Purpose The aim of this study is to assess how clinical outcomes in real-world (effectiveness) correspond to the outcomes in clinical trials (efficacy) of systemic treatments for extensive disease small cell lung cancer (ED SCLC).
Methods All patients diagnosed with ED SCLC between 2008 and 2014 in six Dutch large teaching hospitals (Santeon network) were identified and followed-up from date of diagnosis until death or end of data collection. For every patient, an efficacy-effectiveness factor (EE factor) was calculated by dividing individual patients' overall survival (OS) by the pooled median OS assessed from clinical trials with the respective treatment.
Results From 792 diagnosed patients, 568 (72%) started with first-line treatment. Overall, the median EE factor was 0.79 (P <.001 from 1.00). Poor performance status (ECOG >= 2) and a higher age at diagnosis (age >= 65 years) were independent predictors for a lower EE factor. The EE gap was 43% in patients with both age >= 65 years and ECOG >= 2 (EE factor 0.57). The mean age and the proportion of patients with ECOG >= 2 in real-world were different from those in clinical trials (mean age of 66 versus 62 years, and ECOG >= 2 25% versus 17%; both P <.001).
Conclusion OS of patients with ED SCLC treated with systemic therapy in real-world practice is 21% shorter than for patients included in trials. Age at diagnosis and performance status partly explain this gap.