3% (12/427) of patients were found to carry dual or multiple mutations before TKI treatment and 5 out of these 12 patients carried main T790M mutation. or more mutations recognized prior to TKI treatment. Peripheral blood mononuclear cells were sequenced for germ-line mutation on two patients with main T790M mutation. Results 55 out of 427 (13%) patients with lung adenocarcinomas were found to have mutations; twelve of which were recognized to have either dual or multiple mutations. Five of these 12 patients (42%) experienced main T790M mutation and three of them showed similar heights of the mutant and wild-type peaks on sequencing electropherogram, suggesting the possibility of germline mutation. One case of germline T790M mutation was confirmed via sequencing a peripheral blood sample. Conclusions Dual or multiple mutations comprised 2.8% of lung adenocarcinomas in our study. Main T790M mutation are presented with high frequency (5/12; 42%) in patients transporting dual or multiple mutations. Mutations, T790M germline mutation, Lung Adenocarcinoma Introduction Exon 19 deletions and point mutations in L858R are the most common somatic activating mutations in the epidermal growth factor receptor (gene that confer sensitivity to tyrosine kinase inhibitors (TKI) in lung malignancy1. However, despite the initial response to TKIs, all patients will eventually develop resistance. One of the most common mechanisms of resistance is usually acquisition of a second mutation at exon 20 which causes a T790M substitution.2,3. Although most of these cases are acquired resistance through somatic mutations, a small number of germline T790M have been reported, and are estimated to occur in 1% of non-small cell lung malignancy cases4,5,6. These germline T790M mutations are believed to predispose patients to lung malignancy, as preclinical studies have shown the germline T790M mutation to be a poor oncogene that often requires a secondary mutation to potentiate malignancy development5,6. In Asia, a few cases of dual mutations made up of main T790M substitution prior to TKI treatment have been explained7,8, however none were recognized to be germline mutations. In contrast, thus far germline T790M mutations have only been explained In Caucasian patients with lung malignancy5,6. Several family members of European descent with hereditary bronchioalveolar carcinoma were identified to have germline T790M mutations9. Our group previously reported a case of a 72 year-old patient with a solitary T790M mutation who experienced a germline T790M Mouse monoclonal to RAG2 mutation in her peripheral blood mononuclear cells (PBMC)10. Recently, two USA cases with germline T790M mutations were reported in by no means smoking female Caucasian patients5,6. In this brief statement, we describe another case of a Caucasian female patient with lung adenocarcinoma who experienced a germline T790M mutation and concurrent somatic L858R mutation. We further describe a case series of patient demographics and tumor characteristics associated with main T790M mutations in NSCLC patients. Material and methods Patient Selection and Data Collection Following Institutional Review Table approval at MD Anderson Malignancy Center, clinical and demographic data were collected on all patients with lung adenocarcinomas between May 2005 and Aug 2009 recognized to have two or more mutations. Of 2 patients identified to have a main T790M mutation, peripheral blood mononuclear cells were isolated and assessed for germline mutation status. Tumor and Germline Genotyping Caftaric acid DNA sequences for (exons 18C21) extracted from paraffin-embedded tissue (NSCLC tumors) or PBMC (for germline assessment) were amplified using standard PCR primers and sequenced. All sequence variants were confirmed by impartial PCR amplifications from at least 2 impartial DNA extractions, and sequenced in both directions. Results Frequency of main dual or multiple EGFR Mutations in patients with lung adenocarcinomas We evaluated 427 patients treated at the MD Anderson Malignancy Center Thoracic Medical center with lung adenocarcinomas between May 2005 and Aug 2009. Among these NSCLC patients, 55 patients were identified to have mutations in their tumors. Twelve patients (12/427, 2.8%) were found to have either dual or multiple mutations, of whom 5 patients had main T790M mutations. The clinical and demographic information of patients with main T790M mutations are shown in Table 1. The information of patients who experienced dual or multiple mutations without T790M mutations are included in Supplementary Table 1. All of the mutations were tested in tumor samples, except patient # 4# 4 and # 5# 5 whose peripheral blood samples were also available for germline mutation screening. Table 1 Summary of lung malignancy patients with Caftaric acid dual or.In addition, environmental factors may also play a role. twelve of which were identified to have either dual or multiple mutations. Five of these 12 patients (42%) experienced main T790M mutation and three of them showed similar heights of the mutant and wild-type peaks on sequencing electropherogram, suggesting the possibility of germline mutation. One case of germline T790M mutation was confirmed via sequencing a peripheral blood sample. Conclusions Dual or multiple mutations comprised 2.8% of lung adenocarcinomas in our study. Primary T790M mutation are presented with high frequency (5/12; 42%) in patients carrying dual or multiple mutations. Mutations, T790M germline mutation, Lung Adenocarcinoma Introduction Exon 19 deletions and point mutations in L858R are the most common somatic activating mutations in the epidermal growth factor receptor (gene that confer sensitivity to tyrosine kinase inhibitors (TKI) in lung cancer1. However, Caftaric acid despite the initial response to TKIs, all patients will eventually develop resistance. One of the most common mechanisms of resistance is acquisition of a second mutation at exon 20 which causes a T790M substitution.2,3. Although most of these cases are acquired resistance through somatic mutations, a small number of germline T790M have been reported, and are estimated to occur in 1% of non-small cell lung cancer cases4,5,6. These germline T790M mutations are believed to predispose patients to lung cancer, as preclinical studies have shown the germline T790M mutation to be a weak oncogene that often requires a secondary mutation to potentiate cancer development5,6. In Asia, a few cases of dual mutations containing primary T790M substitution prior to TKI treatment have been described7,8, however none were identified to be germline mutations. In contrast, thus far germline T790M mutations have only been described In Caucasian patients with lung cancer5,6. Several family members of European descent with hereditary bronchioalveolar carcinoma were identified to have germline T790M mutations9. Our group previously reported a case of a 72 year-old patient with a solitary T790M mutation who had a germline T790M mutation in her peripheral blood mononuclear cells (PBMC)10. Recently, two USA cases with germline T790M mutations were reported in never smoking female Caucasian patients5,6. In this brief report, we describe another case of a Caucasian female patient with lung adenocarcinoma who had a germline T790M mutation and concurrent somatic L858R mutation. We further describe a case series of patient demographics and tumor characteristics associated with primary T790M mutations in NSCLC patients. Material and methods Patient Selection and Data Collection Following Institutional Review Board approval at MD Anderson Cancer Center, clinical and demographic data were collected on all patients with lung adenocarcinomas between May 2005 and Aug 2009 identified to have two or more mutations. Of 2 patients identified to have a primary T790M mutation, peripheral blood mononuclear cells were isolated and assessed for germline mutation status. Tumor and Germline Genotyping DNA sequences for (exons 18C21) extracted from paraffin-embedded tissue (NSCLC tumors) or PBMC (for germline assessment) were amplified using standard PCR primers and sequenced. All sequence variants were confirmed by independent PCR amplifications from at least 2 independent DNA extractions, and sequenced in both directions. Results Frequency of primary dual or multiple EGFR Mutations in patients with lung adenocarcinomas We evaluated 427 patients treated at the MD Anderson Cancer Center Thoracic Clinic with lung adenocarcinomas between May 2005 and Aug 2009. Among these NSCLC patients, 55 patients were identified to have mutations in their tumors. Twelve patients (12/427, 2.8%) were found to have either dual or multiple mutations, of whom 5 patients had primary T790M mutations. The clinical and demographic information of patients with primary T790M mutations are shown in Table 1. The information of patients who had dual or multiple mutations without T790M mutations are included in Supplementary Table 1. All of the mutations were tested in tumor samples, except patient # 4# 4 and.