The role of hepatic metastases and pulmonary tumor burden in predicting survival after complete pulmonary resection for colorectal cancer

Objective: Our objective was to investigate the role of clinicopathologic factors as predictors of outcome after complete pulmonary resection for metastatic colorectal cancer. Methods: Consecutive patients undergoing radical pulmonary resection for colorectal cancer at our institution were included in the study. Clinicopathologic variables including sex, age, site and stage of the primary tumor, disease-free interval, prior hepatic resection, timing of pulmonary metastases, preoperative chemotherapy, type of pulmonary resection, number, size, and location of pulmonary metastases, and thoracic lymph node involvement were retrospectively collected and investigated for prognostic significance. Survival curves were generated by the Kaplan-Meier technique and difference between factors were evaluated by the log-rank test. Results: A total of 127 patients undergoing pulmonary resection between 1997 and 2009 were included in the study. The median follow-up was 67.1 months. The median overall survival from the time of pulmonary resection was 48.9 months. The 5-year overall survival was 45.4%. Among all investigated prognostic variables, the number of pulmonary metastases (1 vs > 1) was the most important factor affecting the outcome after pulmonary resection (5-year overall survival 55.4% vs 32.2%; hazard rate, 1.92; P = .006). Conclusions: In this study, the presence of a single pulmonary metastasis was a favorable predictor of survival after complete pulmonary resection for metastatic colorectal cancer. All the other prognostic variables did not seem to affect survival and should not contraindicate such surgery in clinical practice. However, the study sample size does not allow us to draw any definitive conclusion, and further investigation of the role of these prognostic factors in larger series is warranted.