A comprehensive review of uncommon EGFR mutations in patients with non-small cell lung cancer.

Patients with non-small cell lung cancer (NSCLC) harboring uncommon epidermal growth factor receptor (EGFR) mutations are a heterogeneous group exhibiting differential responses to EGFR inhibitors. This retrospective study reviews the prevalence of uncommon EGFR mutations in a Chinese NSCLC cohort and the clinical characteristics and efficacy of EGFR tyrosine kinase inhibitors (TKIs) associated with these patients. A total of 5363 lung cancer patients were screened and underwent EGFR genotyping at the Guangdong Lung Cancer Institute. Of those with uncommon EGFR mutations, the clinical characteristics and responses to EGFR-TKIs were reviewed retrospectively. Uncommon EGFR mutations were observed in 218 patients, comprising 11.9% of all patients with documented EGFR mutations. More smokers (30.7% vs. 24.3%, P=0.039) and males (54.1% vs. 44.4%, P=0.007) were among the patients with uncommon mutations compared with common mutations. The most frequent uncommon mutations were exon 20 insertions (30.7%, n=67), followed by G719X mutations (21.1%, n=46) and compound L858R mutations (17.0%, n=37). Favorable efficacy was observed in patients harboring compound L858R or G719X mutations, with a median progression-free survival (PFS) of 15.2 (95% CI: 8.7-21.7) or 11.6 (95% CI: 3.6-19.6) months, respectively. The median PFS of those with the T790M mutation or an exon 20 insertion was 1.0 (95% CI: 0.0-2.2) and 3.0 (95% CI: 1.3-4.7) months, respectively. This study reviewed the prevalence of uncommon EGFR mutations and their sensitivity to EGFR-TKIs. Favorable responses were observed in patients with G719X and compound L858R mutations, indicating that they may benefit from EGFR-TKIs as a first-line therapy.

Tu HY ，Ke EE ，Yang JJ ，Sun YL ，Yan HH ，Zheng MY ，Bai XY ，Wang Z ，Su J ，Chen ZH ，Zhang XC ，Dong ZY ，Wu SP ，Jiang BY ，Chen HJ ，Wang BC ，Xu CR ，Zhou Q ，Mei P ，Luo DL ，Zhong WZ ，Yang XN ，Wu YL ... -  《-》

Effectiveness of Tyrosine Kinase Inhibitors in Japanese Patients with Non-small Cell Lung Cancer Harboring Minor Epidermal Growth Factor Receptor Mutations: Results from a Multicenter Retrospective Study (HANSHIN Oncology Group 0212).

Non-small cell lung cancer (NSCLC) with minor mutations in the epidermal growth factor receptor (EGFR) gene, except for the common 15 base-pair deletions in exon 19 and the L858R mutation in exon 21, is rare, and only few data exist on this patient population. The aim of the present study was to describe the clinical characteristics and to clarify the efficacy of EGFR-tyrosine kinase inhibitors (TKIs) in patients with NSCLC harboring minor mutations of the EGFR gene. This was a multicenter, retrospective study that analyzed specimens from patients with NSCLC who had minor EGFR gene mutations and were treated with EGFR-TKIs between June 2002 and March 2012. Out of 56 patients with minor mutations of the EGFR gene, 44 were treated with either gefitinib or erlotinib. Mutation sites were G719X in exon 18 (n=35), L861Q in exon 21 (n=11), and G874S in exon 21 (n=1). Three patients had both the G719S and the L861Q mutation. The response rate to TKI treatment was 29.5%, and the disease control rate was 63.6%. The median progression-free survival (PFS) was 6.7 months [95% confidence interval (CI)=2.06-8.66 months]. The median PFS was 7.2 months (95% CI=4.23-12.3 months) in 32 patients who received first- or second-line treatment with EGFR-TKIs, whereas the median PFS was 1.57 months (95% CI=0.73-3.8 months) in 12 patients treated with EGFR-TKIs as a third-line or later treatment. In multivariate Cox analysis, erlotinib therapy was associated with a longer PFS than gefitinib (p=0.025). Patients with NSCLC harboring minor mutations of the EGFR gene exhibited a modest response to EGFR-TKI treatment. Treatment with first-generation EGFR-TKIs, in particular erlotinib, may be considered a first- or second-line option for patients with NSCLC with minor EGFR mutations.

Otsuka T ，Mori M ，Yano Y ，Uchida J ，Nishino K ，Kaji R ，Hata A ，Hattori Y ，Urata Y ，Kaneda T ，Tachihara M ，Imamura F ，Katakami N ，Negoro S ，Morita S ，Yokota S ... -  《-》

Non-small cell lung cancer harbouring non-resistant uncommon EGFR mutations: Mutation patterns, effectiveness of epidermal growth factor receptor-tyrosine kinase inhibitors and prognostic factors.

Non-small cell lung cancer (NSCLC) harbouring EGFR exon 19 deletions or L858R mutation usually respond to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), whereas T790M mutation and exon 20 insertion are frequently resistant to EGFR-TKIs. EGFR mutations other than those above are seldom investigated. In this multicentre, retrospective study, we enrolled NSCLC patients with non-resistant uncommon EGFR mutations, which were defined as mutations other than L858R, exon 19 deletions, exon 20 insertions and T790M. The mutation patterns, clinical data and treatment outcomes were analysed. Patients were classified as gefitinib/erlotinib and afatinib groups according to the EGFR-TKIs received as the first-line therapy. A total of 177 patients were identified (177/1983, 8.9%). Sixty-six patients had more than one EGFR mutation, including those coexisting with exon 19 deletion or L858R mutation. In treatment-naïve patients with advanced stages (n = 72), the objective response rate was 35.8% for gefitinib/erlotinib group and 60.6% for afatinib group (p = 0.036). In multivariate analysis, no significant differences were found between gefitinib/erlotinib and afatinib groups in median progression-free survival (PFS) and overall survival (OS). Brain metastasis at diagnosis was associated with a shorter PFS (hazard ratio [HR] = 2.49, 95% confidence interval [CI] = 1.29-4.83) and OS (HR = 3.22, 95% CI = 1.41-7.35). For patients with NSCLC harbouring non-resistant uncommon EGFR mutations, afatinib use as the first-line therapy may provide a better treatment response but no survival benefit, as compared with gefitinib or erlotinib. Brain metastasis at diagnosis is associated with a poor prognosis.

Chang LC ，Lim CK ，Chang LY ，Chen KY ，Shih JY ，Yu CJ ... -  《-》

Epidermal growth factor receptor tyrosine kinase inhibitors for non-small cell lung cancer harboring uncommon EGFR mutations: Real-world data from Taiwan.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the standard treatment for patients with non-small cell lung cancer (NSCLC) harboring EGFR mutations. This study aimed to evaluate the efficacy of EGFR-TKIs and prognostic factors for patients with NSCLC harboring uncommon EGFR mutations, which account for 10% of EGFR mutations. A total of 230 treatment-naive patients with NSCLC harboring uncommon EGFR mutations treated with first-line EGFR-TKIs between 2011 and 2018 at four hospitals (belonging to four institutions, Linkou, Kaohsiung, Keelung, and Chiayi, of the Chang Gung Memorial Hospital) in Taiwan were retrospectively reviewed. Their clinicopathological characteristics, adverse events (AEs), objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were collected. Univariate and multivariate analyses were performed to identify potential prognostic factors for PFS. Overall, patients who received afatinib (n = 62) had better PFS (median: 6.4 vs. 5.9 months, p = 0.022) and OS (median: 13.4 vs. 13.0 months, p = 0.008) than those who received gefitinib/erlotinib (n = 124), although no significant differences were observed for ORR (46.8% vs. 35.5%, p = 0.137) or DCR (59.7% vs. 58.9%, p = 0.916). Patients who received afatinib showed significantly higher ORR (58.3% vs. 31.3%, p = 0.027) but not DCR compared with gefitinib/erlotinib for major uncommon mutations. Afatinib trended toward better PFS and OS for major uncommon mutations and compound mutations. No EGFR-TKIs were effective for most NSCLC patients with exon 20 insertions. Performance status, metastasis of the liver and pleura, and dose reduction were independent prognostic factors for PFS. Afatinib demonstrated better survival outcomes than gefitinib/erlotinib for NSCLC patients harboring major EGFR uncommon mutations and compound mutations. Performance status and metastatic sites may be useful for predicting PFS for major uncommon mutations and compound mutations.

Chang JW ，Huang CY ，Fang YF ，Chang CF ，Yang CT ，Kuo CS ，Hsu PC ，Wu CE ... -  《-》

Clinical outcomes of gefitinib and erlotinib in patients with NSCLC harboring uncommon EGFR mutations: A pooled analysis of 438 patients.

The purpose of this study was to investigate the outcomes of gefitinib and erlotinib in patients with non-small cell lung cancer (NSCLC) with uncommon epidermal growth factor receptor (EGFR) mutations. Relevant researches were identified by a literature search of the PubMed database. Patients with EGFR mutations other than exon 19 deletion and L858R were eligible for the study. Clinical outcomes included objective response rate (ORR), progression free survival (PFS), and overall survival (OS). We categorized all uncommon EGFR mutations as: single uncommon EGFR mutations and compound mutations that containing 2 or more kinds of EGFR mutations. We also assessed outcomes in patients categorized by EGFR-TKIs: (1) gefitinib group; (2) erlotinib group. A total of 438 patients with NSCLC harboring uncommon EGFR mutations were included in this study. The ORR for gefitinib and erlotinib was 43.8 %, with a median PFS (mPFS) of 6.00 months and a median OS (mOS) of 20.50 months. Patients with compound mutations had an ORR of 56.3 % and an mPFS of 8.10 months. Both of them were significantly better than these in patients with single uncommon EGFR mutation, which were 29.3 % and 3.90 months, respectively (odds ratio (ORa): 2.74, 95 % confidence interval (CI): 1.86-4.05, P < 0.001; hazard ratio (HR): 0.58, 95 % CI: 0.48-0.71, P < 0.001). Moreover, patients with compound mutations containing 19 deletion or L858R had a superior response and survival benefits compared to patients with other compound mutation patterns. In addition, the gefitinib group showed a favorable efficacy advantage (P = 0.003) and PFS benefit (P = 0.021) compared to the erlotinib group. Uncommon EGFR mutations exhibit favorable but inconsistent treatment responses and survival outcomes to gefitinib and erlotinib, which are closely related to the mutation pattern, the cooccurring partner mutant genes, and the type of EGFR-TKIs received.

Wang C ，Zhao K ，Hu S ，Dong W ，Gong Y ，Li M ，Xie C ... -  《-》