EGFR mutation testing in NSCLC: Patterns of care and outcomes in Western Australia

Aims: This study evaluated the EGFR mutation status, administration of gefitinib or erlotinib and outcomes of patients assessed for EGFR mutations since the commencement of testing in Western Australia. Methods: A retrospective study identified patients with NSCLC who undergone EGFR mutation testing in the Department of Anatomical Pathology, Royal Perth Hospital, Western Australia from March 2005 until May 2007. Patient characteristics, cancer history, treatment, outcomes and survival were collected from the medical records and pathology reports. Results: Tumor samples from 64 patients were sequenced for mutations in exons 18-21 EGFR and, of these, 53 patients with NSCLC were included in the analysis. The mean age at diagnosis was 61 years (range 19-80) and most of the tumor samples tested were from female patients (76%). Overall 36% of patients tested were mutation-positive with 95% of mutations occurring in exons 19 or 21. A total of 63% of mutation-positive and 18% of mutation-negative patients were treated with gefitinib or erlotinib. Of these, 83% of patients whose tumors had an EGFR mutation had a favorable response following treatment, compared to 17% of mutation-negative patients. The duration of treatment was longer in mutation-positive patients (mean 30 weeks vs 9 weeks). Conclusion: EGFR mutation testing is not routinely performed in NSCLC in Western Australia. Referral for testing is at the discretion of the treating physician, accounting for the high proportion of women and adenocarcinoma histology. Selection of mutation-positive tumors for treatment with gefitinib or erlotinib is associated with good responses to treatment. This study supports the use of gefitinib or erlotinib in routine clinical practice in patients with NSCLC carrying an EGFR mutation.