Molecular Epidemiology of ROS1 Alterations in Advanced Non-Small Cell Lung Cancer (NSCLC): Temporal Patterns of Testing and Positivity Across Europe Between 2018 and 2022

OBJECTIVES: To describe temporal patterns of ROS1 testing and associated ROS1 positivity rates among patients with advanced NSCLC in Europe.

METHODS: Using the Oncology Dynamics database, rates of ROS1 alteration testing and ROS1 positivity were estimated based on records of patients with incident stage IIIB-IV NSCLC from centres with electronic health records in France, Germany, Italy, Spain, and the UK, collected on a yearly cross-sectional basis between 2018 and 2022. Projection was then used to estimate patient numbers at a national level for each country. Additional data from Sweden will be available for presentation.

RESULTS: Patient numbers ranged from 60,424 (Spain) to 153,933 (Germany). In all 5 countries, ROS1 alteration testing rates increased over time: in 2018, testing rates ranged from 15% (UK) to 66% (Germany); by 2022, testing rates ranged from 57% (Italy) to 75% (Germany). The largest increase occurred in the UK, with testing rates increasing from 15% in 2018 to 72% in 2022. Testing rates were consistently higher in patients with non-squamous versus squamous histology. By 2022, testing rates ranged from 69% (Italy) to 86% (France) for non-squamous histology and from 16% (Italy) to 58% (Germany) for squamous histology.

ROS1 positivity rates were generally consistent throughout the study period and across countries: France (min-max range, 1%-4%), Germany (2%-3%), Italy (2%-4%), Spain (3%-4%), and UK (2%-5%). With increased ROS1 testing and relatively stable positivity rates, the projected number of patients identified with ROS1-positive disease across the 5 countries increased over time, from 1096 in 2018 to 2090 in 2022. Throughout the study period, ROS1 alterations were considerably more prevalent in patients with non-squamous versus squamous histology across all countries.

CONCLUSIONS: These data provide further evidence of increased ROS1 testing across Europe and associated increased numbers of patients identified with ROS1-positive advanced NSCLC who may benefit from targeted therapy.