Abstract
Purpose: Few studies have described real-world treatment patterns and survival before the widespread use of immune checkpoint inhibitors (ICIs). We aimed to describe anti-cancer treatment including the use of programmed cell death-1 and ligand-1 (PD-1/PD-L1) ICIs and overall survival (OS) in advanced cancer patients as a benchmarking real-world standard before widespread use of ICIs. Patients and Methods: Using nationwide Danish medical registries, we assembled cohorts of Danish patients with advanced non-small cell lung cancer (NSCLC) (n=12,283), urothelial carcinoma (n=2504), epithelial ovarian cancer (n=1466), gastric adenocarcinoma (n=1457), and renal cell carcinoma (RCC) (n=1261) diagnosed between 1/1/2013 and 31/12/2017. We describe anti-cancer treatment and OS using proportions, medians, and Kaplan-Meier methods. Results: Between 9% (ovarian cancer) and 25% (gastric adenocarcinoma) of patients did not receive anti-cancer treatment. The remaining patients received surgery, radiation therapy, and/or medical therapy. Chemotherapy was the most frequent medical therapy in all cohorts except for RCC (tyrosine kinase inhibitors). PD-L1/PD-1 ICIs were used in 7-8% of the NSCLC and RCC cohorts-mainly as second or higher line treatments. OS was longest in patients starting treatment with surgery (eg 25.6 months [95%-confidence interval (CI) =21.9-29.4] for NSCLC and 21.4 months [95%-CI=19.8-23.5] for urothelial carcinoma) and shortest for radiation therapy (eg 3.9 months [95%-CI=3.6-4.2] for NSCLC and 12.6 months [95%-CI=9.2-17.5] for urothelial carcinoma). NSCLC patients starting with medical therapy had OS between these limits. Median OS for NSCLC patients starting treatment with PD-L1/PD-1 ICIs was 21.4 months (95%-CI=13.9-not estimable). Conclusion: Most patients with advanced NSCLC, urothelial carcinoma, epithelial ovarian cancer, gastric adenocarcinoma and RCC had poor OS in an era where only a minority received PD-L1/PD-1 ICIs. This information on treatment patterns and survival is important as a benchmarking real-world standard before widespread use of ICIs.