The in cis compound EGFR mutations in Chinese advanced non-small cell lung cancer patients

EGFR V834L and L858R Comutation Is Associated With Response to Osimertinib in Non-Small-Cell Lung Cancer

Up-front osimertinib leads to clinical benefit in EGFR V834L and L858R comutated NSCLC.

[A Rare Case of Lung Adenocarcinoma with EGFR L833V/H835L Co-mutation and Literature Review]

Epidermal growth factor receptor (EGFR) mutations are the most common driver genes in the development of non-small cell lung cancer (NSCLC), of which mutations in exons 18-21 are frequent, especially the loss of exon 19 and exon 21 L858R mutation are the most frequent. Other rare gene mutations are rare. Simultaneous occurrence of two or more rare EGFR mutations are extremely rare in lung cancer, and the incidence of EGFR L833V/H835L rare gene compound mutations is very low, and there is little clinical data and evidence of relevant treatment methods. Some EGFR-tyrosine kinase inhibitors (EGFR-TKIs) are effective in treating lung cancer patients with rare gene mutations. In this article, we reported a case of NSCLC patient with a rare gene compound mutation EGFR L833V/H835L, who responded to Afatinib in combination with Anilotinib treatment well after 5 months of treatment, and computed tomography (CT) showed shrinkage of lung lesions. Meanwhile, we also compiled previously reported NSCLC patients with EGFR L833V/H835L rare gene compound mutation and summarized the characteristics of this group of patients and the effect of applying different kinds of EGFR-TKIs treatment.
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Co-Occurring EGFR S645C and EGFR L858R in a Patient with Lung Adenocarcinoma Induced Primary Resistance to Osimertinib

Approximately 10-20% of patients demonstrate primary resistance to EGFR-TKIs, and different EGFR mutations vary in sensitivity to EGFR-TKIs. We report a case of a 78-year-old male with lung adenocarcinoma that EGFR L858R (AF = 1.32%) coexisting with EGFR S645C (AF = 7.13%) in his diagnosed tissues analyzed by NGS. The patient was primarily resistant to first-line osimertinib and rapidly progressed after pembrolizumab in combination with pemetrexed and bevacizumab, as demonstrated by persistently elevated CEA levels during treatment. ctDNA-based NGS analysis revealed loss of EGFR L858R while persistence of highly abundant EGFR S645C in the pleural fluid and plasma after treatment, suggesting that EGFR L858R may be a subclone. We provide the first clinical evidence of the primary resistance of EGFR S645C to osimertinib and emphasize the importance of identifying clones and subclones. Our patient did not respond to immunotherapy either, and preclinical studies have shown that EGFR S645C activates the MEK signaling pathway, the combination of EGFR-TKIs and MEK inhibitors may be effective.

Germline mutations and developmental mosaicism underlying EGFR-mutant lung cancer

While the development of multiple primary tumors in smokers with lung cancer can be attributed to carcinogen-induced field cancerization, the occurrence of multiple primary tumors in individuals with EGFR-mutant lung cancer who lack known environmental exposures remains unexplained. We identified ten patients with early-stage, resectable non-small cell lung cancer who presented with multiple anatomically distinct EGFR-mutant tumors. We analyzed the phylogenetic relationships among multiple tumors from each patient using whole exome sequencing (WES) and hypermutable poly-guanine (poly-G) repeat genotyping, as orthogonal methods for lineage tracing. In two patients, we identified germline EGFR variants, which confer moderately enhanced signaling when modeled in vitro. In four other patients, developmental mosaicism is supported by the poly-G lineage tracing and WES, indicating a common non-germline cell-of-origin. Thus, developmental mosaicism and germline variants define two distinct mechanisms of genetic predisposition to multiple EGFR-mutant primary tumors, with implications for understanding their etiology and clinical management.

Successful treatment of lung adenocarcinoma complicated with a rare compound EGFR mutation L833V/H835L using aumolertinib: a case report and literature review

Background: The deletion of exon 19 and the Leu858Arg mutation of exon 21 are the most frequently observed mutations in the epidermal growth factor receptor (EGFR) gene, and patients with these mutations have shown significant benefits from EGFR-tyrosine kinase inhibitors (TKIs). However, there exists a small subgroup of patients with uncommon/rare mutations of EGFR, including compound mutations, which display a high degree of heterogeneity in terms of clinical features and variable sensitivities to EGFR-TKIs. The understanding of these uncommon mutations and their response to targeted therapy is still unclear and requires further investigation. Case presentation: We presented a case of a never-smoking patient with lung adenocarcinoma and brain metastasis. Initially, she received chemotherapy plus immune checkpoint inhibitor as first-line therapy as no EGFR mutations were detected by amplification-refractory mutation system-polymerase chain reaction. However, disease progressed rapidly. Subsequently, next-generation sequencing was carried out and revealed a rare compound mutation, L833V/H835L, in exon 21 of EGFR. As a result, she was switched to second-line therapy with the third-generation TKI aumolertinib, which demonstrated good efficacy. The patient was evaluated for a remarkable progression-free survival of 18 months and an overall survival of 29 months. Conclusion: The present study supports that aumolertinib might be a good treatment option for advanced NSCLC patients with EGFR L833V/H835L mutation, particularly in patients with brain metastasis. Furthermore, conducting a comprehensive screening for gene mutations is crucial in effectively identifying potential oncogenic driver mutations and guiding mutation-targeted therapy decisions in clinical practice.

Non-small-cell lung cancer with epidermal growth factor receptor L861Q-L833F compound mutation benefits from both afatinib and osimertinib: A case report

BACKGROUND

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been adopted as the standard of care for non-small cell lung cancer (NSCLC) patients harboring EGFR sensitizing mutations. Besides the two common mutations exon 19 deletion and L858R, which together comprise approximately 85% of EGFR mutations in NSCLC, rare EGFR mutations also exist, including point mutations, deletions, and insertions spanning EGFR exons 18-25. However, the responsiveness of uncommon EGFR mutations to EGFR TKIs remains elusive and attracts increasing interest.

CASE SUMMARY

Herein, we report a 55-year-old male patient with stage IV NSCLC harboring a rare EGFR L833F-L861Q compound mutation in cis. The patient achieved a partial response to first-line treatment with afatinib and a progression-free survival of 10 mo. After afatinib failure, the patient received multiple line treatments with chemotherapy. Upon disease progression, the heavily pretreated patient was treated with osimertinib and bevacizumab, and both lung lesion and brain metastases were stable for more than 3 mo. He had an overall survival of 25 mo.

CONCLUSION

Our case revealed that both afatinib and the osimertinib + bevacizumab combination demonstrated clinical efficacy in NSCLC harboring an EGFR L833F-L861Q compound mutation. The results provide more therapeutic options for patients with rare compound mutations.

The emergence of various genetic alterations mediated the Osimertinib resistance of a patient harboring heterozygous germline EGFR T790M: a case report

Epidermal growth factor receptor (EGFR) T790M is the major mechanism mediating resistance to first- and second-generation EGFR tyrosine kinase inhibitors. Despite the high frequency of EGFR activating mutations among East Asian lung cancer patients, germline T790M has been the subject of very little research. Questions remain as to whether germline T790M develops resistance to Osimertinib and if so, through which mechanisms. This study examined a patient harboring germline EGFR T790M who acquired resistance to Osimertinib therapy. After the failure of first-line icotinib therapy, which was administered for only 3 months, targeted next-generation sequencing of plasma samples collected at icotinib progression and the re-analysis of the baseline tissue biopsy sample revealed EGFR T790M with allelic frequencies approximating 50%. Lymphocyte genomic deoxyribonucleic acid (DNA) sequencing confirmed the germline heterozygous status of the T790M mutation. In addition to the EGFR T790M, a concurrent EGFR L858R was detected from the baseline tissue sample. Osimertinib therapy was initiated resulting in a partial response within 1 month of the commencement of the therapy. After 15.2 months of Osimertinib therapy, disease progression was evaluated due to the presence of pleural effusion. The targeted sequencing of plasma and pleural effusion samples revealed the emergence of EGFR G719A, tumor protein p53 (TP53) Q136X, and the co-amplification of Cyclin D1, fibroblast growth factor (FGF) 19, FGF3, and FGF4. This case highlights the importance of conducting next-generation sequencing–based molecular testing during both diagnostic and disease progression assessments to reveal sensitizing mutations and mutations that could mediate primary and acquired resistance to targeted therapeutics.

The therapeutic potential of attenuated diphtheria toxin delivered by an adenovirus vector with survivin promoter on human lung cancer cells

Adenoviral vectors are superior to plasmid vectors in their gene transport efficiency. The A subunit of the diphtheria toxin (DTA) gene is a popular suicide gene in cancer gene therapy. However, DTA is seldom used in adenoviral therapy due to its great toxicity. The toxicity of DTA is so great that even a single molecule of DTA is enough to kill one cell. To avoid this highly toxic effect on normal cells, DTA should be controlled by tumor-specific promoters. The survivin promoter is a widely used tumor-specific promoter. But genes driven by the survivin promoter show a low level of basal gene expression in non-cancer cells. DTA driven by the survivin promoter in adenoviral vectors may be highly toxic not only to cancer cells but also to normal cells. Therefore, DTA should be attenuated when it is used in adenoviral vectors driven by the survivin promoter. In this study, we compared the three kinds of recombinant adenoviruses that carry DTA or its attenuated forms (DTA176 and DTA197) in the treatment of human lung cancer. The results showed that in comparison with both DTA and DTA176, DTA197 is more suitable for adenoviral cancer therapy controlled by the survivin promoter. In addition, Adsur-DTA197 (DTA197 delivered by an adenoviral vector with the survivin promoter) sensitized human lung cancer cells to cisplatin both in vitro and in vivo. These results indicated that Adsur-DTA197 may be a potential chemosensitizer in cancer therapy.

Next Generation Sequencing Reveals a Synchronous Trilateral Lung Adenocarcinoma Case with Distinct Driver Alterations of EGFR 19 Deletion or EGFR 20 Insertion or EZR-ROS1 Fusion

OBJECTIVE

Synchronous multiple primary lung cancer (SMPLC) has a reported occurrence from 0.5% to 2% in lung cancer, and the surgical treatment and prognosis were quite diverse. With the discovery of driver mutations in lung adenocarcinoma (ADC), next-generation sequencing (NGS) would provide an explicit answer to the key question, whether individual tumors represent intrapulmonary metastases or independent tumors. Here, we reported a 64-year-old female diagnosed with a synchronous trilateral early-stage ADC with distinct driver alterations.

MATERIALS AND METHODS

NGS test targeting 31 cancer-relevant genes and amplification RNA sequencing (if gene fusion was found on DNA level) were performed on the surgical tumor tissue.

RESULTS

A 64-year-old Chinese female never smoker was found with one nodule in the right upper lobe and two nodules in the right middle lobe through chest computed tomography. The lesions were resected through video-assisted thoracic surgery and diagnosed with stage IA ADC, T1N0M0, in the postoperative pathology. NGS detected three independent driver mutations in three primary sites, respectively, EGFR 19del, EGFR 20ins and ROS1 fusion.

CONCLUSION

This is the first report of a synchronous trilateral early-stage ADC with distinct driver alterations. All individual tumors were independent identified by NGS methodology, which had provided a clear answer to the key question of SMPLC in this case and should be used as a routine genetic test to explore fully pathological diagnosis and more comprehensive oncogenesis information in the early-stage ADC clinical prevention.

Great Efficacy of Afatinib in a Patient with Lung Adenocarcinoma Harboring EGFR L833V/H835L Mutations: A Case Report

Uncommon mutations account for 10-15% of epidermal growth factor receptor (EGFR) mutations in patients with non-small-cell lung cancer (NSCLC). Most of them are proved to be sensitive or resistant to EGFR-tyrosine kinase inhibitors (TKIs). However, there is insufficient evidence for other less common types of EGFR mutations, such as complex mutations. Here, we present a 65-year-old never-smoking male who was diagnosed with stage IV lung adenocarcinoma. A rare L833V/H835L complex mutation in exon 21 of EGFR was detected in plasma and pleural effusion by next generation sequencing (NGS). Afatinib was used as first-line therapy and showed very good efficacy. To date, the patient is still benefited from afatinib treatment for a total of 10 months, with no signs of disease progression. Our case suggests that a comprehensive screening for EGFR mutations should be conducted before treatment in clinical practice, and afatinib could be a first-line treatment option in NSCLC patients harboring H833V/H835L mutations.

The prevalence and prognostic value of KRAS co-mutation subtypes in Chinese advanced non-small cell lung cancer patients

Objective

KRAS mutation plays a critical role in the initiation and development of non‐small cell lung cancer (NSCLC). KRAS‐mutant patients exhibit diverse response to chemotherapy. KRAS co‐mutation subtypes and their prognosis value in advanced Chinese NSCLC patients remain largely elusive.

Methods

A total of 1126 Chinese advanced NSCLC patients from Xiangya hospital were screened by capture‐based ultra‐deep sequencing for KRAS mutation between January 2015 and December 2016. Survival analyses were performed using Kaplan‐Meier analysis.

Results

Among the patients screened, 84 cases were detected with KRAS mutation (7.5%). All of them were non‐squamous NSCLC and received pemetrexed plus platinum as the first‐line treatment. The most frequent KRAS co‐mutation genes were TP53 (29%), TP53/LKB1 (19%), and LKB1 (14%). Our data revealed that patients with KRAS co‐mutation had poorer prognosis in comparison with those harboring single KRAS mutation. Furthermore, patients with KPL (KRAS mutated with TP53 and LKB1) subtype, which was a novel subtype, had the shortest progression‐free survival (PFS) in all types of KRAS co‐mutation patients (P < .0001). The PFS and overall survival (OS) of patients with KRAS^G12D mutation were inferior than those with KRAS^G12C mutation or KRAS^G12Vmutation. Patients in KRAS^G>T type had significantly longer survival than those in KRAS^G>C type or KRAS^G>A type.

Conclusion

Our study revealed that concurrent genomic alterations can further stratify KRAS‐mutant lung adenocarcinoma patients into various subgroups with distinctive therapeutic responses and differential survival outcomes. The KPL is a novel and less responsive subtype among KRAS‐mutated NSCLC, and further investigation of effective treatment for this subtype is warranted.