumor size (P ¼ 0.029). Subgroup analysis with a combination of these 2 independent prognostic factors revealed 2-year survival rates of 100%, 92.3%, and 0% for patients with 0, 1, and 2 risk factors, respectively. We identified 2 independent poor prognostic factors for pulmonary metastasectomy in patients with previously resected liver metastases: high serum carcinoembryonic antigen level before lung metastasectomy, and maximum size of lung metastases. When these 2 factors are combined, higher- and lower-risk subgroups can be identified, which may help select patients with previously resected liver metastases who benefit most from lung metastasectomy.