478P - EGFR mutation in NSCLC in Pakistan

Date 18 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Biomarkers
Non-Small-Cell Lung Cancer, Metastatic
Presenter Zeeshan Ahmed
Citation Annals of Oncology (2016) 27 (suppl_9): ix139-ix156. 10.1093/annonc/mdw594
Authors Z.A. Ahmed, T. Moatter, S. Pervez, W. Khan
  • Pathology And Laboratory Medicine, The Aga Khan University Hospital, 3500 - Karachi/PK

Abstract

Background

Lung cancer is the 4th leading cause of death in all cancers. Histological types; 1)Small cell Lung carcinoma (SCLC 20%)2)Non-small cell Lung carcinoma (NSCLC 80%).Adenocarcinomas of lung constitute up to 50% of NSCLC.In Pakistan like rest of the world lung cancer prevalence is high (15%) and primary lung adenocarcinoma constitute about 40-45% of primary lung cancer. Mutations in EGFR tyrosine kinase domain have been reported in adenocarcinoma. In lung cancer, the discovery of acquired genetic alteration in EGFR has changed the way it is currently being diagnosed and treated. EGFR mutation screening has become imperative for the selection of metastatic NSCLC patients eligible for targeted treatment.

Methods

EGFR mutation in tumor samples was screened by multiplex RT-PCR according to the manufacturer’s instructions. Briefly, DNA from FFPE tissue, obtained from Histopathology sections, was extracted and amplified with primers and probes specific to 43 different EGFR mutations in Cobas z 480 instrument. The assay can detect 43 mutations in four exons (18-21) of EGFR gene

Results

Out of 315 patients, 208 were male and 107 were females; male to female ratio was 2:1. The mean age of the patients was 62 years and age distribution was 23 and 85 years. On the basis of immuno histopathological finding tumors were categorized into two groups; well to poorly differentiated adenocarcinoma 231(73%) and metastatic adenocarcinoma 84 (27%). EGFR mutation Del 19 was detected in 38 patients, its short in-frame deletion in exon 19, clustered around the amino acid resideus747-750(most common variant delL746-A750, delL747-T751insS, and delL747-P753insS). Whereas L858R point mutation (substitution of amino acid leucine to arginine) was found in 27 patients. In two patients compound mutation, two point mutations together [S768I and G719X] and another one insertion (amino acid residues inserted) on Exon 20 was observed. L858R (exon 21) and deletion 19 exon were most frequent mutations in primary lung adenocarcinoma patients of Pakistani origin, in published literature female preponderance was significant. .

Conclusions

Our study showed Del 19 and L858R were the most frequent mutations in Pakistani lung cancer patients. In additions, 25% of the patients were found eligible for targeted therapy.

Clinical trial indentification

Its a rondom study for local populations

Legal entity responsible for the study

N/A

Funding

Aga Khan University

Disclosure

All authors have declared no conflicts of interest.