Driver mutations of young lung adenocarcinoma patients with malignant pleural effusion

Advancements in the diagnosis and treatment of sub‑centimeter lung cancer in the era of precision medicine (Review)

Lung cancer is the malignancy with the highest global mortality rate and imposes a substantial burden on society. The increasing popularity of lung cancer screening has led to increasing number of patients being diagnosed with pulmonary nodules due to their potential for malignancy, causing considerable distress in the affected population. However, the diagnosis and treatment of sub-centimeter grade pulmonary nodules remain controversial. The evolution of genetic detection technology and the development of targeted drugs have positioned the diagnosis and treatment of lung cancer in the precision medicine era, leading to a marked improvement in the survival rate of patients with lung cancer. It has been established that lung cancer driver genes serve a key role in the development and progression of sub-centimeter lung cancer. The present review aimed to consolidate the findings on genes associated with sub-centimeter lung cancer, with the intent of serving as a reference for future studies and the personalized management of sub-centimeter lung cancer through genetic testing.

Economic Analysis of Tissue-First, Plasma-First, and Complementary NGS Approaches for Treatment-Naïve Metastatic Lung Adenocarcinoma

Background

To compare the testing costs and testing turnaround times of tissue-first, plasma-first, and complementary next-generation sequencing (NGS) approaches in patients with treatment-naïve metastatic lung adenocarcinoma.

Materials and Methods

We developed a decision tree model to compare three different approaches. Patients were entered into the model upon cancer diagnosis and those with both insufficient tissue specimens and negative liquid-based NGS were subjected to tissue re-biopsy. Actionable gene alterations with the U.S. Food and Drug Administration (FDA)-approved therapies included epidermal growth factor receptor (EGFR) mutation, anaplastic lymphoma kinase (ALK) gene rearrangement, ROS proto-oncogene 1 (ROS1) rearrangement, B-Raf proto-oncogene (BRAF) V600E mutation, rearranged during transfection (RET) gene rearrangement, mesenchymal-epithelial transition factor (MET) mutation, neurotrophic tyrosine receptor kinase (NTRK) gene rearrangement, K-Ras proto-oncogene (KRAS) G12C mutation, and human epidermal growth factor receptor 2 (HER2) mutation. Model outcomes were testing costs, testing turnaround times, and monetary losses taking both cost and time into consideration. We presented base-case results using probabilistic analysis. Stacked one-way and three-way sensitivity analyses were also performed.

Results

In terms of testing costs, tissue-first approach incurred US$2,354($1,963-$2,779) and was the most cost-efficient strategy. Complementary approach testing turnaround time (days) of 12.7 (10.8 to 14.9) was found as the least time-consuming strategy. Tissue-first, complementary, and plasma-first approaches resulted in monetary losses in USD of $4,745 ($4,010-$5,480), $6,778 ($5,923-$7,600), and $7,006 ($6,047-$7,964) respectively, and identified the same percentage of patients with appropriate FDA-approved therapies. Costs for liquid-based NGS, EGFR mutation rates, and quantity of tissue specimens were the major determinants in minimizing monetary loss. Plasma-first approach would be the preferable strategy if its testing price was reduced in USD to $818, $1,343, and $1,869 for populations with EGFR mutation rates of 30%, 45%, and 60% respectively.

Conclusion

The tissue-first approach is currently the best strategy in minimizing monetary loss. The complementary approach is an alternative for populations with a low EGFR mutation rate. The plasma-first approach becomes increasingly preferable as EGFR mutation rates gradually increase.

Culture and multiomic analysis of lung cancer patient-derived pleural effusions revealed distinct druggable molecular types

Malignant pleural effusion (MPE) is an independent determinant of poor prognostic factor of non-small cell lung cancer (NSCLC). The course of anchorage independent growth within the pleural cavity likely reforms the innate molecular characteristics of malignant cells, which largely accounts for resistance to chemotherapy and poor prognosis after the surgical resection. Nevertheless, the genetic and transcriptomic features with respect to various drug responses of MPE-complicated NSCLC remain poorly understood. To obtain a clearer overview of the MPE-complicated NSCLC, we established 28 MPE-derived lung cancer cell lines which were subjected to genomic, transcriptomic and pharmacological analysis. Our results demonstrated MPE-derived NSCLC cell lines recapitulated representative driver mutations generally found in the primary NSCLC. It also exhibited the presence of distinct translational subtypes in accordance with the mutational profiles. The drug responses of several targeted chemotherapies accords with both genomic and transcriptomic characteristics of MPE-derived NSCLC cell lines. Our data also suggest that the impending drawback of mutation-based clinical diagnosis in evaluating MPE-complicated NSCLS patient responses. As a potential solution, our work showed the importance of comprehending transcriptomic characteristics in order to defy potential drug resistance caused by MPE.

Economic Analysis of Exclusionary EGFR Test Versus Up-Front NGS for Lung Adenocarcinoma in High EGFR Mutation Prevalence Areas

BACKGROUND

This study sought to determine whether exclusionary EGFR mutation testing followed by next-generation sequencing (NGS) is a cost-efficient and timely strategy in areas with high prevalence rates of EGFR mutation.

METHODS

We developed a decision tree model to compare exclusionary EGFR testing followed by NGS and up-front NGS. Patients entered the model upon diagnosis of metastatic lung adenocarcinoma. Gene alterations with FDA-approved targeted therapies included EGFR, ALK, ROS1, BRAF, RET, MET, NTRK, and KRAS. Model outcomes were testing-related costs; time-to-test results; monetary loss, taking both costs and time into consideration; and percentage of patients who could be treated by FDA-approved therapies. Stacked 1-way and 3-way sensitivity analyses were performed.

RESULTS

Exclusionary EGFR testing incurred testing-related costs of US $1,387 per patient, a savings of US $1,091 compared with the costs of up-front NGS. The time-to-test results for exclusionary EGFR testing and up-front NGS were 13.0 and 13.6 days, respectively. Exclusionary EGFR testing resulted in a savings of US $1,116 in terms of net monetary loss, without a reduction of patients identified with FDA-approved therapies. The EGFR mutation rate and NGS cost had the greatest impact on minimizing monetary loss. Given that the tissue-based NGS turnaround time was shortened to 7 days, up-front NGS testing would become the best strategy if its price could be reduced to US $568 in Taiwan.

CONCLUSIONS

In areas with high prevalence rates of EGFR mutation, exclusionary EGFR testing followed by NGS, rather than up-front NGS, is currently a cost-efficient strategy for metastatic lung adenocarcinoma.

N-glycosylated GPNMB ligand independently activates mutated EGFR signaling and promotes metastasis in NSCLC

Lung cancer is the leading cause of cancer‐related death worldwide. As well as the identified role of epidermal growth factor receptor (EGFR), its association with driver mutations has improved the therapeutics for patients with lung cancer harboring EGFR mutations. These patients usually display shorter overall survival and a higher tendency to develop distant metastasis compared with those carrying the wild‐type EGFR. Nevertheless, the way to control mutated EGFR signaling remains unclear. Here, we performed membrane proteomic analysis to determine potential components that may act with EGFR mutations to promote lung cancer malignancy. Expression of transmembrane glycoprotein non‐metastatic melanoma protein B (GPNMB) was positively correlated with the status of mutated EGFR in non‐small‐cell lung cancer (NSCLC). This protein was not only overexpressed but also highly glycosylated in EGFR‐mutated, especially EGFR‐L858R mutated, NSCLC cells. Further examination showed that GPNMB could activate mutated EGFR without ligand stimulation and could bind to the C‐terminus of EGFR, assist phosphorylation at Y845, turn on downstream STAT3 signaling, and promote cancer metastasis. Moreover, we also found that Asn134 (N134) glycosylation of GPNMB played a crucial role in this ligand‐independent regulation. Depleting N134‐glycosylation on GPNMB could dramatically inhibit binding of GPNMB to mutated EGFR, blocking its downstream signaling, and ultimately inhibiting cancer metastasis in NSCLC. Clarifying the role of N‐glycosylated GPNMB in regulating the ligand‐independent activation of mutated EGFR may soon give new insight into the development of novel therapeutics for NSCLC.

Genomic profiling in non-small-cell lung cancer in young patients. A systematic review

Lung cancer in young patients is an uncommon and understudied entity that harbors distinctive epidemiological, clinic-demographic, and genomic features. We carried out a systematic review of genomic profiling in young patients with lung cancer from 2010 to 2020 in the main electronic databases and selected 23 manuscripts. Lung cancer in young patients occurs more frequently in women with adenocarcinoma histology and at more advanced stages. Some studies report higher oncogenic genomic alteration in this population, with higher anaplastic lymphoma kinase rearrangements, a distinct profile of epidermal growth factor receptor mutations, and other novel genomic alterations. Although still uncommon, the implementation of next-generation sequencing (NGS) has shed some light on germline genomic alterations associated with lung cancer in young patients. Although outcomes when compared with the older population are conflicting, the overall prognosis is still poor in this subset of patients and efforts to find targetable genomic alterations should be made to improve survival.

PIK3CA Gene Mutations in Solid Malignancies: Association with Clinicopathological Parameters and Prognosis

Phosphoinositide kinases (PIKs) are a group of lipid kinases that are important upstream activators of various significant signaling pathways. Hyperactivation of the PI3K/AKT/mTOR pathways—either via mutations or genomic amplification—confers key oncogenic activity, essential for the development and progression of several solid tumors. Alterations in the PIK3CA gene are associated with poor prognosis of solid malignancies. Although the literature reports contradictory prognostic values of PIK3CA in aggressive cancers, most of the available data highlight the important role of PIK3CA mutation in mediating tumorigenesis via increased signaling of the PI3K/AKT/mTOR survival pathway. Several inhibitors of PI3K/AKT/mTOR pathways are investigated as potential therapeutic options in solid malignancies. This article reviews the role of PIK3CA mutations and inhibitors of PI3K/AKT/mTOR pathways in major cancer types and examines its association with clinicopathological parameters and prognosis.

Sensitive molecular testing methods can demonstrate NSCLC driver mutations in malignant pleural effusion despite non-malignant cytology

Malignant pleural effusion (MPE) may be diagnosed by cytologic evaluation of pleural fluid, though false negative results can occur. Pleural effusions may provide a source of tumour material for genotyping in lung cancer patients. Detection of MPE may be improved through use of highly sensitive molecular techniques. We identified five patients with non-small cell lung cancer (NSCLC) with initial pleural fluid samples that were non-malignant on cytology, but were subsequently clinically confirmed to have MPE. Tumour mutation status was confirmed via routine testing of diagnostic clinical specimens. Cytologically negative pleural fluid cell-block specimens were analysed by amplicon-based parallel sequencing (APS) for somatic mutations commonly detected in NSCLC, and selected cases by improved and complete enrichment CO-amplification at lower denaturation temperature PCR (ICECOLD PCR) for known mutations. Mutations were detected in three out of three (sensitivity 100%) cytologically non-malignant pleural fluids from patients with a known mutation: two patients with known Kirsten rat sarcoma (KRAS) mutation demonstrated the same KRAS mutation in their pleural fluids by APS, both at approximately 2% mutant allele frequency. In one patient with a known KRAS mutation, ICECOLD PCR detected the same KRAS variant at 0.7% frequency. No mutations were detected in patients with wild-type findings from reference samples (specificity 100%). Sensitive DNA sequencing methods can detect cancer-driver mutations in cytologically non-malignant pleural fluid specimens from NSCLC patients with MPE. Our findings demonstrate the feasibility of sensitive molecular diagnostic techniques for improvement of diagnostic assessment of pleural effusions in patients with lung cancer.

Validation of Immunohistochemistry for the Detection of BRAF V600E-Mutated Lung Adenocarcinomas

BRAF V600E mutation, a missense mutation in exon 15 resulting in valine substitution for glutamate at position 600 within the kinase domain of BRAF oncogene, is found in a subset of lung adenocarcinoma (ADC). The usefulness of immunohistochemistry (IHC) as an alternative diagnostic tool has not been validated. Moreover, the clinical information of patients with BRAF V600E-mutated lung ADC is limited. We retrospectively identified 31 lung ADCs diagnosed with BRAF V600E mutation by standard molecular sequencing methods and reviewed their clinical characteristics and pathological features. An anti-BRAF V600E monoclonal VE1 antibody for IHC was used to confirm the expression patterns. The series was comprised of 99 cases, 29 with BRAF V600E mutation and 70 without BRAF V600E but with other types or undetected mutations. The majority of BRAF V600E-mutated biopsied tissues were poorly differentiated and micropapillary patterns. Application of the IHC VE1 assay was highly feasible in primary/metastatic sites or effusion blocks, yielding positive findings in 28 of 29 (96.6%) BRAF V600E-mutated tumors and negative results in 69 of 70 (98.6%) tumors harboring other types or undetected mutations. Patients who received pemetrexed/platinum-based rather than mutation-targeted chemotherapy as the first-line therapy for metastatic disease showed median overall survival of 15.5 months. Our findings indicated that VE1 antibody-based IHC analysis demonstrated high sensitivity and specificity to detect BRAF V600E-mutated lung ADCs in tissues from primary or metastatic sites.