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Background: Lung adenocarcinoma (LUAD) is the most predominant histological subtype of lung cancer characterized by driver mutations detected in a substantial proportion of the cases. Tyrosine kinase inhibitors (TKIs) are standard care for the patients with these mutations. In this study, we evaluated the efficiency of an NGS-based 8-gene test in selecting TKIs-sensitive patients in a cohort of treatment-naive Chinese LUAD patients and evaluated the sensitivity of rare compound mutations to different EGFR-TKIs in vitro. Material and methods: Targeted sequencing covering the hotspot regions of eight LUAD driver genes was performed across 853 treatment-naive LUAD patients admitted in Henan Cancer Hospital (HNCH cohort). The mutational landscape of HNCH patients was compared with TCGA patients. Logistic regression analysis was used to determine the factors associated with presence of these mutations. Genetically modified LUAD PC9 cells were established to evaluate the sensitivity of selected EGFR rare compound mutations to different EGFR-TKIs. Results: A total of 574 single nucleotide variants (SNVs), 270 indels, 88 amplifications, and 87 rearrangements were identified in this study, with EGFR and KRAS being the most frequently mutated genes. Females, mostly life-long non-smokers, had significantly higher EGFR mutation rates than males. Males, primarily smokers, more frequently had KRAS mutations. HNCH patients in general had a higher mutation count than TCGA patients (1.09 vs 0.93 mutations per patient (m/p)), in consistent with its higher proportion of patients with advanced disease. Rare EGFR compound mutations identified in this study, including Exon19del plus L747S/I744V and L858R plus V843I/T854A/G873, conferred genetically modified PC9 cells more sensitive to second-generation EGFR-TKI afatinib in-vivo. Conclusion: This NGS-based 8-gene test efficiently identified over 70% of Chinese treatment-naive LUAD patients who are targetable for TKIs. Patients with rare EGFR compound mutations might consider second-generation EGFR-TKIs for treatment. [ABSTRACT FROM AUTHOR]

Abstract Background Lung adenocarcinoma (LUAD) is the most predominant histological subtype of lung cancer characterized by driver mutations detected in a substantial proportion of the cases. Tyrosine kinase inhibitors (TKIs) are standard care for the patients with these mutations. In this study, we evaluated the efficiency of an NGS-based 8-gene test in selecting TKIs-sensitive patients in a cohort of treatment-naive Chinese LUAD patients and evaluated the sensitivity of rare compound mutations to different EGFR-TKIs in vitro. Material and methods Targeted sequencing covering the hotspot regions of eight LUAD driver genes was performed across 853 treatment-naive LUAD patients admitted in Henan Cancer Hospital (HNCH cohort). The mutational landscape of HNCH patients was compared with TCGA patients. Logistic regression analysis was used to determine the factors associated with presence of these mutations. Genetically modified LUAD PC9 cells were established to evaluate the sensitivity of selected EGFR rare compound mutations to different EGFR-TKIs. Results A total of 574 single nucleotide variants (SNVs), 270 indels, 88 amplifications, and 87 rearrangements were identified in this study, with EGFR and KRAS being the most frequently mutated genes. Females, mostly life-long non-smokers, had significantly higher EGFR mutation rates than males. Males, primarily smokers, more frequently had KRAS mutations. HNCH patients in general had a higher mutation count than TCGA patients (1.09 vs 0.93 mutations per patient (m/p)), in consistent with its higher proportion of patients with advanced disease. Rare EGFR compound mutations identified in this study, including Exon19del plus L747S/I744V and L858R plus V843I/T854A/G873, conferred genetically modified PC9 cells more sensitive to second-generation EGFR-TKI afatinib in-vivo. Conclusion This NGS-based 8-gene test efficiently identified over 70% of Chinese treatment-naive LUAD patients who are targetable for TKIs. Patients with rare EGFR compound mutations might consider second-generation EGFR-TKIs for treatment.

Zhicong Liu,1,* Pengtao Song,2,* Lingyan Zhou,1 Dongxiang Ji,1 Hui Shen,1 Hui Dong,1 Xueren Feng1 1Department of Respiratory Medicine, Huzhou Central Hospital, Affiliated Central Hospital Huzhou University, Huzhou, People’s Republic of China; 2Department of Pathology, Huzhou Central Hospital, Affiliated Central Hospital Huzhou University, Huzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Hui Dong; Xueren Feng, Department of Respiratory Medicine, Huzhou Centre Hospital, Affiliated Centre Hospital Huzhou University, Huzhou, People’s Republic of China, Email 1150861366@qq.com; fxr9301006@163.comBackground: Lung cancer remains the leading cause of cancer-related mortality. Studies have revealed that a combination of crizotinib and EGFR tyrosine kinase inhibitors (TKIs) could be an effective treatment option for patients with sensitizing EGFR mutations and de novo or acquired MET amplification. Until now, there have been few reports of the response in patients harboring three mutations.Case Presentation: A patient was diagnosed with advanced lung adenocarcinoma harboring EGFR Del19, L858R mutation and METex14. She received osimertinib, and repeated imaging revealed further tumor progression. Sixty-six days later, combined treatment with osimertinib and crizotinib was initiated. Unfortunately, the patient succumbed to death at home after 17 days.Conclusion: This report firstly provided a lung adenocarcinoma patient with two common EGFR mutations (Del19 and L858R) and METex14. Our case raises a reminder about the tolerance and safety of combination therapy, especially in older peoples.Keywords: lung adenocarcinoma, compound mutations, osimertinib, crizotinib, combination therapy, case report

The availability of targeted therapies for molecular aberrations have substantially improved the outcomes of advanced non-small-cell lung cancer (NSCLC) patients harboring sensitive mutations. However, patients harboring uncommon epidermal growth factor receptor (EGFR) mutations such as G719X and L861Q often resulted in a lack of response to the first and third generation of EGFR TKIs. In this study, we reported a 64-year-old female patient, who initially presented with symptoms of pneumonia and showed positive response to anti-infection treatment, eventually diagnosed with stage Ⅳ lung adenocarcinoma (LUAD) harboring a rare EGFR G719X and L861Q compound mutations. The patient received 40 mg/day of afatinib and experienced no severe adverse events. As a result, partial response (PR) was observed based on CT scan and a progression free survival of 24 month was achieved. Her follow-up is still ongoing. The results of the present case support the effectiveness and safety of afatinib in LUAD patients carrying EGFR G719X and L861Q compound mutations.

Enlarged vestibular aqueduct is an autosomal genetic disease mainly caused by mutations in the SLC26A4 gene and includes non-syndromic and syndromic types. This study aimed to identify genetic defects in a Chinese patient with nonsyndromic enlarged vestibular aqueduct (NSEVA) and to investigate the impact of variants on the severity of non-syndromic enlarged vestibular aqueduct. A male patient with NSEVA, aged approximately 6 years, was recruited for this study. The clinical characteristics and results of auxiliary examinations, including laboratory and imaging examinations, were collected, and 127 common hereditary deafness genes were detected by chip capture high-throughput sequencing. Protein structure predictions, the potential impact of mutations, and multiple sequence alignments were analyzed in silico. Compound heterozygote mutations c.1523_ 1528delinsAC (p.Thr508Asnfs*3) and c.422T>C (p.Phe141Ser) in the SLC26A4 gene were identified. The novel frameshift mutation c.1523_1528delinsAC produces a severely truncated pendrin protein, and c.422T>C has been suggested to be a disease-causing mutation. Therefore, this study demonstrates that the novel mutation c.1523_1528delinsAC in compound heterozygosity with c.422T>C in the SLC26A4 gene is likely to be the cause of NSEVA. Cochlear implants are the preferred treatment modality for patients with NSEVA and severe-to-profound sensorineural hearing loss Genetic counseling and prenatal diagnosis are essential for early diagnosis. These findings expand the mutational spectrum of SLC26A4 and improve our understanding of the molecular mechanisms underlying NSEVA. [ABSTRACT FROM AUTHOR]

Objective To compare and investigate the molecular profiles in acquired resistance-associated genetic alterations of second-generation anaplastic lymphoma kinase-tyrosine kinase inhibitors (ALK-TKIs) in order to provide evidence for the management of ALK fusion positive advanced non-small cell lung cancer (NSCLC). Methods An observational study was conducted on 103 patients with ALK-fusion positive advanced NSCLC who received first-line treatment of crizotinib and then second-line treatment of second-generation ALK-TKIs in Zhongshan Hospital from 2014 to 2020. Genetic alteration profiles were analyzed by next generation sequencing (NGS) on tissue or liquid samples after relapse of second-generation ALK-TKIs. Results The acquired ALK-TKIs-resistant genetic alterations were dominated by ALK kinase domain mutations (66.7%), which had a significant higher incidence in V3 variant compared with V1 variant (85.7% vs 55.6%, P=0.003 9). The most common ALK mutations were G1202R/K and L1196M, and the former was more common in V3 subtype (57.1% vs 4.4%, P < 0.000 1) while the latter in V1 subtype (31.1% vs 14.3%, P=0.079 4). The patients who were resistant to alectinib had the highest incidence of secondary mutations, with G1202R (31.6%) and G1269A (12.3%) were the top 2 mutations. G1202R, L1196M, F1174X and C1156Y were more common in the patients resistant to ceritinib. F1174X, D1203N and E1210K were the top 3 mutations among the patients who progressed after brigatinib therapy. D1203N (0 vs 6.7% vs 20%, P=0.000 2) and E1210K (1.8% vs 0 vs 15.0%, P=0.003 5) mainly occurred in the brigatinib group. The sequential application of ALK TKIs may cause co-mutations of ALK gene. Conclusion The profile of genetic alteration failed from second-line second-generation ALK-TKIs treatment are complex and diverse. There are differences between different drugs and different ALK variants, as well as compound mutations, which increase the difficulty in later line therapy. Therefore, the clinical treatment decisions of advanced NSCLCs with ALK positive should be established on the fully consideration of the drug resistance mechanism.

Lung cancer is the most common cancer-related cause of death worldwide, most of which are non-small cell lung cancers (NSCLC). Epidermal growth factor receptor (EGFR) mutations are common drivers of NSCLC. Treatment plans for NSCLC, specifically adenocarcinomas, rely heavily on the presence or absence of specific actionable driver mutations. Liquid biopsy can guide the treatment protocol to detect the presence of various mechanisms of resistance to treatment. We report three NSCLC EGFR mutated cases, each treated with Osimertinib in a combination therapy regimen to combat resistance mechanisms. The first patient presented with EGFR L858R/L833V compound mutation with MET amplification alongside CEP85L-ROS1 fusion gene, the second with EGFR exon 19del and MKRN1-BRAF fusion, and the last EGFR L858R/V834L compound mutation with MET amplification. Each regimen utilized a tyrosine kinase inhibitor or monoclonal antibody in addition to osimertinib and allowed for a prompt and relatively durable treatment response. [ABSTRACT FROM AUTHOR]

Lung cancer is the most common cancer-related cause of death worldwide, most of which are non-small cell lung cancers (NSCLC). Epidermal growth factor receptor (EGFR) mutations are common drivers of NSCLC. Treatment plans for NSCLC, specifically adenocarcinomas, rely heavily on the presence or absence of specific actionable driver mutations. Liquid biopsy can guide the treatment protocol to detect the presence of various mechanisms of resistance to treatment. We report three NSCLC EGFR mutated cases, each treated with Osimertinib in a combination therapy regimen to combat resistance mechanisms. The first patient presented with EGFR L858R/L833V compound mutation with MET amplification alongside CEP85L-ROS1 fusion gene, the second with EGFR exon 19del and MKRN1-BRAF fusion, and the last EGFR L858R/V834L compound mutation with MET amplification. Each regimen utilized a tyrosine kinase inhibitor or monoclonal antibody in addition to osimertinib and allowed for a prompt and relatively durable treatment response.

Background/Aim: Next-generation sequencing (NGS) has recently made it possible to investigate polar charged amino acids in compound mutations in the epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC). Several preclinical studies have suggested the involvement of polar charged amino acids in the treatment of EGFR mutations and EGFR-tyrosine kinase inhibitors (TKIs). With this background, a retrospective study was conducted aiming to clarify the prognostic significance of these amino acids in complex mutations in NSCLC patients with common EGFR mutations. Patients and Methods: EGFR gene mutations were investigated using nonoverlapping integrated read sequencing system (NOIR-SS) in pathological specimens of 20 EGFR-mutated NSCLC patients. For clinical information, the medical records were retrospectively investigated. We investigated prognostic significance of these amino acids in compound mutations in progression free survival (PFS) and overall survival (OS) in patients treated with first-line afatinib. Results: Among the 20 patients examined, 5 patients had polar charged amino acids in compound mutations and 15 had not. There were no statistically significant differences in the clinical background factors examined in these two groups of patients. In uni- and multivariate analysis, 'poor performance status' and 'polar charged amino acids in compound mutations' were significant favorable factors in OS. Conclusion: Patients with 'polar charged amino acids in compound mutations' might have favorable prognosis than those without them. Detailed examination of EGFR gene information might contribute to the understanding of TKI response duration. [ABSTRACT FROM AUTHOR]

BackgroundNew mutational detection techniques like next-generation sequencing have resulted in an increased number of cases with uncommon mutation and compound mutations [3%–14% of all epidermal growth factor receptor (EGFR) mutations]. In rare exon 18 mutations (3%–6%), G719X and E709X represent the majority, but CMut associating these exon 18 points mutations are even rarer, making the understanding of the impact of epidermal growth factor receptor tyrosine kinase inhibitors still limited. Three generations of EGFR tyrosine kinase inhibitors (TKIs) are available to target EGFR mutations, but according to the types of mutations, the sensitivity to TKI is different. Afatinib, osimertinib, and neratinib have showed some effectiveness in single exon 18, but no report has precisely described their efficiency and acquired mechanism of resistance in a CMut of exon 18–18 (G719A and E709A).Case presentationWe report a case of a 26-year-old woman with bilateral advanced adenocarcinoma of the lung harboring a compound mutation associating G719A and E709A in exon 18, who developed an EGFR amplification as resistance mechanism to osimertinib. She presented a significant clinical and morphological response under sequential TKIs treatment (afatinib, osimertinib, and then neratinib).ConclusionA non-small cell lung cancer (NSCLC) with rare compound mutation exon 18–exon 18 (G719A and E709A) and EGFR amplification can be overcome with adapted sequential second- and third-generation TKIs. This report has potential implications in guiding decisions for the treatment of these rare EGFR mutations.

Introduction: Previously, we developed a database of 693 patients with NSCLC and uncommon EGFR mutations treated with afatinib. Here, we provide an update of >1000 patients, with more data on specific mutations. Methods: Patients were identified from a prospective database developed by Boehringer Ingelheim and via literature review. Mutations were categorized as T790M-positive, exon 20 insertions, major uncommon (G719X, L861Q, S768I) and 'others'. Patients with compound mutations (≥2 EGFR mutations) were analyzed separately. Key endpoints were time to treatment failure (TTF) and objective response rate (ORR). Results: Of 1023 patients included, 587 patients were EGFR TKI-naïve and 425 were EGFR TKI-pretreated. The distribution of mutation categories was: major uncommon (41.4%); exon 20 insertions (22.3%); T790M (20.3%); and 'others' (15.9%); 38.6% had compound mutations. Overall, median TTF (TKI naïve/pretreated) was 10.7 and 4.5 months. ORR was 49.8% and 26.8%, respectively. In TKI-naïve patients, afatinib demonstrated activity against major uncommon mutations (median TTF: 12.6 months; ORR: 59.0%), 'other' mutations (median TTF: 10.7 months; ORR: 63.9%) including strong activity against E709X (11.4 months; 84.6%) and L747X (14.7 months; 80.0%), and compound mutations (11.5 months; 63.9%). Although sample sizes were small, notable activity was observed against specific exon 20 insertions at residues A763, M766, N771, and V769, and against osimertinib resistance mutations (G724S, L718X, C797S). Conclusion: Afatinib should be considered as a first-line treatment option for NSCLC patients with major uncommon, compound, 'other' (including E709X and L747X) and some specific exon 20 insertion mutations. Moderate activity was seen against osimertinib resistance EGFR mutations. [ABSTRACT FROM AUTHOR]

Patients with uncommon EGFR-mutated non-small-cell lung cancer (NSCLC) demonstrated lower clinical efficacy of first-generation EGFR-tyrosine kinase inhibitors compared with patients harboring common EGFR-mutated NSCLC. The US FDA has approved afatinib for uncommon EGFR mutation positive NSCLC based on the pooled analysis in the first- or second-line setting. Osimertinib has limited evidence in the small sample sizes of phase 2 studies in any-line settings. The aim of the present single-arm, multicenter, phase 2 study is to evaluate the efficacy of osimertinib for previously untreated NSCLC. The primary end point is to assess the overall response to osimertinib. The secondary end points include disease control rate, progression-free survival, duration of time-to-treatment failure, overall survival and safety. Clinical trial registration: jRCTs071200002. [ABSTRACT FROM AUTHOR]

IntroductionPreviously, we developed a database of 693 patients with NSCLC and uncommon EGFR mutations treated with afatinib. Here, we provide an update of >1000 patients, with more data on specific mutations.MethodsPatients were identified from a prospective database developed by Boehringer Ingelheim and via literature review. Mutations were categorized as T790M-positive, exon 20 insertions, major uncommon (G719X, L861Q, S768I) and ‘others’. Patients with compound mutations (≥2 EGFR mutations) were analyzed separately. Key endpoints were time to treatment failure (TTF) and objective response rate (ORR).ResultsOf 1023 patients included, 587 patients were EGFR TKI-naïve and 425 were EGFR TKI-pretreated. The distribution of mutation categories was: major uncommon (41.4%); exon 20 insertions (22.3%); T790M (20.3%); and ‘others’ (15.9%); 38.6% had compound mutations. Overall, median TTF (TKI naïve/pretreated) was 10.7 and 4.5 months. ORR was 49.8% and 26.8%, respectively. In TKI-naïve patients, afatinib demonstrated activity against major uncommon mutations (median TTF: 12.6 months; ORR: 59.0%), ‘other’ mutations (median TTF: 10.7 months; ORR: 63.9%) including strong activity against E709X (11.4 months; 84.6%) and L747X (14.7 months; 80.0%), and compound mutations (11.5 months; 63.9%). Although sample sizes were small, notable activity was observed against specific exon 20 insertions at residues A763, M766, N771, and V769, and against osimertinib resistance mutations (G724S, L718X, C797S).ConclusionAfatinib should be considered as a first-line treatment option for NSCLC patients with major uncommon, compound, ‘other’ (including E709X and L747X) and some specific exon 20 insertion mutations. Moderate activity was seen against osimertinib resistance EGFR mutations.

Molecular profiling of lung tumors is crucial for guiding targeted therapeutic strategies and identifying potential resistance mechanisms to specific therapies, such as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). During this profiling, mutations with uncertain treatment implications can be identified. This case study represents a 69-year-old female with a co-occurring EGFR mutation profile that presents a unique therapeutic challenge. Tumor DNA was used for next-generation sequencing (NGS) of a custom 275 cancer-related QIAseq Human Comprehensive Cancer Panel (Qiagen). Next-generation RNA sequencing was performed using the Illumina TruSight panel. FISH analysis and PD-L1 22C3 immunohistochemical testing were also performed. Microscopic analysis revealed an invasive adenocarcinoma with papillary, acinar, and focal micropapillary features with a 6 mm invasive component. The final pathology stage was determined to be pT1aN0M0. NGS for DNA variant detection identified two mutations in EGFR, an EGFR G719A and EGFR L833&#95;V834delinsFL with a variant allele frequency (VAF) of 22.2% and 21.1%, respectively. Targeted NGS RNA fusion analysis was also performed, which came back negative. PD-L1 22C3 immunohistochemical testing showed only 1% of the tumor cells expression. FISH analysis revealed one copy of MET and D7Z1 in 27% of cells, indicating an aneuploid neoplastic clone with monosomy 7. EGFR TKIs are universally accepted as a first-line treatment for advanced non-small cell lung cancer (NSCLC) patients with a sensitizing EGFR mutation. While mutations such as G719A are sensitive to all generations of EGFR-TKI, the effects are unknown for rare compound mutations in EGFR, such as EGFR L833&#95;V834delinsFL. There are no reports in the literature with any mention of an algorithm of treatment for such a case. The patient had two metachronous lung primary cancers resected in 2022 and 2024. Due to the complete surgical resection, the sensitivity of this mutation of TKIs could not be established. This unique mutation profile still remains of paramount importance to understand if the patient relapses or presents with a new tumor with the same genetic profile., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Hussain et al.)

Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib are approved for advanced non–small-cell lung cancer (NSCLC) with ALK rearrangement. However, the mechanisms of resistance remain largely unclear. This prospective multicenter study analyzed cell-free DNA (cfDNA) and/or cancer tissues of patients with NSCLC after progression on ALK TKI(s), using targeted next-generation sequencing. Patients' clinicopathologic characteristics and treatment outcomes were analyzed. Overall, 88 patients were enrolled; 31 cancer tissues and 90 cfDNA samples were analyzed. Five (16%) ALK mutations (L1196M × 2, I1171T, D1203N, G1269A/F1174L) and 3 possible bypass mutations (NRAS G12V, EGFR R108K, PIK3CA E545K) were found in 32 crizotinib-resistant cancers. Four (22%) ALK mutations (G1128A, G1202R, G1269A, I1171T/E1210K) and 3 possible bypass mutations (KIT D820E, MET E1012∗, EGFR P265_C291del) were found in 18 ceritinib-resistant cancers. Four (17%) ALK mutations (G1202R × 2, W1295C, G1202R/L1196M) and 1 possible bypass mutation (EGFR P753S) were found in 24 alectinib-resistant cancers. Two (11%) ALK mutations (G1202R/G1269A × 2) and 2 possible bypass mutations (BRAF V600E, MET D1246N) were found in 18 lorlatinib-resistant cancers. In patients with simultaneous paired tissue and cfDNA samples (n = 20), mutations were identified in 9 (45%) and 6 (30%) cases, respectively; the concordance rate was 45%. The mechanisms of ALK TKI resistance were heterogeneous; ALK mutations were found in less than one-third of patients. Compound ALK mutations, which may confer lorlatinib resistance, may occur in crizotinib, ceritinib, and alectinib-resistant lung cancers. • We analyzed cfDNA and rebiopsied tumors by NGS after ALK inhibitor resistance. • ALK kinase domain mutations were found in less than one-third of patients. • At rebiopsy, adding cfDNA NGS to tissue NGS may increase mutation detection rate. • Compound mutations were found in crizotinib, ceritinib, and alectinib resistance. • Lorlatinib was not effective against compound ALK mutations in this cohort. [ABSTRACT FROM AUTHOR]

Resistance remains the major clinical challenge for the therapy of Philadelphia chromosome–positive (Ph+) leukemia. With the exception of ponatinib, all approved tyrosine kinase inhibitors (TKIs) are unable to inhibit the common "gatekeeper" mutation T315I. Here we investigated the therapeutic potential of crizotinib, a TKI approved for targeting ALK and ROS1 in non-small cell lung cancer patients, which inhibited also the ABL1 kinase in cell-free systems, for the treatment of advanced and therapy-resistant Ph+ leukemia. By inhibiting the BCR-ABL1 kinase, crizotinib efficiently suppressed growth of Ph+ cells without affecting growth of Ph− cells. It was also active in Ph+ patient-derived long-term cultures (PD-LTCs) independently of the responsiveness/resistance to other TKIs. The efficacy of crizotinib was confirmed in vivo in syngeneic mouse models of BCR-ABL1- or BCR-ABL1T315I-driven chronic myeloid leukemia–like disease and in BCR-ABL1-driven acute lymphoblastic leukemia (ALL). Although crizotinib binds to the ATP-binding site, it also allosterically affected the myristol binding pocket, the binding site of GNF2 and asciminib (former ABL001). Therefore, crizotinib has a seemingly unique double mechanism of action, on the ATP-binding site and on the myristoylation binding pocket. These findings strongly suggest the clinical evaluation of crizotinib for the treatment of advanced and therapy-resistant Ph+ leukemia. [ABSTRACT FROM AUTHOR]

Abstract Background In lung cancer, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor sensitizing mutations co-existing with rare minor EGFR mutations are known as compound mutations. These minor EGFR mutations can lead to acquired resistance after EGFR tyrosine kinase inhibitor treatment, so determining the mutation status of patients is important. However, using amplicon-based targeted deep sequencing based on next-generation sequencing to characterize mutations is prone to sequencing error. We therefore assessed the benefit of incorporating molecular barcoding with high-throughput sequencing to investigate genomic heterogeneity in treatment-naïve patients who have undergone resection of their non-small cell lung cancer (NSCLC) EGFR mutations. Methods We performed amplicon-based targeted sequencing with the molecular barcoding system (MBS) to detect major common EGFR mutations and uncommon minor mutations at a 0.5% allele frequency in fresh–frozen lung cancer samples. Results Profiles of the common mutations of EGFR identified by MBS corresponded with the results of clinical testing in 63 (98.4%) out of 64 cases. Uncommon mutations of EGFR were detected in seven cases (10.9%). Among the three types of major EGFR mutations, patients with the G719X mutation had a significantly higher incidence of compound mutations than those with the L858R mutation or exon 19 deletion (p = 0.0052). This was validated in an independent cohort from the Cancer Genome Atlas dataset (p = 0.018). Conclusions Our findings demonstrate the feasibility of using the MBS to establish an accurate NSCLC patient genotype. This work will help understand the molecular basis of EGFR compound mutations in NSCLC, and could aid the development of new treatment modalities.

Background: Osimertinib represents the standard of care for the treatment of advanced non-small-cell lung cancer (NSCLC) harboring classical epidermal growth factor receptor (EGFR) mutations, constituting 80%-90% of all EGFR alterations. In the remaining cases, an assorted group of uncommon alterations of EGFR (uEGFR) can be detected, which confer variable sensitivity to previous generations of EGFR inhibitors, overall with lower therapeutic activity. Data on osimertinib in this setting are limited and strongly warranted., Patients and Methods: The ARTICUNO study retrospectively evaluated data on osimertinib activity from patients with advanced NSCLC harboring uEGFR treated in 21 clinical centers between August 2017 and March 2023. Data analysis was carried out with a descriptive aim. Investigators collected response data according to RECIST version 1.1 criteria. The median duration of response, progression-free survival (mPFS), and overall survival were estimated by the Kaplan-Meier method., Results: Eighty-six patients harboring uEGFR and treated with osimertinib were identified. Patients with 'major' uEGFR, that is, G719X, L861X, and S768I mutations (n = 51), had an overall response rate (ORR) and mPFS of 50% and 9 months, respectively. Variable outcomes were registered in cases with rarer 'minor' mutations (n = 27), with ORR and mPFS of 31% and 4 months, respectively. Among seven patients with exon 20 insertions, ORR was 14%, while the best outcome was registered among patients with compound mutations including at least one classical EGFR mutation (n = 13). Thirty patients presented brain metastases (BMs) and intracranial ORR and mPFS were 58% and 9 months, respectively. Amplification of EGFR or MET, TP53 mutations, and EGFR E709K emerged after osimertinib failure in a dataset of 18 patients with available rebiopsy., Conclusion: The ARTICUNO study confirms the activity of osimertinib in patients with uEGFR, especially in those with compound uncommon-common mutations, or major uEGFR, even in the presence of BMs. Alterations at the E709 residue of EGFR are associated with resistance to osimertinib., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

BackgroundCerebrotendinous xanthomatosis (CTX) is an autosomal recessive disorder of bile acid synthesis caused by mutations in the CYP27A1 gene. CTX is an underdiagnosed and potentially treatable disease, thus a detailed appreciation of the phenotypic spectrum and genetic characteristics are crucial for early diagnosis and treatment.Objectives and MethodsFour CTX families with mutations in the CYP27A1 gene were enrolled in our study. We investigated the clinical characteristics and molecular genetic features of the probands with CTX. Genetic analysis was performed for detecting gene variants. Sanger sequencing and segregation analysis were conducted for haplotype analysis.ResultsAll the four probands were compound heterozygote for two CYP27A1 variants, including one mutation in c.1263+1G>A (intron 7) splice site, two novel likely pathogenic mutations (c.255+1G>T and c.1561dupA) and three pathogenic mutations including c.379C>T, c.1263+1G>A and c.1537C>T previously reported. All of the subjects presented with spastic paraparesis. The other common clinical features included ataxia, childhood-onset diarrhea, cataracts, intellectual disability, tendinous xanthomas and dentate nuclei signal alterations at MRI.ConclusionTwo novel likely pathogenic mutations (c.255+1G>T and c.1561dupA) were reported in our study. The 1263+1G>A mutation was commonly seen in Chinese reported case series (7/25, 28%) and could be a latent hotspot for Chinese CTX mutations. Our study expanded the mutation spectrum of CYP27A1 gene and provide an insightful view of the phenotypic spectrum and genetic characteristics to help early diagnosis and treatment with to improve neurologic dysfunction.

Abstract Background The antitumour efficacy of tyrosine kinase inhibitors (TKIs) in lung cancer patients with compound epidermal growth factor receptor (EGFR) mutations has not been resolved. Our study summarizes a single institutional experience of first-generation TKI therapy for lung cancers with compound EGFR mutations. Methods A total of 106 consecutive patients with tumours bearing compound EGFR mutations were identified between January 2012 and May 2016; all patients received first-generation TKI therapy. Deletions in exon 19 and the L858R point mutation in exon 21 were considered common mutations; T790M was considered separately because of its association with TKIs resistances. Any other mutation was defined as a rare mutation. Patients were divided as follows: double common mutations (group A); common plus T790M mutations (group B); common plus rare mutations (group C); double rare mutations (group D); and rare plus T790M mutations (group E). A separate group of 115 consecutive patients with a single common mutation was created for comparative analysis (group F). Results The frequency of patients with compound EGFR was 2.9% (114/3925) and their response rate to first-generation TKIs was 50.9%, which was not significantly different from group F (67.0%, P = 0.088). The progression-free survival (PFS) of the 106 patients receiving TKI therapy was worse than that of group F (median, 9.1 vs. 13.0 months, respectively; P

Mitochondrion regulates cellular metabolism with the aid of its respiratory complexes; any defect within these complexes can result in mitochondrial malfunction and various conditions. One such mutation can occur in SLC25A10, resulting in mitochondrial DNA depletion syndrome. It should be noted that the pattern of inheritance of this syndrome is autosomal recessive. However, we present a case with compound heterozygous mutations within this gene resulting in disease. An 18-year-old female was referred to our clinic due to menopause with a medical history of hearing loss, spasticity, hypotonia and quadriparesis. The child's birth and development were uneventful until the initiation of movement reduction and hypotonia when she was 12 months old. Afterward, the hypotonia progressed to quadriparesis and spasticity throughout the years. Our patient became completely quadriplegic up to the age of 3 and became completely deaf at 10. Her puberty onset was at the age of 9, and no significant event took place until she was 17 years old when suddenly her periods, which were regular until that time, became irregular and ceased after a year; hence, a thorough evaluation began, but similar to her previous evaluations all tests were insignificant. Nonetheless, we suspected an underlying metabolic or genetic defect; thus, we ordered a whole-exome sequencing (WES) workup and found simultaneous heterozygous mutations within SLC25A10, HFE and TTN genes that could explain her condition. When all other tests fail, and we suspect an underlying genetic or metabolic cause, WES can be of great value. [ABSTRACT FROM AUTHOR]

Dynamic evolution of ponatinib-resistant mutations in BCR-ABL1-positive leukaemias revealed by next-generation sequencing Keywords: BCR-ABL1; tyrosine kinase inhibitors; next-generation sequencing; drug-resistant mutation; compound mutations EN BCR-ABL1 tyrosine kinase inhibitors next-generation sequencing drug-resistant mutation compound mutations e113 e116 4 12/07/20 20201201 NES 201201 Tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1 oncoprotein revolutionized the therapy of leukaemias carrying this fusion. The black line represents the BCR-ABL1 transcript level (%). gl Case 2 (Fig 1B) was a seven-year-old boy with a diagnosis of BCR-ABL1-positive B-ALL. With the increase of CML patients who underwent long-term TKI therapy and the increasing application of TKIs in BCR-ABL1-positive B-ALL, as well as the extensive use of sequential TKIs, the dynamics of resistant clones has become more complicated. [Extracted from the article]

Background: Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive disorder of bile acid synthesis caused by mutations in the CYP27A1 gene. CTX is an underdiagnosed and potentially treatable disease, thus a detailed appreciation of the phenotypic spectrum and genetic characteristics are crucial for early diagnosis and treatment. Objectives and Methods: Four CTX families with mutations in the CYP27A1 gene were enrolled in our study. We investigated the clinical characteristics and molecular genetic features of the probands with CTX. Genetic analysis was performed for detecting gene variants. Sanger sequencing and segregation analysis were conducted for haplotype analysis. Results: All the four probands were compound heterozygote for two CYP27A1 variants, including one mutation in c.1263+1G>A (intron 7) splice site, two novel likely pathogenic mutations (c.255+1G>T and c.1561dupA) and three pathogenic mutations including c.379C>T, c.1263+1G>A and c.1537C>T previously reported. All of the subjects presented with spastic paraparesis. The other common clinical features included ataxia, childhood-onset diarrhea, cataracts, intellectual disability, tendinous xanthomas and dentate nuclei signal alterations at MRI. Conclusion: Two novel likely pathogenic mutations (c.255+1G>T and c.1561dupA) were reported in our study. The 1263+1G>A mutation was commonly seen in Chinese reported case series (7/25, 28%) and could be a latent hotspot for Chinese CTX mutations. Our study expanded the mutation spectrum of CYP27A1 gene and provide an insightful view of the phenotypic spectrum and genetic characteristics to help early diagnosis and treatment with to improve neurologic dysfunction. [ABSTRACT FROM AUTHOR]

The availability of targeted therapies for molecular aberrations have substantially improved the outcomes of advanced non-small-cell lung cancer (NSCLC) patients harboring sensitive mutations. However, patients harboring uncommon epidermal growth factor receptor (EGFR) mutations such as G719X and L861Q often resulted in a lack of response to the first and third generation of EGFR TKIs. In this study, we reported a 64-year-old female patient, who initially presented with symptoms of pneumonia and showed positive response to anti-infection treatment, eventually diagnosed with stage Ⅳ lung adenocarcinoma (LUAD) harboring a rare EGFR G719X and L861Q compound mutations. The patient received 40 mg/day of afatinib and experienced no severe adverse events. As a result, partial response (PR) was observed based on CT scan and a progression free survival of 24 month was achieved. Her follow-up is still ongoing. The results of the present case support the effectiveness and safety of afatinib in LUAD patients carrying EGFR G719X and L861Q compound mutations. [ABSTRACT FROM AUTHOR]

Literatures regarding the prevalence and clinical significance of compound EGFR mutations are limited. Until now, none of retrospective or prospective research has focused on in cis compound EGFR mutations except case reports. In this study, we screened a cohort of 3,000 treatment-naïve Chinese advanced NSCLC patients using capture-based ultra-deep targeted sequencing to evaluate the prevalence of EGFR in cis compound mutations and the efficacy of EGFR-TKI in this population. Of the 3,000 patients screened, 1,266 (42.2%) had EGFR mutation; among them, 15 patients (1.2%) harboring in cis compound EGFR mutations, with 10 patients carrying EGFR L858R in combination with a rare mutation and five patients carrying two rare EGFR mutations. No patient with EGFR 19del was observed. Interestingly, no in trans configuration was identified in this cohort. All of the patients harboring in cis compound EGFR mutations were non-smokers, histologically diagnosed with adenocarcinoma and received first-generation EGFR-TKI. Furthermore, our data also revealed that patients with in cis compound EGFR mutations exhibit comparable PFS to first generation EGFR-TKI comparing to patients with single activating EGFR mutation. This observation was further supported by in silico molecular modeling analyses which demonstrated in cis compound mutations do not alter the ATP-binding pocket of EGFR, thus having no effect on the interaction between gefitinib and EGFR. [ABSTRACT FROM AUTHOR]

Dilated cardiomyopathy (DCM) is characterized by left or bilateral ventricular dilation and systolic dysfunction without rational conditions, which can lead to progressive heart failure and sudden cardiac death. Most of the pathogenic genes have been reported in adult population by locus mapping in familial cases and animal model studies. However, it still remains challenging to decipher the role of genetics in the etiology of pediatric DCM. We applied whole-exome sequencing (WES) for 30 sporadic pediatric DCM subjects and 100 non-DCM local controls. We identified the pathogenic mutations using bioinformatics tools based on genomic strategies synergistically and confirmed mutations by Sanger sequencing. We identified compound heterozygous nonsense mutations in DSP (c.3799C > T, p.R1267X; c.4444G > T, p.E1482X). In sporadic cases, the two heterozygous mutations in XIRP2 were identified. Then we performed an exome-wide association study with 30 case and 100 control subjects. Interestingly, we could not identify TTN truncating variants in all cases. Collectively, we observed a significant risk signal between carriers of TTN deleterious missense variants and DCM risk (odds ratio 4.0, 95% confidence interval 1.1–22.2, p = 3.12 × 10−2). Our observations expanded the spectrum of mutations and were valuable in the pre- and postnatal screening and genetic diagnosis for DCM. [ABSTRACT FROM AUTHOR]

Background: In lung cancer, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor sensitizing mutations co-existing with rare minor EGFR mutations are known as compound mutations. These minor EGFR mutations can lead to acquired resistance after EGFR tyrosine kinase inhibitor treatment, so determining the mutation status of patients is important. However, using amplicon-based targeted deep sequencing based on next-generation sequencing to characterize mutations is prone to sequencing error. We therefore assessed the benefit of incorporating molecular barcoding with high-throughput sequencing to investigate genomic heterogeneity in treatment-naïve patients who have undergone resection of their non-small cell lung cancer (NSCLC) EGFR mutations.Methods: We performed amplicon-based targeted sequencing with the molecular barcoding system (MBS) to detect major common EGFR mutations and uncommon minor mutations at a 0.5% allele frequency in fresh-frozen lung cancer samples.Results: Profiles of the common mutations of EGFR identified by MBS corresponded with the results of clinical testing in 63 (98.4%) out of 64 cases. Uncommon mutations of EGFR were detected in seven cases (10.9%). Among the three types of major EGFR mutations, patients with the G719X mutation had a significantly higher incidence of compound mutations than those with the L858R mutation or exon 19 deletion (p = 0.0052). This was validated in an independent cohort from the Cancer Genome Atlas dataset (p = 0.018).Conclusions: Our findings demonstrate the feasibility of using the MBS to establish an accurate NSCLC patient genotype. This work will help understand the molecular basis of EGFR compound mutations in NSCLC, and could aid the development of new treatment modalities. [ABSTRACT FROM AUTHOR]

BCR-ABL kinase domain (KD) mutations are well known for causing resistance against tyrosine kinase inhibitors (TKIs) and disease progression in chronic myeloid leukemia (CML). In recent years, compound BCR-ABL mutations have emerged as a new threat to CML patients by causing higher degrees of resistance involving multiple TKIs, including ponatinib. However, there are limited reports about association of compound BCR-ABL mutations with disease progression in imatinib (IM) sensitive CML patients. Therefore, we investigated presence of ABL-KDmutations in chronic phase (n = 41), late chronic phase (n = 33) and accelerated phase (n = 16) imatinib responders. Direct sequencing analysis was used for this purpose. Eleven patients (12.22%) in late-CP CML were detected having total 24 types of point mutations, out of which 8 (72.72%) harbored compound mutated sites. SH2 contact site mutations were dominant in our study cohort, with E355G (3.33%) being the most prevalent. Five patients (45%) all having compound mutated sites, progressed to advanced phases of disease during follow up studies. Two novel silent mutations G208G and E292E/E were detected in combination with other mutants, indicating limited tolerance for BCR-ABL1 kinase domain for missense mutations. However, no patient in early CP of disease manifested mutated ABL-KD. Occurrence of mutations was found associated with elevated platelet count (p = 0.037) and patients of male sex (p = 0.049). The median overall survival and event free survival of CML patients (n = 90) was 6.98 and 5.8 y respectively. The compound missense mutations in BCR-ABL kinase domain responsible to elicit disease progression, drug resistance or disease relapse in CML, can be present in yet Imatinib sensitive patients. Disease progression observed here, emphasizes the need of ABL-KDmutation screening in late chronic phase CML patients for improved clinical management of disease. [ABSTRACT FROM PUBLISHER]

Lorlatinib is an active treatment for advanced anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC) pretreated with ALK-tyrosine kinase inhibitors (-TKIs). However, there is paucity of data on the activity of platinum/pemetrexed chemotherapy administered at the time of progression on lorlatinib. In addition, it is uncertain whether continuation of lorlatinib beyond progression (LBP) would provide any additional clinical benefit. Here, we describe two cases experiencing an exceptional response to platinum/pemetrexed chemotherapy plus LBP and make an attempt to identify which patients' characteristics and biologic profiles of the tumor could predict benefit from such an approach. In this report, presence of controlled brain metastases, rapidly progressing extracranial disease, and presence of ALK-dependent mechanisms of resistance were associated with benefit from platinum/pemetrexed chemotherapy plus lorlatinib beyond progression.

Objectives: To discover the incidence and characteristics of EGFR mutations in non-small cell lung cancer (NSCLC) in a single, large cohort as a part of routine diagnostic investigations. Methods: We reviewed EGFR mutations investigated by Amplification Refractory Mutation System (ARMS) PCR (covering 29 known mutations) using DNA samples from FFPE tissue or cell clot specimens in a total of 3894 cases of NSCLC analysed between 2012-2014. Results: EGFR mutations are preferentially associated with adenocarcinomaand adenosquamous histology, particularly those well to moderately differentiated, and were significantly more common in female than male patients irrespective of histological subtypes. Exon 19 deletion (45.7%) and exon 21 L858R (45.6%) accounted for the vast majority of the EGFR mutations detected, with the remaining mutations being infrequent (<2%). Compound mutations were seen in 51 (3%) of the mutant cases, the combination of these compound mutations could be classified into three subgroups according to the potential impact of individual mutations on EGFR TKI therapy. Accordingly, 7 cases had both sensitive mutations, 4 cases harboured one sensitive and one less responsive /uncertain mutation, 19 cases contained one sensitive and one resistant change, and a further 21 cases had two less responsive /uncertain mutations. Conclusion: Our data represents the largest EGFR mutation survey based on routine clinical diagnostic laboratory data from a single institution, it confirms the incidence and characteristics of EGFR mutations in NSCLC seen in Asian patients, and also unravels the combinatorial nature of rare compound EGFR mutations. [ABSTRACT FROM AUTHOR]

Introduction: Approximately 10% of EGFR mutations (EGFRmuts) are uncommon (ucEGFRmuts). We aimed to collect real-world data about osimertinib for patients with ucEGFRmuts., Methods: This is a multicenter, retrospective study of ucEGFRmut (exon 20 insertions excluded) metastatic NSCLC treated with osimertinib as first EGFR inhibitor. The Response Evaluation Criteria in Solid Tumors and response assessment in neuro-oncology brain metastases brain objective response rate (ORR) were evaluated by the investigators. Median progression-free survival (mPFS), median overall survival, and median duration of response (mDOR) were calculated from osimertinib initiation. Mutations found at resistance were collected., Results: A total of 60 patients were included (22 centers, nine countries), with median age of 64 years, 75% females, and 83% Caucasian. The largest subgroups were G719X (30%), L861Q (20%), and de novo Thr790Met (T790M) (15%). The ORR was 61%, mPFS 9.5 months, mDOR 17.4 months, and median overall survival 24.5 months. Regarding patients with no concurrent common mutations or T790M (group A, n = 44), ORR was 60%, mPFS 8.6 months, and mDOR 11 months. For G719X, ORR was 47%, mPFS 8.8 months, and mDOR 9.1 months. For L861Q, ORR was 80%, mPFS 16 months, and mDOR 16 months. For de novo T790M, ORR was 44%, mPFS 12.7 months, and mDOR 46.2 months. Compound EGFRmut including common mutations had better outcome compared with only ucEGFRmut. For 13 patients with a response assessment in neuro-oncology brain metastases-evaluable brain metastases, brain ORR was 46%. For 14 patients, rebiopsy results were analyzed: four patients with additional EGFR mutation (C797S, D585Y, E709K), three with new TP53 mutation, one with c-Met amplification, one with PIK3CA mutation, and one with neuroendocrine transformation., Conclusions: Osimertinib was found to have an activity in ucEGFRmut with a high rate of disease control systemically and intracranially. Several resistance mechanisms were identified. This report comprises, to the best of our knowledge, the largest data set of its kind., (Copyright © 2022 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

Non-small-cell lung cancer with epidermal growth factor receptor (EGFR) mutation is sensitive to EGFR tyrosine kinase inhibitors (TKIs). But little is known about the response to EGFR TKIs and the prognostic role of compound mutations. This study compared the uncommon EGFR exon 21 L858R compound mutations with single mutation to characterize EGFR compound mutations and investigated their response to EGFR TKI treatment. We retrospectively screened 799 non-small-cell lung cancer patients from August 1, 2009 to June 1, 2012 by EGFR mutation testing. EGFR mutations were detected in 443 patients, with 22 (4.97%) compound mutations. Subsequently, six patients with EGFR exon 21 L858R compound mutations and 18 paired patients with single L858R mutation were well characterized. Finally, we also analyzed the EGFR TKI treatment response and patients' outcomes of compound or single L858R mutations. There was no differential treatment effect on the disease control rate and objective response rate between the L858R compound mutations and single mutation groups. No significant difference in overall survival or progression-free survival of these two groups was found by log-rank test. In conclusion, we demonstrated that no significant difference was detected in the response to EGFR TKIs and patients' outcomes in the compound and single mutation groups. [ABSTRACT FROM AUTHOR]

Imatinib resistance in chronic myeloid leukemia (CML) is commonly due to BCR-ABL kinase domain mutations (KDMs). In this single-institution retrospective analysis, patients with KDMs were identified from a cohort of patients treated for CML at our institution. Clinical outcomes were assessed based on the characteristics of the KDMs and results of cytogenetic analysis. In total, we compared 26 patients with KDM to those without; 46 % ( n = 12) versus 20 % ( n = 57) progressed to advanced phase ( P = 0.003). Median overall survival was 22 months, 109 months, and not reached in patients with P-loop, T315I, and non-P-loop mutations ( P = 0.127). KDM patients had a median progression-free survival (PFS) and overall survival of 75 and 109 months; however, neither was reached in the non-mutation cohort ( P = 0.0007, P = 0.235). Median PFS in patients with single versus compound or double mutations was not reached versus 10 months ( P = 0.014). We conclude that T315I, P-loop, and compound mutations may worsen prognosis in CML. [ABSTRACT FROM AUTHOR]

In 2012, ponatinib (Iclusig®), an orally available pan-BCR-ABL tyrosine kinase inhibitor (TKI) developed by ARIAD Pharmaceuticals, Inc., was approved by the US Food and Drug Administration for use in resistant or intolerant chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL). Ponatinib is the only approved TKI capable of inhibiting BCR-ABL with the gatekeeper T315I kinase domain mutation, known to be the cause for 20% of resistant or relapsed CML cases. In 2013, ponatinib sales were temporarily suspended due to serious side effects seen in nearly 12% of the patient population. These side effects are thought to stem from the potent nature and pan-activity of this TKI. ARIAD Pharmaceuticals, Inc. has since been permitted to resume sales and marketing of ponatinib to a limited patient population with an expanded black box warning. In the following review, the use of ponatinib in CML and Ph+ALL will be discussed. Mechanisms of resistance in CML are discussed, which provide insight and background into the need for this third generation TKI, followed by the molecular design and pharmacology of ponatinib, which lead to its success as a therapeutic. Finally, the efficacy, safety, and tolerability of ponatinib will be highlighted, including summaries of the important clinical trials involving ponatinib as well as its current place in therapy. [ABSTRACT FROM AUTHOR]

Molecular characterization of non-small-cell lung cancer (NSCLC) is essential to define the correct therapeutic algorithm in metastatic disease. Approximately 90% of epidermal growth factor receptor (EGFR) mutations are usually associated with sensitivity to EGFR tyrosine kinase inhibitors (TKIs). The remaining 10% defines a small, extremely heterogeneous subgroup of mutations, with a varied profile of sensitivity and response to target therapies.This retrospective observational study includes 47 patients affected by metastatic NSCLC harboring uncommon EGFR mutations (single or compound mutation). Patients were treated with EGFR-targeting TKIs or platinum-based chemotherapy as first-line treatment.Median OS resulted longer in the compound mutation group when compared to single rare mutations (33.6 vs 12 months; P = 0.473); a similar result was observed for PFS (16 vs 7.6 months; P = 0.281), although statistical significance was not reached. ORR, PFS and OS resulted similar for patients treated with first-line EGFR TKIs or chemotherapy. No difference in terms of PFS and OS was found according to the TKI administered.Compound mutations seem to be a good prognostic indicator for OS; they are also predictive of response to 1st and 2nd generation EGFR TKIs, as well as exon 19 insertions and mutations in codon 719 of exon 18. For mutations in exon 18 (not in codon 719) and exon 20 insertions, chemotherapy seems the most effective available option. The addition of immunotherapy to chemotherapy could change this approach in the next future. [ABSTRACT FROM AUTHOR]

Background: Long QT syndrome (LQTS) is a cardiovascular disorder characterized by prolonged QTc time, syncope, or sudden death caused by torsades de pointes and ventricular fibrillation. We investigated the clinical and electrophysiologic phenotype of individual mutations and the compound mutations in a family in which different genotypes could be found. Objectives: The purpose of this study was to determine the impact of genotype-based diagnostic assessment in LQTS. Methods: We used cascade screening and functional analyses to investigate the phenotype in a family with LQTS. The contributions of the compound mutations in the KCNQ1 and KCNH2 genes (KCNQ1 R591H, KCNH2 R328C) were analyzed by heterologous expression in Xenopus laevis oocytes using two-electrode voltage clamp and by confocal imaging. Results: KCNH2 R328C did not show any functional phenotype whereas KCNQ1 R591H resulted in severe reduction of current. Neither wild-type nor mutant channels affected each other functionally in coexpression experiments. Therefore, a direct interaction between KCNQ1 and KCNH2 was ruled out under these conditions. Conclusion: Assessment of novel mutational findings in LQTS should include accurate genetic and functional analysis. Notably, appropriate studies are needed if two or more mutations in different genes are present in one proband. Our findings prompt reconsideration of the impact of compound mutations in LQTS families and reinforce the need for thorough functional evaluation of novel ion channel mutations before assignment of pathogenic status. [ABSTRACT FROM AUTHOR]

Background/aim: Next-generation sequencing (NGS) has recently made it possible to investigate polar charged amino acids in compound mutations in the epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC). Several preclinical studies have suggested the involvement of polar charged amino acids in the treatment of EGFR mutations and EGFR-tyrosine kinase inhibitors (TKIs). With this background, a retrospective study was conducted aiming to clarify the prognostic significance of these amino acids in complex mutations in NSCLC patients with common EGFR mutations., Patients and Methods: EGFR gene mutations were investigated using nonoverlapping integrated read sequencing system (NOIR-SS) in pathological specimens of 20 EGFR-mutated NSCLC patients. For clinical information, the medical records were retrospectively investigated. We investigated prognostic significance of these amino acids in compound mutations in progression free survival (PFS) and overall survival (OS) in patients treated with first-line afatinib., Results: Among the 20 patients examined, 5 patients had polar charged amino acids in compound mutations and 15 had not. There were no statistically significant differences in the clinical background factors examined in these two groups of patients. In uni- and multivariate analysis, 'poor performance status' and 'polar charged amino acids in compound mutations' were significant favorable factors in OS., Conclusion: Patients with 'polar charged amino acids in compound mutations' might have favorable prognosis than those without them. Detailed examination of EGFR gene information might contribute to the understanding of TKI response duration., (Copyright © 2022, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Patients with uncommon EGFR- mutated non-small-cell lung cancer (NSCLC) demonstrated lower clinical efficacy of first-generation EGFR-tyrosine kinase inhibitors compared with patients harboring common EGFR- mutated NSCLC. The US FDA has approved afatinib for uncommon EGFR mutation positive NSCLC based on the pooled analysis in the first- or second-line setting. Osimertinib has limited evidence in the small sample sizes of phase 2 studies in any-line settings. The aim of the present single-arm, multicenter, phase 2 study is to evaluate the efficacy of osimertinib for previously untreated NSCLC. The primary end point is to assess the overall response to osimertinib. The secondary end points include disease control rate, progression-free survival, duration of time-to-treatment failure, overall survival and safety. Clinical trial registration: jRCTs071200002.