Tumor clonality and resistance mechanisms in EGFR mutation-positive non-small-cell lung cancer: implications for therapeutic sequencing

Efficacy and Safety of Chemotherapy or EGFR-TKIs as First-Line Therapy in NSCLC Patients Harboring Non-Ex 20 Ins Uncommon EGFR Mutations: A Retrospective Study in China

BACKGROUND

Uncommon EGFR mutations are a kind of heterogeneous group of mutations with various responses to EGFR-TKIs and are often excluded from most prospective clinical trials. In this real-world retrospective study, we retrospectively compared the efficacy and safety of chemotherapy or various generations of EGFR-TKIs as first-line therapy in NSCLC Chinese patients harboring non-ex 20 ins uncommon EGFR mutations.

METHODS

We enrolled 139 NSCLC patients with non-ex 20 ins uncommon EGFR mutations in this study retrospectively. Patients' clinical characteristics and the efficacy and safety of different first-line therapies were analyzed and compared.

RESULTS

Our data reviewed that for first-line therapy, NSCLC patients harboring non-ex 20 ins uncommon EGFR mutations benefited more from EGFR-TKIs compared with chemotherapy. Afatinib performed with great efficacy for the majority of non-ex 20 ins uncommon EGFR mutations (N = 43, ORR = 41.86%, mPFS = 13.5 months, mOS = 20.8 months), especially in L861Q mutation (mPFS = 18.4 months). Osimertinib also demonstrated efficacy in patients harboring non-ex 20 ins uncommon EGFR mutations (N = 36, ORR = 27.78%, mPFS = 10.0 months, mOS = 21.0 months), especially in those without L861Q and G719X mutations (mPFS = 12.1 months). When treated with afatinib, patients harboring non-ex 20 ins uncommon EGFR mutations should pay attention to the management of safety, especially for gastrointestinal-related AE and rash, while osimertinib was safer.

CONCLUSION

Taking into account both efficacy and safety, afatinib and osimertinib are better choices than chemotherapy and first-generation EGFR-TKIs for NSCLC patients with non-ex 20 ins uncommon EGFR mutations. L861Q showed a trend toward a better response to afatinib, while in those without L861Q and G719X mutations, osimertinib might be a better choice. Safety also should be a concern when choosing EGFR-TKI for treatment, patients should pay attention to the management of safety when using afatinib while osimertinib is safer.

Targeting clonal mutations with synthetic microbes

Recently concluded, large-scale cancer genomics studies involving multiregion sequencing of primary tumors and paired metastases appear to indicate that many or most cancer patients have one or more "clonal" mutations in their tumors. Clonal mutations are those that are present in all of a patient's cancer cells. Clonally mutated proteins can potentially be targeted by inhibitors or E3 ligase small molecule glues, but developing new small molecule drugs for each patient is not feasible currently. Certain companies are using immunotherapies to target clonal mutations. I have devised another approach for exploiting clonal mutations, which I call "Oncolytic Vector Efficient Replication Contingent on Omnipresent Mutation Engagement" (OVERCOME). The ideal version of OVERCOME would likely employ a bioengineered facultative intracellular bacterium. The bacterium would initially be attenuated, but (transiently) reverse its attenuation upon clonal mutation detection.

Selective expansion of motor cortical projections in the evolution of vocal novelty

Deciphering how cortical architecture evolves to drive behavioral innovations is a long-standing challenge in neuroscience and evolutionary biology. Here, we leverage a striking behavioral novelty in the Alston's singing mouse (Scotinomys teguina), compared to the laboratory mouse (Mus musculus), to quantitatively test models of motor cortical evolution. We used bulk tracing, serial two-photon tomography, and high-throughput DNA sequencing of over 76,000 barcoded neurons to discover a specific and substantial expansion (200%) of orofacial motor cortical (OMC) projections to the auditory cortical region (AudR) and the midbrain periaqueductal gray (PAG), both implicated in vocal behaviors. Moreover, analysis of individual OMC neurons' projection motifs revealed preferential expansion of exclusive projections to AudR. Our results imply that selective expansion of ancestral motor cortical projections can underlie behavioral divergence over short evolutionary timescales, suggesting potential mechanisms for the evolution of enhanced cortical control over vocalizations-a crucial preadaptation for human language.

Comprehensive liquid biopsy analysis for monitoring NSCLC patients under second-line osimertinib treatment

Background

The heterogeneous and complex genetic landscape of NSCLC impacts the clinical outcomes of patients who will eventually develop resistance to osimertinib. Liquid biopsy (LB) analysis as a minimally invasive approach is a key step to efficiently identify resistance mechanisms and adjust to proper subsequent treatments.

Materials and methods

In the present study, we combined plasma-cfDNA and CTC analysis from 30 NSCLC patients in samples collected before treatment and at the progression of disease (PD). We detected molecular alterations at the DNA mutation (EGFR, PIK3CA, KRAS G12C, BRAF V600E), DNA methylation (RASSF1A, BRMS1, FOXA1, SLFN1, SHISA3, RARβ,, WIF-1, RASSF10 and APC), gene expression (CK-19, CK-18, CK-8, AXL, TWIST-1, PD-L1, PIM-1, Vimentin, ALDH-1, and B2M) and chromosomal level (HER2 and MET amplification) as possible resistance mechanisms and druggable targets. We also studied the expression of PD-L1 in single CTCs using immunofluorescence.

Results

In some cases, T790M resistance EGFR mutation was detected at baseline in CTCs but not in the corresponding plasma cfDNA. PIK3CA mutations were detected only in plasma-cfDNA but not in corresponding CTCs. KRAS G12C and BRAF V600E mutations were not detected in the samples analyzed. MET amplification was detected in the CTCs of two patients before treatment whereas HER2 amplification was detected in the CTCs of three patients at baseline and in one patient at PD. DNA methylation analysis revealed low concordance between CTCs and cfDNA, indicating the complementary information obtained through parallel LB analysis. Results from gene expression analysis indicated high rates of vimentin-positive CTCs detected at all time points during osimertinib. Moreover, there was an increased number of NSCLC patients at PD harboring CTCs positive in PD-L1. AXL and PIM-1 expression detected in CTCs during treatment suggesting new possible therapeutic strategies.

Discussion

Our results reveal that comprehensive liquid biopsy analysis can efficiently represent the heterogeneous molecular landscape and provide prominent information on subsequent treatments for NSCLC patients at PD since druggable molecular alterations were detected in CTCs.

Are 19del and L858R really different disease entities?

Clinicians have recognized the similarities and differences between the two subtypes of common epidermal growth factor receptor (EGFR) mutations, but actual treatment strategies have not yet changed. The L858R mutation can be understood by considering the pharmacological conformational plasticity of the receptor protein and the presence of other co-occurring mutations, whether subtypes of EGFR or non-EGFR mutations and differences in downstream signaling pathways. As long as we know that molecular differences lead to biological differences, it is a challenge for all of us that our treatment strategies must change.

The ultrasonic vocalization (USV) syllable profile during neonatal opioid withdrawal and a kappa opioid receptor component to increased USV emissions in female mice

Rationale

Opioid use during pregnancy can lead to negative infant health outcomes, including neonatal opioid withdrawal syndrome (NOWS). NOWS comprises gastrointestinal, autonomic nervous system, and neurological dysfunction that manifest during spontaneous withdrawal. Variability in NOWS severity necessitates a more individualized treatment approach. Ultrasonic vocalizations (USVs) in neonatal mice are emitted in isolation as a stress response and are increased during opioid withdrawal, thus modeling a negative affective state that can be utilized to test new treatments.

Objectives

We sought to identify the behavioral and USV profile, brainstem transcriptomic adaptations, and role of kappa opioid receptors in USVs during neonatal opioid withdrawal.

Methods

We employed a third trimester-approximate opioid exposure model, where neonatal inbred FVB/NJ pups were injected twice-daily with morphine (10mg/kg, s.c.) or saline (0.9%, 20 ul/g, s.c.) from postnatal day(P) 1 to P14. This protocol induces reduced weight gain, hypothermia, thermal hyperalgesia, and increased USVs during spontaneous morphine withdrawal.

Results

On P14, there were increased USV emissions and altered USV syllables during withdrawal, including an increase in Complex 3 syllables in FVB/NJ females (but not males). Brainstem bulk mRNA sequencing revealed an upregulation of the kappa opioid receptor (Oprk1), which contributes to withdrawal-induced dysphoria. The kappa opioid receptor (KOR) antagonist, nor-BNI (30 mg/kg, s.c.), significantly reduced USVs in FVB/NJ females, but not males during spontaneous morphine withdrawal. Furthermore, the KOR agonist, U50,488h (0.625 mg/kg, s.c.), was sufficient to increase USVs on P10 (both sexes) and P14 (females only) in FVB/NJ mice.

Conclusions

We identified an elevated USV syllable, Complex 3, and a female-specific recruitment of the dynorphin/KOR system in increased USVs associated with neonatal opioid withdrawal severity.

Case report of a patient with stage IV lung adenocarcinoma and uncommon/compound EGFR mutations who responded to afatinib

There is no established treatment for lung adenocarcinoma with uncommon/compound epidermal growth factor receptor (EGFR) mutations. We report a case of a 73-year-old man with stage IVB lung adenocarcinoma harboring E709G and L861Q EGFR mutations. After 2 months of afatinib treatment, significant tumor shrinkage was observed, and the patient's condition remained stable for 1 year. This case highlights the potential effectiveness of afatinib for treating rare stage IV lung adenocarcinoma with these specific EGFR mutations.

Liquid biopsy for the management of NSCLC patients under osimertinib treatment

Therapeutic management of NSCLC patients is quite challenging as they are mainly diagnosed at a late stage of disease, and they present a high heterogeneous molecular profile. Osimertinib changed the paradigm shift in treatment of EGFR mutant NSCLC patients achieving significantly better clinical outcomes. To date, osimertinib is successfully administered not only as first- or second-line treatment, but also as adjuvant treatment while its efficacy is currently investigated during neoadjuvant treatment or in stage III, unresectable EGFR mutant NSCLC patients. However, resistance to osimertinib may occur due to clonal evolution, under the pressure of the targeted therapy. The utilization of liquid biopsy as a minimally invasive tool provides insight into molecular heterogeneity of tumor clonal evolution and potent resistance mechanisms which may help to develop more suitable therapeutic approaches. Longitudinal monitoring of NSCLC patients through ctDNA or CTC analysis could reveal valuable information about clinical outcomes during osimertinib treatment. Therefore, several guidelines suggest that liquid biopsy in addition to tissue biopsy should be considered as a standard of care in the advanced NSCLC setting. This practice could significantly increase the number of NSCLC patients that will eventually benefit from targeted therapies, such as EGFR TKIs.

Mixed responses to targeted therapy driven by chromosomal instability through p53 dysfunction and genome doubling

The phenomenon of mixed/heterogenous treatment responses to cancer therapies within an individual patient presents a challenging clinical scenario. Furthermore, the molecular basis of mixed intra-patient tumor responses remains unclear. Here, we show that patients with metastatic lung adenocarcinoma harbouring co-mutations of EGFR and TP53, are more likely to have mixed intra-patient tumor responses to EGFR tyrosine kinase inhibition (TKI), compared to those with an EGFR mutation alone. The combined presence of whole genome doubling (WGD) and TP53 co-mutations leads to increased genome instability and genomic copy number aberrations in genes implicated in EGFR TKI resistance. Using mouse models and an in vitro isogenic p53-mutant model system, we provide evidence that WGD provides diverse routes to drug resistance by increasing the probability of acquiring copy-number gains or losses relative to non-WGD cells. These data provide a molecular basis for mixed tumor responses to targeted therapy, within an individual patient, with implications for therapeutic strategies.

Prolonged Response to Afatinib and Crizotinib in a Rare Case of EGFR-, HER2-, MET- and ROS1-Alterated Lung Adenocarcinoma

We present the case of a 70-year-old never-smoking female patient with epidermal growth factor receptor (EGFR) p.L858R-mutated metastatic non-small cell lung cancer (NSCLC). After three months of first-line treatment with erlotinib, progression occurred and platinum/pemetrexed was initiated, followed by a response for more than two years. After the progression, the molecular testing of a vertebral metastasis revealed a ROS proto-oncogene 1 (ROS1) translocation and a human epidermal growth factor receptor 2 (HER2) p.S310F mutation, in addition to the known EGFR p.L858R mutation. Crizotinib then led to a durable response of 17 months. The molecular retesting of the tumour cells obtained from the recurrent pleural effusion revealed the absence of the ROS1 translocation, whereas the EGFR and HER2 mutations were still present. Afatinib was added to the crizotinib, and the combination treatment resulted in another durable response of more than two years. The patient died more than 7 years after the initial diagnosis of metastatic NSCLC. This case demonstrates that the repeated molecular testing of metastatic NSCLC may identify new druggable genomic alterations that can impact the patient management and improve the patient outcome.

Distinguishing EGFR mutation molecular subtypes based on MRI radiomics features of lung adenocarcinoma brain metastases

OBJECTIVE

To explore the feasibility of identifying epidermal growth factor receptor (EGFR) mutation molecular subtypes in primary lesions based on the radiomics features of lung adenocarcinoma brain metastases using magnetic resonance imaging (MRI).

METHODS

We retrospectively analyzed clinical, imaging, and genetic testing data of patients with lung adenocarcinoma with EGFR gene mutations who had brain metastases. Three-dimensional radiomics features were extracted from contrast-enhanced T1-weighted images. The volume of interest was delineated and normalized using Z-score, dimensionality reduction was performed using principal component analysis, feature selection using Relief, and radiomics model construction using adaptive boosting as a classifier. Data were randomly divided into training and testing datasets at an 8:2 ratio. Five-fold cross-validation was conducted in the training set to select the optimal radiomics features and establish a predictive model for distinguishing between exon 19 deletion (19Del) and exon 21 L858R point mutation (21L858R), the two most common EGFR gene mutations. The testing set was used for external validation of the models. Model performance was evaluated using receiver operating characteristic curve and decision curve analyses.

RESULTS

Overall, 86 patients with 228 brain metastases were included. Patient age was identified as an independent predictor for distinguishing between 19Del and 21L858R. The area under the curve (AUC) values of the radiomics model in the training and testing datasets were 0.895 (95% confidence interval [CI]: 0.850-0.939) and 0.759 (95% CI: 0.0.614-0.903), respectively. The AUC for diagnosis of all cases using a combined model of age and radiomics was 0.888 (95% CI: 0.846-0.930), slightly higher than that of the radiomics model alone (0.866, 95% CI: 0.820-0.913), but without statistical significance (p=0.1626). In the decision curve analysis, both models demonstrated clinical net benefits.

CONCLUSIONS

The radiomics model based on MRI of lung adenocarcinoma brain metastases could distinguish between EGFR 19Del and 21L858R mutations in the primary lesion.

Discovery of a novel natural compound, vitekwangin B, with ANO1 protein reduction properties and anticancer potential

Background: Prostate cancer and non-small cell lung cancer (NSCLC) present significant challenges in the development of effective therapeutic strategies. Hormone therapies for prostate cancer target androgen receptors and prostate-specific antigen markers. However, treatment options for prostatic small-cell neuroendocrine carcinoma are limited. NSCLC, on the other hand, is primarily treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors but exhibits resistance. This study explored a novel therapeutic approach by investigating the potential anticancer properties of vitekwangin B, a natural compound derived from Vitex trifolia. Methods: Vitekwangin B was chromatographically isolated from the fruits of V. trifolia. ANO1 protein levels in prostate cancer and NSCLC cells were verified and evaluated again after vitekwangin B treatment. Results: Vitekwangin B did not inhibit anoctamin1 (ANO1) channel function but significantly reduced ANO1 protein levels. These results demonstrate that vitekwangin B effectively inhibited cancer cell viability and induced apoptosis in prostate cancer and NSCLC cells. Moreover, it exhibited minimal toxicity to liver cells and did not affect hERG channel activity, making it a promising candidate for further development as an anticancer drug. Conclusion: Vitekwangin B may offer a new direction for cancer therapy by targeting ANO1 protein, potentially improving treatment outcomes in patients with prostate cancer and NSCLC. Further research is needed to explore its full potential and overcome existing drug resistance challenges.

Characterization of Ultrasonic Vocalization-Modulated Neurons in Rat Motor Cortex Based on Their Activity Modulation and Axonal Projection to the Periaqueductal Gray

Vocalization, a means of social communication, is prevalent among many species, including humans. Both rats and mice use ultrasonic vocalizations (USVs) in various social contexts and affective states. The motor cortex is hypothesized to be involved in precisely controlling USVs through connections with critical regions of the brain for vocalization, such as the periaqueductal gray matter (PAG). However, it is unclear how neurons in the motor cortex are modulated during USVs. Moreover, the relationship between USV modulation of neurons and anatomical connections from the motor cortex to PAG is also not clearly understood. In this study, we first characterized the activity patterns of neurons in the primary and secondary motor cortices during emission of USVs in rats using large-scale electrophysiological recordings. We also examined the axonal projection of the motor cortex to PAG using retrograde labeling and identified two clusters of PAG-projecting neurons in the anterior and posterior parts of the motor cortex. The neural activity patterns around the emission of USVs differed between the anterior and posterior regions, which were divided based on the distribution of PAG-projecting neurons in the motor cortex. Furthermore, using optogenetic tagging, we recorded the USV modulation of PAG-projecting neurons in the posterior part of the motor cortex and found that they showed predominantly sustained excitatory responses during USVs. These results contribute to our understanding of the involvement of the motor cortex in the generation of USV at the neuronal and circuit levels.

An epidermal growth factor receptor compound mutation of L858R with S768I in advanced non-small-cell lung cancer: a case report

BACKGROUND

In the current treatment landscape for non-small cell lung cancers, epidermal growth factor receptor-tyrosine kinase inhibitors have emerged as a well-established treatment option for patients with advanced or metastatic disease. This is particularly true for those with commonly occurring epidermal growth factor receptor mutations. However, the therapeutic efficacy of these agents for so-called rare epidermal growth factor receptor mutations, and in particular those characterized by a high degree of complexity, such as double mutations, remains a subject of clinical uncertainty.

CASE PRESENTATION

In this context, we present the case of a 64-year-old man of Moroccan descent, a lifelong non-smoker, diagnosed with metastatic non-small cell lung cancer characterized by a complex epidermal growth factor receptor mutation encompassing L858R and S768I. The patient subsequently underwent afatinib-based treatment, showing notable clinical results. These included a remarkable overall survival of 51 months, with a median progression-free survival of more than 39 months.

CONCLUSIONS

This case report is a compelling testimony to the evolving therapeutic landscape of non-small cell lung cancers, providing valuable insight into the potential therapeutic efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors in the realm of rare and complex epidermal growth factor receptor mutations.

Optimized whole-genome sequencing workflow for tumor diagnostics in routine pathology practice

Two decades after the genomics revolution, oncology is rapidly transforming into a genome-driven discipline, yet routine cancer diagnostics is still mainly microscopy based, except for tumor type-specific predictive molecular tests. Pathology laboratories struggle to quickly validate and adopt biomarkers identified by genomics studies of new targeted therapies. Consequently, clinical implementation of newly approved biomarkers suffers substantial delays, leading to unequal patient access to these therapies. Whole-genome sequencing (WGS) can successfully address these challenges by providing a stable molecular diagnostic platform that allows detection of a multitude of genomic alterations in a single cost-efficient assay and facilitating rapid implementation, as well as by the development of new genomic biomarkers. Recently, the Whole-genome sequencing Implementation in standard Diagnostics for Every cancer patient (WIDE) study demonstrated that WGS is a feasible and clinically valid technique in routine clinical practice with a turnaround time of 11 workdays. As a result, WGS was successfully implemented at the Netherlands Cancer Institute as part of routine diagnostics in January 2021. The success of implementing WGS has relied on adhering to a comprehensive protocol including recording patient information, sample collection, shipment and storage logistics, sequencing data interpretation and reporting, integration into clinical decision-making and data usage. This protocol describes the use of fresh-frozen samples that are necessary for WGS but can be challenging to implement in pathology laboratories accustomed to using formalin-fixed paraffin-embedded samples. In addition, the protocol outlines key considerations to guide uptake of WGS in routine clinical care in hospitals worldwide.

Prenatal exposure to valproic acid reduces synaptic δ-catenin levels and disrupts ultrasonic vocalization in neonates

Valproic acid (VPA) is an effective and commonly prescribed drug for epilepsy and bipolar disorder. However, children born from mothers treated with VPA during pregnancy exhibit an increased incidence of autism spectrum disorder (ASD). Although VPA may impair brain development at the cellular level, the mechanism of VPA-induced ASD has not been completely addressed. A previous study has found that VPA treatment strongly reduces δ-catenin mRNA levels in cultured human neurons. δ-catenin is important for the control of glutamatergic synapses and is strongly associated with ASD. VPA inhibits dendritic morphogenesis in developing neurons, an effect that is also found in neurons lacking δ-catenin expression. We thus hypothesize that prenatal exposure to VPA significantly reduces δ-catenin levels in the brain, which impairs glutamatergic synapses to cause ASD. Here, we found that prenatal exposure to VPA markedly reduced δ-catenin levels in the brain of mouse pups. VPA treatment also impaired dendritic branching in developing mouse cortical neurons, which was reversed by elevating δ-catenin expression. Prenatal VPA exposure significantly reduced synaptic AMPA receptor levels and postsynaptic density 95 (PSD95) in the brain of mouse pups, indicating dysfunctions in glutamatergic synaptic transmission. VPA exposure also significantly altered ultrasonic vocalization (USV) in newly born pups when they were isolated from their nest. Moreover, VPA-exposed pups show impaired hypothalamic response to isolation, which is required to produce animals' USVs following isolation from the nest. Therefore, these results suggest that VPA-induced ASD pathology can be mediated by the loss of δ-catenin functions.

Highlights

Prenatal exposure of valproic acid (VPA) in mice significantly reduces synaptic δ-catenin protein and AMPA receptor levels in the pups' brains.VPA treatment significantly impairs dendritic branching in cultured cortical neurons, which is reversed by increased δ-catenin expression.VPA exposed pups exhibit impaired communication such as ultrasonic vocalization.Neuronal activation linked to ultrasonic vocalization is absent in VPA-exposed pups.The loss of δ-catenin functions underlies VPA-induced autism spectrum disorder (ASD) in early childhood.

Meta-analysis of the Boyle van 't Hoff relation: Turgor and leak models explain non-ideal volume equilibrium

There has been much recent attention paid to the interaction of cell volume, its regulation, and the molecular biology of the cell. Cells are generally assumed to behave as linear osmometers, with their water volume linearly proportionate to the inverse of osmotic pressure as described by the Boyle van 't Hoff (BvH) relation. This study evaluates the generality of this and other long-standing assumptions about cell responses to anisotonic conditions. We present alternative models that account for osmoregulation including mechanical resistance to volumetric expansion (the turgor model) and ion-osmolyte leakage (the leak model). To evaluate the generality of the BvH relation and determine the suitability of alternative models, we performed a comprehensive survey of the literature and a careful analysis of the resulting data, and then we used these data to compare among models. We identified 137 articles published from 1964 to 2019 spanning 14 animal species and 26 cell types and determined the BvH relation is not an appropriate general model but is adequate when restricted to the hypertonic region. In contrast, models that account for either mechanical resistance or ion-osmolyte leakage fit well to almost all collected data. The leak model has fitted parameters that are in the same range as the current literature estimate, while the turgor model typically requires an elastic modulus value of one or multiple orders of magnitude larger than literature values. However, confirmation of the underlying mechanism of osmotic regulation is required at the cell-specific level and cannot be assumed a priori.

Real-world evidence of osimertinib in Chinese patients with EGFR T790M-positive non-small cell lung cancer: a subgroup analysis from ASTRIS study

PURPOSE

ASTRIS study aimed the largest to evaluate the effectiveness and safety of second- or higher-line osimertinib in patients with advanced/metastatic epidermal growth factor receptor (EGFR) T790M mutation-positive non-small cell lung cancer (NSCLC) in the real-world setting. Here we report the results of Chinese patients in ASTRIS study.

METHODS

Adults with EGFR T790M-positive advanced NSCLC pretreated with EGFR-tyrosine kinase inhibitor (EGFR-TKI), having a WHO performance status score of 0-2 and asymptomatic, stable central nervous system (CNS) metastases were included. All patients received once-daily osimertinib 80 mg orally. The outcomes included investigator-assessed clinical response, progression-free survival (PFS), time-to-treatment discontinuation (TTD), and safety.

RESULTS

A total of 1350 patients were included. Response rate was 55.7% (95% confidence interval [CI] 0.53-0.58). The median PFS and the median TTD were 11.7 months (95% CI 11.1-12.5) and 13.9 months (95% CI 13.1-15.2), respectively. Overall, 389 patients (28.8%) had at least one protocol-specified adverse event (AE); AEs of interstitial lung diseases/pneumonitis-like events and QT prolongation were reported in 3 (0.2%) and 59 (4.4%) patients, respectively.

CONCLUSION

Osimertinib was effective in Chinese patients with T790M-positive NSCLC who had progressed after first- or second-generation EGFR-TKI in real-word setting and the results were consistent with ASTRIS study overall population and AURA studies. No new safety signals or events were identified.

CLINICAL TRIAL NUMBER

NCT02474355.

The broad spectrum of tyrosine kinase inhibitors. Treatment of a rare EGFR R776H mutation with Osimertinib: Case report

EGFR mutations comprise a sizeable portion of non-small cell lung cancers. While the most common EGFR mutation consists of exon 19 in-frame deletions and exon 21 point mutations, rare EGFR mutations have become a more frequent occurrence. Currently, no clinical guidelines exist for the treatment of such mutations. In this case, we see a 68-year-old non-small cell lung cancer male patient with a history of smoking presenting with a rare exon 20 R776H EGFR mutation who demonstrates a response to Osimertinib, further exploring potential standard treatments for patients with rare EGFR mutations.

Predictive Mouse Ultrasonic Vocalization Sequences: Uncovering Behavioral Significance, Auditory Cortex Neuronal Preferences, and Social-Experience-Driven Plasticity

Mouse ultrasonic vocalizations (USVs) contain predictable sequential structures like bird songs and speech. Neural representation of USVs in the mouse primary auditory cortex (Au1) and its plasticity with experience has been largely studied with single-syllables or dyads, without using the predictability in USV sequences. Studies using playback of USV sequences have used randomly selected sequences from numerous possibilities. The current study uses mutual information to obtain context-specific natural sequences (NSeqs) of USV syllables capturing the observed predictability in male USVs in different contexts of social interaction with females. Behavioral and physiological significance of NSeqs over random sequences (RSeqs) lacking predictability were examined. Female mice, never having the social experience of being exposed to males, showed higher selectivity for NSeqs behaviorally and at cellular levels probed by expression of immediate early gene c-fos in Au1. The Au1 supragranular single units also showed higher selectivity to NSeqs over RSeqs. Social-experience-driven plasticity in encoding NSeqs and RSeqs in adult females was probed by examining neural selectivities to the same sequences before and after the above social experience. Single units showed enhanced selectivity for NSeqs over RSeqs after the social experience. Further, using two-photon Ca2+ imaging, we observed social experience-dependent changes in the selectivity of sequences of excitatory and somatostatin-positive inhibitory neurons but not parvalbumin-positive inhibitory neurons of Au1. Using optogenetics, somatostatin-positive neurons were identified as a possible mediator of the observed social-experience-driven plasticity. Our study uncovers the importance of predictive sequences and introduces mouse USVs as a promising model to study context-dependent speech like communications.SIGNIFICANCE STATEMENT Humans need to detect patterns in the sensory world. For instance, speech is meaningful sequences of acoustic tokens easily differentiated from random ordered tokens. The structure derives from the predictability of the tokens. Similarly, mouse vocalization sequences have predictability and undergo context-dependent modulation. Our work investigated whether mice differentiate such informative predictable sequences (NSeqs) of communicative significance from RSeqs at the behavioral, molecular, and neuronal levels. Following a social experience in which NSeqs occur as a crucial component, mouse auditory cortical neurons become more sensitive to differences between NSeqs and RSeqs, although preference for individual tokens is unchanged. Thus, speech-like communication and its dysfunction may be studied in circuit, cellular, and molecular levels in mice.

Arsenic Inhibits Proliferation and Induces Autophagy of Tumor Cells in Pleural Effusion of Patients with Non-Small Cell Lung Cancer Expressing EGFR with or without Mutations via PI3K/AKT/mTOR Pathway

To clarify whether arsenic could exert inhibitory effects on tumor cells in pleural effusions of patients with non-small cell lung cancer (NSCLC), 36 NSCLC pleural effusion samples were collected from Changzheng Hospital and Ruijin Hospital, from 2019 to 2022. The genotype of epidermal growth factor receptor (EGFR) was identified. Tumor cells were isolated and treated with arsenic trioxide (ATO) or/and gefitinib. Additionally, six patients were intrapleurally administrated with ATO. Results showed that 25 samples bore EGFR wild type (WT) and 11 harbored EGFR mutations, including 6 with L858R, 3 with ΔE746-A750, and 2 with T790M. ATO diminished the number of tumor cells from patients with WT and mutant EGFR, down-regulated the expression or phosphorylation of EGFR, pmTOR, PI3K, PTEN, and p4E-BP1, and up-regulated the expression of LC3. Immunofluorescent experiments showed that ATO enhanced LC3 and P62. By contrast, gefitinib was only effective in those harboring EGFR sensitizing mutations. Notably, in patients with intrapleural ATO injection, the pleural effusion underwent a bloody to pale yellow color change, the volume of the pleural effusion was reduced, and the number of the tumor cells was significantly reduced. In conclusion, arsenic is effective against NSCLC with various EGFR genotypes in vitro and in vivo, and potentially circumvents gefitinib resistance.

The Resistance to EGFR-TKIs in Non-Small Cell Lung Cancer: From Molecular Mechanisms to Clinical Application of New Therapeutic Strategies

Almost 17% of Western patients affected by non-small cell lung cancer (NSCLC) have an activating epidermal growth factor receptor (EGFR) gene mutation. Del19 and L858R are the most-common ones; they are positive predictive factors for EGFR tyrosine kinase inhibitors (TKIs). Currently, osimertinib, a third-generation TKI, is the standard first-line therapy for advanced NSCLC patients with common EGFR mutations. This drug is also administered as a second-line treatment for those patients with the T790M EGFR mutation and previously treated with first- (erlotinib, gefitinib) or second- (afatinib) generation TKIs. However, despite the high clinical efficacy, the prognosis remains severe due to intrinsic or acquired resistance to EGRF-TKIs. Various mechanisms of resistance have been reported including the activation of other signalling pathways, the development of secondary mutations, the alteration of the downstream pathways, and phenotypic transformation. However, further data are needed to achieve the goal of overcoming resistance to EGFR-TKIs, hence the necessity of discovering novel genetic targets and developing new-generation drugs. This review aimed to deepen the knowledge of intrinsic and acquired molecular mechanisms of resistance to EGFR-TKIs and the development of new therapeutic strategies to overcome TKIs' resistance.

Heterogeneous distribution of EGFR mutation in NSCLC: Case report

Background

We herein report the case of a patient with advanced lung adenocarcinoma who presented a heterogeneous distribution of EGFR mutation.

Case report

A 74-year-old Moroccan male former smoker was diagnosed with advanced lung adenocarcinoma, harboring S768I exon 20 substitution mutation confirmed by Real Time PCR and Pyrosequencing, but not detected by direct sequencing despite 70% of tumor cells. The present report describes a case of minor histologic intratumoral heterogeneity with heterogeneous distribution of EGFR mutation.

Conclusion

Both sensitivity and specificity of molecular methods can provide evidence of intratumoral heterogeneity, which may explain the mismatch between the validation of oncology biomarkers and predicting therapeutic response to targeted therapy.

Therapeutic strategies of dual-target small molecules to overcome drug resistance in cancer therapy

Despite some advances in targeted therapeutics of human cancers, curative cancer treatment still remains a tremendous challenge due to the occurrence of drug resistance. A variety of underlying resistance mechanisms to targeted cancer drugs have recently revealed that the dual-target therapeutic strategy would be an attractive avenue. Compared to drug combination strategies, one agent simultaneously modulating two druggable targets generally shows fewer adverse reactions and lower toxicity. As a consequence, the dual-target small molecule has been extensively explored to overcome drug resistance in cancer therapy. Thus, in this review, we focus on summarizing drug resistance mechanisms of cancer cells, such as enhanced drug efflux, deregulated cell death, DNA damage repair, and epigenetic alterations. Based upon the resistance mechanisms, we further discuss the current therapeutic strategies of dual-target small molecules to overcome drug resistance, which will shed new light on exploiting more intricate mechanisms and relevant dual-target drugs for future cancer therapeutics.

Sounding the Alarm: Sex Differences in Rat Ultrasonic Vocalizations during Pavlovian Fear Conditioning and Extinction

Pavlovian fear conditioning is a prevalent tool in the study of aversive learning, which is a key component of stress-related psychiatric disorders. Adult rats can exhibit various threat-related behaviors, including freezing, motor responses, and ultrasonic vocalizations (USVs). While these responses can all signal aversion, we know little about how they relate to one another. Here we characterize USVs emitted by male and female rats during cued fear acquisition and extinction, and assess the relationship between different threat-related behaviors. We found that males consistently emitted >22 kHz calls (referred to here as "alarm calls") than females, and that alarm call frequency in males, but not females, related to the intensity of the shock stimulus. Interestingly, 25% of males and 45% of females did not emit any alarm calls at all. Males that did make alarm calls had significantly higher levels of freezing than males who did not, while no differences in freezing were observed between female Alarm callers and Non-alarm callers. Alarm call emission was also affected by the predictability of the shock; when unpaired from a tone cue, both males and females started emitting alarm calls significantly later. During extinction learning and retrieval sessions, males were again more likely than females to emit alarm calls, which followed an extinction-like reduction in frequency. Collectively these data suggest sex dependence in how behavioral readouts relate to innate and conditioned threat responses. Importantly, we suggest that the same behaviors can signal sex-dependent features of aversion.

EGFR-TKI re-administration after osimertinib failure in T790M mutation loss cases with re-biopsy

Data on the re-administration of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) after osimertinib failure in patients with T790M-positive non-small cell lung cancer (NSCLC) is limited. EGFR-TKI re-administration efficacy may vary between patients with T790M loss and those with T790M persistent with re-biopsy after osimertinib treatment. Patients who received EGFR-TKI re-administration (gefitinib, erlotinib, afatinib, dacomitinib, and osimertinib) after osimertinib failure were identified from our database. T790M mutation status before EGFR-TKI re-administration was analyzed via repeat biopsy. We retrospectively evaluated the efficacy of EGFR-TKI re-administration, especially differences according to the T790M mutation status, via repeat biopsy. Until June 2020, 28 patients received EGFR-TKI re-administration and 17 underwent repeat biopsy after osimertinib failure. Patients were divided into three groups, including the T790M loss group, where active mutation persisted and T790M was lost (13/17); T790M remaining group, where both the active mutation and T790M persisted (3/17); and active mutation loss group where both the active mutation and T790M were lost (1/17). The overall response rate (ORR) of EGFR-TKI re-administration in the T790M loss group was 31% and the disease control rate (DCR) was 54%, which were higher than the ORR of 21% and DCR of 43% in the entire patient population. ORR and DCR of the not re-biopsy group were low (9% and 27%, respectively). The therapeutic effect of EGFR-TKI re-administration in patients with T790M-positive NSCLC after osimertinib failure is limited. EGFR-TKI re-administration may be considered in cases of T790M loss after repeat biopsy.

Minimal residual disease in EGFR-mutant non-small-cell lung cancer

Targeted therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is an effective treatment for EGFR-mutant non-small-cell lung cancer (NSCLC), however most patients invariably relapse after a period of minimal residual disease (MRD). This mini-review explores the mechanistic pathways leading to tumour dormancy, cellular senescence and epigenetic changes involving YAP/TEAD activation. We describe the various approaches of utilising TKIs in combination with agents to intensify initial depth of response, enhance apoptosis and target senescence-like dormancy. This mini-review will also highlight the potential novel therapies under development targeting MRD to improve outcomes for patients with EGFR-mutant NSCLC.

Rapid intraoperative Ki-67 immunohistochemistry for lung cancer using non-contact alternating current electric field mixing

OBJECTIVES

Locoregional recurrence of non-small cell lung cancer (NSCLC) occurs even among patients with stage I disease, as a result of tumor proliferative activity. The aim of this study was to evaluate the clinical reliability of a new rapid immunohistochemistry (IHC) technique for assessing malignant potential through detection of tumoral Ki-67 expression.

MATERIALS AND METHODS

The rapid IHC method uses non-contact alternating current (AC) mixing to achieve more rapid/stable staining within 20 min during surgery. First, to investigate the association between clinical outcomes and tumoral Ki-67 labeling with rapid IHC, 21 pairs of surgical patients treated between 2012 and 2020 for pStage IA1-3 NSCLC with/without recurrence were retrospectively reviewed. Second, 40 frozen section (FS) samples in patients with NSCLC for whom radical surgery was planned between April 2021 and February 2022 were deemed eligible for comparison of the clinical performance of conventional IHC and intraoperative rapid Ki-67 IHC with FS.

RESULTS

Detection of tumoral Ki-67 expression using rapid IHC with formalin-fixed, paraffin-embedded (FFPE) blocks was significantly associated with clinical outcomes in R0 pStage IA NSCLC surgical patients, including overall and recurrence-free survival (P = 0.0043 and P < 0.0001, respectively). Levels of Ki-67 expression among resectable NSCLC patients detected using rapid IHC with FS significantly correlated with those detected using conventional FFPE-IHC (p < 0.001). An intraoperative cut-off of > 7.5 % tumor cell Ki-67 positivity accurately predicted pathological stage more advanced than IA3 [P = 0.0185, Odds ratio = 20.477, 95 % confidence interval (CI): 1.660-252.55].

CONCLUSION

Rapid Ki-67 IHC with AC mixing could potentially serve as a clinical tool for intraoperative determination of tumor malignancy status. The present study suggests that segmentectomy for early small NSCLCs is oncologically safe and a reasonable alternative to lobectomy, but only when there is adequate intraoperative selection for primary tumors with low-grade malignancy, which could be verified using intraoperative rapid Ki-67 IHC with FS.

Landscape of EGFR mutations in lung adenocarcinoma: a single institute experience with comparison of PANAMutyper testing and targeted next-generation sequencing

Background

Activating mutations in the tyrosine kinase domain of epidermal growth factor receptor (EGFR) are predictive biomarkers for response to EGFR–tyrosine kinase inhibitor (TKI) therapy in lung adenocarcinoma (LUAD). Here, we characterized the clinicopathologic features associated with EGFR mutations via peptide nucleic acid clamping-assisted fluorescence melting curve analysis (PANAMutyper) and evaluated the feasibility of targeted deep sequencing for detecting the mutations.

Methods

We examined EGFR mutations in exons 18 through 21 for 2,088 LUADs from July 2017 to April 2020 using PANAMutyper. Of these, we performed targeted deep sequencing in 73 patients and evaluated EGFR-mutation status and TKI clinical response.

Results

EGFR mutation was identified in 55.7% of LUADs by PANAMutyper, with mutation rates higher in females (69.3%) and never smokers (67.1%) and highest in the age range of 50 to 59 years (64.9%). For the 73 patients evaluated using both methods, next-generation sequencing (NGS) identified EGFR mutation–positive results in 14 of 61 patients (23.0%) who were EGFR-negative according to PANAMutyper testing. Of the 10 patients reportedly harboring a sensitizing mutation according to NGS, seven received TKI treatment, with all showing partial response or stable disease. In the 12 PANAMutyper-positive cases, NGS identified two additional mutations in exon 18, whereas a discordant negative result was observed in two cases.

Conclusions

Although PANAMutyper identified high frequencies of EGFR mutations, targeted deep sequencing revealed additional uncommon EGFR mutations. These findings suggested that appropriate use of NGS may benefit LUAD patients with otherwise negative screening test results.

Engaging innate immunity for targeting the epidermal growth factor receptor: Therapeutic options leveraging innate immunity versus adaptive immunity versus inhibition of signaling

The epidermal growth factor receptor (EGFR) is a key player in the normal tissue physiology and the pathology of cancer. Therapeutic approaches have now been developed to target oncogenic genetic aberrations of EGFR, found in a subset of tumors, and to take advantage of overexpression of EGFR in tumors. The development of small-molecule inhibitors and anti-EGFR antibodies targeting EGFR activation have resulted in effective but limited treatment options for patients with mutated or wild-type EGFR-expressing cancers, while therapeutic approaches that deploy effectors of the adaptive or innate immune system are still undergoing development. This review discusses EGFR-targeting therapies acting through distinct molecular mechanisms to destroy EGFR-expressing cancer cells. The focus is on the successes and limitations of therapies targeting the activation of EGFR versus those that exploit the cytotoxic T cells and innate immune cells to target EGFR-expressing cancer cells. Moreover, we discuss alternative approaches that may have the potential to overcome limitations of current therapies; in particular the innate cell engagers are discussed. Furthermore, this review highlights the potential to combine innate cell engagers with immunotherapies, to maximize their effectiveness, or with unspecific cell therapies, to convert them into tumor-specific agents.

Technical Validation and Clinical Implications of Ultrasensitive PCR Approaches for EGFR-Thr790Met Mutation Detection in Pretreatment FFPE Samples and in Liquid Biopsies from Non-Small Cell Lung Cancer Patients

In pretreatment tumor samples of EGFR-mutated non-small cell lung cancer (NSCLC) patients, EGFR-Thr790Met mutation has been detected in a variable prevalence by different ultrasensitive assays with controversial prognostic value. Furthermore, its detection in liquid biopsy (LB) samples remains challenging, being hampered by the shortage of circulating tumor DNA (ctDNA). Here, we describe the technical validation and clinical implications of a real-time PCR with peptide nucleic acid (PNA-Clamp) and digital droplet PCR (ddPCR) for EGFR-Thr790Met detection in diagnosis FFPE samples and in LB. Limit of blank (LOB) and limit of detection (LOD) were established by analyzing negative and low variant allele frequency (VAF) FFPE and LB specimens. In a cohort of 78 FFPE samples, both techniques showed an overall agreement (OA) of 94.20%. EGFR-Thr790Met was detected in 26.47% of cases and was associated with better progression-free survival (PFS) (16.83 ± 7.76 vs. 11.47 ± 1.83 months; p = 0.047). In LB, ddPCR was implemented in routine diagnostics under UNE-EN ISO 15189:2013 accreditation, increasing the detection rate of 32.43% by conventional methods up to 45.95%. During follow-up, ddPCR detected EGFR-Thr790Met up to 7 months before radiological progression. Extensively validated ultrasensitive assays might decipher the utility of pretreatment EGFR-Thr790Met and improve its detection rate in LB studies, even anticipating radiological progression.

Optimizing Patient Outcomes Through Sequential EGFR TKI Treatment in Asian Patients With EGFR Mutation-Positive NSCLC

Patients from Asia with non-small-cell lung cancer (NSCLC) often have mutations in the epidermal growth factor receptor (EGFR) gene. While an increasing number of EGFR tyrosine kinase inhibitors (TKIs) are now available for patients with EGFR mutation-positive NSCLC, most patients inevitably develop resistance to the treatment. Evidence from clinical studies suggests that treatment outcomes and resistance mechanisms vary depending on the choice of TKI therapy in the first-line setting. Hence, it is important to develop optimal treatment sequencing strategies that can provide maximum survival benefit for the patient. In this review we present clinical evidence in Asian patients with NSCLC for various EGFR TKIs, with the goal of supporting the optimization of treatment sequencing.

A Lung Cancer Patient Harboring a Rare Oncogenic EGFR Exon 20 V786M Mutation Responded to a Third-Generation Tyrosine Kinase Inhibitor: Case Report and Review of the Literature

Background

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are effective treatments for non-small cell lung cancer (NSCLC) patients with activating EGFR mutations. There are many uncommon and rare mutations in the EGFR gene. The efficacy of the EGFR-TKIs is largely unknown for cancers harboring uncommon or rare EGFR mutations.

Case Presentation

A 69-year-old woman was diagnosed with adenocarcinoma cT4N2M1c, stage IVB. Next-generation sequencing (NGS) confirmed a rare EGFR V786M mutation. During chemotherapy, immune checkpoint inhibitor (ICI), and anti-angiogenic treatment, no radiological response was observed. Subsequent third-generation EGFR TKI showed a remarkable therapeutic effect. Structural prediction revealed that the V786M mutation induces conformational change at the dimer interface, without altering the ATP binding to the EGFR tyrosine kinase domain (TKD). Consistently, docking simulations indicated that the affinity of ATP to the V786M mutant was not disturbed, which explained the TKI sensitivity.

Conclusions

Our data confirmed the activating role on EGFR V786M mutation. Together with structural predictions and clinical evidence for activity of TKIs against EGFR V786M mutations, these findings warrant further investigation.

Utility of Next-Generation Sequencing in the Reconstruction of Clonal Architecture in a Patient with an EGFR Mutated Advanced Non-Small Cell Lung Cancer: A Case Report

EGFR tyrosine kinase inhibitors (EGFR-TKIs) have revolutionized the treatment of non-small cell lung cancer (NSCLC) patients with activating EGFR mutations. However, targeted therapies impose a strong selective pressure against the coexisting tumor populations that lead to the emergence of resistant clones. Molecular characterization of the disease is essential for the clinical management of the patient, both at diagnosis and after progression. Next-generation sequencing (NGS) has been established as a technique capable of providing clinically useful molecular profiling of the disease in tissue samples and in non-invasive liquid biopsy samples (LB). Here, we describe a case report of a patient with metastatic NSCLC harboring EGFR mutation who developed two independent resistance mechanisms (EGFR-T790M and TP53 + RB1 mutations) to dacomitinib. Osimertinib given as a second-line treatment eliminated the EGFR-T790M population and simultaneously consolidated the proliferation of the TP53 + RB1 clone that eventually led to the histologic transformation to small-cell lung cancer (SCLC). Comprehensive NGS profiling revealed the presence of the TP53 + RB1 clone in the pretreatment biopsy, while EGFR-T790M was only detected after progression on dacomitinib. Implementation of NGS studies in routine molecular diagnosis of tissue and LB samples provides a more comprehensive view of the clonal architecture of the disease in order to guide therapeutic decision-making.

Molecular target therapeutics of EGF-TKI and downstream signaling pathways in non-small cell lung cancers

Lung carcinoma (LC) is the third most common cancer diagnosis and accounted for the most cancer-related mortality worldwide in 2018. Based on the type of cells from which it originates, LC is commonly classified into non-small cell lung cancers (NSCLC) and small cell lung cancers (SCLC). NSCLC account for the majority of LC and can be further categories into adenocarcinoma, large cell carcinoma, and squamous cell carcinoma. Accurate classification of LC is critical for its adequate treatment and therapeutic outcome. Since NSCLC express more epidermal growth factor receptor (EGFR) with activation mutations, targeted therapy EGFR-tyrosine kinase inhibitors (TKIs) have been considered as primary option of NSCLC patients with activation EGFR mutation. In this review, we present the genetic alterations, reported mutations in EGFR, and TKIs treatment in NSCLC patients with an emphasis on the downstream signaling pathways in NSCLC progression. Among the signaling pathways identified, mitogen activation protein kinase (MAPK), known also as extracellular signal-regulated protein kinase (Erk) pathway, is the most investigated among the related pathways. EGFR activation leads to the autophosphorylation of its kinase domain and subsequent activation of Ras, phosphorylation of Raf and MEK1/2, and the activation of ERK1/2. Phosphatidylinositol 3-kinase (PI3K)/Akt is another signal pathway that regulates cell cycle and has been linked to NSCLC progression. Currently, three generations of EGFR TKIs have been developed as a first-line treatment of NSCLC patients with EGFR activation and mutation in which these treatment options will be further discussed in this review. The Supplementary Appendix for this article is available at http://links.lww.com/JCMA/A138.

Effects of Different Centrifugation Protocols on the Detection of EGFR Mutations in Plasma Cell-Free DNA

Objectives

Various preanalytical factors, including the collection tube, storage conditions, and centrifugation, affect the detection results of plasma cell-free DNA (cfDNA). We compared the effect of different centrifugation protocols on the detection of EGFR mutations in cfDNA.

Methods

We analyzed 117 plasma specimens from 110 patients with non–small cell lung cancer using the cobas EGFR Mutation Test v2 (Roche Diagnostics). We compared the identified EGFR mutations and semiquantitative index values from the 1- and 2-step centrifugation groups and confirmed the clinical impact of differences in the results after further high-speed centrifugation.

Results

We detected EGFR mutations in 44 (37.6%) and 47 (40.2%) samples that were centrifuged once and twice, respectively; the 2 groups showed an 89.7% (105/117) concordance and a strong correlation in their semiquantitative index values (r = 0.929). Among the 12 inconsistent result pairs, 9 samples of 2-step centrifugation (75%) were consistent with the results of a recent tissue biopsy.

Conclusions

Additional high-speed centrifugation has been shown to increase the sensitivity of EGFR mutation detection in a commercial in vitro diagnostic real-time polymerase chain reaction device and is an optimal preanalytical factor for detecting low-allele frequency gene mutations using low concentrations of cfDNA.

Role of Circulating Tumor DNA Profiling in Patients with Non-Small Cell Lung Cancer Treated with EGFR Inhibitor

OBJECTIVES

During targeted therapy, tumor heterogeneity can drive the evolution of multiple tumor subclones harboring unique resistance mechanisms. Sequential profiling of plasma cell-free DNA (cfDNA) provides a noninvasive method for early detection of patient progression. We investigated whether the genetic dynamics detected in cfDNA during treatment can act as a predictive or prognostic marker of outcome.

METHODS

Patients with advanced EGFR-mutated non-small cell lung cancer (NSCLC) were included for consecutive blood sampling during EGFR-tyrosine kinase inhibitor (TKI) treatment. Blood samples were serially collected from patients at baseline, first follow-up, and progression. Extracted cfDNA was analyzed with next-generation sequencing.

RESULTS

Serial plasma samples (n = 187) from 63 patients were analyzed, and 44 patients showed circulating tumor DNA (ctDNA). EGFR mutations were detected in 36 of the 44 patients at baseline (81.8%). EGFR mutations were no longer detected in 19 of 36 shedders (52.8%) at 2 months after EGFR-TKI treatment and rebounded with resistant EGFR mutations (T790M or C797S) at progression. Other driver mutations such as KRAS G12D and BRAF V600E were found at baseline regardless of tissue EGFR status, suggesting tumor heterogeneity. Detection of ctDNA (shedder) at baseline associated with poor overall survival (p = 0.04) compared to nonshedder. Furthermore, in patients showing EGFR mutations in plasma at baseline, the clearing rate of those during the first 8 weeks of treatment served as a positive predictor for clinical outcome.

CONCLUSION

Longitudinal liquid biopsies capture spatial and temporal heterogeneity underlining resistance to EGFR-TKIs in NSCLC. Thus, ctDNA monitoring during EGFR-TKI treatment is useful for detecting resistance mutations or predicting response. Dense serial monitoring using blood enables early prediction of treatment failure and provides a window of opportunity for well-timed intervention.

Predictive value of multiple metabolic and heterogeneity parameters of 18F-FDG PET/CT for EGFR mutations in non-small cell lung cancer

OBJECTIVES

To explore the value of multiple metabolic and heterogeneity parameters of 2-deoxy-2-[fluorine-18] fluoro-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in predicting epidermal growth factor receptor gene (EGFR) mutations in non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

A retrospective analysis was performed by reviewing 98 patients with NSCLC who underwent EGFR mutation testing and ¹⁸F-FDG PET/CT examination in our hospital between March 2016 and March 2021. Patients were divided into an EGFR-mutant group and a wild-type group. A multivariate logistic regression analysis was performed to screen and construct a prediction model. The diagnostic performance of the model was evaluated using a receiver-operating characteristic (ROC) curve.

RESULTS

The study found that EGFR mutations were more likely to occur in women, non-smokers, and patients with peripheral lesions, shorter maximum tumor diameter, adenocarcinoma, and T1 stage cancer. Low maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume, total lesion glycolysis, and high coefficient of variation (COV) were significantly correlated with EGFR mutations, and the area under the ROC curve (AUC) was 0.622, 0.638, 0.679, 0.687, and 0.672, respectively. Multivariate logistic regression analysis indicated that non-smokers (odds ratio (OR) = 0.109, P = 0.014), peripheral lesions (OR = 6.917, P = 0.022), low SUVmax (≤ 7.85, OR = 5.471, P = 0.001), SUVmean (≤ 5.34, OR = 0.044, P = 0.000), and high COV (≥ 106.08, OR = 0.996, P = 0.045) were independent predictors of EGFR mutations. The AUC of the prediction model established by combining the above factors was 0.926; the diagnostic efficiency was significantly higher than that of a single parameter.

CONCLUSION

Among the metabolic and heterogeneity parameters of ¹⁸F-FDG PET/CT, low SUVmax, SUVmean, and high COV were significantly associated with EGFR mutations, and the predictive value of EGFR mutations could be enhanced when combined with clinicopathological features.

New PET/CT criterion for predicting lymph node metastasis in resectable advanced (stage IB-III) lung cancer: The standard uptake values ratio of ipsilateral/contralateral hilar nodes

Background

The aim of the present study was to use surgical and histological results to develop a simple noninvasive technique to improve nodal staging using preoperative PET/CT in patients with resectable lung cancer.

Methods

Preoperative PET/CT findings (pStage IB–III 182 patients) and pathological diagnoses after surgical resection were evaluated. Using PET/CT images to determine the standardized uptake value (SUV) ratio, the SUV_max of a contralateral hilar lymph node (on the side of the chest opposite to the primary tumor) was measured simultaneously. The I/C‐SUV ratio was calculated as ipsilateral hilar node SUV/contralateral hilar node SUV. Receiver operating characteristic (ROC) curves were then used to analyze those data.

Results

Based on ROC analyses, the cutoff I/C‐SUV ratio for diagnosis of lymph node metastasis was 1.34. With a tumor ipsilateral lymph node SUV_max ≥2.5, an IC‐SUV ratio ≥1.34 had the highest accuracy for predicting N1/N2 metastasis; the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of nodal staging were 60.66, 85.11, 84.09, 62.5 and 71.29%, respectively.

Conclusions

When diagnosing nodal stage, a lymph node I/C‐SUV ratio ≥1.34 can be an effective criterion for determining surgical indications in advanced lung cancer.

GZ17-6.02 and palbociclib interact to kill ER+ breast cancer cells

GZ17-6.02 is presently undergoing clinical evaluation in solid tumors and lymphoma. The present studies were performed to define its biology in estrogen receptor positive breast cancer cells and to determine whether it interacted with palbociclib to enhance tumor cell killing. GZ17-6.02 interacted in an additive fashion with palbociclib to kill ER+ breast cancer cells. GZ17-6.02 and palbociclib cooperated to inactivate mTOR and AKT and to activate ULK1 and PERK. The drugs interacted to increase the expression of FAS-L and BAX, and to decrease the levels of MCL1, the estrogen receptor, and HDACs 1–3. Palbociclib activated ERBB3, an effect blocked by GZ17-6.02. GZ17-6.02 and palbociclib interacted to increase the expression of multiple toxic BH3 domain proteins and to reduce MCL1 and BCL-XL expression. Knock down of FAS-L reduced the lethality of [GZ17-6.02 + palbociclib]. GZ17-6.02 and palbociclib interacted to enhance autophagosome formation and autophagic flux. Knock down of Beclin1, ATG5, BAG3, eIF2α, toxic BH3 domain proteins or CD95 significantly reduced drug combination lethality. GZ17-6.02 and palbociclib increased the expression of Beclin1 and ATG5, effects blocked by knock down of eIF2α. The drugs also increased the phosphorylation of the AMPK and ATG13, effects blocked by knock down of ATM. Knock down of ATM or the AMPK, or expression of activated mTOR significantly reduced the abilities of GZ17-6.02 and palbociclib to enhance autophagosome formation and autophagic flux.

Heterogeneity among tumors with acquired resistance to EGFR tyrosine kinase inhibitors harboring EGFR ‐T790M mutation in non‐small cell lung cancer cells

EGFR‐T790M mutation is a major mechanism underlying acquired resistance to first‐ and second‐generation EGFR tyrosine kinase inhibitors (EGFR‐TKIs) in lung cancer with mutated EGFR. However, differences in the biological characteristics of T790M tumors based on treatment regimens with each generation of EGFR‐TKI are not fully understood. We established cell lines with acquired resistance harboring EGFR‐T790M mutation derived from xenograft tumors treated with each generation of EGFR‐TKI and examined their biological characteristics with respect to third‐generation EGFR‐TKI osimertinib sensitivity. Second‐generation EGFR‐TKI dacomitinib‐resistant cells with T790M‐exhibited higher sensitivity to osimertinib than first‐generation EGFR‐TKI gefitinib‐resistant cells with T790M via inhibition of AKT and ERK signaling and promotion of apoptosis. Furthermore, gefitinib‐resistant cells showed enhanced intratumor heterogeneity accompanied by genomic instability and activation of alternative resistance mechanisms compared with dacomitinib‐resistant cells; this suggests that the maintenance of EGFR dependency after acquiring resistance might depend on the type of EGFR‐TKI. Our results demonstrate that the progression of tumor heterogeneity via both genetic and non‐genetic mechanisms might affect osimertinib sensitivity in tumors with acquired resistance harboring EGFR‐T790M mutation.

Subclonal landscape of cancer drives resistance to immune therapy

Tumor mutation burden (TMB) is often used as a biomarker for immunogenicity and prerequisite for immune checkpoint inhibitor (ICI) therapy. However, it is becoming increasingly evident that not all tumors with high TMB respond to ICIs as expected. It has been shown that the ability of T-cells to infiltrate the tumor microenvironment and elicit a specific immune response is dependent not only on the TMB, but also on intra-tumor heterogeneity and the fraction of low-frequency subclonal mutations that make up the tumor. High intra-tumor heterogeneity leads to inefficient recognition of tumor neoantigens by T-cells due to their diluted frequency and spatial heterogeneity. Clinical studies have shown that tumors with a high degree of intra-tumor heterogeneity respond poorly to ICI therapy, and previous cytotoxic treatment may increase the intra-tumor heterogeneity and render second-line ICI therapy less effective. This paper reviews the role of ICI therapy when following chemotherapy or radiation to determine if they may be better suited as first-line therapy in patients with high TMB, low intra-tumor heterogeneity, and high PD-1, PD-L1, or CTLA-4 expression.

Subregional radiomics analysis for the detection of the EGFR mutation on thoracic spinal metastases from lung cancer

The present study intended to use radiomic analysis of spinal metastasis subregions to detect epidermal growth factor receptor (EGFR) mutation. In total, 94 patients with thoracic spinal metastasis originated from primary lung adenocarcinoma (2017-2020) were studied. All patients underwent T1-weighted (T1W) and T2 fat-suppressed (T2FS) MRI scans. The spinal metastases (tumor region) were subdivided into phenotypically consistent subregions based on patient- and population-level clustering: Three subregions, S1, S2 and S3, and the total tumor region. Radiomics features were extracted from each subregion and from the whole tumor region as well. Least shrinkage and selection operator (LASSO) regression were used for feature selection and radiomics signature definition. Detection performance of S3 was better than all other regions using T1W (AUCs, S1 versus S2 versus S3 versus whole tumor, 0.720 versus 0.764 versus 0.786 versus 0.758) and T2FS (AUCs, S1 versus S2 versus S3 versus whole tumor, 0.791 versus 0.708 versus 0.838 versus 0.797) MRI. The multi-regional radiomics signature derived from the joint of inner subregion S3 from T1W and T2FS MRI achieved the best detection capabilities with AUCs of 0.879 (ACC = 0.774, SEN = 0.838, SPE = 0.840) and 0.777 (ACC = 0.688, SEN = 0.947, SPE = 0.615) in the training and test sets, respectively. Our study revealed that MRI-based radiomic analysis of spinal metastasis subregions has the potential to detect the EGFR mutation in patients with primary lung adenocarcinoma.

Molecular Mechanism of EGFR-TKI Resistance in EGFR-Mutated Non-Small Cell Lung Cancer: Application to Biological Diagnostic and Monitoring

Non-small cell lung cancer (NSCLC) is the most common cancer in the world. Activating epidermal growth factor receptor (EGFR) gene mutations are a positive predictive factor for EGFR tyrosine kinase inhibitors (TKIs). For common EGFR mutations (Del19, L858R), the standard first-line treatment is actually third-generation TKI, osimertinib. In the case of first-line treatment by first (erlotinib, gefitinib)- or second-generation (afatinib) TKIs, osimertinib is approved in second-line treatment for patients with T790M EGFR mutation. Despite the excellent disease control results with EGFR TKIs, acquired resistance inevitably occurs and remains a biological challenge. This leads to the discovery of novel biomarkers and possible drug targets, which vary among the generation/line of EGFR TKIs. Besides EGFR second/third mutations, alternative mechanisms could be involved, such as gene amplification or gene fusion, which could be detected by different molecular techniques on different types of biological samples. Histological transformation is another mechanism of resistance with some biological predictive factors that needs tumor biopsy. The place of liquid biopsy also depends on the generation/line of EGFR TKIs and should be a good candidate for molecular monitoring. This article is based on the literature and proposes actual and future directions in clinical and translational research.

An open-label expanded access program of afatinib in EGFR tyrosine kinase inhibitor-naïve patients with locally advanced or metastatic non-small cell lung cancer harboring EGFR mutations

BACKGROUND

Afatinib is approved globally for EGFR-TKI treatment-naïve patients with EGFR mutation-positive non-small cell lung cancer (NSCLC). In this Korean expanded access program, we evaluated its 'real-world' safety and efficacy.

METHODS

EGFR-TKI treatment-naïve patients with EGFR mutation-positive NSCLC received afatinib 40 mg/day until disease progression or other withdrawal criteria. Dose reductions were permitted for adverse events (AEs). The primary endpoint was the number of patients with AEs (CTCAE version 3.0). Other endpoints included progression-free survival (PFS), overall response rate (ORR), duration of response (DOR), and changes in investigator-assessed cancer-related symptoms.

RESULTS

Eighty-eight patients received afatinib, including 27 (31%) with brain metastases and 16 (18%) with uncommon EGFR mutations. Median PFS was 17.0 months (95% confidence interval [CI] 12.9-23.3 months). Grade 3 treatment-related AEs (TRAEs) were reported in 51 (58%) patients; the most common were diarrhea (22%) and rash/acne (20%). No grade > 3 TRAEs were reported. AEs leading to dose reduction occurred in 49 (56%) patients. Treatment discontinuation due to TRAEs occurred in 4 (5%) patients. ORR was 81% overall, 89% in patients with brain metastases, and 55% in patients with uncommon mutations (excluding T790M/exon 20 insertions). Median DOR was 15.1 months (95% CI 12.4-21.4 months). Cancer-related symptoms were improved/unchanged/worsened in 34-66%/36-66%/0-3% of patients over the first year.

CONCLUSIONS

No unexpected safety signals for afatinib were observed. AEs were manageable; the treatment discontinuation rate was low. Afatinib showed encouraging efficacy in a broad patient population including those with brain metastases or tumors harboring uncommon EGFR mutations.

TRIALS REGISTRATION

ClinicalTrials.gov NCT01931306 ; 29/08/2013.

Afatinib in EGFR TKI-Naïve Patients with Locally Advanced or Metastatic EGFR Mutation-Positive Non-Small Cell Lung Cancer: A Pooled Analysis of Three Phase IIIb Studies

Background

Afatinib is approved for first-line treatment of patients with epidermal growth factor receptor mutation-positive (EGFRm+) non-small-cell lung cancer (NSCLC). Here, we report findings from a combined analysis of three phase IIIb studies of afatinib in EGFR tyrosine kinase inhibitor (TKI)-naïve patients.

Methods

EGFR-TKI-naïve patients with EGFRm+ NSCLC received afatinib 40 mg/day. Dose reductions were permitted for adverse events (AEs). Efficacy endpoints included progression-free survival (PFS), time to symptomatic progression (TTSP), and tumor response. Subgroup analyses were performed by Eastern Cooperative Oncology Group performance status (ECOG PS), presence of brain metastasis, age and common/uncommon EGFR mutations (plus other factors).

Results

1108 patients were treated. Median age was 61 years (range, 25-89); 19.2% had baseline brain metastases, 4.4% had ECOG PS ≥2, and 17.9% had tumors harboring uncommon mutations. Treatment-related AEs (TRAEs) were reported in 97.2%, most commonly diarrhea and rash. 41.6% had AEs leading to dose reduction. Median PFS was 13.0 months [95% confidence interval (CI): 12.0-13.8]; median TTSP was 14.8 months (95% CI: 13.9-16.1). Objective response rate (ORR) was 55.0%. Age, presence of baseline brain metastases, major (G719X, L861Q, S768I) or compound uncommon mutations had little/no effect on PFS, TTSP, or ORR, while outcomes were poorer in patients with ECOG PS 2 or exon 20 insertion/T790M mutations.

Conclusions

Afatinib was tolerable with no new safety signals. Afatinib demonstrated encouraging efficacy in a broad patient population, including those with brain metastases or uncommon EGFR mutations.

A new sensitive and fast assay for the detection of EGFR mutations in liquid biopsies

BACKGROUND

A major perspective for the use of circulating tumor DNA (ctDNA) in the clinical setting of non-small cell lung cancer (NSCLC) is expected as predictive factor for resistance and response to EGFR TKI therapy and, especially, as a non-invasive alternative to tissue biopsy. However, ctDNA is both highly fragmented and mostly low concentrated in plasma and serum. On this basis, it is important to use a platform characterized by high sensitivity and linear performance in the low concentration range. This motivated us to evaluate the newly developed and commercially available SensiScreen® EGFR Liquid assay platform (PentaBase) with regard to sensitivity, linearity, repeatability and accuracy and finally to compare it to our already implemented methods. The validation was made in three independent European laboratories using two cohorts on a total of 68 unique liquid biopsies.

RESULTS

Using artificial samples containing 1600 copies of WT DNA spiked with 50% - 0.1% of mutant copies across a seven-log dilution scale, we assessed the sensitivity, linearity, repeatability and accuracy for the p.T790M, p.L858R and exon 19 deletion assays of the SensiScreen® EGFR Liquid assay platform. The lowest value detectable ranged from 0.5% to 0.1% with R2≥0,97 indicating good linearity. High PCR efficiency was shown for all three assays. In 102 single PCRs each containing theoretical one copy of the mutant at initiating, assays showed repeatable positivity in 75.5% - 80.4% of reactions. At low ctDNA levels, as in plasma, the SensiScreen® EGFR Liquid assay platform showed better sensitivity than the Therascreen® EGFR platform (Qiagen) and equal performance to the ctEGFR Mutation Detection Kit (EntroGen) and the IOT® Oncomine cell-free nucleic acids assay (Thermo Fisher Scientific) with 100% concordance at the sequence level.

CONCLUSION

For profiling clinical plasma samples, characterized by low ctDNA abundance, the SensiScreen® EGFR Liquid assay is able to identify down to 1 copy of mutant alleles and with its high sensitivity, linearity and accuracy it may be a competitive platform of choice.

Afatinib as first-line treatment in patients with EGFR-mutated non-small cell lung cancer in routine clinical practice

Background:

Lung cancer is a leading cause of cancer-related death in Germany and worldwide. Non-small cell lung cancer (NSCLC) comprises ~80% of lung cancer diagnoses; in White patients, around 10% of NSCLC cases are epidermal growth factor receptor mutation-positive (EGFRm+). Head-to-head clinical trials have demonstrated superior efficacy with second-/third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) versus first-generation EGFR TKIs in EGFRm+ NSCLC. Data from routine clinical practice are necessary to confirm that clinical trial findings are transferable to real-world populations.

Methods:

In NCT02047903, a prospective non-interventional study in Germany, patients with EGFRm+ NSCLC received first-line afatinib until disease progression or intolerable adverse events. Key objectives were progression-free survival (PFS) rate at 12 months, objective response rate (ORR) and overall survival (OS). Safety/tolerability was also assessed.

Results:

Of 152 patients, 106 (69.7%) were female, 20 (13.1%) patients had an uncommon EGFR mutation and 51 patients (33.6%) had brain metastases. A starting dose of <40 mg was received by 39 (25.7%) patients. Overall, the 12-month PFS rate was 50.2% while the median PFS was 12.2 months. The ORR was 74.6% and the median OS was 30.4 months. In patients with brain metastases and uncommon mutations, the median PFS was 10.5 and 10.7 months, and the ORR was 77.3% and 83.3%, respectively. Treatment effectiveness was similar in patients with a starting dose of <40 mg (median PFS: 16.4 months; ORR, 81.3%) and a starting dose of 40 mg (median PFS: 10.8 months; ORR, 72.1%). Adverse drug reactions were manageable and consistent with the known afatinib safety profile.

Conclusion:

The results support clinical trial data for afatinib in routine clinical practice, including in patients generally excluded from clinical trials. Outcomes were positive in patients with uncommon EGFR mutations and in those with brain metastases. Treatment benefit was also seen in patients receiving a <40 mg afatinib starting dose, supporting patient-tailored dosing.

The ratio of T790M to EGFR-activating mutation predicts response of osimertinib in 1st or 2nd generation EGFR-TKI-refractory NSCLC

The most frequent mechanism of resistance after 1st/2nd-generation (G) epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) is secondary point mutation Thr790Met (T790M) in EGFR. Afatinib followed by osimertinib (Afa group) may provide better outcomes for T790M-positive non-small cell lung cancer (NSCLC) than 1st-G EGFR-TKI followed by osimertinib (1st-G group). We studied 111 consecutive NSCLC patients with T790M mutation treated with osimertinib after progression following 1st/2nd-G EGFR-TKI between March 28, 2016 and March 31, 2018. We analyzed the ratio of T790M to EGFR-activating mutation (T790M ratio) in post EGFR-TKI resistance re-biopsy tissue using droplet digital polymerase chain reaction. And investigated whether afatinib purified the T790M mutation more than 1st-G EGFR-TKI. Among 60 patients with preserved re-biopsy tissue, we analyzed 38 having adequate DNA content. The response rate in Afa group was 81.8% (n = 11) and 1st-G group was 85.2% (n = 27). The mean T790M ratio in total population was 0.3643. The ratio in those with response to osimertinib was significantly higher than in the non-responders (0.395, 0.202; p = 0.0231) and was similar in Afa and 1st-G group (0.371, 0.362; p = 0.9693). T790M ratio significantly correlated with osimertinib response and was similar between the 1st/2nd-G EGFR-TKIs in 1st/2nd-G EGFR-TKI-refractory tumors.

Afatinib as First-Line Treatment in Asian Patients with EGFR Mutation-Positive NSCLC: A Narrative Review of Real-World Evidence

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are a standard of care in the first-line treatment of patients with EGFR mutation-positive metastatic non-small-cell lung cancer (NSCLC). EGFR mutations are relatively common in Asian patients with NSCLC, and there is an increasing number of studies supporting the effectiveness of the second-generation TKI afatinib in routine clinical practice in Asia. This article reviews these real-world studies investigating afatinib as first-line treatment for EGFR mutation-positive NSCLC in Asian patients. Evidence from real-world studies with afatinib in this patient population supports findings from randomized controlled trials (RCTs) showing that afatinib is associated with more favorable outcomes compared with the first-generation EGFR TKIs. The effectiveness of afatinib has also been shown in real-world studies in Asian patients with poor prognostic factors, who are often under-represented or excluded from RCTs, such as those with uncommon EGFR mutations, brain metastases, or poor performance status, and elderly patients. The tolerability profile of afatinib in the real-world setting reflects that seen in RCTs, with no new safety signals reported in real-world studies in Asian patients with EGFR mutation-positive NSCLC. Dose-modification strategies also seem to be effective in the real world, with results of the RealGido study, which included 44% Asian patients, confirming findings from prospective clinical trials showing that tolerability-guided afatinib dose modifications can reduce the incidence of adverse events without adversely affecting clinical outcomes. While further research, including clinical trial data, is needed, real-world data have also demonstrated the feasibility of sequential afatinib followed by the third-generation TKI osimertinib in T790M-positive EGFR mutation-positive patients, which showed longer overall survival. Together, these real-world results demonstrate the real-world clinical effectiveness of afatinib as first-line treatment for patients with EGFR mutation-positive NSCLC.