Pulmonary metastasectomy for colorectal cancer: long-term survival and prognostic factors

Despite the development of novel chemotherapy and biological agents, surgery is still an important option for patients with pulmonary metastases. Predictors of survival usually include disease-free interval, histology of the primary tumor, number of metastases and complete resection. The aim of this study was to report the outcomes of patients with pulmonary metastases from colorectal carcinoma submitted to surgical resection, and to identify prognostic factors that significantly affect overall survival.

We retrospectively analyzed 120 patients with previously treated colorectal carcinoma that had developed pulmonary metastases, admitted between 1990 and 2006. Overall survival was estimated using Kaplan-Meier analysis. The log-rank and Breslow tests were used to compare survival differences for each variable. Multivariate analyses to determine the independent prognostic factors for overall survival were performed using the Cox proportional hazard model as identified by the univariate analyses.

The median follow-up was 20.3 months (range: 3.27-134.2 months). The patients included in this study underwent a total of 165 thoracotomies (mean of 1.37 thoracotomies/patient). The median overall survival for all patients was 34.73 months, with an estimated 5-year survival rate of 24.39%. Multivariate analyses identified unilateral lesions, neoadjuvant chemotherapy at lung resection and complete resection as independent prognostic factors for overall survival.

These results indicate that prognostic factors identified in studies on pulmonary metastasectomy for all primary tumors should be interpreted carefully for patients with possibility of pulmonary metastasectomy from colorectal carcinoma.