Lung metastases from colorectal cancer: analysis of prognostic factors in a single institution study.

Background: The aim of our study was to evaluate retrospectively in a large single institution setting all cases of lung resections for colorectal metastases from 1998 to 2008 and to assess clinicopathologic factors influencing outcome.

Methods: In all, 199 patients, 125 men and 74 women, with lung metastases of colorectal cancer, 120 colon and 79 rectum, underwent resection with curative intent; mean interval between primary surgery and lung metastasis was 35 months. Carcinoembryonic antigen preoperative value was abnormal in 52 patients; K-RAS wild-type was detected in 60 of 97 examined cases; 75 patients received preoperative or postoperative chemotherapy or both. A solitary lesion was described in 95 patients (47.7%), two or three metastases in 72 (36.2%), and more than three metastases in 26 (13.1%). Nodal status was reported in 130 patients (73%). One hundred twenty patients (60.3%) underwent wedge resection, 27 (13.6%) underwent segmentectomy, and 52 (26.1%) had lobectomy. An R0 resection was achieved in 178 cases (89.4%).

Results: Median overall survival was 4.2 years (95% confidence interval: 3.1 to 5.1) with a 5-year overall survival of 43% (95% confidence interval: 36% to 50%). An R1 resection (log rank p = 0.0001), thoracic nodal involvement (log rank p = 0.0002), and preoperative abnormal carcinoembryonic antigen value (log rank p < 0.001) were significantly associated with poor outcome in univariate analysis. In multivariate analysis, the same variables plus the number of lesions (single versus multiple, p = 0.04) were shown to affect outcome.

Conclusions: An R0 resection, preoperative carcinoembryonic antigen, nodal involvement, and number of lesions represent strong prognostic factors in patient with lung metastases of colorectal cancer. The role of systemic treatments and biomolecular tests deserve future prospective investigations.