The resistance mechanisms and treatment strategies for EGFR-mutant advanced non-small-cell lung cancer

PIK3CA mutation as an acquired resistance driver to EGFR-TKIs in non-small cell lung cancer: Clinical challenges and opportunities

Epithelial growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have significantly enhanced the treatment outcomes in non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. However, the occurrence of acquired resistance to EGFR-TKIs is an unavoidable outcome observed in these patients. Disruption of the PI3K/AKT/mTOR signaling pathway can contribute to the emergence of resistance to EGFR TKIs in lung cancer. The emergence of PIK3CA mutations following treatment with EGFR-TKIs can lead to resistance against EGFR-TKIs. This review provides an overview of the current perspectives regarding the involvement of PI3K/AKT/mTOR signaling in the development of lung cancer. Furthermore, we outline the state-of-the-art therapeutic strategies targeting the PI3K/AKT/mTOR signaling pathway in lung cancer. We highlight the role of PIK3CA mutation as an acquired resistance mechanism against EGFR-TKIs in EGFR-mutant NSCLC. Crucially, we explore therapeutic strategies targeting PIK3CA-mediated resistance to EGFR TKIs in lung cancer, aiming to optimize the effectiveness of treatment.

EGFR TKI resistance in lung cancer cells using RNA sequencing and analytical bioinformatics tools

Epidermal Growth Factor Receptor (EGFR) signaling and EGFR mutations play key roles in cancer pathogenesis, particularly in the development of drug resistance. For the ∼20% of all non-small cell lung cancer (NSCLC) patients that harbor an activating mutation, EGFR tyrosine kinase inhibitors (TKIs) provide initial clinical responses. However, long-term efficacy is not possible due to acquired drug resistance. Despite a gradually increasing knowledge of the mechanisms underpinning the development of resistance in tumors, there has been very little success in overcoming it and it is probable that many additional mechanisms are still unknown. Herein, publicly available RNASeq (RNA sequencing) datasets comparing lung cancer cell lines treated with EGFR TKIs until resistance developed with their corresponding parental cells and protein array data from our own EGFR TKI treated xenograft tumors, were analyzed for differential gene expression, with the intent to investigate the potential mechanisms of drug resistance to EGFR TKIs. Pathway analysis, as well as structural disorder analysis of proteins in these pathways, revealed several key proteins, including DUSP1, DUSP6, GAB2, and FOS, that could be targeted using novel combination therapies to overcome EGFR TKI resistance in lung cancer.

Role of EGFR and FASN in breast cancer progression

Breast cancer (BC) emerged as one of the life-threatening diseases among females. Despite notable improvements made in cancer detection and treatment worldwide, according to GLOBACAN 2020, BC is the fifth leading cancer, with an estimated 1 in 6 cancer deaths, in a majority of countries. However, the exact cause that leads to BC progression still needs to be determined. Here, we reviewed the role of two novel biomarkers responsible for 50-70% of BC progression. The first one is epidermal growth factor receptor (EGFR) which belongs to the ErbB tyrosine kinases family, signalling pathways associated with it play a significant role in regulating cell proliferation and division. Another one is fatty acid synthase (FASN), a key enzyme responsible for the de novo lipid synthesis required for cancer cell development. This review presents a rationale for the EGFR-mediated pathways, their interaction with FASN, communion of these two biomarkers with BC, and improvements to overcome drug resistance caused by them.

Insights into fourth generation selective inhibitors of (C797S) EGFR mutation combating non-small cell lung cancer resistance: a critical review

Lung cancer is the second most common cause of morbidity and mortality among cancer types worldwide, with non-small cell lung cancer (NSCLC) representing the majority of most cases. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are among the most commonly used targeted therapy to treat NSCLC. Recent years have seen the evaluation of many synthetic EGFR TKIs, most of which showed therapeutic activity in pertinent models and were classified as first, second, and third-generation. The latest studies have concluded that their efficacy was also compromised by additional acquired mutations, including C797S. Because second- and third-generation EGFR TKIs are irreversible inhibitors, they are ineffective against C797S containing EGFR triple mutations (Del19/T790M/C797S and L858R/T790M/C797S). Therefore, there is an urgent unmet medical need to develop next-generation EGFR TKIs that selectively inhibit EGFR triple mutations via a non-irreversible mechanism. This review covers the fourth-generation EGFR-TKIs' most recent design with their essential binding interactions, the clinical difficulties, and the potential outcomes of treating patients with EGFR mutation C797S resistant to third-generation EGFR-TKIs was also discussed. Moreover, the utilization of various therapeutic strategies, including multi-targeting drugs and combination therapies, has also been reviewed.

Investigating regulated signaling pathways in therapeutic targeting of non-small cell lung carcinoma

Non-small cell lung carcinoma (NSCLC) is the most common malignancy worldwide. The signaling cascades are stimulated via genetic modifications in upstream signaling molecules, which affect apoptotic, proliferative, and differentiation pathways. Dysregulation of these signaling cascades causes cancer-initiating cell proliferation, cancer development, and drug resistance. Numerous efforts in the treatment of NSCLC have been undertaken in the past few decades, enhancing our understanding of the mechanisms of cancer development and moving forward to develop effective therapeutic approaches. Modifications of transcription factors and connected pathways are utilized to develop new treatment options for NSCLC. Developing designed inhibitors targeting specific cellular signaling pathways in tumor progression has been recommended for the therapeutic management of NSCLC. This comprehensive review provided deeper mechanistic insights into the molecular mechanism of action of various signaling molecules and their targeting in the clinical management of NSCLC.

Nanotechnology - a robust tool for fighting the challenges of drug resistance in non-small cell lung cancer

Genomic and proteomic mutation analysis is the standard of care for selecting candidates for therapies with tyrosine kinase inhibitors against the human epidermal growth factor receptor (EGFR TKI therapies) and further monitoring cancer treatment efficacy and cancer development. Acquired resistance due to various genetic aberrations is an unavoidable problem during EGFR TKI therapy, leading to the rapid exhaustion of standard molecularly targeted therapeutic options against mutant variants. Attacking multiple molecular targets within one or several signaling pathways by co-delivery of multiple agents is a viable strategy for overcoming and preventing resistance to EGFR TKIs. However, because of the difference in pharmacokinetics among agents, combined therapies may not effectively reach their targets. The obstacles regarding the simultaneous co-delivery of therapeutic agents at the site of action can be overcome using nanomedicine as a platform and nanotools as delivery agents. Precision oncology research to identify targetable biomarkers and optimize tumor homing agents, hand in hand with designing multifunctional and multistage nanocarriers that respond to the inherent heterogeneity of the tumors, may resolve the challenges of inadequate tumor localization, improve intracellular internalization, and bring advantages over conventional nanocarriers.

From targeted therapy to a novel way: Immunogenic cell death in lung cancer

Lung cancer (LC) is one of the most incident malignancies and a leading cause of cancer mortality worldwide. Common tumorigenic drivers of LC mainly include genetic alterations of EGFR, ALK, KRAS, BRAF, ROS1, and MET. Small inhibitory molecules and antibodies selectively targeting these alterations or/and their downstream signaling pathways have been approved for treatment of LC. Unfortunately, following initial positive responses to these targeted therapies, a large number of patients show dismal prognosis due to the occurrence of resistance mechanisms, such as novel mutations of these genes and activation of alternative signaling pathways. Over the past decade, it has become clear that there is no possible cure for LC unless potent antitumor immune responses are induced by therapeutic intervention. Immunogenic cell death (ICD) is a newly emerged concept, a form of regulated cell death that is sufficient to activate adaptive immune responses against tumor cells. It transforms dying cancer cells into a therapeutic vaccine and stimulates long-lasting protective antitumor immunity. In this review, we discuss the key targetable genetic aberrations and the underlying mechanism of ICD in LC. Various agents inducing ICD are summarized and the possibility of harnessing ICD in LC immunotherapy is further explored.

Efficacy and Failure Patterns of Early SBRT to the Primary Tumor in Advanced EGFR-Mutation-Positive Lung Cancer with EFGR-TKI Treatment: A Prospective, Single Arm, Phase II Study

Early stereotactic body radiation therapy (SBRT) to the primary tumor combined with epidermal growth factor receptor tyrosine kinase inhibitor (EFGR-TKI) treatment may increase progression-free survival (PFS) by delaying resistance in patients with advanced EGFR-mutant non-small cell lung cancer (NSCLC). In this prospective, single arm, phase II study, patients with advanced NSCLC were treated with EGFR-TKI (icotinib 125 mg tid or gefitinib 250 mg qd) for one month followed by SBRT (40-60 Gy/5-8 F/5-10 d) to the primary tumor with concurrent EGFR-TKI until disease progression. The primary endpoint was PFS and the patterns of failure. Overall survival (OS) and adverse effects (AEs) were secondary endpoints. Overall, 41 advanced NSCLC patients with EGFR mutations received treatment with 24.42 months of median follow-up time. On average, SBRT was initiated 1.49 months after EGFR-TKI administration. Tumors were found to have an average shrinkage rate of 42.50%. Median PFS was 15.23 months (95% CI 13.10-17.36), while median OS was 27.57 months (95% CI 23.05-32.09). Thirty-three patients were found to have disease progression, of which new site failure (NF) (22 patients, 66.66%) was the most common pattern, followed by original site failure (OF) (7 patients, 21.21%) and simultaneous OF/NF (ONF) (4 patients, 12.12%). There were no Aes equal to or greater than grade 3, with the most frequent AE being radiation pneumonitis. Therefore, administering therapy targeted at the primary tumor using early SBRT after EGFR-TKI initiation is a new potentially safe and effective approach to treat EGFR-mutant advanced NSCLC.

The role of antiangiogenic monoclonal antibodies combined to EGFR-TKIs in the treatment of advanced non-small cell lung cancer with activating EGFR mutations: acquired resistance mechanisms and strategies to overcome them

As of today, only two antiangiogenic monoclonal antibodies plus epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) combinations are FDA and EMA-approved and are recommended by American Society of Clinical Oncology, European Society for Medical Oncology, and National Comprehensive Cancer Network for the first-line treatment of EGFR+ advanced non-small cell lung cancer patients: erlotinib plus bevacizumab and erlotinib plus ramucirumab. However, all treated patients eventually become unresponsive to such drugs, due to several different acquired resistance mechanisms, mainly represented by T790M substitutions and MET amplifications. While osimertinib treatment in T790M+ patients still represents the only approved treatment, MET-TKIs will likely change this status quo in the near future. In fact, existing clinical data strongly support a role for MET-TKI-based combinations in EGFR+ MET-amplified patients, possibly revolutionizing our current treatment algorithm. Chemotherapy plus immunotherapy plus antiangiogenic therapy combinations could also represent another useful addition.

Efficacy and potential resistance mechanisms of afatinib in advanced non-small cell lung cancer patients with EGFR G719X/L861Q/S768I

BACKGROUND

Afatinib is the only currently approved EGFR-tyrosine kinase inhibitors for advanced non-small cell lung cancer (NSCLC) patients with EGFR G719X/L861Q/S768I. However, there are limited real-world data concerning the benefits and resistance mechanisms of afatinib in patients with these nonclassical mutations. To fill this gap, the present study was conducted.

METHODS

All NSCLC patients treated with afatinib were screened, and patients with EGFR G719X/L861Q/S768I were enrolled into the analysis. Either tumor tissue or blood specimens were detected by the commercial next-generation sequencing (NGS) panels or amplification-refractory mutation system (ARMS)-polymerase chain reaction (PCR) to figure out the mutation genotype.

RESULTS

A total of 106 advanced NSCLC patients with EGFR G719X/L861Q/S768I received afatinib treatment. The benefits of afatinib exhibited heterogeneity in different mutation genotypes. Notably, at baseline, NGS testing was performed in 59 patients, and TP53 was the most frequently coexisting mutation. Patients with TP53 mutations obtained fewer survival benefits than those with TP53 wild-type. A total of 68 patients ultimately experienced progression, and 27 patients received NGS testing to clarify the potential resistance mechanisms. EGFR-T790M, CDK4 amplification, FGFR1 amplification, PIK3CA, MET amplification, RET fusions, HER2, and BRAF mutations were identified in three (11.1%), three (11.1%), three (11.1%), three (11.1%), three (11.1%), one (3.7%), one (3.7%), and one (3.7%) of the cases, respectively. Five patients underwent ARMS-PCR testing for detecting EGFR-T790M mutation, and only one patient was T790M-positive.

CONCLUSIONS

The present study elucidated the differential benefits of afatinib within different mutation genotypes and first revealed the spectrum of potential resistance mechanisms in patients with EGFR G719X/L861Q/S768I. The results of this study may provide practical clinical information that can guide optimal treatment in this setting.

National trends in the use of oral chemotherapy over 13 years

Background: Systemic cancer therapy has traditionally been administered using an intravenous (IV) route, implying patients’ frequent visits to hospitals to access to their therapy. If we consider the actual pipeline in oncology, oral chemotherapy will be the main component of cancer treatment in the next few years. This shift in the administration route requires different care models in order to guarantee treatment efficacy and safety.

Objective: To analyze time trends in oral chemotherapy consumption in Portugal.

Method: Oral chemotherapy consumption over a 13-year period (2008–2020) was analyzed, considering dispensed units by the administration route with respective costs, resorting to the drug regulatory agency (INFARMED I.P.) database. Oral consumption patterns were further explored using common daily doses (CDD) for three conditions, including chronic myeloid leukemia (CML), non-small-cell lung cancer (NSCLC), and breast cancer (BC), to adjust for the effect of varying doses. Data were analyzed descriptively resorting to Microsoft Office Excel 2010.

Results: Overall chemotherapy consumption increased +Δ54.7%, with the highest contribution in units observed in oral forms (+Δ58.8%). The total expenditure increased +Δ96.5%, and despite the increase in oral forms (+Δ221.6%), intravenous forms continued to be the major cost driver, with an important contribution from immunotherapy. Much of the increase was led by the approval of 40 new IV and 48 new oral cancer medications with higher costs introduced in the market. Using CDD as an alternative metric to units had varying impacts by indication. The observed increases seemed to focus on specific cancer sites with varying effect; in CML, there was a 2.39-fold increase, compared to 4.41 for NSCLC and 1.86 for BC. However, for BC, two distinct sub-patterns were observed for hormone therapy (increasing 1.83) and for the novel tyrosine kinase inhibitors (increasing 40.8).

Conclusion: The growing use of oral chemotherapy is obvious and calls for investments in supporting patients in managing medication adherence and adverse events. The shifts in the healthcare system are complex and need to be prioritized. Our data suggest that priority could be attributed to cancer sites driving innovation, namely, advanced breast cancer.

Dissecting the ferroptosis-related prognostic biomarker and immune microenvironment of driver gene-negative lung cancer

Despite significant advances in targeted and immune therapy for non-small cell lung cancer (NSCLC), effective therapies for wild-type epidermal growth factor receptor/anaplastic lymphoma kinase (EGFR/ALK^WT) with low expression of programmed death ligand-1 (PD-L1) NSCLC remain elusive. Numerous studies have shown that ferroptosis plays an essential role in antitumor activity. To identify the molecular regulation patterns associated with ferroptosis, 351 EGFR/ALK^WT NSCLC samples with low-level PD-L1 were extracted from The Cancer Genome Atlas (TCGA) and clustered using the k-means clustering technique. The two clusters associated with ferroptosis showed significantly different prognoses. In total, 169 differential expression genes (DEGs) were identified. Cluster differential analysis revealed that Cluster 1 had a significantly poorer overall survival (OS) and was associated with more negative immune regulation. In addition, TCGA samples were randomly assigned in a 7:3 ratio to a training group or testing group. A signature of eight genes associated with ferroptosis was established in the training cohort using DEGs and validated in the test cohort and three independent cohorts (GSE72049, GSE41271, and GSE50081). The 5-year area under the curve (AUC) was 0.713, which was significantly higher than that of other predictors, including TNM stage and age. Furthermore, the risk score was associated with immune function, immune infiltration, and immunotherapy response, with high-risk patients having a worse prognosis, an immune-suppressing phenotype, and a poor response to immune checkpoint inhibitors. This study aims to contribute to our understanding of the biological role of ferroptosis in EGFR/ALK^WT NSCLC with low-level PD-L1, laying the groundwork for the development of novel therapeutic strategies.

Bax/Bcl-2 Cascade Is Regulated by the EGFR Pathway: Therapeutic Targeting of Non-Small Cell Lung Cancer

Non-small cell lung carcinoma (NSCLC) comprises 80%-85% of lung cancer cases. EGFR is involved in several cancer developments, including NSCLC. The EGFR pathway regulates the Bax/Bcl-2 cascade in NSCLC. Increasing understanding of the molecular mechanisms of fundamental tumor progression has guided the development of numerous antitumor drugs. The development and improvement of rationally planned inhibitors and agents targeting particular cellular and biological pathways in cancer have been signified as a most important paradigm shift in the strategy to treat and manage lung cancer. Newer approaches and novel chemotherapeutic agents are required to accompany present cancer therapies for improving efficiency. Using natural products as a drug with an effective delivery system may benefit therapeutics. Naturally originated compounds such as phytochemicals provide crucial sources for novel agents/drugs and resources for tumor therapy. Applying the small-molecule inhibitors (SMIs)/phytochemicals has led to potent preclinical discoveries in various human tumor preclinical models, including lung cancer. In this review, we summarize recent information on the molecular mechanisms of the Bax/Bcl-2 cascade and EGFR pathway in NSCLC and target them for therapeutic implications. We further described the therapeutic potential of Bax/Bcl-2/EGFR SMIs, mainly those with more potent and selectivity, including gefitinib, EGCG, ABT-737, thymoquinone, quercetin, and venetoclax. In addition, we explained the targeting EGFR pathway and ongoing in vitro and in vivo and clinical investigations in NSCLC. Exploration of such inhibitors facilitates the future treatment and management of NSCLC.

Durable response to durvalumab-based immunochemotherapy in small-cell lung carcinoma transformation from EGFR-mutant non-small cell lung cancer: A case report

Combined small‐cell lung carcinoma (C‐SCLC) is small‐cell lung carcinoma (SCLC) with added non–small‐cell morphology. We report a case of epidermal growth factor receptor (EGFR) mutation‐positive C‐SCLC in an 84‐year‐old patient with metastatic brain lesions who developed intrinsic resistance to osimertinib, a tyrosine kinase inhibitor (TKI). The patient was diagnosed with small‐cell transformation of non–small‐cell lung carcinoma (NSCLC) and received 6 cycles of dose‐adjusted durvalumab with etoposide and carboplatin. In December 2021, the patient received the seventeenth cycle of maintenance durvalumab 19 months after diagnosis and showed continued treatment response and disease control. Comprehensive molecular profiling and repeated biopsies are recommended in NSCLC patients who progress on first‐line EGFR‐TKIs. Durvalumab in combination with chemotherapy appears to be beneficial for EGFR mutation‐positive C‐SCLC patients that are resistant to TKIs.

Detailed Analysis and Radiomic Prediction of First Progression Sites of First-Line Targeted Therapy for EGFR-Mutant Lung Adenocarcinoma Patients With Systemic Metastasis

Background

We aimed to analyze the first progression sites of first-line tyrosine kinase inhibitor (TKI) treatment for EGFR-mutant lung adenocarcinoma patients with systemic metastasis to recognize the potential candidates who might benefit from radiotherapy and establish a radiomic-based model to predict the first progression sites.

Materials and Methods

We retrospectively collected the clinical information and pre-treatment chest CT images of patients in Shanghai Chest Hospital from 2013 to 2017. All patients were diagnosed with stage IV EGFR-mutant lung adenocarcinoma and received TKI as first-line treatment. The first progression sites and survival were analyzed. The pre-treatment chest non-contrast CT images were utilized to establish a radiomic-based model to predict the first progression sites.

Results

We totally collected 233 patients with systemic metastasis, among whom, there were 84 (36.1%) and 149 (63.9%) patients developing first progression in original lesions (OP) and new lesions (NP), respectively. The PFS and OS of patients with OP were longer than those with NP (PFS 11 months vs. 8 months, p = 0.03, OS 50 months vs. 35 months, p = 0.046). For 67.9% of the patients with OF, disease progressed within five sites (oligoprogression). The radiomic-based model could predict the progression sites with an AUC value of 0.736, a specificity of 0.60, and a sensitivity of 0.750 in the independent validation set.

Conclusion

Among patients with systemic metastasis, there were 36.1% of patients developing OP at first progression who had a better prognosis than those developing NP. Patients with OP may be potential candidates who might benefit from radiotherapy. Radiomics is a useful method to distinguish patients developing OP and could provide some indications for radiotherapy.

Transformation of advanced lung adenocarcinoma to acquired T790M resistance mutation adenosquamous carcinoma following tyrosine kinase inhibitor: a case report

BACKGROUND

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are recommended for patients with non-small cell lung cancer with EGFR mutations. However, acquired resistance to EGFR-TKIs seems inevitable and the mechanism of drug resistance has not been fully defined. There is no effective treatment for patients with advanced lung adenocarcinoma who are resistant to TKIs owing to pathologic type conversion.

CASE PRESENTATION

We report a patient who was initially diagnosed with lung adenocarcinoma. At first, she was sensitive to the first-generation TKI icotinib. After 17 months of treatment, the patient acquired resistance to icotinib. Moreover, after tumor resection, immunohistochemical analysis showed pathologic change from adenocarcinoma to adenosquamous carcinoma, and next-generation sequencing technology discovered EGFR exon19 p.745-750 del, exon20 p.T790M, and KMT2C exon 18 p.R973G mutations. After video-assisted tumor resection, the patient is receiving osimertinib (AZD 9291). Current overall survival is 60 months.

CONCLUSIONS

Surgical intervention may prolong survival time in patients with acquired TKI resistance, especially when there is no evidence of metastasis.

Afatinib for the first-line treatment of EGFR mutation-positive NSCLC in China: a review of clinical data

Mutations in the EGFR gene are particularly prevalent among Chinese patients with non-small-cell lung carcinoma. Six EGFR tyrosine kinase inhibitors are approved for the first-line treatment of EGFR mutation-positive non-small-cell lung carcinoma in China, which poses questions about which agent is most suitable for a particular patient. In this article, we review available clinical trial and real-world data with afatinib in Chinese patients. We assess its efficacy and safety in key patient subgroups such as those with uncommon mutations or brain metastases. We also consider possible subsequent therapies following afatinib. Encouragingly, available data suggest that sequential afatinib and osimertinib confer prolonged overall time to failure of almost 4 years in Asian patients, and represents a viable option in this setting.

Polymorphisms in DNA repair genes in lung cancer patients living in a coal-mining region

Air pollutants and ionizing radiation are well-known carcinogens involved in the pathogenesis of lung cancer, and residents of coal-mining regions are exposed routinely to these agents. Polymorphisms in DNA repair genes may be associated with an increased risk of malignant transformation. We investigated associations between the risk of lung cancer in residents of the coal-mining region and polymorphisms in the genes APEX1 (rs1130409), hOGG1 (rs1052133), XRCC1 (rs25489, rs25487), XRCC2 (rs3218536), XRCC3 (rs861539), ADPRT/PARP1 (rs1136410), XPD/ERCC2 (rs13181), XPG/ERCC5 (rs17655), XPC (rs2228001), ATM (rs1801516), and NBS1 (rs1805794). Three hundred and forty residents of the Kemerovo Region (a coal-mining region of western Siberia) were lung cancer patients exposed to air pollutants and ionizing radiation (case) and 335 were healthy donors (control). Genotyping was performed by real-time PCR and allele-specific PCR. We discovered that polymorphisms in the XPD gene in men [log-additive model: odds ratio (OR) = 1.64, 95% confidence interval (CI): 1.17-2.31], the ATM gene in women and nonsmokers (codominant model: OR = 0.11, 95% CI: 0.02-0.49 and OR = 0.25, 95% CI: 0.08-0.72, respectively), the APEX1 gene for smokers (recessive model: OR = 2.55, 95% CI: 1.34-4.85), and the NBS1 gene for those who work in the coal industry (overdominant model: OR = 0.40, 95% CI: 0.21-0.75) are associated with an increased risk of lung cancer. Using the multifactor dimensionality reduction method, we found a model of gene-gene interactions associated with the risk of lung cancer: NBS1 (rs1805794)-XRCC1 (rs25487)-hOGG1 (rs1052133)-XPG (rs17655). These results indicate an association between combinations of polymorphisms in the studied genes and the risk of lung cancer in residents of a coal-mining region.

Phenethyl isothiocyanate synergistically induces apoptosis with Gefitinib in non-small cell lung cancer cells via endoplasmic reticulum stress-mediated degradation of Mcl-1

Isothiocyanates (ITCs) are natural compounds abundant in cruciferous vegetables. Numerous studies have shown that ITCs exhibit anticancer activity by affecting multiple pathways including apoptosis and oxidative stress, and are expected to be developed into novel anticancer drugs. In our previous studies, we demonstrated that ITCs effectively inhibit the proliferation of non-small cell lung cancer (NSCLC) cells, also induce apoptosis and autophagy. In the present study, we found that phenethyl isothiocyanate (PEITC) had significant synergistic effects with epidermal growth factor receptor tyrosine kinase inhibitor Gefitinib in NSCLC cell lines NCI-H1299 and SK-MES-1; and the degradation of antiapoptotic factor myeloid cell leukemia 1 (Mcl-1) caused by PEITC treatment played key roles in the sensitivity of NSCLC cells to Gefitinib. We further illustrated that PEITC regulated the expression of Mcl-1 through protein kinase RNA-like endoplasmic reticulum kinase (PERK)-eukaryotic translation initiation factor 2α-CHOP-Noxa pathway by a posttranscriptional modulation. Pretreatment with endoplasmic reticulum stress (ER stress) inhibitor tauroursodeoxycholic acid and knockdown of PERK expression attenuated the degradation of Mcl-1 caused by PEITC. In in vivo study, nude mice bearing NCI-H1299 xenograft were administrated with PEITC (50 mg/kg, ip) and Gefitinib (50 mg/kg, ig) for 15 days, the PEITC-Gefitinib combination treatment resulted in a significant synergistic reduction in tumor growth, and significantly induced both ER stress and Mcl-1 degradation in tumor tissues. In conclusion, we explored the prospect of PEITC in improving the efficacy of targeted drug therapy and demonstrated the synergistic effects and underlined mechanisms of PEITC combined with Gefitinib in NSCLC cells treatment. This study provided useful information for developing novel therapy strategies by combination treatment of PEITC with targeted drugs.

Serum C-Reactive Protein Level Predicts Clinical Outcomes in Patients With Non-Small Cell Lung Cancer Harboring EGFR Mutations

The aim of this study was to assess the association of serum C-reactive protein (CRP) levels with outcomes in 81 patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). Patients with high serum CRP levels had lower therapeutic responses to EGFR-tyrosine kinase inhibitors (43.8%), and shorter time to treatment failure (TTF; 5.8 months) and overall survival (OS; 14.2 months) than those with low CRP levels. In multivariate analysis, serum CRP level was associated with TTF (hazard ratio [HR] 4.86) and OS (HR 49.42). High serum CRP levels may predict poor outcomes in patients with EGFR-mutated NSCLC.

Timing in combination with radiotherapy and patterns of disease progression in non-small cell lung cancer treated with EGFR-TKI

OBJECTIVES

Tyrosine kinase inhibitor (TKI) has been the standard of care for advanced non-small cell lung cancers (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation, but these tumors invariably develop drug resistance. As progression most frequently advances in sites of original disease, our study sought to explore the time to response for NSCLC to TKI therapy and the patterns of disease progression, to provide evidence for timing and candidates for local therapy intervention.

MATERIALS AND METHODS

A cohort of 105 EGFR-mutated IIIB or IV NSCLC patients treated with EGFR-TKI were retrospectively analyzed. The disease progression patterns were divided into 3 categories: progression in sites of original disease, progression in new distant sites, and combined progression.

RESULTS

Before cut-off date, 80 patients had disease progression. Thirty-three (41.25 %) patients had progression in sites of original disease, 34 (42.5 %) patients had progression in new sites and 13 (16.25 %) patients had combined progression, respectively. The median time to response for responders was 2.00 months (95 %CI 1.28-2.92 months), and the median time to maximal tumor shrinkage for SD patients was 2.00 months (95 %CI 1.42-2.58 months). Multivariate logistic regression model showed that the 21 exon mutation is related to the incidence of original site failure.

CONCLUSION

Over 1/3 of the patients progress at the original sites, which indicated that this subset of patients may benefit from local therapy. Moreover, as the results indicate that considerable shrinkage for TKI therapy occurs in first two months after TKI initiation, local therapy can be adopted after this timepoint, before disease progression. We also propose EGFR gene mutation type as potential inclusion criteria to identify candidates for combined local therapy.

Research progress on the relationship between lung cancer drug-resistance and microRNAs

Lung cancer, a malignant tumor with the highest death rate of cancer, seriously endangers human health. And its pathogenesis and mechanism of drug resistance has been partially clarified, especially for the signal pathway of epidermal growth factor receptor (EGFR). The targeting therapy of EGFR signaling pathway in non-small cell lung cancer (NSCLC) has achieved a certain effect, but the two mutation of EGFR and other mechanisms of lung cancer resistance still greatly reduce the therapeutic effect of chemotherapy on it. MicroRNA is an endogenous non coding RNA, which has a regulatory function after transcriptional level. Recent studies on the mechanism of lung cancer resistance have found that a variety of microRNAs are related to the mechanism of lung cancer drug-resistance. They can regulate lung cancer resistance by participating in signal pathways, drug resistance genes and cell apoptosis, thus affecting the sensitivity of cancer cells to drugs. Therefore, microRNAs can be used as a specific target for the treatment of lung cancer and plays a vital role in the early diagnosis, prognosis and treatment of lung cancer. This article reviews the mechanisms of lung cancer resistance and its relationship with microRNAs.

Excellent platinum dependent response to chemotherapy after relapse under TKI treatment in NSCLC with sensitizing EGFR mutations and no detectable resistance mutations: three case studies

First-line tyrosine-kinase inhibitor (TKI) treatment is the current standard for patients with metastasized non-small cell lung cancer (NSCLC) and sensitizing epidermal growth factor receptor (EGFR) mutations. Despite good initial responses, patients treated with TKIs relapse after an average of 12 months. About half of them develop known resistance mechanisms and therefore are qualified for further targeted therapies. However, many patients still have to be treated with standard chemotherapeutic regimens. In this case series we describe three patients with similar progression patterns under TKI treatment in the absence of treatable resistance mechanisms and excellent platinum dependent response to chemotherapy and review the current literature focusing on effectiveness of standard chemotherapy in this cohort.

Impact of clinical features on the efficacy of osimertinib therapy in patients with T790M-positive non-small cell lung cancer and acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors

Background

Osimertinib exhibits good efficacy in patients with T790M-positive non-small cell lung cancer (NSCLC) and acquired resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs). Compared with the clinical trials, in real-world clinical practice, osimertinib must be administered to older patients and those with poor Eastern Cooperative Oncology Group performance status (ECOG-PS). Therefore, we investigated the association between osimertinib efficacy/safety and PS score, age, and other clinical features in patients with T790M-positive NSCLC.

Methods

We reviewed all patients with T790M-positive NSCLC and acquired resistance to initial EGFR-TKIs who were administered osimertinib between March 2016 and January 2018 at the Tokyo Metropolitan Cancer and Infectious Diseases Center in Komagome Hospital, Japan.

Results

In total, 31 patients, including 8 young (<65 years) and 23 elderly (≥65 years) patients, were included in the study. Of these, 10 (32.3%) patients had poor PS scores. The progression-free survival (PFS) was significantly shorter in young patients was than elderly patients [3.5 vs. 6.4 months, P=0.041; hazard ratio (HR), 2.41]. The overall survival (OS) of the young patients tended to be shorter than that of the elderly patients (5.3 vs. 19.4 months, P=0.067; HR, 2.58). The PFS (9.1 vs. 5.5 months; P=0.071; HR, 0.38) and the OS (not reached vs. 6.6 months, P=0.061; HR, 0.39) were shorter in patients with poor ECOG-PS than those with good ECOG-PS. The toxic effects of osimertinib were manageable. By multivariate analysis, both age and ECOG-PS were independent predictors of osimertinib efficacy.

Conclusions

Poor ECOG-PS and younger age were associated with lower efficacy of osimertinib in T790M-positive NSCLC.

Profiling of circulating tumor DNA in plasma of non-small cell lung cancer patients, monitoring of epidermal growth factor receptor p.T790M mutated allelic fraction using beads, emulsion, amplification, and magnetics companion assay and evaluation in future application in mimicking circulating tumor cells

Cell-free plasma DNA (cfDNA) and mimicking circulating tumor cells (mCTCs) have demonstrated tremendous potential for molecular diagnosis of cancer and have been rapidly implemented in specific settings. However, widespread clinical adoption still faces some obstacles. The purpose was to compare the performance of a BEAMing (beads, emulsion, amplification, and magnetics) assay (OncoBEAM™-epidermal growth factor receptor [EGFR] [Sysmex Inostics]) and a next-generation sequencing assay (NGS; 56G Oncology panel kit, Swift Bioscience) to detect the p.T790M EGFR mutation in cfDNA of non-small cell lung cancer (NSCLC) patients. CfDNA samples (n = 183) were collected within our hospital from patients having a known EGFR sensitizing mutation, and presenting disease progression while under first-line therapy. EGFR mutations were detected using NGS in 42.1% of samples during progression in cfDNA. Testing using the OncoBEAM™-EGFR assay enabled detection of the p.T790M EGFR mutation in 40/183 NSCLC patients (21.8%) versus 20/183 (10.9%), using the NGS assay. Samples that were only positive with the OncoBEAM™-EGFR assay had lower mutant allelic fractions (Mean = 0.1304%; SD ± 0.1463%). In addition, we investigated the detection of p.T790M in mCTCs using H1975 cells. These cells spiked into whole blood were enriched using the ClearCellFX1 microfluidic device. Using the OncoBEAM™-EGFR assay, p.T790M was detected in as few as 1.33 tumoral cells/mL. Overall, these findings highlight the value of using the OncoBEAM™-EGFR to optimize detection of the p.T790M mutation, as well as the complementary clinical value that each of the mutation detection assay offers: NGS enabled the detection of mutations in other oncogenes that may be relevant to secondary resistance mechanisms, whereas the OncoBEAM™-EGFR assay achieved higher sensitivity for detection of clinically actionable mutations.

ProGRP as early predictive marker of non-small-cell lung cancer to small-cell lung cancer transformation after EGFR-TKI treatment

We report a case of non-small-cell lung cancer (NSCLC) to small-cell lung cancer (SCLC) transformation after epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment. The patient was a man who diagnosed with EGFR-mutant advanced NSCLC. After he was introduced afatinib, his tumor had been reduced by the treatment. However, plasma pro-gastrin-releasing peptide (ProGRP) became higher with disease progression, and SCLC was detected at the second biopsy. It is suggested that elevation of plasma ProGRP level before EGFR-TKI therapy is useful for predicting EGFR-mutant NSCLC to SCLC transformation.

Defining aggressive or early progressing nononcogene-addicted non-small-cell lung cancer: a separate disease entity?

A substantial proportion of patients with nononcogene-addicted non-small-cell lung cancer (NSCLC) has 'aggressive disease', as reflected in short time to progression or lack of disease control with initial platinum-based chemotherapy. Recently, clinical correlates of aggressive disease behavior during first-line therapy have been shown to predict greater benefit from addition of nintedanib to second-line docetaxel in adenocarcinoma NSCLC. Positive predictive effects of aggressive disease have since been reported with other anti-angiogenic agents (ramucirumab and bevacizumab), while such features may negatively impact on outcomes with nivolumab in nonsquamous NSCLC with low PD-L1 expression. Based on a review of the clinical data, we recommend aggressive nonsquamous NSCLC should be defined by progression within <6-9 months of first-line treatment initiation.

Ultra-sensitive EGFR T790M Detection as an Independent Prognostic Marker for Lung Cancer Patients Harboring EGFR del19 Mutations and Treated with First-generation TKIs

PURPOSE

The detection of preexisting EGFR ^T790M subclones and the assessment of their clinical significance in the pretreatment of patients with EGFR ^T790M non-small cell lung cancer (NSCLC) remain unclear.

EXPERIMENTAL DESIGN

A total of 179 tumor samples from patients treated or not with a first-generation tyrosine kinase inhibitor (TKI) was analyzed. The presence of ultra-low levels of preexisting EGFR^T790M mutation was evaluated using ultra-sensitive droplet digital PCR (ddPCR) and the clinical implication of these mutations on first-generation TKI efficiency assessed.

RESULTS

With a ddPCR linear performance of 0.999 and an analytical sensitivity of approximately 0.001%, we observed a 66% (99/150) overall incidence of ultra-low EGFR ^T790M mutation. Among 82 patients harboring EGFR ^activating mutations, the presence of a preexisting EGFR ^T790M mutation prior to any treatment was significantly associated with a longer progression-free survival (PFS; P = 0.009; log-rank test). Interestingly, longer PFS was linked to concomitant EGFR ^del19 and ultra-low EGFR ^T790M mutations. Moreover, the presence of both EGFR ^del19 and ultra-low EGFR ^T790M mutations was identified as the best fit for predicting the clinical outcome of patients treated with TKI compared with an ultra-low EGFR ^T790M mutation status or an activating mutation alone (P = 0.042 and P = 0.0071, respectively).

CONCLUSIONS

We demonstrate that the detection of the ultra-low EGFR ^T790M mutation in TKI-naïve patients is not a rare event. We suggest that ddPCR should be used in clinical practice to distinguish patients who may respond to first- or third-generation TKIs.

Cancer Immunotherapy: The Dawn of Antibody Cocktails

Since the approval of the first monoclonal antibody (mAb), rituximab, for hematological malignancies, almost 30 additional mAbs have been approved in oncology. Despite remarkable advances, relatively weak responses and resistance to antibody monotherapy remain major open issue. Overcoming resistance might require combinations of drugs blocking both the major target and the emerging secondary target. We review clinically approved combinations of antibodies and either cytotoxic regimens (chemotherapy and irradiation) or kinase inhibitors. Thereafter, we focus on the most promising and currently very active arena that combines mAbs inhibiting immune checkpoints or growth factor receptors. Clinically approved and experimental oligoclonal mixtures of mAbs targeting different antigens (hetero-combinations) or different epitopes of the same antigen (homo-combinations) are described. Effective oligoclonal mixtures of antibodies that mimic the polyclonal immune response will likely become a mainstay of cancer therapy.

Outcome of EGFR-mutated adenocarcinoma NSCLC patients with changed phenotype to squamous cell carcinoma after tyrosine kinase inhibitors: A pooled analysis with an additional case

The onset of a new histology is a resistant mechanism to tyrosine kinase inhibitors (TKI) in lung adenocarcinoma (ADK), but this phenomenon has not yet been fully clarified. We present a pooled analysis of the outcomes of EGFR-mutated ADK patients with changed phenotype to squamous cell carcinoma (SqCC) following TKI, along with the description of an additional case. A 67-year-old woman with EGFR-mutated NSCLC received gefitinib and subsequently osimertinib, due to the presence of T790 M at progression. The re-biopsy after third-generation TKI revealed SqCC histology along with the basal EGFR mutation, while T790 M disappeared. The patient rapidly progressed and died despite two chemotherapy cycles. Since this first description of SqCC transformation appearing after treatment with the third-generation TKI osimertinib, other 16 patients, with EGFR-mutated ADK developing a transformation to SqCC histology after treatment with TKIs, were up to now published. From our pooled analysis emerged that most patients were female (82%), 41% were former smokers and no current smokers were identified. Median time to SqCC onset was 11.5 months. In all cases, basal EGFR mutation was maintained, and 11 patients (65%) developed an acquired mutation on exon 20. Interestingly also 790 M mutation appeared in 8 patients (47%). The median survival after SqCC diagnosis was 3.5 months regardless the treatments received. Therefore, EGFR-mutated lung ADK destined to develop a squamous phenotype were often smokers and maintained the baseline genomic alterations. The prognosis after SqCC diagnosis was extremely poor and current treatments largely inefficacious.

Calpain 2 knockdown promotes cell apoptosis and restores gefitinib sensitivity through epidermal growth factor receptor/protein kinase B/survivin signaling

Gefitinib, an epidermal growth factor receptor (EGFR)-specific drug, is effective for ~1 year, after which resistance is inevitable. Calpain 2 (CAPN2) is known to serve a role in the drug response and resistance in certain cancer therapies. However, the full function of CAPN2, particularly in non-small cell lung cancer, has not yet been elucidated. In the present study, CAPN2 expression in gefitinib-resistant lung adenocarcinoma cells was investigated. CAPN2 function in these cells was further evaluated using gene knockdown both in vitro and in vivo. The results demonstrated that CAPN2 was strongly associated with gefitinib-resistance, and CAPN2 mRNA and protein expression levels were significantly increased in gefitinib-resistant cell lines. Furthermore, CAPN2 knockdown inhibited gefitinib-resistant cell proliferation in vitro and in vivo. CAPN2 conferred gefitinib-resistance by inhibiting cell apoptosis and arresting the cell cycle. CAPN2 knockdown also induced caspase activation and mitochondrial dysfunction, and its function in gefitinib resistance appeared to be largely mediated by EGFR/protein kinase B/survivin signaling pathway activation. These results suggest that CAPN2 is responsible for EGFR-tyrosine kinase inhibitor resistance, and CAPN2 inhibition may be used to provide therapeutic benefits in the treatment of gefitinib resistance.

Selection of Luteolin as a potential antagonist from molecular docking analysis of EGFR mutant

The life-threatening sides effect of the current EGFR mutant inhibitors (drugs) such as the eruption of rash which can be seen on the face, chest, back and even the trunk, diarrhea, nausea, vomiting, anorexia and stomatitis, necessitates the discovery of new potent and safe compounds as a chemo-therapeutic measure against lung cancer. Approximately about 10% of patients with Non-small cell lung cancer (NSCLC) in the US and about 35% in East Asia have tumor associated EGFR. These mutations occur within EGFR exon 18-21, which encodes a portion of the EGFR kinase domain and enables researchers to identify compounds that only recognizes and binds to the cancer cells. Thus, mutations in EGFR play a role as both biomarkers and rational targets for targeted therapy. In view of this, we out-source for the best-in -class inhibitor for this druggable target via computational tools. The purpose of this study was to analyze the inhibitory potential of luteolin by computational docking studies. For this, three (3) flavone chemical compounds (phytochemicals) retrieved from literatures were screened for their inhibitory effects on the epidermal growth factor receptor (EGFR). Luteolin was the lead compound with a binding energy of -7.7 kcal/mol. Computational docking analysis was performed using PyRx, AutoDock Vina option based on scoring functions and the target was validated so as to ensure that the right target and appropriate docking protocol was used for this analysis.

DNA terminal structure-mediated enzymatic reaction for ultra-sensitive discrimination of single nucleotide variations in circulating cell-free DNA

Sensitive detection of the single nucleotide variants in cell-free DNA (cfDNA) may provide great opportunity for minimally invasive diagnosis and prognosis of cancer and other related diseases. Here, we demonstrate a facile new strategy for quantitative measurement of cfDNA mutations at low abundance in the cancer patients' plasma samples. The method takes advantage of a novel property of lambda exonuclease which effectively digests a 5'-fluorophore modified dsDNA with a 2-nt overhang structure and sensitively responds to the presence of mismatched base pairs in the duplex. It achieves a limit of detection as low as 0.02% (percentage of the mutant type) for BRAFV600E mutation, NRASQ61R mutation and three types of EGFR mutations (G719S, T790M and L858R). The method enabled identification of BRAFV600E and EGFRL858R mutations in the plasma of different cancer patients within only 3.5 h. Moreover, the terminal structure-dependent reaction greatly simplifies the probe design and reduces the cost, and the assay only requires a regular real-time PCR machine. This new method may serve as a practical tool for quantitative measurement of low-abundance mutations in clinical samples for providing genetic mutation information with prognostic or therapeutic implications.

Navigating the "No Man's Land" of TKI-Failed EGFR-Mutated Non-Small Cell Lung Cancer (NSCLC): A Review

As the leading cause of cancer-related mortality, lung cancer is a worldwide health issue that is overwhelmingly caused by smoking. However, a substantial minority (~25%) of patients with non–small cell lung cancer (NSCLC) has never smoked. In these patients, activating mutations of the epidermal growth factor receptor (EGFR) are more likely, which render their tumors susceptible for a finite period to treatment with EGFR tyrosine kinase inhibitors (TKIs) and confer a better prognosis than EGFR wild-type NSCLC. On progression, due to the inevitable insurgence of resistance, TKIs are generally followed by second- or third-line salvage chemotherapy until treatment failure, after which no standard treatment options are available, resulting in a poor prognosis and a high risk of death. With the focus of clinical attention on treatment with TKIs, few studies on optimal salvage therapies, including cytotoxic chemotherapy, after failure of EGFR TKIs have been reported. Despite a paucity of available data, the aim of this review is to summarize the “no-man's land” of TKI-failed EGFR-mutated NSCLC and expand on alternative strategies as well as potential future directions.

Liquid Biopsy and Therapeutic Targets: Present and Future Issues in Thoracic Oncology

The practice of liquid biopsy (LB) has revolutionized the care of patients with metastatic lung cancer. Many oncologists now use this approach in daily practice, applying precise procedures for the detection of activating or resistance mutations in EGFR. These tests are performed with plasma DNA and have been approved as companion diagnostic test for patients treated with tyrosine kinase inhibitors. ALK is another important target in lung cancer since it leads to treatment of patients who are positive for a rearrangement in ALK identified with tumor tissue. By analogy with EGFR, LB for detection of genomic alterations in ALK (rearrangements or mutations) has been rapidly adopted in the clinic. However, this promising approach has some limitations and has not yet been disseminated as much as the blood test targeting EGFR. In addition to these two therapeutic targets LB can be used for evaluation of the genomic status of other genes of interest of patients with lung cancer (ROS1, RET, NTRK MET, BRAF, HER2, etc.). LB can be performed to evaluate a specific target or for a more or less complex panel of genes. Considering the number of potential targets for clinical trials, techniques of next-generation sequencing of circulating DNA are on the rise. This review will provide an update on the contribution of LB to care of patients with metastatic lung cancer, including the present limits of this approach, and will consider certain perspectives.