Project description:Metabolic reprogramming is widely known as a hallmark of cancer cells to allow adaptation of cells to sustain survival signals. In this report, we describe a novel oncogenic signaling pathway exclusively acting in mutated epidermal growth factor receptor (EGFR) non-small cell lung cancer (NSCLC) with acquired tyrosine kinase inhibitor (TKI) resistance. Mutated EGFR mediates TKI resistance through regulation of the fatty acid synthase (FASN), which produces 16-C saturated fatty acid palmitate. Our work shows that the persistent signaling by mutated EGFR in TKI-resistant tumor cells relies on EGFR palmitoylation and can be targeted by Orlistat, an FDA-approved anti-obesity drug. Inhibition of FASN with Orlistat induces EGFR ubiquitination and abrogates EGFR mutant signaling, and reduces tumor growths both in culture systems and in vivo Together, our data provide compelling evidence on the functional interrelationship between mutated EGFR and FASN and that the fatty acid metabolism pathway is a candidate target for acquired TKI-resistant EGFR mutant NSCLC patients.
Project description:Epidermal growth factor receptor (EGFR) mutations are present in 20-40% of non-small cell lung cancers (NSCLCs). Brain metastasis (BM) is more common in EGFR-mutated NSCLC (25-45%) compared to EGFR wild-type (15-30%). First and second-generation tyrosine kinase inhibitors (TKIs), such as erlotinib and afatinib have proven to be superior to chemotherapy in the front-line treatment of EGFR-mutated NSCLC. Osimertinib, a third-generation EGFR TKI, has demonstrated better blood brain barrier (BBB) penetration, higher rate of intracranial response (66% vs. 43%) and a lower rate of CNS progression when compared to first generation EGFR TKI. Evidence on upfront radiation vs. upfront osimertinib is limited, but rapidly evolving and being tested in ongoing comparative trials. Stereotactic radiation (SRS) is very effective in the control of BMs and has been increasingly used and consequently replacing resection of BMs. SRS also has been increasingly used in the treatment of multiple BMs. Considering the effectiveness of targeted agents such as third generation EGFR inhibitors clinicians now are more frequently faced with the decision, if systemic therapy is safe and effective enough to withhold SRS. Third generation EGFR inhibitors also have fewer adverse events as previous generations. This review discusses the current literature available for management of BM in EGFR-mutated NSCLC.
Project description:Osimertinib is an irreversible, third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that is highly selective for EGFR-activating mutations as well as the EGFR T790M mutation in patients with advanced non-small cell lung cancer (NSCLC) with EGFR oncogene addiction. Despite the documented efficacy of osimertinib in first- and second-line settings, patients inevitably develop resistance, with no further clear-cut therapeutic options to date other than chemotherapy and locally ablative therapy for selected individuals. On account of the high degree of tumour heterogeneity and adaptive cellular signalling pathways in NSCLC, the acquired osimertinib resistance is highly heterogeneous, encompassing EGFR-dependent as well as EGFR-independent mechanisms. Furthermore, data from repeat plasma genotyping analyses have highlighted differences in the frequency and preponderance of resistance mechanisms when osimertinib is administered in a front-line versus second-line setting, underlying the discrepancies in selection pressure and clonal evolution. This review summarises the molecular mechanisms of resistance to osimertinib in patients with advanced EGFR-mutated NSCLC, including MET/HER2 amplification, activation of the RAS-mitogen-activated protein kinase (MAPK) or RAS-phosphatidylinositol 3-kinase (PI3K) pathways, novel fusion events and histological/phenotypic transformation, as well as discussing the current evidence regarding potential new approaches to counteract osimertinib resistance.
Project description:Although epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are the preferred treatment for patients with EGFR-mutated non-small cell lung cancer (NSCLC), not all patients benefit. We therefore explored the impact of the presence of mutations found in cell-free DNA (cfDNA) and TKI plasma concentrations during treatment on progression-free survival (PFS). In the prospective START-TKI study blood samples from 41 patients with EGFR-mutated NSCLC treated with EGFR-TKIs were available. Next generation sequencing (NGS) on cfDNA was performed, and plasma TKI concentrations were measured. Patients without complete plasma conversion of EGFR mutation at week 6 had a significantly shorter PFS (5.5 vs. 17.0 months, p = 0.002) and OS (14.0 vs. 25.5 months, p = 0.003) compared to patients with plasma conversion. In thirteen (second line) osimertinib-treated patients with a (plasma or tissue) concomitant TP53 mutation at baseline, PFS was significantly shorter compared to six wild-type cases; 8.8 vs. 18.8 months, p = 0.017. Erlotinib Cmean decrease of ≥10% in the second tertile of treatment was also associated with a significantly shorter PFS; 8.9 vs. 23.6 months, p = 0.037. We obtained evidence that absence of plasma loss of the primary EGFR mutation, isolated plasma p.T790M loss after six weeks, baseline concomitant TP53 mutations, and erlotinib Cmean decrease during treatment are probably related to worse outcome.
Project description:For appropriate treatment selection, the updated NCCN Guidelines for Non-Small Cell Lung Cancer (NSCLC) recommend broad molecular profiling for all patients with nonsquamous disease. Three different tyrosine kinase inhibitors (TKIs) are recommended as first-line treatment of EGFR mutation-positive NSCLC: gefitinib, erlotinib, and afatinib. Most patients whose disease responds will still experience progression, and the type of disease progression drives management. Systemic progression requires switching TKI treatment, whereas patients with oligoprogression and central nervous system progression may have their new lesions treated but continue on their TKI. A new third-generation TKI has been approved and others are currently under development, and new combinations of these drugs with a VEGFR inhibitor offer promise to improve outcomes.
Project description:The treatment of non-small-cell lung cancer (NSCLC) harbouring EGFR mutations has witnessed some major breakthroughs in the last years. On the one hand, the recent advent of the third-generation tyrosine kinase inhibitor (TKI) osimertinib has reshaped the therapeutic algorithm both in the first-line and adjuvant settings for patients with common activating Ex19del and L858R EGFR mutations. On the other hand, the availability of new comprehensive next-generation sequencing panels, to be used on tumour tissue or on liquid biopsy, has revealed the existence of uncommon as well as compound mutations that partially explain the onset of resistance. Nevertheless, dissecting the biological mechanisms underlying primary and secondary resistance to EGFR-TKIs is crucial to developing alternative therapeutic strategies and further improving patient outcomes. Herein, we provide an updated and comprehensive summary of the latest advancements in the quest for compounds targeting EGFR-mutant advanced non-small-cell lung cancer, discussing the biological rationale underlying the development of a forefront combination of TKI and/or new antibody-drug conjugates. We also suggest a treatment algorithm that could be followed considering the latest published data.
Project description:BackgroundLittle is known about the difference between black and non-black patients with epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC), particularly regarding survival. We thus characterized the EGFR expression profile, clinical characteristics, and survival outcome in these patients.Patient and methodsWe reviewed the cancer registry and patient charts at a New York-Bronx network (n = 2773) treating a large population of minority patients, for non-squamous NSCLC (n = 1986) diagnosed between 2009 and 2015. Survival was adjusted for smoking, gender, age, weight, and stage.ResultsThe EGFR mutation rate was 15% (98/652) in tested patients (black, 14%; non-black, 16%). There was no significant difference between the 2 cohorts with respect to age at diagnosis, gender, presenting stages, and socioeconomic status. On the other hand, weight was noted to be heavier in black patients with EGFR-mutated NSCLC than their non-black counterparts (P = .012). After adjusting for gender, age, smoking status, weight, and stage, the multivariate analysis revealed no racial disparity in survival among patients with wild-type EGFR (P = .774); However, among patients with EGFR-mutated NSCLC, black patients had shorter survival in comparison with non-black patients (P = .001), with 2-year survival rates being 33% versus 61%, respectively. Such shorter survival was also observed among EGFR-inhibitor treated patients with common EGFR mutations (P = .040).ConclusionsTo our knowledge, this is the first report of inferior survival among black patients with NSCLC with EGFR mutations, relative to non-black patients. The survival disparities suggest the need of more tailored management for this patient population.
Project description:BackgroundThe recruitment of a sufficient number of immune cells to induce an inflamed tumor microenvironment (TME) is a prerequisite for effective response to cancer immunotherapy. The immunological phenotypes in the TME of EGFR-mutated lung cancer were characterized as non-inflamed, for which immunotherapy is largely ineffective.MethodsGlobal proteomic and phosphoproteomic data from lung cancer tissues were analyzed aiming to map proteins related to non-inflamed TME. The ex vivo and in vivo studies were carried out to evaluate the anti-tumor effect. Proteomics was applied to identify the potential target and signaling pathways. CRISPR-Cas9 was used to knock out target genes. The changes of immune cells were monitored by flow cytometry. The correlation between PKCδ and PD-L1 was verified by clinical samples.ResultsWe proposed that PKCδ, a gatekeeper of immune homeostasis with kinase activity, is responsible for the un-inflamed phenotype in EGFR-mutated lung tumors. It promotes tumor progression by stimulating extracellular matrix (ECM) and PD-L1 expression which leads to immune exclusion and assists cancer cell escape from T cell surveillance. Ablation of PKCδ enhances the intratumoral penetration of T cells and suppresses the growth of tumors. Furthermore, blocking PKCδ significantly sensitizes the tumor to immune checkpoint blockade (ICB) therapy (αPD-1) in vitro and in vivo model.ConclusionsThese findings revealed that PKCδ is a critical switch to induce inflamed tumors and consequently enhances the efficacy of ICB therapy in EGFR-mutated lung cancer. This opens a new avenue for applying immunotherapy against recalcitrant tumors.