Background: Our main objective was to identify, in healthcare claims data, patients with advanced or metastatic: urothelial carcinoma (amUC), gastric cancer (amGC) and non-small cell lung cancer (amNSCLC) and to report on their characteristics, treatments, and survival rates using contemporaneous real-world data. Methods: This cohort study was conducted in the HealthCore Integrated Research Database (HIRD), from January 2010 to January 2018, which contains healthcare claims data from commercial health plans across the US (60 million lives). We applied algorithms, previously validated on registry data, to the HIRD to define 3 cohorts of advanced stage cancer. Cohort characteristics and treatment patterns were described. Patient vital status was captured through probabilistic linkage with the National Death Index (NDI) and survival was assessed using the Kaplan-Meier method. Results: Algorithms to predict advanced stage cancer resulted in the following cohorts: 1,501 amUC, 6,253 amGC and 38,451 amNSCLC cases. Most patients in each cohort were de novo advanced or metastatic, but subsets were diagnosed at early stage and progressed to advanced stage (ranging from 15.1% for amNSCLC to 23.1% for amUC). Patient characteristics, treatments and survival outcomes are described in Table 1. Not all received systemic treatment; Immune Checkpoint inhibitors (ICI) were used in 5.3%, 2.2% and 10.8% of treated amUC, amGC and amNSCLC patients, respectively. Conclusions: In these cohorts of advanced or metastatic cancer patients, median survival time was limited despite most receiving treatment: radiation, systemic therapy or surgery. Treatment with ICI was low despite recent data in amUC and amNSCLC.