Prognostic factors in patients undergoing complete resection of pulmonary metastases of colorectal cancer: a multi-institutional cumulative follow-up study.
The aim of this retrospective study was to establish the prognostic factors for overall survival after pulmonary resection for lung metastases of colorectal carcinoma (CRC). The baseline characteristics and outcomes of 266 CRC patients undergoing complete pulmonary resection were collected from 19 institutions by the Japanese Society for Cancer of the Colon and Rectum (JSCCR) Study Group. We used the Cox proportional hazard regression to identify independent prognostic factors for OS. The 5-year overall survival rate of patients undergoing complete resection of isolated pulmonary metastases was 56.5 %. The independent unfavorable prognostic factors after pulmonary resection included stage T4 (p = 0.0004) and N2 (p = 0.0082) as primary cancer-related factors, and more than three metastases (p = 0.0342), bilateral distribution (p = 0.0450), metastatic disease-free interval (DFI) of less than 2 years (p = 0.0257), and a preoperative carcinoembryonic antigen (CEA) level greater than 5.0 ng/mL (p = 0.0209) as pulmonary metastases-related factors. This retrospective analysis suggested that the indications for pulmonary resection of CRC metastases should be decided not only by the status of lung metastases, but also by pulmonary-related factors such as the T and N stage of the primary lesion, preoperative CEA level, and the DFI.