ABSTRACT
BACKGROUND: Worldwide, the frequency of ALK rearrangement ranges between 3-6%, however its prevalence in the Middle Eastern population has not been reported. The aim of this study is to determine the frequency of the ALK rearrangement, as well as the clinico-pathologic characteristics of Lebanese patients with ALK-rearranged lung adenocarcinoma. METHODS: 152 patients diagnosed with non-squamous non-small cell lung carcinomas (NSCLC), at Hôtel-Dieu de France University Hospital between February 2014 and July 2016, were included in the study. ALK gene rearrangement expression was screened by immunohistochemistry (IHC) (D5F3 Clone). Positive cases were then sent for confirmation with Fluorescence in situ hybridization (FISH) technique. RESULTS: On immunohistochemistry, patients were distributed as following: score 0: n=108, score 1+: n=26, score 2+: n= 9, score 3+: n= 9. ALK gene rearrangement was detected in 6 out of 18 (2+ and 3+ score) tested patients by FISH technique. The presence of ALK rearrangement was significantly associated with the female gender (n=6, p=0.003) and with non-smoking status (n=4, p=0.0.18). CONCLUSION: This study confirms that the prevalence of the ALK gene rearrangement in the Middle Eastern region is within the worldwide ranges and is almost exclusive to patients with adenocarcinoma subtype and tends to occur more frequently in women and non-smokers.
