Effect of primary colorectal cancer tumor location on survival after pulmonary metastasectomy

Objectives: Although colorectal cancer bowel segment location has been shown to independently predict the outcomes in early stage disease, it has not been previously studied in the setting of pulmonary metastases. We sought to determine whether colorectal cancer location affects survival after pulmonary metastasectomy. Methods: Patients who had undergone pulmonary metastasectomy for colorectal cancer at a single institution from 2011 to 2018 were reviewed. Univariable and multivariable Cox regression analyses were performed to identify predictors of overall survival and disease-free survival. The Kaplan-Meier survival method was used to determine differences between groups. Results: A total of 194 patients were evaluated. The median follow-up, survival time, and 5-year survival rate were 36.8 months, 75.8 months, and 57%, respectively, and 122 patients (63%) had experienced disease recurrence at any location. On univariable analysis, age, primary tumor location, pulmonary nodule size, ≥3 pulmonary nodules, and intrathoracic nodal disease were associated with overall survival. On multivariable analysis, patients with left-sided tumors experienced a survival benefit (hazard ratio, 0.31; P =.036). Kaplan-Meier analysis revealed a median survival time of 90 months (95% confidence interval, 82 months to not reached) compared with 55 months (95% confidence interval, 49 months to not reached) for patients with left-sided and rectal tumors, respectively, after metastasectomy (P =.078). Location was not associated with disease-free survival on Cox multivariable regression. Conclusions: We found that left-sided colorectal cancer is associated with prolonged survival after pulmonary metastasectomy. Future investigations are required to determine the validity of such findings, including the effect of location in the prognostication for patients who are candidates for pulmonary metastasectomy.