Therapeutic application of extracellular vesicular EGFR isoform D as a co-drug to target squamous cell cancers with tyrosine kinase inhibitors.

Targeting wild-type epidermal growth factor receptor (EGFR) using tyrosine kinase inhibitors (TKIs) never achieved its purported success in cancers such as head and neck squamous cell carcinoma, which are largely EGFR-dependent. We had previously shown that exceptional responders to TKIs have a genetic aberration that results in overexpression of an EGFR splice variant, isoform D (IsoD). IsoD lacks an integral transmembrane and kinase domain and is secreted in extracellular vesicles (EVs) in TKI-sensitive patient-derived cultures. Remarkably, the exquisite sensitivity to TKIs could be transferred to TKI-resistant tumor cells, and IsoD protein in the EV is necessary and sufficient to transfer the phenotype in vitro and in vivo across multiple models and drugs. This drug response requires an intact endocytic mechanism, binding to full-length EGFR, and signaling through Src-phosphorylation within the endosomal compartment. We propose a therapeutic strategy using EVs containing EGFR IsoD as a co-drug to expand the use of TKI therapy to EGFR-driven cancers.

Combination of betulinic acid and EGFR-TKIs exerts synergistic anti-tumor effects against wild-type EGFR NSCLC by inducing autophagy-related cell death via EGFR signaling pathway.

BACKGROUND: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of lung cancer patients with mutated EGFR. However, the efficacy of EGFR-TKIs in wild-type EGFR tumors has been shown to be marginal. Methods that can sensitize EGFR-TKIs to EGFR wild-type NSCLC remain rare. Hence, we determined whether combination treatment can maximize the therapeutic efficacy of EGFR-TKIs. METHODS: We established a focused drug screening system to investigate candidates for overcoming the intrinsic resistance of wild-type EGFR NSCLC to EGFR-TKIs. Molecular docking assays and western blotting were used to identify the binding mode and blocking effect of the candidate compounds. Proliferation assays, analyses of drug interactions, colony formation assays, flow cytometry and nude mice xenograft models were used to determine the effects and investigate the molecular mechanism of the combination treatment. RESULTS: Betulinic acid (BA) is effective at targeting EGFR and synergizes with EGFR-TKIs (gefitinib and osimertinib) preferentially against wild-type EGFR. BA showed inhibitory activity due to its interaction with the ATP-binding pocket of EGFR and dramatically enhanced the suppressive effects of EGFR-TKIs by blocking EGFR and modulating the EGFR-ATK-mTOR axis. Mechanistic studies revealed that the combination strategy activated EGFR-induced autophagic cell death and that the EGFR-AKT-mTOR signaling pathway was essential for completing autophagy and cell cycle arrest. Activation of the mTOR pathway or blockade of autophagy by specific chemical agents markedly attenuated the effect of cell cycle arrest. In vivo administration of the combination treatment caused marked tumor regression in the A549 xenografts. CONCLUSIONS: BA is a potential wild-type EGFR inhibitor that plays a critical role in sensitizing EGFR-TKI activity. BA combined with an EGFR-TKI effectively suppressed the proliferation and survival of intrinsically resistant lung cancer cells via the inhibition of EGFR as well as the induction of autophagy-related cell death, indicating that BA combined with an EGFR-TKI may be a potential therapeutic strategy for overcoming the primary resistance of wild-type EGFR-positive lung cancers.

An EGCG Derivative in Combination with Nimotuzumab for the Treatment of Wild-Type EGFR NSCLC.

Inhibiting the tyrosine kinase activity of epidermal growth factor receptor (EGFR) using small-molecule tyrosine kinase inhibitors (TKIs) or monoclonal antibodies is often ineffective in treating cancers harboring wild-type EGFR. Given the fact that EGFR possesses a kinase-independent pro-survival function, more effective inhibition of EGFR-mediated signals is therefore necessary. In this study, we investigated the effects of using a combination of low-dose nimotuzumab and theasinensin A to evaluate whether the inhibitory effect of nimotuzumab on NCI-H441 cancer cells was enhanced. Here, theasinensin A, a novel epigallocatechin-3-gallate (EGCG) derivative, was identified and its potent anticancer activity against wild-type EGFR NSCLC was demonstrated in vitro; the anticancer activity was induced through degradation of EGFR. Mechanistic studies further revealed that theasinensin A bound directly to the EGFR extracellular domain, which decreased interaction with its ligand EGF in combination with nimotuzumab. Theasinensin A significantly promoted EGFR degradation and repressed downstream survival pathways in combination with nimotuzumab. Meanwhile, treatment with theasinensin A and nimotuzumab prevented xenograft growth, whereas the single agents had limited effect. Thus, the combination therapy of theasinensin A with nimotuzumab is a powerful candidate for treatment of wild-type EGFR cancers.

Prognostic value of CYFRA 21 - 1 and Ki67 in advanced NSCLC patients with wild-type EGFR.

BACKGROUND: The prognostic value of cytokeratin 19 fragment (CYFRA 21 - 1) and Ki67 in advanced non-small cell lung cancer (NSCLC) patients with wild-type epidermal growth factor receptor (EGFR) remains to be explored. METHODS: In this study, 983 primary NSCLC patients from January 2016 to December 2019 were retrospectively reviewed. Finally, 117 advanced NSCLC patients with wild-type EGFR and 37 patients with EGFR mutation were included and prognostic value of CYFRA 21 - 1 and Ki67 were also identified. RESULTS: The patients age, smoking history and the Eastern Corporative Oncology Group (ECOG) performance scores were significantly different between CYFRA21-1 positive and negative groups (p < 0.05), while no significant differences were found in Ki67 high and low groups. The results of over survival (OS) demonstrated that patients with CYFRA21-1 positive had markedly shorter survival time than CYFRA21-1 negative (p < 0.001, For whole cohorts; p = 0.002, For wild-type EGFR). Besides, patients with wild-type EGFR also had shorter survival times than Ki67 high group. Moreover, In CYFRA 21 - 1 positive group, patients with Ki67 high had obviously shorter survival time compared to patients with Ki67 low (median: 24vs23.5 months; p = 0.048). However, Ki67 could not be used as an adverse risk factor for patients with EGFR mutation. Multivariate cox analysis showed that age (HR, 1.031; 95%CI, 1.003 ~ 1.006; p = 0.028), Histopathology (HR, 1.760; 95%CI,1.152 ~ 2.690; p = 0.009), CYFRA 21 - 1 (HR, 2.304; 95%CI,1.224 ~ 4.335; p = 0.01) and Ki67 (HR, 2.130; 95%CI,1.242 ~ 3.652; p = 0.006) served as independent prognostic risk factor for advanced NSCLC patients. CONCLUSIONS: Our finding indicated that CYFRA 21 - 1 was an independent prognostic factor for advanced NSCLC patients and Ki67 status could be a risk stratification marker for CYFRA 21 - 1 positive NSCLC patients with wild-type EGFR.

Survival Analysis and Clinical Outcomes between Paclitaxel and Carboplatin Versus Carboplatin and Gemcitabine in Patients with Advanced-stage Non-small-cell Lung Cancer: A Single-center Cohort Study.

BACKGROUND: Palliative chemotherapy using platinum-based doublet chemotherapy was recommended as one of the standard treatments in patients with advanced-stage non-small cell lung cancer (NSCLC) with negative EGFR mutation. This study aimed to compare clinical outcomes between patients treated with paclitaxel and carboplatin (PC) and those treated with carboplatin and gemcitabine (CG). METHODS: We conducted a retrospective cohort study comparing PC and CG at Hatyai Hospital between 2012 and 2019. The primary outcome was survival analysis, and the secondary outcome was chemotherapy-related adverse events, and the rate and reason for stopping chemotherapy. RESULT: The median overall survivals of both groups was comparable (9.0 months for the PC group and 9.6 months for the CG group; log-rank, p=0.287). The CG group had a higher incidence of adverse events (89.7% vs. 77.9%, p=0.010) and tended to have a lower rate of chemotherapy discontinuation (29.6% vs. 41.2%, p=0.080) than the PC group. In the multivariate analysis, female sex (odds ratio [OR]=0.351; 95% confidence interval [CI], 0.158-0.780; p=0.010) and higher performance status (OR=76.374; 95%CI, 32.533-179.295; p<0.001) were independent predictive factors for stopping chemotherapy. In the proportional hazards model, the factors associated with decreased survival included higher performance status (hazard ratio [HR]=1.939; 95%CI, 1.388-2.709; P<0.001) and discontinuation of chemotherapy (HR=2.572; 95%CI, 1.792-3.691; p=<0.001). CONCLUSION: These two platinum-based regimens had comparable effects on overall survival. The CG group had a higher incidence of chemotherapy-related adverse events, while the PC group had a marginally significantly higher rate of stopping chemotherapy from unacceptable adverse events and deterioration of patients' clinical status.

Intercellular transfer of exosomal wild type EGFR triggers osimertinib resistance in non-small cell lung cancer.

BACKGROUND: Epidermal growth factor receptor (EGFR)-mutated lung cancer constitutes a major subgroup of non-small cell lung cancer (NSCLC) and osimertinib is administrated as first-line treatment. However, most patients with osimertinib treatment eventually relapse within one year. The underlying mechanisms of osimertinib resistance remain largely unexplored. METHODS: Exosomes isolation was performed by differential centrifugation. Co-culture assays were conducted to explore the alteration of drug sensitivity by cell viability and apoptosis assays. Immunofluorescence and flow cytometry were performed to visualize the formation or absorption of exosomes. Exosomes secretion was measured by Nanoparticle Tracking Analysis or ELISA. The xenograft tumor model in mice was established to evaluate the effect of exosomes on osimertinib sensitivity in vivo. RESULTS: Intercellular transfer of exosomal wild type EGFR protein confers osimertinib resistance to EGFR-mutated sensitive cancer cells in vitro and in vivo. Co-culture of EGFR-mutated sensitive cells and EGFR-nonmutated resistant cells promoted osimertinib resistance phenotype in EGFR-mutated cancer cells, while depletion of exosomes from conditioned medium or blockade of exosomal EGFR by neutralizing antibody alleviated this phenotype. Mechanistically, osimertinib promoted the release of exosomes by upregulated a Rab GTPase (RAB17). Knockdown of RAB17 resulted in the decrease of exosomes secretion. Moreover, exosomes could be internalized by EGFR-mutated cancer cells via Clathrin-dependent endocytosis and then the encapsulated exosomal wild type EGFR protein activated downstream PI3K/AKT and MAPK signaling pathways and triggered osimertinib resistance. CONCLUSIONS: Intercellular transfer of exosomal wild type EGFR promotes osimertinib resistance in NSCLC, which may represent a novel resistant mechanism of osimertinib and provide a proof of concept for targeting exosomes to prevent and reverse the osimertinib resistance.

Increased efficacy of gefitinib on cisplatin-resistant wild-type epidermal growth factor receptor non-small cell lung cancer cells.

BACKGROUND: Gefitinib is a first-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) that has become first-line treatment for patients with mutant EGFR non-small cell lung cancer (NSCLC). Despite its anti-tumor activity, the benefit of gefitinib in patients with wild-type EGFR NSCLC is debated. This work aimed to evaluate the effects of gefitinib on cisplatin-resistant wild-type EGFR NSCLC cells in in vitro and in vivo animal xenografts. METHODS: We established a cisplatin-resistant wild-type EGFR NSCLC cell line, H358R, to evaluate the cells' sensitivity to gefitinib compared with that of parental cell line H358. We first tested the p-EGFR of gefitinib's target in H358R and H358 cell line by western blot and immunofluorescence. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), clone formation assay, flow cytometry and annexin V-fluorescein/propidium iodide staining were used to investigate cellular proliferation and apoptosis of H358R/H358 cells treated with gefitinib, and the anti-tumor effect was evaluated in female BALB/c nude mice models of xenografts in vivo. RESULTS: EGFR and the downstream node molecules ERK and AKT were significantly more phosphorylated in H358R than in the parental cells and were inhibited by gefitinib. In H358R cells, gefitinib increased the inhibition of cell survival/proliferation, and the promotion of apoptosis in vitro. The increased anti-tumor effect was present also in H358R xenografts in vivo. CONCLUSIONS: Abnormal activation of EGFR in H358R cells results in enhanced sensitivity to gefitinib. The improved efficacy of gefitinib on cisplatin-resistant wild-type EGFR NSCLC cells suggests that gefitinib as sequential therapy for patients with cisplatin-resistant wild-type EGFR NSCLC should be considered.

Apatinib, a novel VEGFR inhibitor plus docetaxel in advanced lung adenocarcinoma patients with wild-type EGFR: a phase I trial.

Background This phase I trial was primarily conducted to determine the maximum tolerated dose (MTD) of apatinib combined with docetaxel in advanced lung adenocarcinoma patients with wild-type EGFR who have failed to first-line platinum-based chemotherapy, and to evaluate the safety and tolerability of apatinib plus docetaxel. Methods This was a single-center, open-label, dose-escalating phase I trial. The study used a standard 3 + 3 dose escalation design with the primary aim of determining the MTD. Twelve patients with advanced lung adenocarcinoma were enrolled, the primary endpoint was safety. Two doses of apatinib, 250 mg/day (level 1) and 500 mg/day (level 2), were evaluated in combination with 60 mg/m2 doxetacel every 3 weeks. Six patients have been treated at levels 1 and 2, respectively. Optimal dose of apatinib was determined by dose-limiting toxicity (DLT). Results Six patients have been treated at levels 1 and 2. At level 1, one of six patients experienced grade 3 acneiform rash as DLTs. At level 2, two patients experienced grade 3 hypertension and one experienced grade 3 nasal bleeding. MTD and recommended dose for phase II study was 250 mg/day. Most frequent adverse events of any grade were bilirubin elevation, hypertension, alanine aminotransferase elevation, transglutaminase elevation, hand foot syndrome and fatigue. The median progression-free survival was 2.76 month. Moreover, three patients had developed progressive disease and the mean duration of response was 2.79 months. Conclusion Apatinib plus docetaxel was well tolerated and showed promising efficacy in advanced lung adenocarcinoma. This combination therapy may represent a potent therapeutic option for advanced lung adenocarcinoma patients with wild-type EGFR.

A method for treatment monitoring using circulating tumour DNA in cancer patients without targetable mutations.

BACKGROUND: The potentials of circulating tumour DNA (ctDNA) have been studied for non-invasive disease monitoring in patients with targetable mutations. However, the majority of cancer patients harbour no targetable mutations. A workflow including targeted next-generation sequencing (NGS) and droplet digital PCR (ddPCR) could be used for monitoring treatment in these patients. Thus, our aim was to evaluate the workflow for ctDNA monitoring in a cohort of non-small cell lung cancer patients. METHODS: Forty patients were prospectively included. Plasma samples were collected prior to and during treatment. NGS (Ion AmpliSeq Colon and Lung Cancer panel v2) was performed on ctDNA from pre-treatment samples. The identified mutations were monitored by ddPCR in consecutively collected samples. RESULTS: Mutations were detected in 21 patients. The most commonly mutated genes were TP53 (N=20) and KRAS (N=13). Treatment was discontinued due to non-response in 18 patients. In 16 of these, a simultaneous increase in ctDNA concentration was observed. A twofold ctDNA concentration increase confirmed in a second successive sample predicted non-response on the following imaging in 83% of patients (10/12). CONCLUSION: ctDNA monitoring can be used for early detection of non-response in patients without targetable mutations, and therefore could supplement imaging data for treatment monitoring in this subset of patients.

Lycorine inhibits glioblastoma multiforme growth through EGFR suppression.

BACKGROUND: Lycorine has been revealed to inhibit the development of many kinds of malignant tumors, including glioblastoma multiforme (GBM). Although compelling evidences demonstrated Lycorine's inhibition on cancers through some peripheral mechanism, in-depth mechanism studies of Lycotine's anti-GBM effects still call for further exploration. Epidermal Growth Factor Receptor (EGFR) gene amplification and mutations are the most common oncogenic events in GBM. Targeting EGFR by small molecular inhibitors is a rational strategy for GBM treatment. METHODS: The molecular docking modeling and in vitro EGFR kinase activity system were employed to identify the potential inhibitory effects of Lycorine on EGFR. And the Biacore assay was used to confirm the direct binding status between Lycorine and the intracellular EGFR (696-1022) domain. In vitro assays were conducted to test the suppression of Lycorine on the biological behavior of GBM cells. By RNA interference, EGFR expression was reduced then cells underwent proliferation assay to investigate whether Lycorine's inhibition on GBM cells was EGFR-dependent or not. RT-PCR and western blotting analysis were carried out to investigate the underlined molecular mechanism that Lycorine exerted on EGFR itself and EGFR signaling pathway. Three different xenograft models (an U251-luc intracranially orthotopic transplantation model, an EGFR stably knockdown U251 subcutaneous xenograft model and a patient-derived xenograft model) were performed to verify Lycorine's therapeutic potential on GBM in vivo. RESULTS: We identified a novel small natural molecule Lycorine binding to the intracellular EGFR (696-1022) domain as an inhibitor of EGFR. Lycorine decreased GBM cell proliferation, migration and colony formation by inducing cell apoptosis in an EGFR-mediated manner. Furthermore, Lycorine inhibited the xenograft tumor growths in three animal models in vivo. Besides, Lycorine impaired the phosphorylation of EGFR, AKT, which were mechanistically associated with expression alteration of a series of cell survival and death regulators and metastasis-related MMP9 protein. CONCLUSIONS: Our findings identify Lycorine directly interacts with EGFR and inhibits EGFR activation. The most significant result is that Lycorine displays satisfactory therapeutic effect in our patient-derived GBM tumor xenograft, thus supporting the conclusion that Lycorine may be considered as a promising candidate in clinical therapy for GBM.

Comparative efficacy and safety of second-line treatments for advanced non-small cell lung cancer with wild-type or unknown status for epidermal growth factor receptor: a systematic review and network meta-analysis.

BACKGROUND: Docetaxel, pemetrexed, erlotinib, and gefitinib are recommended as second-line treatment for advanced non-small cell lung cancer (NSCLC) with wild-type or unknown status for epidermal growth factor receptor (EGFR). However, the number of published randomized clinical trials (RCTs) on this topic is increasing. Our objective was to assess the comparative effectiveness and tolerability of all second-line treatments for advanced NSCLC with wild-type or unknown status for EGFR by a systematic review and network meta-analysis. METHODS: MEDLINE, EMBASE, CENTRAL, ClinicalTrials.gov, and the US Food and Drug Administration website, as well as other sources, were searched for available reports up to June 6, 2017. Two reviewers independently selected published and unpublished reports of RCTs comparing any second-line treatments, extracted data and assessed the risk of bias of all included trials. We performed a Bayesian network meta-analysis. The primary outcomes were overall survival (OS) and progression-free survival (PFS). Secondary outcomes included objective response (ObR), the number of serious adverse events, and quality of life. RESULTS: We included 102 RCTs involving 36,058 patients (62% male, median age 61 years, 81% with stage IV cancer, 80% smokers, and 92% with performance status 0-1). We revealed a differential reporting of outcomes between efficacy and safety outcomes. Half of the trials reported safety outcomes and less than 20% quality of life. For OS, nivolumab was more effective than docetaxel (hazard ratio (HR) 0.69, 95% credible interval (CrI) 0.56-0.83), pemetrexed (0.67, 0.52-0.83), erlotinib (0.68, 0.53-0.86), and gefitinib (0.66, 0.53-0.83). Pembrolizumab, atezolizumab, and pemetrexed plus erlotinib were also significantly more effective than docetaxel, pemetrexed, erlotinib, and gefitinib. For PFS, erlotinib plus cabozantinib was more effective than docetaxel (HR 0.39, 95% CrI 0.18-0.84), pemetrexed (0.38, 0.18-0.82), erlotinib (0.37, 0.18-0.78), and gefitinib (0.38, 0.18-0.82). Cabozantinib and pemetrexed plus erlotinib were also significantly more effective than the four recommended treatments. For ObR, no treatment was significantly more effective. The effectiveness of the four recommended treatments was similar and they were ranked among the 25 less-effective treatments. For safety, evidence is insufficient to draw certain conclusions. CONCLUSIONS: Nivolumab, pembrolizumab, atezolizumab, and pemetrexed plus erlotinib may be the most effective second-line treatments for NSCLC in terms of OS. The four recommended treatments seem to have relatively poor performance. However, the impact on life expectancy of immunotherapy versus other treatments should be further explored by future analyses, and more trials comparing the novel treatments are needed to reduce uncertainty in these results. TRIAL REGISTRATION: Registration number: PROSPERO ( CRD42015017592 ).

Hepatocyte growth factor reduces sensitivity to the epidermal growth factor receptor-tyrosine kinase inhibitor, gefitinib, in lung adenocarcinoma cells harboring wild-type EGFR.

Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy is an option for lung cancers harboring wild-type EGFR when chemotherapeutic reagents have failed. In this study, we found that the EGFR-TKI, gefitinib, modestly suppressed proliferation of the lung cancer cell lines, A549 and H358, which both harbor wild-type EGFR. Treatment with hepatocyte growth factor (HGF) reduced the sensitivity to gefitinib, whereas sensitivity was restored by treatment with an HGF antibody, a MET inhibitor, or depletion of MET but not ErbB3 gene. Moreover, both PI3K/mTOR inhibitors and MEK inhibitors suppressed proliferation of A549 cells, whereas only PI3K/mTOR inhibitors effectively suppressed cell viability of EGFR mutant PC-9 cells. Our findings suggest that HGF reduced the gefitinib sensitivity through MET and downstream PI3K and MAPK pathways. Combined use of EGFR-TKI and MET inhibitors or inhibition of downstream signaling molecules might be a better second or third line choice for a group of patients with advanced lung cancer harboring wild-type EGFR.

Clinical and biological significance of erlotinib therapy after pemetrexed in non-small cell lung cancer with wild-type EGFR.

Pemetrexed is a multi-targeted anti-folate agent that confers favorable benefits to patients with non-small cell lung cancer (NSCLC). However, the optimal use including treatment schedule of pemetrexed and other drugs in clinical practice remains to be determined, particularly for NSCLC with wild-type epidermal growth factor receptor (EGFR). The present study investigated a potential therapeutic strategy for NSCLC patients with wild-type EGFR who were treated with pemetrexed. To identify factors associated with a survival, medical record data from 130 patients were retrospectively reviewed, using the Kaplan-Meier method with log-rank test. Factors identified in the clinical analysis were further investigated within in vitro studies. Patients who underwent the treatment schedule of erlotinib at the time of progression after pemetrexed-based chemotherapy prolonged overall survival, compared to those treated with other schedules (p=0.010; hazard ratio, 0.418). This survival benefit was also observed in the treatment schedule of pemetrexed monotherapy and subsequent erlotinib (p=0.008; hazard ratio, 0.220). As a treatment at the time of progression after pemetrexed-based chemotherapy, erlotinib conferred a survival benefit when compared to docetaxel (p=0.024; hazard ratio, 0.377). The cell growth assay confirmed that treatment with pemetrexed followed by erlotinib significantly inhibited proliferation of NSCLC cells regardless of EGFR mutation status. In conclusion, use of erlotinib at the time of progression after pemetrexed therapy confers a survival benefit in NSCLC patients with wild-type EGFR. The result of this study provides an important clue to the optimal treatment schedule for NSCLC.

Clinical significance of coexpression of L-type amino acid transporter 1 (LAT1) and ASC amino acid transporter 2 (ASCT2) in lung adenocarcinoma.

BACKGROUND: L-type amino acid transporter 1 (LAT1) and ASC amino acid transporter 2 (ASCT2) have been associated with tumor growth and progression. However, the clinical significance of LAT1 and ASCT2 coexpression in the prognosis of patients with lung adenocarcinoma remains unclear. METHODS: In total, 222 patients with surgically resected lung adenocarcinoma were investigated retrospectively. Tumor sections were stained immunohistochemically for LAT1, ASCT2, CD98, phosphorylated mammalian target-of-rapamycin (p-mTOR), and Ki-67, and microvessel density (MVD) was determined by staining for CD34. Epidermal growth factor receptor (EGFR) mutation status was also examined. RESULTS: LAT1 and ASCT2 were positively expressed in 22% and 40% of cases, respectively. Coexpression of LAT1 and ASCT2 was observed in 12% of cases and was associated significantly with disease stage, lymphatic permeation, vascular invasion, CD98, Ki-67, and p-mTOR. Only LAT1 and ASCT2 coexpression indicated a poor prognosis for lung adenocarcinoma. Furthermore, this characteristic was recognized in early-stage patients, especially those who had wild-type, rather than mutated, EGFR. Multivariate analysis confirmed that the coexpression of LAT1 and ASCT2 was an independent factor for predicting poor outcome. CONCLUSIONS: LAT1 and ASCT2 coexpression is an independent prognostic factor for patients with lung adenocarcinoma, especially during the early stages, expressing wild-type EGFR.

Pemetrexed versus gefitinib as a second-line treatment in advanced nonsquamous nonsmall-cell lung cancer patients harboring wild-type EGFR (CTONG0806): a multicenter randomized trial.

BACKGROUND: CTONG0806 assessed the efficacy of pemetrexed versus gefitinib as second-line treatment in advanced nonsquamous nonsmall-cell lung cancer (NSCLC) harboring wild-type epidermal growth factor receptor (EGFR). PATIENTS AND METHODS: Patients with locally advanced or metastatic nonsquamous NSCLC harboring wild-type EGFR, detected by direct sequencing, and previously treated with platinum-based chemotherapy were randomized to receive gefitinib (250 mg/day) orally or pemetrexed (500 mg/m(2)) i.v. on day 1 of a 21-day cycle until disease progression or unacceptable toxicity. The primary end point was progression-free survival (PFS). The Independent Review Committee (IRC) evaluated all pictorial data. RESULTS: From February 2009 to August 2012, 161 patients were enrolled, and 157 were assessable (81 in the gefitinib arm, 76 in the pemetrexed arm). Baseline characteristics were balanced between the two arms. The median PFSs were 4.8 versus 1.6 months in the pemetrexed and gefitinib arms, respectively [hazard ratio (HR) 0.54, 95% confidence interval (CI) 0.40-0.75, P < 0.001] as confirmed by IRC evaluation (5.6versus 1.7 months, HR 0.53, 95% CI 0.38-0.75, P < 0.001). The median overall survival (OS) showed a trend of superiority in the pemetrexed arm (12.4 versus 9.6 months, HR 0.72, 95% CI 0.49-1.04, P = 0.077). Quality-of-life assessment showed no marked difference between the arms. No unexpected adverse events were found. Of 108 patients with sufficient DNA samples, EGFR mutation status was re-tested by Scorpion amplification refractory mutation system (ARMS); 32 (29.6%) tested positive (19 in the pemetrexed arm, 13 in the gefitinib arm; median PFS: 8.1 versus 7.0 months, HR 0.94, 95% CI 0.43-2.08, P = 0.877). CONCLUSIONS: CTONG0806 is the first trial to show significant improvement in PFS and an improved OS trend with pemetrexed compared with gefitinib as second-line setting treatment of EGFR wild-type advanced nonsquamous NSCLC. ARMS is superior to direct sequencing in excluding false-negative patients. CLINICALTRIALSGOV IDENTIFIER: NCT00891579.

A phase II study of erlotinib monotherapy in pre-treated non-small cell lung cancer without EGFR gene mutation who have never/light smoking history: re-evaluation of EGFR gene status (NEJ006/TCOG0903).

OBJECTIVES: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors are particularly effective in non-small cell lung cancer (NSCLC) patients harboring active EGFR mutations. However, some studies have reported survival benefits in NSCLC patients with wild-type EGFR upon erlotinib treatment. This trial was conducted to evaluate the efficacy of erlotinib monotherapy and investigate the predictive values of several biomarkers. PATIENTS AND METHODS: Patients with previously treated NSCLC but without EGFR gene mutations that had never or light smoked were eligible for this study. Gene status screening was performed using the PNA-LNA PCR clamp method. Erlotinib was administered until disease progression or unacceptable toxicities occurred. EGFR gene status was re-evaluated using the fragment method to detect exon 19 deletions and the Cycleave-PCR method to detect point mutations. Expression of hepatocyte growth factor (HGF), Met, and thymidylate synthase (TS) were evaluated using immunohistochemistry. RESULTS: Forty-seven patients were enrolled in the study between March 2010 and November 2011. Objective response rate (ORR) and disease control rate (DCR) were 15.2% and 41.3%. Re-evaluations for EGFR gene were performed in 32 tumor samples. EGFR gene mutations were found in eight samples (5:exon 19 deletion, 2:G719X, 1:L858R). Six patients had PR and two had SD among these eight patients. A total of 24 patients were confirmed as wild-type EGFR using different methods. ORR and DCR were 4.2% and 41.7%. The median progression free survival (PFS) and median survival times were 2.0 and 6.0 months, respectively. Patients with tumors expressing HGF showed shorter PFS but not MET or TS. CONCLUSIONS: Re-examination of EGFR gene status using different detecting method or different sample should be considered to grasp a chance of erlotinib treatment after first line treatment. In confirmed EGFR wild NSCLC, negative HGF staining could be a biomarker for longer PFS by erlotonib treatment.

Epithelial phenotype as a predictive marker for response to EGFR-TKIs in non-small cell lung cancer patients with wild-type EGFR.

Epithelial-to-mesenchymal transition (EMT) has profound impacts on cancer progression and also on drug resistance, including epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Nowadays, there is still no predictive biomarker identified for the use of EGFR-TKIs in non-small cell lung cancer (NSCLC) patients with wild-type EGFR. To clarify the role of EMT phenotype as a predictive marker for EGFR-TKI, we performed a retrospective study in 202 stage IV or recurrent NSCLC patients receiving gefitinib or erlotinib therapy from June 2008 to September 2012 in our institute. Clinical data and EGFR mutational status were collected, while epithelial, epithelial to mesenchymal, not specified or mesenchymal phenotype were classified according to EMT markers such as E-cadherin, fibronectin, N-cadherin and vimentin by immunohistochemistry. Epithelial phenotype was more frequently found in patients with EGFR mutation (p = 0.044). Epithelial phenotype was associated with a significantly higher objective response rate (23.5 vs. 11.1 vs. 0.0 vs. 2.4%, p = 0.011), longer progression-free survival (4.4 vs. 1.9 vs. 1.7 vs. 1.0 months, p < 0.001) and longer overall survival (11.5 vs. 8.9 vs. 4.5 vs. 4.9 months, p < 0.001) compared to epithelial to mesenchymal, not specified and mesenchymal phenotype in the wild-type EGFR subgroup. In the subgroup with EGFR mutation, the trend remained but without a statistically significant difference. In conclusion, epithelial phenotype was more likely expressed in patients with EGFR mutation and was associated with a better outcome in advanced NSCLC patients with wild-type EGFR, which indicates that the EMT phenotype might be a potential marker to guide EGFR-TKI therapy in this population.