Assessing the Effectiveness of Palliative Chemotherapy for Non-Small Cell Lung Cancer: a Phase IV Study of Patients Treated at Ontario’s Cancer Centres

Abstract

Background: Randomized controlled trials (RCTs) are the gold standard for assessing the efficacy of a medical treatment. However, the efficacy demonstrated by trials does not automatically translate into a comparable level of effectiveness in the real world. RCTs may vary from routine clinical practice in several ways; the patients themselves, the delivery of the treatment, and the collateral care provided during treatment. Phase IV studies that assess outcomes of a treatment in the real-world provide a mechanism for assessing treatment effectiveness. Objectives: The objectives of this study were to: describe the characteristics of patients receiving standard, first-line, palliative, platinum-doublet chemotherapy (PPDC) for non-small cell lung cancer (NSCLC) in routine care; describe the effectiveness of PPDC in terms of wellbeing and symptom control; identify patient characteristics associated with change in wellbeing with treatment; and compare reported treatment efficacy to the effectiveness observed in the current study. Methods: This study was a retrospective cohort study of patients treated at Ontario’s Regional Cancer Centres (RCCs). Patients’ Edmonton Symptom Assessment System (ESAS) scores were used to describe patients’ symptomatic status and wellbeing. The proportions of patients whose wellbeing improved, remained stable or deteriorated at two months were calculated. Using logistic regression, patient and disease characteristics were assessed for association with change in wellbeing at two months (dichotomized as improved/stable and deteriorated). In comparing trial results to this study, adjustments were made for differences in case mix. Results: Patients’ median age was 65, 55% were male and the majority had stage IV disease and adenocarcinoma histology. Patients’ baseline wellbeing and symptomatic status varied widely. 61.3% (95% CI: 55.8 – 66.6%) of patients had improved or stable wellbeing at two months. Histology and baseline wellbeing score were associated with change in wellbeing at two months. The case mix adjusted estimates of the proportion of improved/stable patients (60.0% (95% CI 54.5 – 65.3) and 60.5% (95% CI 54.9 – 65.6)) were consistent with the proportion of patients achieving general quality of life improvement or stabilization in RCTs (55% and 63%). Conclusion: The effectiveness of PPDC delivered in Ontario’s RCCs is consistent with that expected based on the results of RCTs.