ALK Mutation Status in EGFR-negative Non-small-cell Lung Cancer Patients in Bulgaria.

Abstract

Patients with non-small-cell lung cancer (NSCLC) with anaplastic lymphoma kinase (ALK) rearrangement mutation are found to be 3-13%. To evaluate the prevalence of ALK mutations in EGFR-negative NSCLC patients in Bulgaria. One hundred and thirty-two patients with EGFR-negative NSCLC were examined for ALK mutation analysis between January and June 2016. Data were obtained from patients' register of four major oncological hospitals in Bulgaria. Data were available for 124 (93.9%) patients, tumor mass was insufficient for analysis in 8 (6.1%) patients. Most of the patients were with adenocarcinoma (82 patients, 62.1%); 11 patients (8.3%) were with squamous histology and 2 patients (1.5%) were with other type of NSCLC. Histology data were missing in 37 patients (28.0%). ALK mutation was confirmed in 5 patients (3.8%), 119 (90.2%) patients had ALK wild type. ALK positive patients were with adenocarcinoma (n=3), squamous cell carcinoma (n=1) and other type (n=1) NSCLC. All ALK mutations were observed in never smokers (n=3) and former smokers (n=2). The present study is the first of this kind in Bulgaria - it investigates the prevalence of ALK mutation rate in EGFR-negative NSCLC patients, which was found to be 3.8%. The presence of EGFR, ALK or other driver mutations is a prerequisite for targeted therapy and thus needs to be accurately assessed in NSCLC.