A study of incidence of EGFR mutations in non-smoker adenocarcinoma of the lung: disparity between north and south indian ppatients

Background: Lung cancer is the leading cause of cancer deaths worldwide for both men and women. It is the number three cancer among Indian men. Chemotherapy for non–small cell lung carcinoma (NSCLC), which accounts for approximately 85% of lung cancer cases, remains marginally effective. Anti-EGFR therapies have been developed to intervene in the EGFR signalling cascade in NSCLC. Mutations in EGFR gene are an important factor in achieving the desired outcome in case of such patients. We sought to analyse the presence of mutations in EGFR gene in Asian Indian adenocarcinoma patients to highlight the implications for using such therapies in one of the highest populated state. It may also show importance of using a relevant population for research in drug development involving such therapies. Method and findings: A retrospective multicentre study was performed where tumour samples of non-smoker or ex-smoker adenocarcinoma patients were analyzed for EGFR gene mutations. We used ARMS-Scorpion’s real time PCR method for mutation analyses. Overall, 50 NSCLC patients were included in the mutation analyses. The EGFR mutation positive rate was 56% (±14%). South Indians had a higher mutation rate (68%±17%) than North Indians (41%±21%, p=0.06). South Indian female NSCLC patients had a higher mutation rate than that of in North Indian female NSCLC patients. (p=0.02). Conclusions: The EGFR mutation rate in Indian NSCLC patients was higher than that of the European or other western populations. Such a high rate of positive mutation in non-smoker lung adenocarcinoma is remarkable & has important implications in the management of such cases. There is also a disparity in the mutation rate between north & south India especially in women. It is therefore important to evaluate the EGFR mutation status before prescribing the tyrosine kinase inhibitors in the case of non-smoker lung adenocarcinoma patients from North & South India to have effective treatment outcome.