Comparison of Gefitinib Response in NSCLC Patients with EGFR Mutation Exon 19 and Exon 21

· Biomolecular, Thoracic Oncology

Titin Sholihah Agustina, Laksmi Wulandari
Departemen Pulmonologi dan Kedokteran Respirasi Fakultas Kedokteran Universitas Airlangga, RSUD Dr. Soetomo, Surabaya

Background:. Lung cancer categorized as small cell lung cancer (SCLC) and non small cell lung cancer (NSCLC). One major factor of growth of the cancer cell is the mutation of gen epidermal growth factor receptor (EGFR). The most common mutation of EGFR in the intracellular domain in exon 18, 19, 20,21. Gefitinib is one of the first generation of anti-EGFR and was reported has better effect in the mutation of EGFR exon 19 and 21. But never reported the best effect beetwen exon 19 and exon 21 of giving gefitinib. This study is to compare the effect of gefitinib to EGFR mutation exon 19 and exon 21.
Methods: We conducted a cohort retrospective study among patients that diagnosed as NSCLC with EGFR mutation exon 19 and exon 21 who received gefitinib as first line therapy for the lung cancer in Oncology Clinique (POSA )Dr.Soetomo Hospital Surabaya from 2013 until 2016. To compare the response of exon 19 and exon 21 to gefitinib we analize each response such as subjective response, semi subjective response, objective response,side effect, progression free survival(PFS) and overall survival (OS).
Results: Patients with exon 19 mutation has longer PFS, the median was 8 months and 6 months for exon 21 mutation (p= 0,049). The overall survival of exon 19 mutation was 13,67 months and exon 21 was 11,75 months (p= 0,526). In RECIST evaluation exon 19 has higher partial response than exon 21 (p 0,017).
Conclusion: Gefitinib gives better response therapy to NSCLC EGFR mutation exon 19 than exon 21. (J Respir Indo. 2017; 37: 232-40)

Keywords: EGFR mutation exon 19 and exon 21, gefitinib, progression free survival, overall survival, RECIST

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