EGFR-mutant Lung Cancer Patients Research Articles

A tyrosine kinase inhibitor-induced interferon response positively associates with clinical response in EGFR-mutant lung cancer

Tyrosine kinase inhibitors (TKIs) targeting EGFR-mutant lung cancers promote a range of tumor regression responses to yield variable residual disease, a likely incubator for acquired resistance. Herein, rapid transcriptional responses induced by TKIs early in treatment that associate with the range of patient responses were explored. RNAseq was performed on EGFR mutant cell lines treated in vitro with osimertinib and on tumor biopsies of eight EGFR mutant lung cancer patients before and after 2 weeks of TKI treatment. Data were evaluated for gene expression programs altered upon TKI treatment. Chemokine and cytokine expression were measured by ELISA and quantitative RT-PCR. IκB Kinase (IKK) and JAK-STAT pathway dependence was tested with pharmacologic and molecular inhibitors. Tumor sections were stained for the T-cell marker CD3. Osimertinib stimulated dynamic, yet wide-ranging interferon (IFN) program regulation in EGFR mutant cell lines. IL6 and CXCL10 induction varied markedly among the EGFR mutant cell lines and was sensitive to IKK and JAK-STAT inhibitors. Analysis of matched patient biopsy pairs revealed marked, yet varied enrichment of IFN transcriptional programs, effector immune cell signatures and T-cell content in treated tumors that positively correlated with time to progression in the patients. EGFR-specific TKIs induce wide-ranging IFN response program activation originating within the cancer cell. The strong association of IFN program induction and duration of clinical response indicates that the TKI-induced IFN program instructs variable recruitment and participation of immune cells in the overall therapeutic response.

VPS34 suppression reverses osimertinib resistance via simultaneously inhibiting glycolysis and autophagy

Autophagy and glycolysis are associated with osimertinib resistance. The energy complement and dynamic balance between these two processes make it difficult to block the process of drug resistance; breaking the complementary relationship between them may effectively overcome drug resistance. However, the exact mechanisms and the key players for regulating autophagy and glycolysis remain unclear. In this study, we demonstrate that autophagy and glycolysis levels in osimertinib-resistant cells were markedly higher than parental cells, and a dynamic balance existed between them. Inhibition of the class III phosphoinositide 3-kinase vacuolar protein sorting 34 (VPS34) with 3-methyladenine or small interfering RNA can not only inhibit abnormally enhanced autophagy but also inhibit glycolysis by inhibiting the location of epidermal growth factor receptor (EGFR) and the expression of hexokinase II. By demonstrating that VPS34 is the key player controlling autophagy and glycolysis simultaneously, our study may provide a new strategy for overcoming osimertinib resistance for treatment of EGFR-mutant non-small cell lung cancer patients.

Real-World Treatment Patterns, Epidermal Growth Factor Receptor (EGFR) Testing and Outcomes in EGFR-Mutated Advanced Non-small Cell Lung Cancer Patients in Belgium: Results from the REVEAL Study.

BackgroundTreatment of patients with epidermal growth factor receptor-mutated (EGFRm) non-small cell lung cancer (NSCLC) continues to evolve expeditiously.ObjectivesThis retrospective study investigated real-world treatment patterns and EGFR mutation testing in patients with EGFRm advanced NSCLC in Belgium.MethodsData were extracted from medical records of adults diagnosed with EGFRm locally advanced/metastatic NSCLC between 1 September 2015 and 31 December 2017. Patients were followed retrospectively from diagnosis until 1 September 2018, end of clinical activity or death. Data on demographics, patient outcomes and disease characteristics, treatment patterns and EGFR mutation testing at diagnosis and progression were analyzed descriptively.ResultsA total of 141 patients were enrolled. At diagnosis, median age was 69 years, 63.1% were female, 88.7% had metastatic disease, 94.3% had adenocarcinoma histology, 76.6% had ECOG 0/1, 70.9% had common EGFR mutations and 29.1% had only rare mutations. In first line, 73.8% of patients received first/second-generation EGFR–tyrosine kinase inhibitors (1G/2G EGFR-TKIs), while 21.9% received other systemic treatments. Among 61 patients progressing on and discontinuing a first 1G/2G EGFR-TKI, 45 (73.8%) received subsequent systemic treatment while 16 (26.2%) did not; 20 (32.8%) received osimertinib. Among 65 patients progressing on a first 1G/2G EGFR-TKI, 47 (72.3%) were tested for T790M, of whom 25 (53.2%) were positive.ConclusionThese real-world data from Belgium show that a substantial fraction of patients with EGFRm NSCLC do not receive 1G/2G EGFR-TKIs in first line and do not receive subsequent systemic treatment after progression on 1G/2G EGFR-TKIs. Only a third receive osimertinib upon progression on 1G/2G EGFR-TKIs. These observations should be considered in first-line treatment decisions.Trial RegistrationClinicalTrials.gov: NCT03761901—December 3, 2018

Relationship between PD-L1 expression and outcome in EGFR-mutant lung cancer patients treated with EGFR tyrosine kinase inhibitors

ObjectivesPredictive biomarkers for poor response to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is an area of ongoing research. This multicentre retrospective study sought to determine the impact of programmed death-ligand 1 (PD-L1) tumour proportional score (TPS) on outcome in EGFR TKI treated patients. Materials and MethodsPatients with Stage IIIB/IV lung adenocarcinoma harbouring a sensitising EGFR mutation treated with first-line TKI at five metropolitan hospitals were included. PD-L1 TPS was determined using the Ventana anti-PD-L1 (SP263) assay. High PD-L1 expression was defined as TPS ≥ 50 %. Determinants of progression and survival hazards were modelled using Cox regression. ResultsA total of 186 patients were included. Mean age was 67 years, 66 % were female and 54 % were Asian. Patients with high PD-L1 expression (n = 23; 12 %) had significantly shorter progression free survival (6.6 vs 13.0 months, hazard ratio (HR) 2.6 95 % CI 1.6–4.2, p < 0.0001) and overall survival (11.5 vs 32.9 months, HR 3.3, 95 % CI 1.9–5.7, p < 0.0001) compared to patients with PD-L1 low/negative tumours. This remained significant in multivariate analyses. High PD-L1 in post-TKI progression biopsies was not associated with poorer survival. ConclusionIn this large, real-world cohort of EGFR-mutant lung adenocarcinoma patients, high PD-L1 expression was associated with early resistance to 1st generation EGFR TKIs and shorter survival, regardless of ethnicity.

P76.35 Genomic Characteristics and Prognosis of Concomitant with EGFR Copy Numbers Variations in EGFR Mutated Lung Cancer Patients

P76.35 Genomic Characteristics and Prognosis of Concomitant with EGFR Copy Numbers Variations in EGFR Mutated Lung Cancer Patients

Hematological parameters in EGFR-mutated advanced NSCLC patients treated with TKIs: predicting survival and toxicity

ABSTRACT Background: The aim of this study was to analyze the prognostic value of pre-treatment hematological parameters in EGFR-mutated non-small cell lung cancer patients treated with tyrosine-kinase inhibitors (TKIs). Patients and methods: Patients with EGFR mutations were treated with EGFR-TKIs in the first line until progression/unacceptable toxicity. Hematological parameters were derived from the absolute baseline differential counts of a complete blood count. The associations between the patients’ and tumor characteristics were analyzed using Pearson Chi-Square, Fisher’s exact, t-test, and Mann–Whitney tests. Cutoff values were determined using ROC curves, and correlation with survival was examined by Kaplan–Meier method and Cox regression. Results: Patients with NMR<12.62 had a longer PFS compared to patients with higher NMR values (12.0 vs. 10.0 months, p = 0.054) and a significantly longer OS (20.0 vs. 11.0 months, p = 0.010). The same parameter was confirmed as a predictors of favorable response in the patient subgroup with activating EGFR mutations. Patients with NLR>2.9 and LMR<2.5 more often presented with paronichia and diarrhea, and patients with PLR>190 more often had paronichia, diarrhea and hyperbilirubinemia. Conclusion: Low baseline value of the hematological parameter NMR has shown potential as a routine, low-cost, and minimally invasive predictor of survival in EGFR-TKI-treated NSCLC patients.

Deciphering the T790M/L858R-Selective Inhibition Mechanism of an Allosteric Inhibitor of EGFR: Insights from Molecular Simulations.

Allosteric inhibitors have lately received great attention because of their unique advantages, representing a more suitable choice for combinatory therapeutics targeting resistance-relevant signaling cascades. Among the various inhibitors, an allosteric small-molecule inhibitor, JBJ-04-125-02, has been proven to be effective against EGFRT790M/L858R mutant in vivo and in vitro. Herein, an in silico approach was adopted to shed light on the deep understanding of the higher selectivity of JBJ-04-125-02 against EGFRT790M/L858R mutant than wild-type EGFR. Our results indicate that JBJ-04-125-02 prefers to bind with the EGFRT790M/L858R mutant, stabilizes the inactive conformation, and further allosterically affects the conformations and dynamics of the interlobe cleft, including both the allosteric site and the ATP-binding site. Furthermore, docking results confirm that the binding of JBJ-04-125-02 at the allosteric site decreases the binding affinity of ANP (an ATP analogue) at the orthosteric site, especially for the Mut-holo one, which might further inhibit the function of EGFR. The present work provides a clear picture of the mutant-selective inhibition mechanism of an allosteric inhibitor of EGFR. The findings might pave the way for designing allosteric drugs targeting EGFR mutant lung cancer patients, which also takes a step forward in terms of drug resistance caused by protein mutations.

Pharmacokinetics of edoxaban in EGFR-mutated non-small cell lung cancer patients with venous thromboembolism.

The risk of venous thromboembolism (VTE) is increased 7-fold in patients with cancer than in those without. Low-molecular-weight heparin is the standard treatment for cancer-associated VTE. Direct oral anticoagulants (DOACs) are not inferior to low-molecular-weight heparin with respect to the general outcome of recurrent VTE. Warfarin is associated with a risk of bleeding when used in combination with gefitinib or erlotinib which are epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs). It is unclear, however, whether combination treatments with EGFR-TKIs and DOACs pose the same risk. We aimed to identify anticancer drugs and anticoagulants that can be used safely in combination, as accompanying research to an observational study on VTE incidence rates in lung cancer patients (Rising-VTE/NEJ037 study). Twelve patients receiving EFGR-TKI monotherapy and VTE treatment were enrolled. Blood samples were collected in time series after the first dose of edoxaban, and further samples were collected within 8-15 days after administering EGFR-TKIs. The pharmacokinetics (PK) of edoxaban were analyzed using a non-compartmental model. Edoxaban concentrations (30mg once daily) were measured in eight patients. PK analyses showed no significant differences before and after co-administration of EGFR-TKIs (gefitinib, erlotinib, and afatinib). Our findings indicate that the PK of edoxaban was not considerably affected by co-administration of EGFR-TKIs (gefitinib, erlotinib, and afatinib).

Pathological assessment of osimertinib-associated cardiotoxicity in EGFR-mutated non-small cell lung cancer patients

Abstract Background Osimertinib, a third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), inhibits both EGFR-TKI sensitizing mutations and resistant T790M mutations detected in non-small cell lung cancer (NSCLC) patients. Cardiac adverse events (AEs) induced by osimertinib are infrequent; however, cases of severe associated cardiac dysfunction have been reported and remain poorly understood. Purpose To assess pathogenesis of osimertinib-associated cardiac AEs, we analyzed myocardial specimens of three NSCLC cases with osimertinib-associated cardiac dysfunction. Results Analysis of LVEF prior to and after osimertinb administration in 36 NSCLC patients showed significant decrease of LVEF from 69% to 63%. Within this cohort, right ventricular (RV) biopsy was performed in 2 cases to further understand the pathophysiology of cardiac dysfunction. Case 1 was 78-year-old female with advanced NSCLC harboring an EGFR L858R mutation was treated with osimertinib as second line therapy. After 3 moths of osimetinib treatment, she presented with dyspnea, high NT-proBNP and troponin I, and significantly decreased left ventricular ejection fraction (LVEF) at 28%. RV biopsy showed moderate cardiomyocyte hypertrophy without inflammatory cell infiltration. Case 2 was 52-year-old female with advanced NSCLC harboring L858R mutation. She was treated with osimertinib as first line therapy. After 2 weeks of osimertinib, screening echocardiography revealed a reduction of LVEF from 63% to 41% without cardiac symptom. RV biopsy showed mild cardiomyocyte hypertrophy with infiltration of a few inflammatory cells in interstinum. We further analyzed death case of NSCLC. Case 3 was 63-year-old female with advanced NSCLC harboring EGFR ex. 19 del. and T790M mutations. After 6 months of osimertinib, she suffered from severe respiratory failure and severely reduced LVEF at 27%. She died on the 44th day after admission. Pathological autopsy revealed mild to moderate cardiomyocyte hypertrophy without inflammatory cell infiltration in both ventricles. These pathological findings may indicate neither myocyte injury nor myocarditis was induced by osimertinib in myocardium. Conclusion Although additional data collection of advanced NSCLC patients will be important in understanding the pathophysiology of cardiac AEs with osimertinib, osimertinib-associated cardiotoxicity may result from functional inhibition of myocyte contractility by osimertinib without induction of cell death or inflammation. Funding Acknowledgement Type of funding source: None

Genetic diagnostic features after failure of initial treatment with epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors among non-small-cell lung cancer patients harboring EGFR mutations

BackgroundOsimertinib, a third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), can be used as second-line treatment for lung cancer patients harboring the T790M substitution. Although osimertinib is more effective than the first-generation EGFR-TKIs used for first-line treatment, its efficacy with respect to long-term patient survival remains unclear even upon the administration of a complete sequence of EGFR-TKI therapy. Moreover, limited information is available regarding genetic diagnostic approaches after the treatment of EGFR-TKI–naïve patients. This study investigated the clinical characteristics of EGFR-mutated lung cancer patients harboring the T790M substitution resistant to EGFR-TKIs, as well as the advantages of rebiopsy and liquid biopsy for these patients.MethodsThe medical records of patients screened for EGFR mutations were reviewed. Upon failure of naïve treatment with EGFR-TKIs, except for osimertinib, single-plexus cobas version 2 was repeatedly used to detect the T790M substitution in EGFR via tissue or liquid biopsy.ResultsFrom April 2016 through May 2019, 113 patients were found to harbor EGFR mutations. Sixty patients were treated with EGFR-TKIs, among whom 46 underwent tissue or liquid biopsy. Twenty-nine of these 46 (63%) patients harbored the T790M substitution. In total, 141 rebiopsies were performed. The T790M substitution was detected in 24 of 43 tissue biopsies and 11 of 98 liquid biopsies. If patients displayed an EGFR exon 19 deletion, had a new lesion, and were administered gefitinib as first-line therapy, they were suspected to harbor the T790M substitution. Furthermore, the T790M substitution was detected through rebiopsy in patients with coexisting original mutations, brain metastases, tumor enlargement by ≥12 mm, or metastases at minor sites.ConclusionAmong patients with positive factors associated with the T790M mutation, repeated tissue or liquid biopsies are useful to maximize the detection rate of the T790M substitution. Furthermore, these biopsies need to be repeated numerous times in order to reduce “detection overlook” among such patients.

Metformin Overcomes Acquired Resistance to EGFR TKIs in EGFR-Mutant Lung Cancer via AMPK/ERK/NF-κB Signaling Pathway.

Background: The major limitation of EGFR TKIs in EGFR-mutant lung cancer therapy is the development of acquired resistance. The underlying mechanisms remain unknown in about 30% of cases. NF-κB activation was encountered in the acquired resistance to EGFR TKIs. Unfortunately, none of NF-κB inhibitors has been clinically approved. The most commonly used antidiabetic drug metformin has demonstrated antitumor effects associated with NF-κB inhibition. Therefore, in this study, metformin was examined for its antitumor and antiresistance effects and underlying mechanisms.Methods: In vitro and in vivo EGFR-mutant lung cancer models with acquired resistance to EGFR TKIs were used.Results: We found that NF-κB was activated in EGFR-mutant lung cancer cells with acquired resistance to EGFR TKIs. Metformin inhibited proliferation and promoted apoptosis of lung cancer cells, especially those with acquired EGFR TKI resistance. Moreover, metformin reversed and delayed acquired resistance to EGFR TKIs as well as suppressed cancer stemness in EGFR-mutant lung cancer. Mechanistically, those effects of metformin were associated with activation of AMPK, resulting in the inhibition of downstream ERK/NF-κB signaling.Conclusions: Our data provided novel and further molecular rationale and preclinical data to support combination of metformin with EGFR TKIs to treat EGFR-mutant lung cancer patients, especially those with acquired resistance.

Comparative analysis of first-line treatment regimens for advanced EGFR-mutant non-small cell lung cancer patients with stable brain metastases

To compare the survival outcomes of first-line treatment regimens for advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients with stable brain metastases. We conducted a systematic review of available data from randomized controlled trials (RCTs) of first-line treatment regimens of NSCLC patients with stable brain metastases. Progression free survival (PFS) and overall survival (OS) were extracted and analysed from the RCT subgroups. A network meta-analysis was constructed using the Bayesian statistical model to synthesize the survival outcomes of all the treatments. The analysis included 6 eligible RCT subgroups with 417 patients and 7 treatment regimens osimertinib, afatinib, first-generation EGFR-TKI (gefitinib or erlotinib), erlotinib + bevacizumab, gefitinib + pemetrexed + carboplatin, gemcitabine + cisplatin, and pemetrexed + cisplatin. Of these seven treatment regimens, gefitinib + pemetrexed + carboplatin had the highest potential for favorable PFS and OS, followed by osimertinib, in the treatment of advanced EGFR-mutant NSCLC patients with stable brain metastases. None of the results met the predetermined statistical significance of P<0.05. The regimens of "Gefitinib + pemetrexed + carboplatin" and "Osimertinib" were associated with the most favorable PFS and OS compared to the other therapies in advanced EGFR-mutant NSCLC patients with stable brain metastases, although the difference between these regimens and the others was not statistically significantly different.

Key prognostic factors for EGFR-mutated non-adenocarcinoma lung cancer patients in the Japanese Joint Committee of Lung Cancer Registry Database

IntroductionThe efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) for EGFR-mutated non-adenocarcinoma (ADC) non-small cell lung cancer patients is not well established. Herein, we investigated key prognostic factors influencing the efficacy of EGFR-TKIs in these patients. MethodsA total of 12,320 lung cancer patients pathologically diagnosed in 2012 at teaching hospitals in Japan were retrospectively selected. The follow-up survey was closed in 2016. ResultsEGFR-mutated non-ADC patients were more prone to malignant pleural effusion (MPE) and distant metastasis than ADC patients (P = 0.071 and 0.022, respectively). EGFR-mutated ADC patients were likely to have a longer median overall survival (OS) than non-ADC patients [hazard ratio (HR) 1.3 (95 % CI, 0.97–1.8, P = 0.072)—29.5 months (95 % CI, 27.9–31.1 months) versus 19.5 months (95 % CI, 10.8–28.2 months) (P = 0.068)]. There was no significant difference in median OS between EGFR-positive ADC and non-ADC patients receiving treatment with first-generation EGFR-TKI. Among EGFR-positive non-ADC patients, the median OS was significantly longer for patients receiving EGFR-TKI treatment than for those who did not [HR 4.5 (95 % CI, 2.1–9.8, P < 0.001)—25.5 months (95 % CI, 8.1–42.9 months) versus 7.5 months (95 % CI, 3.4–11.6 months) (P < 0.001)]. While there was no significant difference in the median OS for ADC patients with either 19 del or L858R mutations, the median OS was significantly longer for EGFR-mutated non-ADC patients with 19 del than for those with L858R mutation (HR 3.2 [95 % CI, 1.5–6.9, P = 0.004]; it was not reached for 19 del and was 15.5 months for L858R [95 % CI, 6.6–24.4 months], P = 0.002). DiscussionEGFR-mutated non-ADC patients were more prone to MPE and distant metastasis. Both ADC and EGFR del19-positive non-ADC patients can benefit from EGFR-TKI treatment, whereas EGFR L858R-positive non-ADC patients might require different therapeutic options.

Identification and in silico structural insights of rare recurrent EGFR mutations as resistance mechanisms to osimertinib in EGFR-mutated lung cancer.

9531 Background: Inevitable progression on 3rd-generation EGFR-tyrosine kinase inhibitor (TKI) osimertinib of EGFR-mutated lung cancer patients represents a great challenge in clinic. Previous studies have revealed that one-third of the resistant mechanisms are due to acquired EGFR secondary mutations, mainly on C797, L718 and L792 residues. Our study aims to gain insights into novel mechanisms of acquired resistance to osimertinib. Methods: We performed genomic profiling on a total of 1,058 EGFR-mutated lung cancer patients with progressed disease on osimertinib, and a cohort of 1,803 patients who received only 1st-generation EGFR TKIs upon progression. Recurrent EGFR mutations with a significant enrichment in the osimertinib group were identified. We further established and applied molecular dynamic simulation-based computational model of the mutant EGFR protein to predict its sensitivity to osimertinib. Results: As expected, compared with 1st-TKIs alone group, EGFR mutations, including C797S/G (22.1% vs. 0.5%), L718Q/V (6.2% vs. 0.3%), L792F/H (4.4% vs. 0.3%), were significantly more enriched in the osimertinib cohort. Our computational model has also successfully predicted their sensitivities to osimertinib: WT (-35.19 kcal/mol) &gt; L792F (-34.10 kcal/mol) &gt; L718Q (-30.33kcal/mol) &gt; C797S (-28.02 kcal/mol), which are consistent with our previous in vitro validations. Importantly, a total of 14 low-frequency EGFR mutations were exclusively observed in the osimertinib group, seven of which, including EGFR G796S(n = 6), V802F(n = 3), T725M(n = 2), Q791L/H(n = 2), P794S/R(n = 2), were predicted to dramatically reduce the binding affinity of osimertinib to EGFR. Of note, analysis of the pretreatment samples of two patients supported that EGFR V802F and Q791L/H were acquired during osimertinib treatment. Interestingly, EGFR G796S was predicted to be sensitive to gefitinib, suggesting the possibility of administration of gefitinib in patients with acquired EGFR G796S to first-line osimertinib treatment. Further in vitro functional validations are currently ongoing. Conclusions: Our study represents the largest EGFR-mutated lung cancer cohort so far to investigate osimertinib resistance in a real-world setting, and has uncovered a list of recurrent low-frequency EGFR mutations that may confer acquired resistance to osimertinib. Our in silico structural model was proved to be powerful and robust in the prediction of osimertinib sensitivity of EGFR mutants.

EGFR tyrosine kinase inhibitor therapy continuation with high-dose hypofractionated radiotherapy in EGFR-mutated non-small cell lung cancer (NSCLC) patients with oligoprogressive disease.

e21580 Background: EGFR tyrosine kinase inhibitors (TKIs) represent the standard first-line therapy for advanced non-small cell lung cancer (NSCLC) patients with activating EGFR mutations. However, despite initial marked responses, tumors invariably develop acquired resistance to TKIs. Oligoprogression is commonly observed during treatment with oncogene-directed therapies, including EGFR TKIs, and refers to patients who experience disease progression only in limited sites as a result of heterogeneous mechanisms of resistance. The use of local ablative treatments for these resistant lesions may extend the duration of TKI therapy and potentially improve long-term disease control and survival. We e retrospectively analyzed the efficacy of EGFR TKI therapy continuation with high-dose hypofractionated radiation therapy (RT), in EGFR-mutant NSCLC patients with oligoprogressive disease. Methods: Patients with metastatic EGFR mutant NSCLC who developed oligoprogression during first-line treatment with gefitinib were included in this analysis. We evaluated progression-free survival 1 (PFS 1), defined as the time from initiation of TKI therapy until development of oligoprogression or death, and PFS 2, defined as time of focal progression until further progression of disease or death. Overall survival and safety were also assessed. Results: Thirty-six patients were included in the study. The median PFS 1 was 12.5 (4.0-23.2) months. High-dose hypofractionated RT consisted of intensity-modulated RT in 23 patients (64%) and stereotactic radiotherapy in 13 cases (36%). The median PFS 2 was 6.3 (2-12.5) months. Overall survival was 38.7 months (9.0-46.3). The treatment was well-tolerated and no patient had to discontinue TKI therapy because of adverse events during radiotherapy. Conclusions: Our therapeutic strategy, including high-dose hypofractionated RT in addition to TKI therapy, was feasible in the clinical setting and was associated with significant prolongation of disease control and improvement of survival outcomes, while being associated with manageable side effects. Our study further support the use of definitive therapeutic approaches in oligoprogressive disease, especially in oncogene-driven tumors. Molecular profiling of metastatic sites remains crucial to identify novel biomarkers, involved in the development of acquired resistance and oligoprogression, that may be useful to select patients for local treatments.

LncRNA H19 downregulation confers erlotinib resistance through upregulation of PKM2 and phosphorylation of AKT in EGFR-mutant lung cancers.

First-generation EGFR tyrosine kinase inhibitors (TKIs) such as erlotinib have significant activity in NSCLC patients with activating EGFR mutations. However, EGFR-TKI resistance inevitably occurs after approximately 12 months of treatment. Acquired mechanisms of resistance, other than secondary mutations in EGFR (T790M) which account for 50-60%, are less well understood. Here, we identified lncRNA H19 as a significantly downregulated lncRNA in vitro models and clinical specimens with acquired EGFR-TKI resistance, H19 knockdown or overexpression conferred resistance or sensitivity, respectively, both in vitro and in vivo models. H19 downregulation contributed to erlotinib resistance through interaction and upregulation of PKM2, which enhanced the phosphorylation of AKT. AKT inhibitors restored the sensitivity of erlotinib-resistant cells to erlotinib. In EGFR-mutant patients treated with EGFR-TKIs, low H19 levels were associated with a shorter progression-free survival (PFS) (P=0.021). These findings revealed a novel mechanism of low-level H19 in the regulation of erlotinib resistance in EGFR-mutant lung cancers. Combination of AKT inhibitors and EGFR-TKIs could be a rational therapeutic approach for some subgroups of EGFR-mutant lung cancer patients.

Effect of epidermal growth factor receptor mutation on early-stage non-small cell lung cancer according to the 8th TNM classification

ObjectiveThis study evaluated the effect of EGFR mutation on early-stage non-small cell lung cancer (NSCLC) based on the 8th TNM classification. Materials and methodsThe study retrospectively examined 1231 patients who underwent curative resection for pathological stage 0–I (8th TNM classification) NSCLC and EGFR mutation analysis from January 2006 to December 2018 at Kanagawa Cancer Center. The disease-free survival (DFS), overall survival (OS) and disease-specific survival (DSS) of EGFR-mutant lung cancer (Mt) and EGFR wild-type lung cancer (Wt) patients at each stage were compared between two patient groups using the log-rank test. Cox regression analyses were performed to identify prognostic factors. ResultsThe number of stage 0, IA1, IA2, IA3, and IB Mt/Wt patients was 79/92, 202/189, 145/144, 45/75, and 74/186, respectively. There was no statistically significant difference in DFS between Mt and Wt patients at any pathological stage. The 5-year OS of Mt/Wt patients was 96.9 %/98.5 % for stage 0 (p = 0.671), 92.2 %/92.2 % for stage IA1 (p = 0.997), 93.9 %/82.6 % for stage IA2 (p = 0.039), 87.3 %/91.4 % for stage IA3 (p = 0.768), and 85.3 %/69.3 % for stage IB (p = 0.017). The 5-year DSS of Mt/Wt patients was 95.7 %/95.4 % for stage IA2 (p = 0.684) and 93.2 %/77.5 % for stage IB (p = 0.016). In Cox regression analyses, Mt was not identified as a prognostic factor for OS among stage IA2 NSCLC patients (HR, 0.62; 95 % CI, 0.20–1.93; p = 0.413). However, Mt was a favorable prognostic factor for OS (HR, 0.44; 95 % CI, 0.19–1.00; p = 0.049) and DSS (HR, 0.38; 95 % CI, 0.17–0.87; p = 0.022) among stage IB NSCLC patients. ConclusionEGFR mutation had no effect on the prognosis of stage 0–IA NSCLC but significantly affected the OS and DSS of stage IB NSCLC. Effect of EGFR mutations on postoperative prognosis of patients with stage 0–I NSCLC differed with each stage.

Circulating tumor DNA analysis of EGFR-mutant non-small cell lung cancer patients receiving osimertinib following previous tyrosine kinase inhibitor treatment

ObjectivesCirculating tumor (ct)DNA analysis is rapidly gaining acceptance as a diagnostic tool to guide clinical management of advanced non-small cell lung cancer (NSCLC). Clinically-actionable EGFR mutations can be detected in ctDNA before or after first-line EGFR-Tyrosine Kinase Inhibitor (TKI) treatment, but data are limited for patients with a complex treatment history. This study aimed to explore the feasibility of ctDNA testing in a clinical setting of NSCLC patients receiving osimertinib as a second or third line EGFR-TKI. Materials and MethodsTwenty EGFR T790M-positive NSCLC patients, who had received osimertinib as a second or third line EGFR-TKI and had donated blood samples while attending routine follow-up consultations between April and November 2016, were retrospectively selected to test plasma cfDNA for tumor-guided EGFR mutations. We used EGFR mutations previously identified in tumor-tissue to retrospectively test plasma ctDNA from 20 patients who had received osimertinib as a second or third line EGFR-TKI. Both EGFR-TKI sensitising and T790 M resistance mutations were analysed by droplet digital PCR (ddPCR) in plasma taken alongside routine consultations and ctDNA detection was correlated with response under osimertinib. Follow-up solid-tissue biopsies were obtained after disease progression. ResultsCtDNA was detected under osimertinib treatment in four out of the eight patients (50 %) who showed no response, two out of the seven (29 %) who showed an initial response and none of the five patients (0 %) who showed an ongoing response. The fraction of EGFR-mutant ctDNA in plasma tended to be higher in non-responders (0.1–68 %), compared to the initial responders (0.2–1.1 %). Blood samples were donated up to 34, 27 and 49 weeks after the start of osimertinib for the non-, initial and ongoing responders, respectively. ConclusionsThese findings support a potential role for ctDNA analysis in response monitoring of NSCLC patients with a complex EGFR-TKI treatment history. The weak trend between ctDNA detection and disease progression warrants larger studies to further investigate potential clinical utility.

Outcomes according to initial and subsequent therapies following intracranial progression in patients with EGFR-mutant lung cancer and brain metastasis.

In patients with epidermal growth factor receptor (EGFR)-mutant non–small-cell lung cancer (NSCLC) with brain metastases, it remains controversial whether the use of EGFR-tyrosine kinase inhibitor (TKI) alone without radiotherapy (RT) is an optimal approach. Here, we investigated the clinical outcomes according to the use of upfront RT as well as the subsequent therapy following intracranial progression. This single-centre retrospective study included a total of 173 patients who were treated with EGFR-TKI alone (TKI alone group) or with upfront whole-brain RT (WBRT) or stereotactic radiosurgery (SRS) followed by EGFR-TKI (RT plus TKI group). Clinical outcomes according to initial and subsequent therapies following intracranial progression were analysed. There was no significant difference in OS according to the use of upfront RT (TKI alone group, 24.5 months vs. WBRT group, 20.0 months vs. SRS group, 17.8 months; P = 0.186). Intracranial progression was found in 35 (32.7%) of 107 patients in the TKI alone group. Among them, 19 patients who received salvage RT had the better prognosis than others [median overall survival (OS); 28.6 vs. 11.2 months; P = 0.041]. In the RT plus TKI group, 12 (18.1%) of the 66 patients experienced intracranial progression and 3 of them received salvage RT (median OS; 37.4 vs. 20.0 months; P = 0.044). In multivariate analysis, upfront WBRT was associated with trends towards a lower probability of intracranial progression, whereas upfront SRS was found to be an independent risk factor for poor OS. In conclusion, using EGFR-TKI alone for brain metastasis in EGFR-mutant lung cancer patients showed outcomes comparable to those using upfront RT followed by EGFR-TKI. Patients who could not receive salvage RT following intracranial progression had the worst survival regardless of the type of initial treatment.

Concomitant TP53 Mutation Confers Worse Prognosis in EGFR-Mutated Non-Small Cell Lung Cancer Patients Treated with TKIs.

Background: Non-small cell lung cancer (NSCLC) is the primary cause of cancer-related deaths worldwide. Epidermal Growth Factor Receptor (EGFR)-mutated patients usually benefit from TKIs treatment, but a significant portion show unresponsiveness due to primary resistance mechanisms. We investigated the role of TP53 mutations in predicting survival and response to EGFR-TKIs in EGFR-mutated NSCLC patients, to confirm, on an independent case series, our previous results. Methods: An independent retrospective cohort study was conducted, on a case series of 136 EGFR-mutated NSCLC patients receiving first or second generation TKIs as a first line therapy, and a smaller fraction of patients who acquired the T790M resistance mutation and were treated with third generation TKIs in the second or further line of treatment. TP53 mutations were evaluated in relation to disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) of the patients. Results: Forty-two patients (30.9%) showed a TP53 mutation. Considered together, TP53 mutations had no significant impact on time-to-event endpoints. Considering the different TP53 mutations separately, exon 8 mutations confirmed their negative effect on PFS (HR 3.16, 95% 1.59–6.28, p = 0.001). In patients who developed the T790M resistance mutation, treated with third generation TKIs, the TP53 exon 8 mutations predicted worse PFS (even though not statistically significant), and OS (HR 4.86, 95% CI: 1.25–18.90, p = 0.023). Conclusions: TP53 exon 8 mutations confirmed their negative prognostic impact in patients treated with first and second generation TKIs and demonstrated a role in affecting clinical outcome in patients treated with third generation TKIs.