Aggressive Multimodal Treatment and Metastatic Colorectal Cancer Survival

Background: We aimed to assess patient and demographic factors, treatment trends, and survival outcomes of patients with colorectal cancer with metastasis to the liver, lung, or both sites. Differences remain among national guidelines about the optimal management strategy. Methods: Adults from the National Cancer Database (2010 to 2015) with a primary diagnosis of colorectal liver, lung, or liver and lung metastases were included and stratified by metastasis site. The primary end point was 5-year overall survival, analyzed using Kaplan-Meier survival curves, log-rank test, and the Cox proportional hazards model. Results: Among 82,609 included patients, 70.42% had liver, 8.74% had lung, and 20.85% had simultaneous liver and lung metastases. Treatment with chemotherapy alone was used the most (21.11%), followed by chemotherapy with colorectal radical resection (CRRR) (19.4%), no treatment (14.35%), CRRR alone (9.03%), and chemotherapy with CRRR and liver/lung resection (8.22%). Patients with lung metastasis had significantly better 5-year overall survival rates than the other 2 metastatic groups (15.99%, 16.70%, and 5.51%; p < 0.001), even after stratifying by treatment type and adjusting for other factors. Chemotherapy with CRRR and liver/lung resection was associated with the greatest reduction in mortality risk for all sites in both unadjusted (35.15%, 44.52%, and 20.10%; p < 0.001) and adjusted analyses (hazard ratio 0.42; 95% CI, 0.38 to 0.47; p < 0.001; hazard ratio 0.31; 95% CI, 0.18 to 0.53; p < 0.001; and hazard ratio 0.79; 95% CI, 0.62 to 1.01; p = 0.064 for trend), and forgoing treatment or CRRR alone offered the worst overall survival. Conclusions: Patients with metastasis to lung had increased overall survival compared with other sites of metastases, regardless of treatment modality. Combined resection of primary tumor, metastasectomy, and chemotherapy appears to offer the greatest chance of survival.