Frequency of EGFR mutations in lung adenocarcinoma patients - A study from tertiary cancer center of South India

Background and objectives: Epidermal growth factor receptor (EGFR) mutation analysis has become an important part of the initial workup of non-squamous non-small cell lung cancer (NS-NSCLC) patients. This study is attempted as South Indians population is comprised of ethnic groups with diverse genetic makeup and only very limited data on EGFR mutation is available from south India. A detailed understanding of EGFR mutation profile will help in better planning of treatment strategies and resource allocation.

Methods: A retrospective analysis of EGFR mutation frequency in 350 patients diagnosed with adenocarcinoma of lung and its association with pathological characteristics was done.

Results: Out of 350 cases of pulmonary adenocarcinoma, within an age group ranging from 30 to 86 years. EGFR mutations were identified in 34.8% (n = 122) cases, out of which 35.24% (n = 43) were in non-smoker females (P = 0.001). Of the 14 cases with resistant type of EGFR mutations, nine were in smoker males and the remaining five in non-smoker females.

Interpretation and conclusion: Overall EGFR mutation frequency observed in our study was similar to other Indian studies. However, in our study, we observed that mutation in exon 21 was less frequent compared to other studies. A similar slightly increased frequency of rare mutations and double mutations were observed in our study. A detailed study of the molecular epidemiology of lung cancer and its association with different geographical zones of India is needed. This understanding will help in better planning of treatment strategies and resource allocation.