Molecular Diagnosis of Lung Cancers.

Abstract

Recent advances in cancer diagnosis have seen a rapid and accurate diagnostic test. Initially used as research tools the molecular diagnostic tests have been applicable in the clinical scenario. Purpose: Current study focuses on the significant approach of detection of epidermal growth factor receptor (EGFR) mutations in exon 18-21 and anaplastic lymphoma kinase gene (ALK) rearrangement analysis using molecular methods such as pyrosequencing and florescence in-situ hybridization (FISH) on formalin fixed paraffin embedded (FFPE) from tissue biopsy and cell blocks of 267 lung cancer patients. Methods: In this study, FISH using a break-apart probe for the ALK gene was performed on formalin fixed paraffin-embedded tissue to determine the incidence of ALK rearrangements and hybridization patterns in 267 patients with a referred diagnosis of non-small cell lung cancer. EGFR mutations detection was performed on 267 samples by using Pyrosequencing. Results: Among the 267 patients 11 were positive for ALK-1 gene rearrangement. 260 of the 267 cases were confirmed of adenocarcinoma and 7 of the 267 cases were squamous cell carcinoma. EGFR mutations were detected in 55 patients. The most common mutations found were exon 19 (56.36%), exon 21 (27.27%), exon 20 (3.63%) and exon 18 (9.09%). The influence of gender, non-smoking, and histological type on the EGFR mutations showed increase in female group. Conclusions: Mutation detection testing is mandatory in lung carcinomas for the diagnosis and management of NSCLC.