Targeted therapy in the treatment of lung cancer in Iceland 2010-2023

Lung cancer is the third most common malignancy in Iceland and remains the leading cause of cancer-related mortality. Lung cancer may harbor driver mutations affecting the function of Epidermal growth factor receptor (EGFR), Anaplastic lymphoma kinase (ALK), ROS proto-oncogene 1 (ROS1), B-raf proto-oncogene (BRAF), RET proto-oncogene (RET), MET proto-oncogene (MET), and NTRK, which can influence the selection of targeted therapies and treatment outcomes. In Iceland, EGFR testing was initiated in 2005, and in 2016, multigene targeted panel became standard for tumor testing. The objective was to determine the uptake of testing and frequency of targeted mutations in lung cancer nationwide, the utilization of targeted therapies, and duration of such treatments.

Data on lung cancer diagnoses and stage at diagnosis were obtained from the Icelandic Cancer Registry, and molecular testing results were retrieved from the Department of Pathology at Landspitali University Hospital. Treatment data and outcomes were obtained from a central prescription/death registry and chart reviews.

From 2010 to 2023, 2,528 patients were diagnosed with lung cancer, and 25% underwent -molecular tumor testing, with 90% of stage IV adenocarcinomas tested in 2023. During comprehensive molecular testing in 2016-2023, targeted mutations were detected in 19.3% of tested patients: EGFR 9.9%, BRAF 2.3%, MET 2.7%, HER2 1.2%, ALK 2.7%, ROS1 0.6%, and RET 0.2%. Among patients found to have targeted mutations (2010-2023), 61.2% received targeted therapy; 33.8% remained on therapy for ≥ 12 months, and 13.5% for ≥ 24 months.

The use of molecular testing has increased significantly in the last 20 years, and the -adaptation of new targeted therapies has been rapid.