Impact of Single-organ Metastasis to the Liver or Lung and Genetic Mutation Status on Prognosis in Stage IV Colorectal Cancer.
Abstract Background The impact of primary tumor site on overall survival in stage IV colorectal cancer (CRC) patients with single-organ metastases to the liver or lung has not been studied. Furthermore, the prognostic significance of commonly tested genetic variants such as KRAS mutation and microsatellite instability (MSI) are not well-described in this population. Methods This National Cancer Database was used to identify 38,328 patients with CRC that presented with synchronous metastases to the liver or lung between 2010 and 2014. The primary outcome was overall survival, and groups were compared using Kaplan-Meier analyses and Cox proportional hazard models. Results On unadjusted analysis, median survival was significantly longer for patients with lung metastases compared to liver metastases for left-sided (27 vs 25 months, p=0.02) and right-sided CRC (19 vs 15 months, p Conclusions For patients with single-organ metastases to the liver or lung, primary tumor site has an impact on overall survival. Further, KRAS mutation and MSI status are of prognostic importance in selected patients with single-organ metastases.