ABSTRACT
<p><b>OBJECTIVE</b>To study the prevalence of ALK, ROS1 and RET fusion genes in non-small cell lung cancer (NSCLC), and its correlation with clinicopathologic features.</p><p><b>METHODS</b>Formalin-fixed and paraffin-embedded tissue sections from samples of 302 patients with NSCLC were screened for ALK, ROS1, RET fusions by real-time polymerase chain reaction (PCR). All of the cases were validated by Sanger DNA sequencing. The relationship between ALK, ROS1, RET fusion genes and clinicopathologic features were analyzed.</p><p><b>RESULTS</b>In the cohort of 302 NSCLC samples, 3.97% (12/302) were found to contain ALK fusion genes, including 3 cases with E13; A20 gene fusion, 3 cases with E6; A20 gene fusion and 3 cases with E20; A20 gene fusion. There was no statistically significant difference in patient's gender, age, smoking history and histologic type. Moreover, in the 302 NSCLC samples studied, 3.97% (12/302) were found to contain ROS1 fusion genes, with CD74-ROS1 fusion identified in 9 cases. There was no statistically significant difference in patients' gender, age, smoking history and histologic type. One non-smoking elderly female patient with pulmonary adenocarcinoma had RET gene fusion. None of the cases studied had concurrent ALK, ROS1 and RET mutations.</p><p><b>CONCLUSIONS</b>The ALK, ROS1 and RET fusion gene mutation rates in NSCLC are low, they represent some specific molecular subtypes of NSCLC. Genetic testing has significant meaning to guide clinical targeted therapy.</p>