The frequency of driver mutations in non-small cell lung cancer patients: The Turkish nation-wide, observational, Registurk-Lung study (updated analysis).

Abstract

e20501 Background: The role of biomarkers in the treatment of non-small cell lung cancer is increasing. Biomarker evaluation is performed in almost all of the diagnosed patients and treatments are applied according to this evaluation. In this study, the frequency and testing rates of biomarkers in patients with non-small cell lung cancer in Turkey were investigated. Methods: In the "Registurk-Lung" study conducted in our country, histopathological, molecular, radiological and clinical data of more than 9000 patients from 42 centers were collected between December 2021 and January 2024 within the scope of this observational study. Results: The median age was 65 (25-97) years and 15,1% of the patients were female. 60,3% of the patients had non-squamous histology and 39,7% had squamous histology. When we examined the alteration rates, EGFR mutation was 11,1%, ALK rearrangement was 3,2%, ROS-1 was 1.3%, BRAF mutation was 3,6%, MET alteration was 2,2%, RET fusion was 0,6%, KRAS G12C mutation was 17,3%, HER-2 mutation was 1,2%, and NTRK gene fusions were 0,14 %. The PDL-1 expression level was negative (<1%) in 33,9 % of the patients. The rate of patients with PDL-1 expression levels greater than 50% was 26,8%, while the rate of PDL-1 expression level 1-49% was 39,3% of the patients. While single biomarker targeted tests (IHC, PCR, FISH...) were applied as a main method, comprehensive genomic analysis (CGA, NGS) was performed in only 8,9% of the patients. As a result of comprehensive genomic analysis, a druggable result was detected in 17% of the patients. The most important obstacle in the detection of biomarkers was determined as the insufficiency of the evaluated tissue. Conclusions: An awareness has been raised about the use of biomarkers in the treatment of lung cancer in Turkey. This awareness and the identification of biomarkers and directing the treatment will benefit our patients in terms of survival and treatment adherence.