Introduction: This study was undertaken to review a single-institution cohort of patients with metastatic colorectal cancer undergoing lung resection after a multidisciplinary evaluation and to investigate the main prognostic factors for survival.
Methods: Medical records of 129 patients undergoing lung metastasectomy for colorectal cancer with curative intent from 2001 to 2017 were reviewed. Tissue samples from the primary tumor were analyzed with a multiplex genotyping system for the detection of mutations in RAS and BRAF genes. Survival analyses were carried out by the Kaplan-Meier method. Univariate and multivariable analyses were performed using the log-rank test and the Cox regression model.
Results: Postoperative morbidity and mortality were 13.2% and 0%, respectively. At a median follow-up time of 62.5 months, median overall survival was 90.5 months and median relapse-free survival was 42.8 months. Multivariable analysis for overall survival identified synchronous versus metachronous metastatic presentation as the only prognostic factor, whereas relapse-free survival was independently associated with synchronous versus metachronous metastatic presentation, number of metastases, and postoperative chemotherapy.
Conclusions: This study shows particularly favorable survival outcomes for patients undergoing lung metastasectomy. The validity of some of the main prognostic factors was confirmed and a positive effect of postoperative chemotherapy on relapse-free survival was shown. Contrary to other reports, the presence of KRAS mutations was not associated with significant survival differences. Further studies are needed in order to clarify the interactions between molecular, clinical, and pathologic characteristics and treatment-related factors.
Keywords: Colorectal cancer; KRAS mutations; lung metastases; metastasectomy.