Staging by thoracoscopy in potentially radically treatable non-small cell lung cancer associated with minimal pleural effusion (STRATIFY) study: a prospective multicentre study

Abstract

Introduction: Pleural effusion (PE) is common in patients with lung cancer, but routine imaging and fluid cytology offer low sensitivity for detection of pleural metastases. Previous retrospective studies report an association between mini-PE (defined as an ipsilateral PE too small to be safely aspirated, or in which fluid cytology is negative) and adverse survival. This may be critical in patients with otherwise radically treatable lung cancer, where mini-PE may reflect occult pleural metastases (OPM). The STRATIFY (Staging by Thoracoscopy in Potentially Radically Treatable Non-Small Cell Lung Cancer Associated with Minimal Pleural Effusion) study is a multicentre, prospective study designed to determine the true prevalence of OPM in those with otherwise potentially curable NSCLC. The study will determine the role of staging local anaesthetic thoracoscopy (LAT) in this setting. Methods: 96 patients identified at outpatient clinic or multidisciplinary team meetings (MDT) will undergo LAT to obtain pleural biopsies. All participants will have a full diagnostic work up including confirmatory pathology, MDT discussion and provisional treatment plans prior to entering STRATIFY. The primary endpoint will be the true prevalence of OPM, as defined by the by the proportion of recruited patients with NSCLC cells in parietal pleural biopsies or pleural fluid obtained during LAT. Additionally, we will recruit 42 patients into an MRI sub-study. This will involve multiparametric MRI prior to LAT to assess a) the performance of noninvasive MRI measures of OPM b) potential alternative measures of adverse outcome, including cardiac function and altered body composition. Results: Final numbers of OPM/ non-OPM cases will depend on the incidence of OPM in the study population (estimated at 70%). Conclusion: The study has been approved by the West of Scotland Research Ethics Committee (Ref: 19/WS/0093). A Study Management Group meets monthly. Results will be published in peer-reviewed journals, presented at international meetings and disseminated to patient groups.