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Mutations that lead to constitutive activation of key regulators in cellular processes are one of the most important drivers behind vigorous growth of cancer cells, and are thus prime targets in cancer treatment. BRAF V600E mutation transduces strong growth and survival signals for cancer cells, and is widely present in various types of cancers including lung cancer. A combination of BRAF inhibitor (dabrafenib) and MEK inhibitor (trametinib) has recently been approved and significantly improved the survival of patients with advanced NSCLC harboring BRAF V600E/K mutation. To improve the detection of BRAF V600E/K mutation and investigate the incidence and clinicopathological features of the mutation in lung cancer patients of southern Taiwan, a highly sensitive and specific real-time quantitative PCR (RT-qPCR) method, able to detect single-digit copies of mutant DNA, was established and compared with BRAF V600E-specific immunohistochemistry. Results showed that the BRAF V600E mutation was present at low frequency (0.65%, 2/306) in the studied patient group, and the detection sensitivity and specificity of the new RT-qPCR and V600E-specific immunohistochemistry both reached 100% and 97.6%, respectively. Screening the BRAF V600E/K mutation with the RT-qPCR and V600E-specific immunohistochemistry simultaneously could help improve detection accuracy.

Somatic mutations of MET gene are emerging as important driver mutations for lung cancers. To identify the common clinicopathological features of MET exon 14 skipping mutations and amplification and clarify whether the two MET gene alterations cause protein overexpression were investigated using 196 lung cancer samples of Taiwan through real time-qPCR/sequencing, fluorescence in situ hybridization, and immunohistochemistry. The two MET gene alterations are both present in low frequency, ~1%, in the studied lung cancer population of Taiwan. MET exon 14 skipping mutations were identified from two early-stage patients, who were both relatively advanced in age, and did not carry other driver mutations. One was an adenocarcinoma and the other was a rare carcinosarcoma. Three gene amplifications cases were identified. Neither of the two MET gene alterations would lead to protein overexpression; hence, direct detection in nucleic acid level would be a preferred and straightforward solution for the identification of skipping mutations. The presence of MET exon 14 mutations in minor histological types of lung cancers urge to extend screening scope of this mutation in lung cancer and treatment response evaluation in clinical trials. These would be important next steps for the success of MET target therapy in clinical practice., Competing Interests: The authors have declared that no competing interests exist.

Background: Acquired resistance occurs in most non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations experiencing a response to EGFR-tyrosine kinase inhibitor (TKI) initially. We investigated EGFR-TKI retreatment in patients who had previously received EGFR-TKI followed by chemotherapy., Materials and Methods: This was a retrospective multicenter study. Patients with locally advanced or metastatic adenocarcinoma or TTF-1 (+) NSCLC, positive EGFR sensitive mutation, and EGFR-TKI reuse after initial EGFR-TKI followed by chemotherapy were enrolled. The objectives were to assess the objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) of EGFR TKI switched retreatment., Results: In total, 205 patients were enrolled, with a median age of 61.8 years (range 31.4-92.9). There was a larger proportion of females (62.9%) than males, and more never-smokers (73.2%) than ever-smokers. In the initial EGFR-TKI administration, 57.6% of patients showed a complete response (CR) or partial response (PR), and 34.6% had stable disease (SD); in the second-line chemotherapy, 13.7% had PR, and 58.0% had SD; in the EGFR-TKI retreatment, 7.3% had PR, and 37.1% had SD. The median PFS of first-line EGFR-TKI was 8.0 months (95% CI 7.3-8.2), and retreatment EGFR-TKI was 4.1 months (95% CI 2.7-4.6). The median OS since the start of the first-line EGFR-TKI therapy was 35.9 months (95% CI 28.8-50.9), and since the start of EGFR-TKI retreatment was 12.6 months (95% CI 10.4-20.9). In the univariable and multivariable regression analysis of factors associated with PFS of EGFR-TKI retreatment, time interval between the two EGFR TKIs equal to or more than 7 months was statistically significant (HR=0.62, 95% CI 0.44-0.86; HR=0.6, 95% CI 0.43-0.86), both p<0.01. Females with exon 21 mutation also showed a significant difference between the two groups (HR=0.51, 95% CI 0.30-0.86; HR=0.52 (0.31-0.88), both p<0.05)., Conclusions: EGFR-TKI retreatment was effective in prolonging survival, and was shown to be a worthwhile option for EGFR-mutated NSCLC patients after failure of first-line EGFR-TKI and chemotherapy. The survival benefit was especially pronounced in patients with longer drug holidays from the initial EGFR-TKI and in females with the exon 21 mutation., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Lung cancer is relatively rare in young patients as the median age at diagnosis is 65-70 years. The main objective of this nationwide study was to investigate the characteristics of young lung cancer in Taiwan, especially the relationships among smoking behavior, epidermal growth factor receptor (EGFR) mutation, and age. The National Taiwan Lung Cancer Registry, a database contain detailed cancer statistics, was analyzed in this study for the period 2011-2012. Young lung cancer was defined as age ≦ 45 years. There were 21,536 lung cancer patients (13,187 men and 8349 women). Among these patients, 1074 (5.0%) were in the younger group, and 20,462 patients (95.0%) were in the older group. Female gender (48.8% versus 38.2%, P < 0.001), never-smokers (47.3% versus 43.8%, P = 0.015), and adenocarcinoma (70.4% versus 58.1%, P < 0.001) were more frequent in the younger group. While the EGFR mutation rate was lower in the younger group (52.5% versus 60.6%, P = 0.001), the primary site of lung cancer and stage distribution were not significantly different. If only adenocarcinoma patients were included in the analysis, female gender, older age, and never-smokers were more likely to have EGFR mutation. In conclusion, lung cancer in young patients (≦ 45 year-old) was associated with unique characteristics, with greater percentages of female patients, adenocarcinoma, and never-smokers and a lower EGFR mutation rate compared with older patients., Competing Interests: The authors declare that there are no conflicts of interest.

Epidermal growth factor receptor (EGFR) activation has been shown to play a critical role in tumor angiogenesis. In this study, we investigate the correlation between EGFR mutations and cadherin-5 (CDH5), which is an angiogenic factor, in lung cancer cells. Increased expression CDH5 is observed in lung cancer cells with EGFR mutations. Stable lung cancer cell lines expressing mutant (exon 19 deletion E746-A750, and exon 21 missense mutation L858R) and wild type EGFR genes are established. A significantly higher expression of CDH5 is observed in exon 19 deletion stable lung cancer cells and mouse xenografts. Further studies show that expression of CDH5 is decreased after the inhibition of EGFR and downstream Akt pathways in lung cancer cells with EGFR mutation. In addition, mutant EGFR genes potentiates angiogenesis in lung cancer cells, which is inhibited by CDH5 siRNA, and potentiates migration and invasion in lung cancer cells. Our study shows that mutant EGFR genes are associated with overexpression of CDH5 through increased phosphorylation of EGFR and downstream Akt pathways. Our result may provide an insight into the association of mutant EGFR and CDH5 expression in lung cancer and aid further development of target therapy for NSCLC in the future.

Calreticulin (CALR) mutations were recently identified in patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF) devoid of JAK2 and MPL mutations. We evaluated the clinical, laboratory, and molecular features of a Taiwanese population of patients with ET. Among 147 ET patients, CALR mutations were detected in 33 (22.5 %), JAK2V617F in 94 (63.9 %), and MPL mutations in 4 (2.7 %). Sixteen (10.9 %) patients were negative for all three mutations (CALR, JAK2V617F, and MPL; triple negative). Interestingly, one patient with the type 2 CALR mutation also harbored a low allele burden (0.025 %) of JAK2V617F mutation. Furthermore, we found a novel CALR mutation, with the resultant protein sharing an identical amino acid sequence to the type 6 CALR mutant. Compared to those with JAK2 mutation, CALR-mutated ET patients were characterized by younger age, lower leukocyte count, higher platelet count, and decreased risk of thrombosis. CALR mutations had a favorable impact on thrombosis-free survival (TFS) for ET patients, whereas the respective TFS outcomes were similarly poorer in JAK2-mutated ET and PV patients. Multivariate analysis confirmed that younger age (<60 years), presence of CALR mutations, and a lower platelet count (<1,000 × 10(9)/L) were independently associated with a longer TFS in ET patients. The current study demonstrates that CALR mutations characterize a special group of ET patients with unique phenotypes that are not discrepant from those seen in Western countries.

Purpose: Early lung adenocarcinoma may present with ground-glass opacity (GGO) component in computed tomography (CT) scan. Epidermal growth factor receptor (EGFR) mutation had been reported in patients with lung cancer with GGO patterns. Nevertheless, the correlation between clinical characteristics, CT image patterns, and EGFR mutation status was indeterminate., Methods: Patients with stage I lung adenocarcinoma with tumor lesions less than 3 cm were included and classified into pure GGO, part-solid, and solid patterns by CT scan images. All patients had EGFR mutation test from frozen tumors. Available paraffin-embedded archival tissues were microdissected into three different locations similar to CT images with central and peripheral parts of tumor, and adjacent normal part for EGFR mutation tests., Results: Totally, 162 patients were analyzed, 90 women and 72 men, and 128 nonsmokers. The patients included 35 (21.6%) pure GGO, 41 (25.3%) part-solid, and 86 (53.1%) solid lesions. The EGFR mutation rate was 64.2% (n = 104). Analysis of the correlation between CT image patterns and EGFR mutation, the less GGO ratio had more typical mutation, especially L858R (p = 0.037). In 45 microdissected tumors, the central and peripheral parts had the same EGFR mutation status. In adjacent normal parts, 5 of 32 (15.6%) EGFR mutant patients had identical mutation but none in nonmutant patients., Conclusions: In stage I lung adenocarcinoma, typical mutation, especially L858R was detected more frequent in invasive solid pattern and significantly less in pure GGO pattern. EGFR mutation is an early event in the pathogenesis of lung adenocarcinoma and may facilitate the tumor into aggressive behavior.

Purpose: To assess whether polymorphisms of genes related to estrogen biosynthesis and metabolism are associated with EGFR mutations., Experimental Design: We studied 617 patients with lung adenocarcinoma, including 302 never-smoking women. On the basis of multiple candidate genes approach, the effects of polymorphisms of CYP17, CYP19A1, ERα, and COMT in association with the occurrence of EGFR mutations were evaluated using logistic regression analysis., Results: In female never-smokers, significant associations with EGFR L858R mutation were found for the tetranucleotide (TTTA)(n) repeats in CYP19A1 (odds ratio, 2.6; 95%CI, 1.2-5.7 for 1 or 2 alleles with (TTTA)(n) repeats >7 compared with both alleles with (TTTA)(n) repeats ≤ 7), and the rs2234693 in ERα (OR, 2.1; 95% CI, 1.1-4.0 for C/T and C/C genotypes compared with T/T genotype). The C/C genotype (vs. T/T genotype) of ERα was significantly associated with EGFR L858R mutation (OR, 3.0; 95% CI, 1.1-8.1), in-frame deletion (OR, 2.9; 95% CI, 1.1-7.6) and other mutations (OR, 4.3; 95% CI, 1.3-14.0). The genotype of COMT rs4680 was significantly associated with EGFR L858R mutation in female and male never-smokers showing OR's (95% CI) of 1.8 (1.0-3.2) and 3.6 (1.1-11.3), respectively, for genotypes G/A and G/G compared with genotype A/A. The number of risk alleles of CYP17, CYP19A1, ERα, and COMT was associated with an increasing OR of EGFR L858R mutation in female never-smokers (P = 0.0002 for trend)., Conclusions: The L858R mutation of EGFR is associated with polymorphisms of genes related to estrogen biosynthesis and metabolism in never-smoking female lung adenocarcinoma patients., (©2011 AACR.)

Background: The prevalence of epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) patients is about 40-50% in Taiwan, and there are significant correlations between EGFR mutations and clinical responses after gefitinib treatment. For most patients with advanced disease, surgical intervention for tissue sampling is not feasible. We therefore conducted this study to survey EGFR mutations in cells from NSCLC malignant pleural effusions and to evaluate the clinical significance., Methods: In the present study, malignant pleural effusion cells from 29 NSCLC patients were studied for EGFR mutations. Exons 18, 19, 20, 21 of the EGFR gene were analyzed by polymerase chain reaction (PCR) and automated sequencing. For 11 patients who had received gefitinib therapy, correlations between gefitinib effect and EGFR mutations were also evaluated., Results: EGFR mutations were detected in 12 of 29 specimens (41%). In-frame deletion mutations in exon 19 (8 of 12 specimens, 67%) and missense mutations in exon 21 (3 of 12 specimens, 25%) were the most frequent mutations detected. The frequency of EGFR mutations was significantly higher in gefitinib responders (4/4) than non-responders (1/7) (p = 0.015)., Conclusion: Our results suggest that detecting EGFR mutations in cells from malignant pleural effusions is a feasible adjunct method to finding the subgroup with favorable response to gefitinib therapy among patients with advanced NSCLC.