Clinicopathologic features of non-small cell lung cancer in India and correlation with epidermal growth factor receptor mutational status

Introduction: We performed retrospective analysis of 106 patients with lung cancer for which formalin-fixed paraffin-embedded tissues was available. Their epidermal growth factor receptor (EGFR) mutation status and treatment outcomes are described. Materials and Methods: All patients with confirmed non - small cell lung cancer (NSCLC) during Jan 2008 to Dec 2010 were included. EGFR sequencing was performed with ABI PRISM 310 genetic analyzer. Results: Forty-two (39.6%) patients had mutation in one of the four exons characterized. Patients whose EGFR mutational status was not available at presentation before the start of treatment were started on chemotherapy, n = 46 (43.39%). If EGFR mutational analysis was available and mutations were present, the patients were started on either upfront tyrosine kinase inhibitor (TKI), n = 15 (14.15%) or if on chemotherapy arm were allowed to finish six cycles and then start with maintenance TKIs, n = 26 (24.52%). The median progression free survival for patients with and without mutations was 11 months (95% CI,7-14) and 9 months (95% CI,7-10) respectively. A median PFS of 14 months (95%CI, 12-16) was seen in the mutation-positive group that received both chemotherapy followed by switch maintenance with TKIs versus 8 months (95%CI, 7-8 months) in the group that received only TKI. Conclusion: The prevalence of EGFR mutations in this population of NSCLC patients was 39.6% with exon 19 mutation being the most common. The observed benefit of addition of chemotherapy over TKI in EGFR mutation-positive group raises the question, can we offer the therapy of chemotherapy-TKI combination to EGFR mutation-positive lung cancer patients as shown in the present study.