Radical Treatment of the Primary Tumor in Metastatic Bladder Cancer: Potentially Dangerous Findings From Observational Data
December 19, 2017
Population-based observational studies allow investigators to evaluate the adoption of new therapies and to determine whether benefits seen in clinical trials are realized in the real world.1-3 These studies also provide rich insights into factors that affect access and quality of cancer care in the general population.1 However, except in a few specific circumstances,4 real-world data are much less useful in establishing treatment efficacy.5 Studies that compare outcomes between nonrandomized groups of patients are fundamentally problematic because the patients may also differ with respect to other prognostic factors.
Although observational research using real-world data can offer important insights into care and outcome of patients in the general population, it is critical that study methodology and interpretation of results be held to the same scientific standards as a clinical trial. Real-world data can provide insight into measures of comparative effectiveness; however, these analyses are complex and fraught with methodologic shortcomings. Although the focus of this commentary has been metastatic bladder cancer, there is currently even greater interest in the role of aggressive LT for metastatic prostate cancer.