Predicting Survival Outcome of Patients With Colorectal Cancer and Only Lung Metastasis: A Population-Based Real-World Study

Abstract Background: Patients with metastatic colorectal cancer (mCRC) have a poor prognosis, but lung metastasis (LM) generally has a relatively desirable survival outcome. However, clinicians have had few tools for estimating the probability of survival in patients with colorectal cancer (CRC) and only LM (OLM). The present study aimed to develop nomograms estimating survival probability for patients with CRC and OLM.Methods: Data from the Surveillance, Epidemiology, and End Results (SEER) database of patients with CRC between 2010 and 2014 were retrieved for retrospective analysis. Patients with OLM diagnosed between 2010 and 2014, except for 2012 (n = 1,118) were used to conduct multivariate Cox analysis to identify independent prognostic factors. Nomograms estimating 1- and 3-year overall survival (OS) and cancer-specific survival (CSS) were developed. The nomograms were internally validated for concordance index (C-index), calibration plots, receiver operating characteristic (ROC) curves, and were also externally validated with independent patients diagnosed in 2012 (n = 261).Results: Age, marital status, tumor location, tumor size, T and N stage, CEA, tumor deposit, histological grade, primary or metastatic tumor surgery, chemotherapy, radiotherapy, and income were found to be independently associated with OS and/or CSS. The nomograms were constructed based on these prognostic factors. The C-index were high in internal validation (0.736 for OS and 0.741 for CSS) and external validation (0.656 for OS and 0.663 for CSS). Internal and external calibration plots and ROC curves demonstrated a good agreement between actual observation and nomogram prediction.Conclusions: The nomograms individually predict OS and CSS of patients with CRC and OLM and could aid in the personalized prognostic evaluation and clinical decision-making.