Observational study of predictors and outcomes of lung cancer in never-smokers in the UK (OLIVE): study protocol.

INTRODUCTION

Lung cancer is commonly associated with smoking. However, if considered separately, lung cancer in never-smokers (LCINS) is the seventh most common cause of cancer-related death worldwide. Expanding the limited understanding of LCINS, especially in the UK, is crucial to improving diagnosis.

METHODS AND ANALYSIS: We will establish a retrospective and prospective UK multicentre observational cohort comprising never-smoking (lifetime use of <100 tobacco cigarettes) adults with lung cancer using routinely available primary and secondary care electronic health records (EHRs). Demographic data including occupation and ethnicity, exposures and lung cancer outcomes will be extracted. Deep learning-based natural language processing will be used to analyse free-text data. Quantitative or qualitative data collection for information not available in EHR may be initiated in the future. Follow-up will be until death, withdrawal or end of study (5 years from study activation date). Primary outcomes will be sociodemographic characteristics, comorbidities, environmental exposures, pathways to presentation and symptoms. A feasibility pilot of 225 patients (25 participants per year both retrospectively and prospectively) will be undertaken at one hospital before extending the study to multiple sites. Patient representatives have been involved in adapting the research protocol including the recruitment process and patient-facing materials.

ETHICS AND DISSEMINATION: National ethical approval has been obtained from Health Research Authority (HRA) (24/YH/0147). Access to patient records without explicit consent, including deceased patient records, is legally supported by the Confidentiality Advisory Group and HRA. The study is sponsored by University College London Hospital.Data will be anonymised and analysed 2 years after the study start date and on study completion. Together with our patient representatives, we will disseminate data to the scientific and academic community and public through peer-reviewed publications, presentations at conferences, patient-facing charities and social media.