Yuko Oya1, Tatsuya Yoshida2, Hiroaki Kuroda3, Junichi Shimizu1, Yoshitsugu Horio1, Yukinori Sakao3, Yoshitaka Inaba4, Toyoaki Hida1, Yasushi Yatabe5. 1. Department of Thoracic Oncology, Aichi Cancer Center Hospital, Aichi, Japan. 2. Department of Thoracic Oncology, Aichi Cancer Center Hospital, Aichi, Japan. Electronic address: t.yoshida@aichi-cc.jp. 3. Department of Thoracic Surgery, Aichi Cancer Center Hospital, Aichi, Japan. 4. Department of Diagnostic and Interventional Radiology, Aichi Cancer Center Hospital, Aichi, Japan. 5. Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, Aichi, Japan.
Abstract
BACKGROUND: Emergence of the T790M point mutation in exon 20 of the epidermal growth factor receptor (EGFR) is the most common mechanism of resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The aim of this study was to investigate the association between T790M mutation status and the progression patterns during EGFR-TKI treatment. METHODS: We reviewed 181 patients with advanced non-small-cell lung cancer harboring EGFR mutation, who were evaluated for T790M mutation status after initial EGFR-TKI failure (gefitinib, erlotinib, or afatinib). We retrospectively investigated the patient characteristics, initial EGFR-TKI response, T790M mutation status, subsequent treatment after initial EGFR-TKIs, timing of re-biopsy, and progression patterns during the EGFR-TKI treatment. RESULTS: After the resistance to the EGFR-TKIs, the T790M mutation was identified in 87 (48%) of 181 patients. Seventy-three (40%) patients had solitary lesion progression, and 108 (60%) had multiple lesion progression during the initial EGFR-TKI treatment. The prevalence of the T790M mutation was significantly greater in patients with solitary lesion progression than those with multiple lesion progression (58% vs. 24%; P < .0001). The overall response rate and progression-free survival on initial EGFR-TKIs were significantly better in patients who acquired T790M after failure of EGFR-TKIs than those without T790M (overall response rate, 80% vs. 60%; P = .0033 and progression-free survival, 11.4 vs. 9.3 months; P = .0050). The multivariate analysis showed that gender, initial EGFR-TKI response, and progression patterns were significantly associated with T790M mutation status. DISCUSSION: The progression patterns during initial EGFR-TKIs and initial EGFR-TKI response are associated with the T790M mutation.
BACKGROUND: Emergence of the T790M point mutation in exon 20 of the epidermal growth factor receptor (EGFR) is the most common mechanism of resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The aim of this study was to investigate the association between T790M mutation status and the progression patterns during EGFR-TKI treatment. METHODS: We reviewed 181 patients with advanced non-small-cell lung cancer harboring EGFR mutation, who were evaluated for T790M mutation status after initial EGFR-TKI failure (gefitinib, erlotinib, or afatinib). We retrospectively investigated the patient characteristics, initial EGFR-TKI response, T790M mutation status, subsequent treatment after initial EGFR-TKIs, timing of re-biopsy, and progression patterns during the EGFR-TKI treatment. RESULTS: After the resistance to the EGFR-TKIs, the T790M mutation was identified in 87 (48%) of 181 patients. Seventy-three (40%) patients had solitary lesion progression, and 108 (60%) had multiple lesion progression during the initial EGFR-TKI treatment. The prevalence of the T790M mutation was significantly greater in patients with solitary lesion progression than those with multiple lesion progression (58% vs. 24%; P < .0001). The overall response rate and progression-free survival on initial EGFR-TKIs were significantly better in patients who acquired T790M after failure of EGFR-TKIs than those without T790M (overall response rate, 80% vs. 60%; P = .0033 and progression-free survival, 11.4 vs. 9.3 months; P = .0050). The multivariate analysis showed that gender, initial EGFR-TKI response, and progression patterns were significantly associated with T790M mutation status. DISCUSSION: The progression patterns during initial EGFR-TKIs and initial EGFR-TKI response are associated with the T790M mutation.