The impact of primary tumor location on prognosis after colorectal lung metastasectomy.

PURPOSE Currently, right colon cancer (RCC), left colon cancer (LCC), and rectal cancer (REC) are typically seen as different tumor entities. It is unknown if this subdivision by primary tumor location has an influence on the survival of patients with colorectal pulmonary metastasectomy (PM). METHODS We retrospectively analyzed our prospective database of 233 patients operated on for colorectal lung metastases between 1999 and 2014. Differences in the patient characteristics and the primary tumor and metastatic tumor burden were analyzed using χ2-tests. The long-term survival after PM of the three groups was analyzed with the Kaplan-Meier method and log-rank tests. RESULTS In total, PM was performed for 37 patients with RCC, 57 patients with LCC, and 139 patients with REC. Patients with LCC were significantly more likely to have UICC stage IV primary tumor (44.2% LCC vs. 37.5% RCC vs. 22.8% REC, p = 0.012) and significantly more likely to have a history of additional liver metastases (45.6% LCC vs. 32.4% RCC vs. 27.3% REC, p = 0.046). The 5-year survival rates after PM for patients with RCC, LCC, and REC were 47, 66, and 39%, respectively (p = 0.001). The median survival times of patients with RCC, LCC, and REC were 55 months (95% CI: 42.2-66.8), 108 months (95% CI: 52.7-163.3), and 44 months (95% CI: 50.4-63.6), respectively. CONCLUSIONS This study demonstrated a prognostic impact of the primary tumor localization in patients undergoing PM for colorectal lung metastases. Nevertheless, long-term survival was achievable in all groups.