Abstract
Background: A novel fusion gene of echinoderm microtubule-associated protein-like 4 (EML4) and
anaplastic lymphoma kinase (ALK) has been identified in a subset of non-small-cell
lung cancers (NSCLCs). Patients with the ALK-EML4 fusion gene demonstrate unique clinicopathological
and physiological characteristics. Here we present an analysis of clinicopathological
profile of patients of metastatic adenocarcinoma harboring the ALK-EML4 fusion gene.
Methods: A retrospective analysis of advanced ALK positive NSCLC, who presented at this tertiary
care hospital of armed forces from September 2014 to December 2016 was conducted.
The primary goal was to evaluate demographic and clinicopathological profile of ALK
positive advanced NSCLC. Detection of ALK fusion was done by IHC on formalin fixed
paraffin embedded cell blocks. Results: Out of 270 patients of NSCLC, 15 (7.4%) tested positive for ALK-EML4 fusion. Rate
of positivity was higher in females (13.7%) than in males (5%). The correlation of
the ALK-EML4 fusion gene and clinicopathological characteristics of NSCLC patients
demonstrated a significant difference in smoking status, histological types, stage,
and metastatic pattern. Conclusion: Our analysis indicated that ALK-EML4 positive NSCLC comprised a unique subgroup of
adenocarcinomas with distinct clinicopathological and radiological characteristics.
Incidence of ALK positivity was found to be higher in females and never smokers. These
patients have distinct pathological and radiological characteristics.
Keywords
Adenocarcinoma - anaplastic lymphoma kinase-echinoderm microtubule-associated protein-like
4 - fluorescent in situ hybridization - immunohistochemistry - metastasis - nonsmall
cell lung cancer