EGFR-mutant Patients Research Articles

Correlation between Immune Microenvironment Features and EGFR Mutation Status in Lung Adenocarcinoma

The morbidity and mortality rates of lung cancer remain high worldwide, and lung adenocarcinoma is one of the most important tissue subtypes of lung cancer. Epidermal growth factor receptor (EGFR) mutation is an important driver gene mutation for lung adenocarcinoma. In recent years, immune checkpoint inhibitors (ICIs), such as programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors, have achieved remarkable efficacy in some lung cancer patients. Patients with EGFR mutations enjoyed limited benefits from immunotherapy according to recent studies. This study aimed to explore the relationship between EGFR mutation status and the spatial distribution as well as infiltration number of various immune cells in patients with EGFR mutant lung adenocarcinoma. This study included 62 lung adenocarcinoma patients who underwent surgery. Through multi-point sampling of surgically removed tumor tissues in different areas, 223 tumor tissue samples were finally obtained. We aquired EGFR mutations status including variant allele frequency (VAF) and mutation subtype in each tumor tissue by genetic test. Afterwards, hematoxylin-eosin (HE) staining, immunohistochemical staining and multiplex fluorescence immunohistochemistry staining have been performed, therefore the infiltration of various immune cells and the distribution of tertiary lymphoid structure (TLS) in tumor tissues were obtained by calculating the immunohistochemical score. Compared with EGFR wild-type patients, patients with EGFR-mutant lung adenocarcinoma had more infiltration of CD68+ macrophages and major histocompatibility complex (MHC) class II antigen-presenting cells and higher spatial distribution heterogeneity of MHC class II antigen presenting cells in tumor tissues, while CD56+ natural killer cells and CD8+ T cells had lower infiltration. Tumor tissues with higher EGFR VAF were associated with lower cell infiltration such as CD3+ T cells, CD20+ B cells, CD56+ natural killer cells, CD68+ macrophages, CD8+ T cells, and only CD3+ T cells showed a lower spatial distribution heterogeneity. For the two common subtypes of EGFR mutations in Chinese population, tumor tissues with EGFR exon 19 deletion mutations have lower immune cell infiltration but higher spatial distribution heterogeneity of CD3+ T cells, CD56+ natural killer cells, CD68+ macrophages, and CD8+ T cells than that in EGFR exon 21 L858R mutant tumor tissues. Prognostic analysis found that patients with EGFR mutations with high degree of CD3+ T cells, CD20+ B cell infiltration and larger numbers of TLS formation and high spatial distribution heterogeneity of CD8+ T cell had longer disease-free survival. EGFR-mutated lung adenocarcinoma had a unique "non-inflammatory" tumor microenvironment with low infiltration of immune cells, and there was also heterogeneity in the tumor microenvironment among the tumors with different mutation subtypes and mutation abundance. These differences were not only reflected in the number but also the spatial distribution of immune cell infiltration. Hence, further studies on the immune microenvironment of EGFR-mutant lung adenocarcinoma were of great significance for improving the efficacy of immunotherapy in EGFR-mutant lung adenocarcinoma patients in the future.

Multiomics analysis revealed the mechanisms related to the enhancement of proliferation, metastasis and EGFR-TKI resistance in EGFR-mutant LUAD with ARID1A deficiency

IntroductionDysregulated ARID1A expression is frequently detected in lung adenocarcinoma (LUAD) and mediates significant changes in cancer behaviors and a poor prognosis. ARID1A deficiency in LUAD enhances proliferation and metastasis, which could be induced by activation of the Akt signaling pathway. However, no further exploration of the mechanisms has been performed.MethodsLentivirus was used for the establishment of the ARID1A knockdown (ARID1A-KD) cell line. MTS and migration/invasion assays were used to examine changes in cell behaviors. RNA-seq and proteomics methods were applied. ARID1A expression in tissue samples was determined by IHC. R software was used to construct a nomogram.ResultsARID1A KD significantly promoted the cell cycle and accelerated cell division. In addition, ARID1A KD increased the phosphorylation level of a series of oncogenic proteins, such as EGFR, ErbB2 and RAF1, activated the corresponding pathways and resulted in disease progression. In addition, the bypass activation of the ErbB pathway, the activation of the VEGF pathway and the expression level changes in epithelial–mesenchymal transformation biomarkers induced by ARID1A KD contributed to the insensitivity to EGFR-TKIs. The relationship between ARID1A and the sensitivity to EGFR-TKIs was also determined using tissue samples from LUAD patients.ConclusionLoss of ARID1A expression influences the cell cycle, accelerates cell division, and promotes metastasis. EGFR-mutant LUAD patients with low ARID1A expression had poor overall survival. In addition, low ARID1A expression was associated with a poor prognosis in EGFR-mutant LUAD patients who received first-generation EGFR-TKI treatment.7Ri7oJWPiw-vggUB99u973Video abstract

Phase 2 study of osimertinib in combination with platinum and pemetrexed in patients with previously untreated EGFR-mutated advanced non-squamous non-small cell lung cancer: The OPAL Study

BackgroundThis multicenter phase 2 trial evaluated the safety and efficacy of osimertinib and platinum-based chemotherapy (OPP) in patients with previously untreated EGFR-mutated advanced non-squamous non-small cell lung cancer (NSCLC). Patients and methodsPatients received osimertinib 80 mg once daily (QD), with either cisplatin 75 mg/m2 (arm A) or carboplatin (area under the curve [AUC] = 5; arm B), plus pemetrexed 500 mg/m2 for four cycles and maintenance therapy of osimertinib 80 mg QD with pemetrexed 500 mg/m2 every 3 weeks. The primary end-points were safety and objective response rate (ORR), and the secondary end-points were complete response rate (CRR), disease control rate (DCR), and progression-free survival (PFS). ResultsIn total, 67 patients (34 in arm A and 33 in arm B) were enrolled between July 2019 and February 2020. At the data cutoff (28th February 2022), 35 (52.2%) patients had discontinued the protocol treatment, including 10 (14.9%) due to adverse events. No treatment-related deaths occurred. In the full analysis set, the ORR, CRR, and DCR were 90.9% (95% confidence interval [CI], 84.0–97.8), 3.0% (0.0–7.2), and 97.0% (92.8–100.0), respectively. Based on updated survival data (data cutoff on August 31, 2022, median follow-up time: 33.4 months), the median PFS was 31.0 months (95% CI, 26.8 months–not reached) and median overall survival was not reached. ConclusionsThis is the first study to show that OPP has excellent efficacy with acceptable toxicity in previously untreated EGFR-mutated advanced non-squamous NSCLC patients.

Healthcare coverage affects survival of EGFR-mutant Thai lung cancer patients.

Despite significant benefits of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment in patients with EGFR-mutated NSCLC, access remains limited in Thailand and elsewhere. Retrospective analysis of patients with locally advanced/recurrent NSCLC and known EGFR mutation (EGFRm) status treated at Ramathibodi Hospital (2012-2017). Prognostic factors for overall survival (OS), including treatment type and healthcare coverage, were analyzed using Cox regression. Of 750 patients, 56.3% were EGFRm-positive. After first-line therapy (n=646), 29.4% received no subsequent (second-line) treatment. EGFR-TKI-treated EGFRm-positive patients survived significantly longer than EGFRm-negative patients without EGFR-TKIs (median OS [mOS] 36.4 vs. 11.9 months; hazard ratio HR=0.38 [95%CI 0.32-0.46], P<0.001). Cox regression indicated significantly longer OS in patients with comprehensive healthcare coverage that included reimbursement of EGFR-TKIs, versus basic coverage (mOS 27.2 vs. 18.3 months; adjusted HR=0.73 [95%CI 0.59-0.90]). Compared with best supportive care (BSC; reference), EGFR-TKI-treated patients survived significantly longer (mOS 36.5 months; adjusted HR (aHR)=0.26 [95%CI 0.19-0.34]), and versus chemotherapy alone (14.5 months; aHR=0.60 [95%CI 0.47-0.78]). In EGFRm-positive patients (n=422), relative survival benefit of EGFR-TKI treatment remained highly significant (aHR[EGFR-TKI]=0.19 [95%CI 0.12-0.29]; aHR(chemotherapy only)=0.50 [95%CI 0.30-0.85]; reference:BSC), indicating that healthcare coverage (reimbursement) affected treatment choice and survival. Our analysis describes EGFRm prevalence and survival benefit of EGFR-TKI therapy for EGFRm-positive NSCLC patients treated from 2012-2017, one of the largest such Thai datasets. Together with research by others, these findings contributed evidence supporting the decision to broaden erlotinib access on healthcare schemes in Thailand from 2021, demonstrating the value of local real-world outcome data for healthcare policy decision-making.

Experimental study of EGFR-TKI aumolertinib combined with ionizing radiation in EGFR mutated NSCLC brain metastases tumor

Aumolertinib is an irreversible third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), although it has been administered for the treatment of epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC). However, it is unclear whether aumolertinib combined with ionizing radiation (IR) has potential therapeutic effects in treating brain metastases (BM) tumors from NSCLC. This study explored the anti-tumor effects of aumolertinib combined with IR in epidermal growth factor receptor mutated (EGFRm) NSCLC BM tumors. First, we established a xenograft model of NSCLC BM tumors in BALB/c nude mice and assessed the anti-tumor effects of this combination. Furthermore, we examined the concentrations of aumolertinib in brain tissue and blood using liquid chromatography-mass spectrometry (LC-MS); after that, we used CCK-8, colony formation, flow cytometry assay, and immunofluorescence staining to detect the effects of aumolertinib combined with IR upon PC-9 and NCI–H1975 cells, such as cell proliferation, survival, apoptosis, cycle distribution, the situation of DNA damage, and the expression levels of relevant proteins which were detected via western blotting; finally, we chose a clinical case with which to explore the clinical benefits to the EGFRm NSCLC BM patient after the treatment of the aforementioned combination. The experiments of NSCLC BM tumor animal models demonstrated that the combination enhanced the therapeutic effects and increased the intracranial accumulation of aumolertinib; the combination can inhibit cell proliferation and survival, delay the repair of DNA damage, and increase the rates of cell apoptosis and aumolertinib abrogated G2/M phase arrest, which the IR induced; the clinical study verified that the combination demonstrated better patient benefits. In conclusion, our study demonstrated that combining aumolertinib and IR has promising anti-tumor effects in EGFR-mutant NSCLC and that this combined treatment modality may be employed as a potential therapeutic strategy for EGFR-mutant NSCLC BM patients clinically.

Effect of EGFR-TKIs combined with craniocerebral radiotherapy on the prognosis of EGFR-mutant lung adenocarcinoma patients with brain metastasis: A propensity-score matched analysis.

Epidermal growth factor receptor (EGFR)-mutant lung cancers are associated with a high risk of developing brain metastases (BM). Craniocerebral radiotherapy is a cornerstone for the treatment of BM, and EGFR-TKIs act on craniocerebral metastases". However, whether EGFR-TKIs combined with craniocerebral radiotherapy can further increase the efficacy and improve the prognosis of patients is unclear. This study aimed to evaluate the difference in efficacy between targeted-therapy alone and targeted-therapy combined with radiotherapy in EGFR-mutant lung adenocarcinoma patients with BM. A total of 291 patients with advanced non-small cell lung cancer (NSCLC) and EGFR mutations were enrolled in this retrospective cohort study. Propensity score matching (PSM) was conducted using a nearest-neighbor algorithm (1:1) to adjust for demographic and clinical covariates. Patients were divided into two groups: EGFR-TKIs alone and EGFR-TKIs combined with craniocerebral radiotherapy. Intracranial progression-free survival (iPFS) and overall survival (OS) were calculated. Kaplan-Meier analysis was used to compare iPFS and OS between the two groups. Brain radiotherapy included WBRT, local radiotherapy, and WBRT+Boost. The median age at diagnosis was 54 years (range: 28-81 years). Most patients were female (55.9%) and non-smokers (75.5%). Fifty-one pairs of patients were matched using PSM. The median iPFS for EGFR-TKIs alone (n=37) and EGFR-TKIs+craniocerebral radiotherapy (n=24) was 8.9 and 14.7 months, respectively. The median OS for EGFR-TKIs alone (n=52) and EGFR-TKIs+craniocerebral radiotherapy (n=52) was 32.1 and 45.3 months, respectively. In EGFR-mutant lung adenocarcinoma patients with BM, targeted therapy combined with craniocerebral radiotherapy is an optimal treatment.

Real-world data on efficacy and safety of osimertinib in non-small cell lung cancer patients with EGFR T790M mutation detected by first and repeat rebiopsy.

Osimertinib could effectively target epidermal growth factor receptor (EGFR) T790M resistance mutations in non-small cell lung cancer (NSCLC), indicating that rebiopsy may be particularly important. However, the clinical benefit of repeat rebiopsy in T790M-negative patients with NSCLC detected by the first rebiopsy is still unclear, and data on the efficacy and safety of osimertinib in patients with NSCLC who are T790M-positive patients on a repeat rebiopsy remain rare. We retrospectively collected the clinical data of advanced NSCLC patients with common EGFR mutation who were treated with 1/2-generation (1/2G) EGFR-tyrosine kinase inhibitors (TKIs) in first-line therapy in our center from January 2018 to December 2020. The detection rate of T790M by first and repeat rebiopsy was recorded, and we also analyzed the efficacy and safety of osimertinib for T790M-positive patients. Among 190 common EGFR-mutant patients who received 1/2G EGFR-TKIs with advanced NSCLC in the first-line treatment, 141 patients developed progressive disease. In total, 110 of 141 accepted the first rebiopsy, with a T790M prevalence of 50.9% (56/110). In total, 43 T790M-positive patients who received osimertinib were included in first rebiopsy group. Of 54 T790M-negative patients detected by the first rebiopsy, 28 underwent repeated rebiopsy in subsequent clinical treatment, and 10 (35.7%) T790M-positive cases were confirmed. In total, eight T790M-positive patients treated with osimertinib were included in repeat rebiopsy group. Overall, 66 (60%) of 110 patients acquired a T790M mutation. In patients with the T790M mutation discovered by the first and repeat rebiopsy, osimertinib resulted in median progression-free survival of 7 (95% confidence interval [CI]: 5.3-8.7) and 6 (95% CI: 4.7-7.3) months, respectively (p=.656). The median overall survival since osimertinib initiation for T790M-positive patients at first rebiopsy was 20 (95% CI: 15.1-24.9) months and 19 (95% CI: 16.9-21.1) months, for those at repeated rebiopsy (p=.888). Adverse events of grade 3 or higher were similar in the two groups (25.6% vs. 12.5%, p=.616). There was no treatment-related death in the two groups. Repeat rebiopsy can increase the T790M mutation positivity rate. Osimertinib showed similar efficacy and safety in T790M-positive patients whether detected by the first or repeat rebiopsy.

Treatment outcomes of EGFR-TKI with or without locoregional brain therapy in advanced EGFR-mutant non-small cell lung cancer patients with brain metastases.

This study aimed to evaluate the treatment outcomes of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy alone or in combination with locoregional brain therapy for advanced EGFR-mutant non-small cell lung cancer (NSCLC) patients with brain metastases. A retrospective study involving 72 advanced EGFR-mutant NSCLC patients with brain metastases at the Vietnam National Cancer Hospital were conducted. Patients were divided into 2 groups: EGFR-TKI (erlotinib) monotherapy and EGFR-TKI combined with locoregional therapy (γ knife surgery - GKS or whole-brain radiation therapy). Evaluation criteria included clinical and laboratory characteristics, central nervous system (CNS) progression time, progression-free survival (PFS), overall survival (OS), T790M mutation rate, and adverse events. Epidermal growth factor receptor tyrosine kinase inhibitor monotherapy patients had better performance status (PS), fewer CNS symptoms, and significantly fewer brain metastases (p < 0.05). Median PFS and OS were 11 and 25 months, respectively, in both groups. Patients with PS 0-1 had longer median PFS (15 months) than those with PS 2 (7 months) (p = 0.039). Exon 19 deletion patients in both groups had longer median OS (26 months) than those with L858R exon 21 (15 months) (p = 0.023). Patients with T790M mutation who received osimertinib after progression had longer median OS (41 months vs. 23 months, p = 0.0001). Median time to CNS progression was 13.9 months (48 patients). Longer time to CNS progression correlated with longer OS (R2 = 0.89). Epidermal growth factor receptor tyrosine kinase inhibitor therapy, with or without locoregional therapy, is effective for advanced EGFR-mutant NSCLC patients with brain metastases. Exon 19 deletion patients had better prognosis.

Rationale and value of consolidative cranial local therapy in EGFR-mutant non-small cell lung cancer patients with baseline brain metastasis treated with first-line EGFR-TKIs.

To explore the rationale and value of consolidative cranial local therapy (CLT) in epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients with brain metastases (BMs). EGFR-mutant NSCLC patients with baseline BMs who received first-line EGFR-tyrosine kinase inhibitors (TKIs) at two academic centers from May 2015 to June 2020 were retrospectively enrolled. Patterns of tumor response and treatment failure were extensively analyzed in order to explore the rationale of CLT. Cranial lesions with number ⩽3 and largest tumor size ⩽3 cm at baseline and best response to EGFR-TKIs were defined as oligo-BMs and oligo-residual cranial disease (ORCD), respectively. To provide preliminary data supporting CLT, survival outcomes were compared in patients with ORCD, stratified by CLT status. Of the 216 patients enrolled, 57.1% had oligo-BMs and 24.5% received first-line osimertinib. At best response to the first-line EGFR-TKIs, intracranial complete response, partial response, and stable disease occurred in 18.5, 31.9, and 44.4% of the whole population, respectively. For patients without CLT (n = 193), ORCD was observed in 78.1% of the 105 patients with baseline oligo-BMs and 10.2% of the 88 patients with baseline multiple-BMs. With a median follow-up of 22.8 months, 107 patients had cranial first progressive disease (PD); more than 60% developed their first PD solely from the residual tumor sites at best response to EGFR-TKIs. Moreover, among patients with ORCD (n = 108), patients who received CLT (n = 17) achieved significantly longer progression-free survival (13.4 versus 8.5 months, p = 0.001) and overall survival (58.9 versus 28.8 months, p = 0.021) than those without CLT. Meanwhile, CLT remained as an independent prognostic factor associated with improved survival after Cox regression analyses. Cranial progressive disease developed mostly at the residual cranial lesions in EGFR-mutant NSCLC patients with baseline BMs who received first-line EGFR-TKIs. Consolidative cranial local therapy targeting the oligo-residual cranial tumor lesions may provide survival benefit, which warrants future validation.

Advanced Non-small Cell Lung Cancer: EGFR Mutation Analysis Using Pyrosequencing and the Fully Automated qPCR-Based IdyllaTM System.

Epidermal growth factor receptor (EGFR) mutation status is of a major clinical significance in non-small cell lung cancer (NSCLC) management, as it guides therapeutic decision making to target patients for a better response to therapy. This implicates the introduction of EGFR mutation analysis as the standard of care for Moroccan NSCLC patients, which in itself entails the implementation of targeted methods for routine EGFR mutation analysis in our laboratories. In this study, we aimed to present 2 targeted methods for EGFR mutation identification and to determine the prevalence and spectrum of EGFR mutations in NSCLC Moroccan patients. A retrospective investigation of a cohort of 340 patients was undertaken to analyze somatic EGFR mutations in exons 18 to 21 using pyrosequencing and the IdyllaTM system. Of the enrolled patients, 70.9% were males and 29.1% were females. Predominately, 92% of cases had adenocarcinoma, and 53.7% of patients self-reported a history of smoking. Overall, 73 patients (21.7%) harbored an EGFR mutation, the most prevalent of which were the exon 19 deletions (53.4%) followed by exon 21 substitutions (31%). Exon 18 mutations and exon 20 alterations occurred in 8.1% and 6.7% of the positive EGFR mutation cases, respectively. Of the analyzed cases, all of the EGFR-mutated patients had adenocarcinoma. EGFR mutation prevalence was significantly higher in females (females vs males: 38.4% vs 14.5%, P < .001) and non-smokers (non-smokers vs non-smokers: 36% vs 10.3%, P < .001). The featured pyrosequencing and the IdyllaTM system are targeted methods endowed with high sensitivity and specificity as well as other compelling characteristics which make them great options for routine EGFR mutation testing for advanced NSCLC patients. These findings underline the imperious need for implementing quick and efficient targeted methods for routine EGFR mutation testing among NSCLC patients, which is particularly useful in determining patients who are more likely to benefit from targeted therapy.

TP53 Co-Mutation Status Association with Clinical Outcomes in Patients with EGFR-Mutant Non-Small Cell Lung Cancer.

TP53 co-mutations have shown association with poor prognosis in various solid tumors. For EGFR-mutated advanced non-small cell lung cancer (aNSCLC), conflicting results exist regarding its impact on survival. Clinical outcomes and genomic data were obtained retrospectively from the real-world (rw) de-identified clinicogenomic database. Patients who initiated therapy for EGFR-mutated aNSCLC between January 2014 and December 2020 were identified. Clinical outcomes were evaluated by TP53-mutational status. In 356 eligible EGFR-mutated aNSCLC patients (median age 68 years), 210 (59.0%) had TP53 co-mutation and 146 (41.0%) had TP53 wild-type tumor. Unadjusted analysis showed significantly shorter survival in patients with TP53 co-mutation versus TP53 wild-type (rw progression-free survival [rwPFS]: HR = 1.4, 95% CI 1.1-1.9, p = 0.0196; overall survival [OS]: HR = 1.6, 95% CI 1.1-2.2, p = 0.0088). Multivariable analysis confirmed independent association between TP53 co-mutation and worse rwPFS (HR = 1.4, 95% CI 1.0-0.9, p = 0.0280) and OS (HR = 1.4, 95% CI 1.0-2.0, p = 0.0345). Directionally consistent findings were observed for response rates, and subgroups by EGFR-activating mutation and first-line (1 L) therapy, with more pronounced negative effect in 1 L EGFR-TKI subgroup. TP53 co-mutations negatively affected survival in patients with EGFR-mutated aNSCLC receiving standard 1 L therapy in real-world practice.

Therapeutic strategies for EGFR-mutated non-small cell lung cancer patients with osimertinib resistance

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the preferential options for advanced non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. Osimertinib is a potent irreversible third-generation EGFR-TKI targeting EGFR mutations but has little effect on wild-type EGFR. In view of its remarkable efficacy and manageable safety, osimertinib was recommended as the standard first-line treatment for advanced or metastatic NSCLC patients with EGFR mutations. However, as the other EGFR-TKIs, osimertinib will inevitably develop acquired resistance, which limits its efficacy on the treatment of EGFR-mutated NSCLC patients. The etiology of triggering osimertinib resistance is complex including EGFR-dependent and EGFR-independent pathways, and different therapeutic strategies for the NSCLC patients with osimertinib resistance have been developed. Herein, we comprehensively summarized the resistance mechanisms of osimertinib and discuss in detail the potential therapeutic strategies for EGFR-mutated NSCLC patients suffering osimertinib resistance for the sake of the improvement of survival and further achievement of precise medicine.

Evaluation of MET alteration in EGFR-mutant non-small cell lung cancer patients treated with EGFR tyrosine kinase inhibitor from paired biopsy: A retrospective cohort study

Purpose: Mesenchymal-epithelial transition tyrosine kinase receptor (&lt;i&gt;MET&lt;/i&gt;) amplification is one of the common acquired resistance mechanisms to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). To evaluate the usefulness of screening methods for MET status, we studied the impact of &lt;i&gt;MET&lt;/i&gt; amplification or protein overexpression in EGFR-mutant non-small cell lung cancer patients who were treated with EGFR TKI.Methods: A total of 214 patients treated with EGFR TKI as first-line therapy with available tissue biopsy was analyzed. Paired biopsies were obtained from 111 patients at baseline and at onset of resistance. MET status was determined by immunohistochemistry (IHC) and fluorescence &lt;i&gt;in situ&lt;/i&gt; hybridization (FISH).Results: Among 111 patients with paired samples, incidence of MET alteration was increased according to both MET overexpression by IHC (14.4% to 22.5%) and MET amplification by FISH (1.8% to 8.1%) with moderated to strong IHC intensity samples after EGFR TKI treatment. In patients treated with 1st-generation EGFR TKI, &lt;i&gt;MET&lt;/i&gt; amplification by FISH was significantly related to shorter progression-free survival (P=0.04) and overall survival (P=0.01). In contrast, there was no difference in clinical outcomes according to MET intensity of IHC. Patients harboring &lt;i&gt;MET&lt;/i&gt; amplification by FISH were associated with poor clinical outcomes compared to those with T790M mutation at progression.Conclusion: These results suggest that FISH is more informative than IHC for identification of patients with &lt;i&gt;MET&lt;/i&gt; amplification as an EGFR TKI resistance mechanism. Given the poor outcome in patients who developed &lt;i&gt;MET&lt;/i&gt; amplification, combinational trials with more active MET inhibitor are needed to overcome resistance.

Neoadjuvant targeted therapy for resectable EGFR-mutant non-small cell lung cancer: Current status and future considerations.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) targeted therapy has become the standard of care for patients with EGFR-mutated metastatic non-small cell lung cancer (NSCLC) on the basis of improved prognosis and reduced toxicities compared with chemotherapy. In view of the therapeutic potential of EGFR-TKIs in EGFR-mutated advanced NSCLC, several scholars have explored the value of preoperative use of EGFR-TKIs in patients with EGFR-mutated resectable NSCLC. However, the field of neoadjuvant targeted therapy for EGFR-mutated resectable NSCLC is currently in its infancy. In this mini-review, we summarize the current evidence on neoadjuvant EGFR-TKIs targeted therapy for resectable EGFR-mutated NSCLC and focus on discussing potential clinical strategies of treating resectable EGFR-mutated patients by preoperative administration of EGFR-TKIs-based multimodality therapy.

The effect of EGFR-TKIs on survival in advanced non-small-cell lung cancer with EGFR mutations: A real-world study.

Few large-scale studies have been published using real-world data related to overall survival (OS) improvements in advanced epidermal growth factor receptor (EGFR)-mutant lung cancer patients; therefore, little is known regarding the characteristics of patients who could benefit most from EGFR-tyrosine kinase inhibitors (TKIs). Our study aimed to assess whether EGFR-TKI treatment confers survival benefits among advanced non-small-cell lung cancer (NSCLC) patients harboring EGFR mutations in the Chinese population. A total of 6451 advanced NSCLC patients were diagnosed between January 1, 2013 and June 30, 2019 in Zhejiang Cancer Hospital. Ultimately, 2864 patients with a confirmed EGFR mutation genotype were enrolled in our study. OS was measured from the time of diagnosis of advanced NSCLC until death or last follow-up. Median follow-up for OS of advanced EGFR-mutant NSCLC patients was 28.33 months in our study. Patients who received EGFR-TKIs demonstrated better survival compared to those without EGFR-TKI treatment (mOS: 29.77 vs. 22.97 months, p < 0.0001). A total of 451 patients switched to third-generation EGFR-TKI treatment and obtained a significantly better survival than those who adopted first-line third-generation EGFR-TKIs or those who did not receive third-generation EGFR-TKIs after disease progression with first- or second-generation EGFR-TKI treatment (mOS: 38.0 vs. 32.5 vs. 28.3 months, p < 0.0001). As for EGFR genotypes, patients with exon 19 deletion showed better OS, followed by those with L858R mutation (32.4 vs. 24.83 months, p=0.0013). NGS versus PCR testing showed no statistical differences with respect to survival outcomes (mOS: 27.5 vs. 27.47 months, p=0.6745). Advanced EGFR-mutant patients treated with EGFR-TKIs obtained absolute superior survival in the Chinese population.

CNSC-04. CEREBROSPINAL FLUID-DERIVED CIRCULATING TUMOR DNA IS SUPERIOR TO PLASMA IN NSCLC PATIENTS WITH CNS PROGRESSION

Abstract Introduction Central nervous system (CNS) metastases are devastating neurologic complications. However, the clinical value of cerebrospinal fluid (CSF) as liquid biopsy medium in EGFR-mutated or ALK-rearranged patients with brain metastases (BM) or leptomeningeal metastases (LM) remains unclear. Patients and Methods We retrospectively analyzed the gene map of 14/48 NSCLC-BM patients and 34/48 NSCLC-LM patients. Compare the clinical predictive value of CSF and matched plasma (PLA) for patients with single CNS progression (cohort 1) or intracranial progression simultaneously with extracranial disease progression (cohort 2). Circulating cell-free tumor DNA (ctDNA) in CSF and matched PLA underwent next-generation sequencing targeting 168 cancer-relevant genes. Results For patients with single CNS progression, the mutation rate of major driver genes is much higher than the rate in matched PLA. Besides, CSF also demonstrated higher levels of potential prognostic markers in comparison with matched PLA samples, showing EGFR-amp presented more than two times the rate compared to matched PLA, and the detection rate of TBX3, PTEN were almost double the rate in CSF than paired PLA samples. In addition, poor outcomes associated with makers including CDKN2A/B, PIK3CA/G, CDK4/6, and MET showed exclusively in CSF samples.Almost all mutations identified in the PLA could detect in matched CSF samples in NSCLC-LM patients with both intracranial and extracranial disease progression. In addition, detection rates of driver mutations, consisting of EGFR or ALK are much higher in CSF compared to matched PLA, and these potential survival marker genes like CDK4/6, CDKN2A/B, EGFR-amp, MET, and PIK3CA identified uniquely in CSF samples. Conclusion CSF is more comprehensive in genomic mutation profile than matched PLA in NSCLC -LM regardless of single intracranial progression or intracranial progression simultaneously with extracranial evolution.

QOL-21. REAL-WORLD QUALITY-OF-LIFE AND HEALTH UTILITIES FOR PATIENTS WITH CNS CANCERS ON THE XCELSIOR PLATFORM

Abstract OBJECTIVE xCures operates a direct-to-patient, real-world evidence platform according to the nationwide observational research protocol XCELSIOR (NCT03793088), which aggregates medical data in an FDA-compliant electronic database. There is a relative scarcity of published results on real-world Quality-of-Life (QoL) outcomes and resulting health state utilities for patients with Central Nervous System (CNS) cancers. We sought to use the xCures platform to help address this issue. METHODS XCELSIOR participants were invited weekly to complete the EuroQol 5-Dimension (EQ-5D-5L) QoL survey. A EuroQol-endorsed model was used to estimate health state utilities from patient surveys. Survey results, utility estimates, and clinical information were analyzed to understand the influence of common mutations in glioma on patient reported outcomes. RESULTS 30 patients (21 glioblastoma, 4 oligodendroglioma, 2 diffuse midline glioma, 2 diffuse astrocytoma, 1 Schwannoma) completed at least one EQ-5D-5L survey over the course of 9 weeks. Health state utilities were positively correlated (p&amp;lt; .03) with Karnofsky Performance Score (KPS). The average utility for EGFR-mutated patients (N=6) was .578 (SD=.334) while for EGFR-wildtype patients (N=7) it was .747 (SD=.227). The average utility for MGMT-methylated patients (N=13) was .816 (SD=.139) while for non-methylated patients (N=10) it was .583 (SD=.379). The average utility for IDH-mutated patients (N=9) was .789 (SD=.153) while for non-mutated patients (N=17) it was .685 (SD=.324). The average utility for patients with a 1p/19q co-deletion (N=4) was .837 (SD=.126) while for those without a co-deletion (N=8) it was .744 (SD=.244). CONCLUSION The xCures platform has enabled the study of real-world QoL outcomes for patients with CNS cancers. This is the first report studying the influence of genetic mutations on QoL collected through patient reported outcomes. Future research aims to perform similar studies with larger number of patients.

BIOM-36. A STUDY OF CLINICAL AND MOLECULAR PROGNOSTIC FACTORS FOR RESPONSE TO REGORAFENIB IN RECURRENT GLIOBLASTOMA

Abstract Introduction Following the results from the REGOMA study, regorafenib has become the first chemotherapeutic option for recurrent glioblastoma, IDH-wildtype, in many countries. However, predictive factors for response to regorafenib are scarcely recognized. The objective of this study was to identify molecular predictive factors for response to regorafenib using a clinically available platform. METHODS We analyzed a prospective cohort of 30 patients harboring recurrent glioblastoma, IDH-wildtype, and treated with regorafenib. Next-generation sequencing (NGS) analysis was performed on DNA extracted from paraffin-embedded tissues using a rapid, cheap, and clinically validated platform. MGMT methylation was assessed using methylation-specific PCR, and EGFRvIII expression was assessed using RT-PCR. RESULTS In our series, six-month progression-free survival (PFS) was 30% and median overall survival (OS) was 7.5 months: these data are consistent with current literature. Among clinical variables, gross-total resection was endowed with a positive prognostic value for PFS (p=0.0296, log-rank test). NGS analysis revealed a mutation in the EGFR pathway (EGFR and/or PIK3CA) in 18% of cases; a mutation in the mitogen-activated protein-kinase (MAPK) pathway (RAS and/or RET) in 18% of cases; no mutations in the remaining cases. Patients carrying MAPK pathway mutation had a poor response to regorafenib treatment, with a significantly shorter PFS and a nonsignificantly shorter OS compared to EGFR-mutated patients (for PFS, 2.5 vs 4.5 months, p=0.0061; for OS, 7 vs 9 months, p=0.1076). By combining NGS analysis with RT-PCR for EGFRvIII, we identified 14 patients with EGFR pathway activation, who had a significantly longer PFS and OS after regorafenib treatment. Multivariate analysis confirmed that MAPK pathway mutations predicted a scarce response to regorafenib treatment. Conclusions Through an easy-to-use and cheap platform, we identified a mesenchymal, MAPK-altered signature in IDH-wildtype glioblastoma, predictive of scarce response to regorafenib at recurrence. We thus provide a molecular selection criterion to implement in the clinical practice.

Machine learning based personalized drug response prediction for lung cancer patients

Lung cancers with a mutated epidermal growth factor receptor (EGFR) are a major contributor to cancer fatalities globally. Targeted tyrosine kinase inhibitors (TKIs) have been developed against EGFR and show encouraging results for survival rate and quality of life. However, drug resistance may affect treatment plans and treatment efficacy may be lost after about a year. Predicting the response to EGFR-TKIs for EGFR-mutated lung cancer patients is a key research area. In this study, we propose a personalized drug response prediction model (PDRP), based on molecular dynamics simulations and machine learning, to predict the response of first generation FDA-approved small molecule EGFR-TKIs, Gefitinib/Erlotinib, in lung cancer patients. The patient’s mutation status is taken into consideration in molecular dynamics (MD) simulation. Each patient’s unique mutation status was modeled considering MD simulation to extract molecular-level geometric features. Moreover, additional clinical features were incorporated into machine learning model for drug response prediction. The complete feature set includes demographic and clinical information (DCI), geometrical properties of the drug-target binding site, and the binding free energy of the drug-target complex from the MD simulation. PDRP incorporates an XGBoost classifier, which achieves state-of-the-art performance with 97.5% accuracy, 93% recall, 96.5% precision, and 94% F1-score, for a 4-class drug response prediction task. We found that modeling the geometry of the binding pocket combined with binding free energy is a good predictor for drug response. However, we observed that clinical information had a little impact on the performance of the model. The proposed model could be tested on other types of cancers. We believe PDRP will support the planning of effective treatment regimes based on clinical-genomic information. The source code and related files are available on GitHub at: https://github.com/rizwanqureshi123/PDRP/.

Evolution of lung adenocarcinoma from preneoplasia to invasive adenocarcinoma.

Mutations in driver genes contribute to the development and progression of lung adenocarcinoma (LUAD). However, in the dynamic evolutionary process from adenocarcinoma in situ (AIS) to minimally invasive adenocarcinoma (MIA) and eventually to invasive adenocarcinoma (IAC), the role of driver genes is currently unclear. This study aimed to analyse the role of driver gene status in the progression of LUAD from preneoplasia to IAC. Patients with LUAD who underwent surgery in our centre from March 2015 to December 2019 were retrospectively analysed, and LUAD patients with tumour sizes ≤3.0cm and pN0 were included in the final analysis. The mutation status of common driver genes, including EGFR, ALK and ROS1, was detected. According to the pathological characteristics, the patients were divided into three stages: AIS, MIA and IAC. We analysed the distribution of driver gene mutation frequencies across three stages of LUAD. In addition, we performed univariate and multivariate analyses of IAC patients to screen for relevant variables (driver genes and clinicopathological features) affecting their prognosis. Ultimately, 759 patients with LUAD were enrolled, including 135, 130, and 494 cases of AIS, MIA, and IAC, respectively. EGFR mutations were identified in 359 (61.8%) patients, and with the transition from AIS to MIA, the frequency of EGFR mutations increased from 33.3% to 50.8%, p=0.004, whereas the frequency of EGFR mutations was comparable for MIA and IAC (50.8% vs. 50.2%, p=0.922). Moreover, ALK and ROS1 gene fusions were identified in 17 cases (2.2%) and 2 cases (3.0‰) respectively. For AIS, neither ALK gene nor ROS1 gene fusions were observed. When the tumour progressed to MIA, the ALK fusion frequency was 2.3% (3/130), which was basically consistent with the ALK fusion frequency of 2.8% in IAC, p=0.143. For IAC, fusions of ROS1 fell into this category. In addition, we found that 40 patients (5.3%) developed metastasis/recurrence, and 14 patients (1.8%) died of cancer-specific related diseases. Notably, for AIS, there were no recurrences and no deaths, and for MIA, only 1 patient died with LUAD. Finally, survival analysis was performed in patients with stage IA invasive adenocarcinoma, and EGFR-mutant patients showed better DFS than EGFR-wild-type patients (p=0.036). Conversely, patients with ALK fusions showed worse DFS than those with ALK wild-type (p=0.004), and the same results were found in OS analysis. The accumulation of EGFR driver gene mutation frequencies mediates the progression of LUAD from AIS to MIA. When the tumour progresses to stage IA invasive adenocarcinoma, multivariate analysis based on driver gene status can be used as a pivotal prognostic factor.