Purpose: Clinical features of epidermal growth factor receptor (EGFR) mutations, L858R, deletions in exon 19, T790M, and insertions in exon 20, in non-small cell lung cancer (NSCLC) are well known. The clinical significance of other uncommon EGFR mutations, such as their association with the effectiveness of EGFR tyrosine kinase inhibitors (TKI), is not well understood. This study aimed to improve the understanding of these uncommon EGFR mutations of unknown clinical significance.Patients and Methods: Specimens from 1,261 patients were tested for EGFR mutations. We surveyed the clinical data and the effectiveness of gefitinib and erlotinib in NSCLC patients with uncommon EGFR mutations.Results: Of the 1,261 patients, 627 (49.8%) had EGFR mutations. This included 258 patients with deletions in exon 19, 260 patients with L858R, 25 patients with insertions or duplications in exon 20, 6 patients with de novo T790M, and 78 (12.4%) patients with uncommon mutations. Of the 78 patients, 62 received either gefitinib or erlotinib treatment. The response rate of TKIs treatment was 48.4%, and the median progression-free survival (PFS) was 5.0 months. Mutations on G719 and L861 composed a major part (28 of 62) of uncommon mutations, and were associated with a favorable effectiveness of EGFR TKIs (response rate, 57.1%; median PFS, 6.0 months). Mutations other than G719 and L861 led to a worse response to EGFR TKIs (response rate, 20.0%; median PFS, 1.6 months).Conclusions: Uncommon EGFR mutations constituted a distinct part of the whole group of EGFR mutations. Their composition was heterogeneous, and their associations with EGFR TKIs differed. Clin Cancer Res; 17(11); 3812-21. Ó2011 AACR.

Purpose: Clinical reports about responsiveness to gefitinib treatment in patients of non-small cell lung cancer (NSCLC) with mutations in exon 20 of epidermal growth factor receptor (EGFR) are limited. To increase understanding of the influence of exon 20 mutations on NSCLC treatment with gefitinib, we investigated the clinical features of lung cancer in patients with exon 20 mutations and analyzed the gefitinib treatment response. Experimental Design: We surveyed the clinical data and mutational studies of NSCLC patients with EGFR exon 20 mutations in the National Taiwan University Hospital and reviewed the literature reports about EGFR exon 20 mutations and the gefitinib treatment response. Results: Twenty-three patients with mutations in exon 20 were identified. Nine (39%) had coexisting mutations in EGFR exons other than exon 20. Sixteen patients received gefitinib treatment, and a response was noted in 4 patients. The gefitinib response rate of NSCLC with exon 20 mutations was 25%, far lower than those with deletions in exon 19 and L858R mutations. Interestingly, different exon 20 mutations and coexisting mutations seemed to have a different influence on gefitinib response. Conclusions: EGFR exon 20 mutations of NSCLC patients result in poorer responsiveness to gefitinib treatment, but variability exists between different individuals.

Background. Epidermal growth factor receptor (EGFR) mutations are usually detected in lung adenocarcinoma and are associated with a response to EGFR tyrosine kinase inhibitors (TKIs). However, not all EGFR mutations have similarly high clinical response rates. This study aimed to investigate the clinical characteristics and response to gefitinib in lung adenocarcinoma patients with complex EGFR mutations.Materials and Methods. Three hundred thirty-nine specimens of lung adenocarcinoma from patients treated with gefitinib were collected for EGFR sequencing. Nineteen patients with complex EGFR mutations were enrolled for the study after excluding three patients with the EGFR T790M mutation, which confers resistance to gefitinib.

Purpose: Several deletions in exon 19 of epidermal growth factor receptor (EGFR) gene have been reported in non–small cell lung cancer (NSCLC). It is unknown if deletions occurring at different amino acid positions or of different sizes are associated with different clinical outcome to EGFR tyrosine kinase inhibitors (TKI). Experimental Design: This study enrolled NSCLC patients with deletions in EGFR exon 19. Patients who had received EGFR TKIs for advanced NSCLC were further evaluated for response rate (RR), progression-free survival (PFS), and overall survival (OS). Results: In 308 patients with deletions in EGFR exon 19, 298 had deletions encompassing the entire amino acid string from L747 through E749 (LRE deletions). EGFR TKIs were used in 204 patients with advanced NSCLC. Patients with non-LRE deletions had the least RR, compared with those with deletions from E746 or L747 (42.9%, 68.2%, and 79.6%, respectively; P = 0.022). Patients with non-LRE deletions had relatively short median PFS, though not significantly different from those with deletions from E746 or L747 (5.9, 9.8, and 10.5 months, respectively; P = 0.665). The OS was not different among patients with deletions occurring at different amino acid positions (P = 0.776). Deletions in exon 19 of different sizes were not associated with different RR, PFS, or OS. Conclusions: Non-LRE deletions in exon 19 were associated with worse response to EGFR TKIs, compared with LRE deletions. Therefore, the expected clinical outcome under EGFR TKIs depends on not only the existence but also the types of deletions in exon 19. Clin Cancer Res; 18(12); 3470–7. ©2012 AACR.

NIV may be applied to those patients with a low APACHE II score and a lesser degree of metabolic compensation for respiratory acidosis. For patients undergoing invasive mechanical ventilation, extubation failure is associated with significant in-hospital morbidity in myasthenic crisis. Adequate levels of Pemax and cough strength correlate significantly with extubation success.