EGFR Genotyping Research Articles

Tumor markers in non-small cell lung cancer spine metastasis: an assessment of prognosis and overall survival

PurposeThe identification of gene mutations in the modern medical workup of metastatic spine tumors has become more common but has not been highly utilized in surgical planning. Potential utility of these genetic markers as surrogates for cancer behavior in current prognosis scoring systems and overall survival (OS) remains underexplored in existing literature. This study seeks to investigate the association of frequently identified tumor markers, EGFR, ALK, and PD-L1, in metastatic non-small cell lung cancer (NSCLC) to the spine with Tokuhashi prognosis scoring and OS.MethodsPatients with NSCLC metastasis to spine were identified through chart review. EGFR, ALK, and PD-L1 wild type vs. mutant type were identified from targeted chemotherapy genetic testing. Multiple linear regression was performed to assess gene profile contributions to Tokuhashi score. Cox Proportional Hazards models were generated for each tumor marker to assess the relationship between each marker and OS.ResultsA total of 119 patients with NSCLC spine metastasis were identified. We employed a multiple linear regression analysis to investigate the influence of EGFR, ALK, and PD-L1 genotypes on the Tokuhashi score, revealing statistically significant relationships overall (p = 0.002). Individual genotype contributions include EGFR as a non-significant contributor (p = 0.269) and ALK and PD-L1 as significant contributors (p = 0.037 and p = 0.001 respectively). Overall survival was not significantly associated with tumor marker profiles through Kaplan-Meier analysis (p = 0.46) or by multivariable analysis (p = 0.108).ConclusionALK and PD-L1 were significantly associated with Tokuhashi score while EGFR was not. Tumor markers alone were not predictive of OS. These findings indicate that genetic markers found in NSCLC metastases to the spine may demonstrate prognostic value. Therefore, employing standard tumor markers could enhance the identification of appropriate surgical candidates, although they demonstrate limited effectiveness in predicting overall survival.

Detection of High-Risk Human Papillomavirus (HPV), p16 and EGFR in Lung Cancer: Insights from the Mediterranean Region of Turkey.

Human papillomavirus (HPV) is an oncogenic DNA virus that plays a role in different cancer types. The aim of this study was to detect the prevalence and types of HPV and its relation with p16, EGFR and clinical findings in lung cancer. HPV and EGFR detection and genotyping of HPV were performed by polymerase chain reaction (PCR) and p16 by immunohistochemistry. Fifty lung cancer patients and seven patients with non-neoplastic lung disease were enrolled in this study. HPV was positive in 78% (39/50) of lung cancer cases. HPV 51 was the most frequent type, followed by HPV 16. Moreover, p16 was positive in 24% (12/50) of the cancer patients, and all of these patients were HPV-positive, while 27 HPV-positive patients showed no p16 expression. There was no relationship between HPV infection and p16 (p = 0.05), gender (p = 0.42), age (p = 0.38), or smoking history (p = 0.68). Although not statistically significant, the HPV prevalence was found to be higher in cancer patients compared to non-neoplastic patients. The prevalence of HPV in lung cancer varies across different studies, which may be due to differences in the detection methods, number of patients, geographic regions, and vaccination status. Further studies are necessary to understand the role of HPV in lung cancer pathogenesis.

Abstract 5037: Development of multiplexed Absolute Q digital PCR assays to rapidly quantify EGFR and KRAS genotype in advanced non-small cell lung cancer (NSCLC) patients’ plasma

Abstract Introduction: There are needs to identify and serially monitor driver and resistance mutations (muts) in therapy-treated cancer patients (pts). Quantitative liquid biopsy in cell-free (cf)DNA has been widely adopted. We have developed and clinically validated droplet digital PCR (ddPCR) assays to detect common driver/resistance muts such as EGFR del19, L858R, T790M and KRAS G12X in the cfDNA of advanced NSCLC pts. We have established ddPCR assays for 30+ driver/resistance muts in multiple genes (BRAF, MET, ESR1, etc.) relevant to melanoma, breast, and colorectal cancer. Our assays use tumor/cell line DNA as positive controls and serve as benchmarks to develop newer assays such as plasma NGS. In this study, we converted existing/validated EGFR and KRAS G12X ddPCR assays to the QuantStudio Absolute Q digital PCR (dPCR) system. The selected mutations maximize actionable clinical information and are designed to study oncogenic and resistance mutations in NSCLC efficiently. dPCR’s accuracy and efficiency enables target multiplexing, providing comprehensive information from limited materials and contributing to liquid biopsy research progress. Methods: Plasma from pts with tumors harboring EGFR and KRAS muts was collected at progression with advanced disease following consent to protocol DFCI #14-147. We designed a multiplex dPCR assay that identifies the most common and therapy-relevant KRAS muts in NSCLC, G12C/D/V, and detects other G12X using a drop-off probe. We also designed 2 EGFR kits, one identifying driver muts, the other resistance muts. Results: To validate assay performance, we used gDNA derived from cell lines with EGFR or KRAS muts. We serially diluted mut gDNA samples in background wt gDNA (16 ~ 1000 mut copies in 1000 wt copies) and performed KRAS and EGFR dPCR assays. We detected 16 mut copies with sensitivities similar to those of ddPCR assays. We then studied 48 cfDNA samples from plasma of NSCLC pts with tumor confirmed KRAS G12X or EGFR L858R, del19, T790M muts. No samples had both EGFR and KRAS muts detected, suggesting our assays are specific. We detected muts in samples with an allele frequency median of 0.9% for KRAS mut, 11.9% for EGFR driver mut, 2.9% for EGFR T790M. The concordance rate is 91.3% between dPCR and ddPCR results. Our findings suggest these assays are as sensitive and specific as our validated ddPCR assays. Multiplexed Absolute Q dPCR saves cfDNA and cuts turnaround time (TAT) to 90 min for KRAS assay and 3hr for EGFR assays. Conclusions: We developed rapid, sensitive and specific quantitative dPCR assays for KRAS and EGFR muts on the QuantStudio Absolute Q platform to quantify plasma genotyping in NSCLC. We will clinically pilot our validated rapid genotyping approach and quantify TAT advantage of multiplexed genotyping in NSCLC pts undergoing standard-of-care tumor genotyping. Citation Format: Benjamin Hanna, Shidong Xu, Cloud P. Paweletz, Yanan Kuang. Development of multiplexed Absolute Q digital PCR assays to rapidly quantify EGFR and KRAS genotype in advanced non-small cell lung cancer (NSCLC) patients’ plasma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5037.

High-efficiency EGFR genotyping using cell-free DNA in bronchial washing fluid.

EGFR mutation testing is required for treatment of lung adenocarcinoma using epidermal growth factor receptor-tyrosine kinase inhibitor. However, the amounts of tumor tissue or tumor cells obtained by bronchoscopy are often insufficient. Bronchial washing fluid, obtained by lavage with saline after tumor biopsy or brushing, and the supernatant of bronchial washing fluid are thought to contain cell-free DNA that would be potentially applicable for EGFR testing. From among patients with suspected adenocarcinoma or non-small cell lung carcinoma diagnosed from biopsy or surgical specimens at the University of Tsukuba Hospital between 2015 and 2019, cell-free DNAs from 80 specimens of supernatant of bronchial washing fluid (50 with EGFR mutation and 30 with wild type EGFR) and 8 blood serum samples were examined for EGFR mutation using droplet digital PCR. Among the 50 patients harboring EGFR mutation, the rate of positivity for cell-free DNA extracted from supernatant of bronchial washing fluid was 80% (40/50). In nine of the EGFR mutation-positive cases, tumor cells were not detected by either biopsy or cytology, but the mutation was detected in four cases (4/9, 44%). Comparison of the cell-free DNA mutation detection rate between supernatant of bronchial washing fluid and blood serum in six cases showed that mutations were detected from the former in all cases (6/6, 100%), but from the latter in only one case (1/6, 17%). Using supernatant of bronchial washing fluid samples, the detection rate of EGFR mutation was high, and EGFR mutations were detectable even when no tumor cells had been detectable by biopsy or cytology. Supernatant of bronchial washing fluid might be an effective sample source for EGFR mutation testing.

Using Vision Transformer for high robustness and generalization in predicting EGFR mutation status in lung adenocarcinoma.

Lung adenocarcinoma is a common cause of cancer-related deaths worldwide, and accurate EGFR genotyping is crucial for optimal treatment outcomes. Conventional methods for identifying the EGFR genotype have several limitations. Therefore, we proposed a deep learning model using non-invasive CT images to predict EGFR mutation status with robustness and generalizability. A total of 525 patients were enrolled at the local hospital to serve as the internal data set for model training and validation. In addition, a cohort of 30 patients from the publicly available Cancer Imaging Archive Data Set was selected for external testing. All patients underwent plain chest CT, and their EGFR mutation status labels were categorized as either mutant or wild type. The CT images were analyzed using a self-attention-based ViT-B/16 model to predict the EGFR mutation status, and the model's performance was evaluated. To produce an attention map indicating the suspicious locations of EGFR mutations, Grad-CAM was utilized. The ViT deep learning model achieved impressive results, with an accuracy of 0.848, an AUC of 0.868, a sensitivity of 0.924, and a specificity of 0.718 on the validation cohort. Furthermore, in the external test cohort, the model achieved comparable performances, with an accuracy of 0.833, an AUC of 0.885, a sensitivity of 0.900, and a specificity of 0.800. The ViT model demonstrates a high level of accuracy in predicting the EGFR mutation status of lung adenocarcinoma patients. Moreover, with the aid of attention maps, the model can assist clinicians in making informed clinical decisions.

The oncogenic role of LGR6 overexpression induced by aberrant Wnt/β-catenin signaling in lung cancer.

Molecular abnormalities in the Wnt/β-catenin pathway confer malignant phenotypes in lung cancer. Previously, we identified the association of leucine-rich repeat-containing G protein-coupled receptor 6 (LGR6) with oncogenic Wnt signaling, and its downregulation upon β-catenin knockdown in non-small cell lung cancer (NSCLC) cells carrying CTNNB1 mutations. The aim of this study was to explore the mechanisms underlying this association and the accompanying phenotypes. LGR6 expression in lung cancer cell lines and surgical specimens was analyzed using quantitative RT-PCR and immunohistochemistry. Cell growth was assessed using colony formation assay. Additionally, mRNA sequencing was performed to compare the expression profiles of cells subjected to different treatments. LGR6 was overexpressed in small cell lung cancer (SCLC) and NSCLC cell lines, including the CTNNB1-mutated NSCLC cell lines HCC15 and A427. In both cell lines, LGR6 knockdown inhibited cell growth. LGR6 expression was upregulated in spheroids compared to adherent cultures of A427 cells, suggesting that LGR6 participates in the acquisition of cancer stem cell properties. Immunohistochemical analysis of lung cancer specimens revealed that the LGR6 protein was predominantly overexpressed in SCLCs, large cell neuroendocrine carcinomas, and lung adenocarcinomas, wherein LGR6 overexpression was associated with vascular invasion, the wild-type EGFR genotype, and an unfavorable prognosis. Integrated mRNA sequencing analysis of HCC15 and A427 cells with or without LGR6 knockdown revealed LGR6-related pathways and genes associated with cancer development and stemness properties. Our findings highlight the oncogenic roles of LGR6 overexpression induced by aberrant Wnt/β-catenin signaling in lung cancer.

Intelligent prognosis evaluation system for stage I-III resected non-small-cell lung cancer patients on CT images: a multi-center study

Prognosis is crucial for personalized treatment and surveillance suggestion of the resected non-small-cell lung cancer (NSCLC) patients in stage I-III. Although the tumor-node-metastasis (TNM) staging system is a powerful predictor, it is not perfect enough to accurately distinguish all the patients, especially within the same TNM stage. In this study, we developed an intelligent prognosis evaluation system (IPES) using pre-therapy CT images to assist the traditional TNM staging system for more accurate prognosis prediction of resected NSCLC patients. 20,333 CT images of 6371 patients from June 12, 2009 to March 24, 2022 in West China Hospital of Sichuan University, Mianzhu People's Hospital, Peking University People's Hospital, Chengdu Shangjin Nanfu Hospital and Guangan Peoples' Hospital were included in this retrospective study. We developed the IPES based on self-supervised pre-training and multi-task learning, which aimed to predict an overall survival (OS) risk for each patient. We further evaluated the prognostic accuracy of the IPES and its ability to stratify NSCLC patients with the same TNM stage and with the same EGFR genotype. The IPES was able to predict OS risk for stage I-III resected NSCLC patients in the training set (C-index 0.806; 95% CI: 0.744-0.846), internal validation set (0.783; 95% CI: 0.744-0.825) and external validation set (0.817; 95% CI: 0.786-0.849). In addition, IPES performed well in early-stage (stage I) and EGFR genotype prediction. Furthermore, by adopting IPES-based survival score (IPES-score), resected NSCLC patients in the same stage or with the same EGFR genotype could be divided into low- and high-risk subgroups with good and poor prognosis, respectively (p<0.05 for all). The IPES provided a non-invasive way to obtain prognosis-related information from patients. The identification of IPES for resected NSCLC patients with low and high prognostic risk in the same TNM stage or with the same EGFR genotype suggests that IPES have potential to offer more personalized treatment and surveillance suggestion for NSCLC patients. This study was funded by the National Natural Science Foundation of China (grant 62272055, 92259303, 92059203), New Cornerstone Science Foundation through the XPLORER PRIZE, Young Elite Scientists Sponsorship Program by CAST (2021QNRC001), Clinical Medicine Plus X - Young Scholars Project, Peking University, the Fundamental Research Funds for the Central Universities (K.C.), Research Unit of Intelligence Diagnosis and Treatment in Early Non-small Cell Lung Cancer, Chinese Academy of Medical Sciences (2021RU002), BUPT Excellent Ph.D. Students Foundation (CX2022104).

Successful treatment of severe lung cancer caused by third-generation EGFR-TKI resistance due to EGFR genotype conversion with afatinib plus anlotinib.

Third-generation EGFR-TKIs can be used to treat advanced non-small cell lung cancer patients with T790M resistance mutation induced by first- or second-generation EGFR-TKIs. However, it will also result in drug resistance, and the resistance mechanisms of third-generation EGFR-TKIs are complex. Here we reported a patient diagnosed with advanced lung adenocarcinoma and EGFR positive in September 2016. Following first-line targeted therapy with gefitinib, genetic testing showed EGFR T790M positive, which resulted in a change to osimertinib targeted therapy. In May 2021, troponin and creatinine levels were elevated, and the tumor hyperprogressed to severe lung cancer. Repeated genetic testing revealed that EGFR genotype converted to a non-classical mutation and EGFR T790M turned negative, which caused third-generation EGFR-TKI resistance. As a result, afatinib combined with anlotinib was selected to stabilize the patient's condition. We were inspired by the case that it reflects the significance and necessity of exploring the resistance mechanism and dynamically detecting genetic status throughout the course of treatment, which may help realize individualized precision therapy, and maximize the potential of patient.

Abstract 5158: Detection of EGFR mutations in plasma cfDNA and paired CTCs of NSCLC patients before and after osimertinib therapy using crystal digital PCR

Abstract Background: Circulating tumor DNA (ctDNA) analysis has clinical utility in EGFR mutantNSCLC. Circulating tumor cells (CTCs) constitute a unique source of information at thecellular level. Digital PCR (dPCR) is a valuable tool for accurate and valid mutation analysisin liquid biopsy. The aim of the current study was to detect EGFR mutations in plasma cfDNA and paired CTC-fractions of NSCLC patients before the initiation of osimertinib therapy and at progression of disease using crystal digital PCR (cdPCR). Patients and Methods: Forty-eight patients with EGFR mutated lung adenocarcinomas resistant to 1st or 2nd generation EGFR TKIs were treated with osimertinib in the context of a multicenter Phase II clinical study (NCT02771314). 2 mL of plasma were used for cfDNA extraction using the IDXtract kit (ID-Solutions, France). Crystal dPCR (naica® system, StillaTechnologies, France) was used to quantify mutation allele frequencies (MAF) of EGFRmutations in 91 cfDNA samples before and after osimertinib. 80 identical plasma samples were also analyzed with the FDA-approved cobas® technology. In parallel, EGFR mutations were detected with cdPCR in 64 matched CTC-fractions enriched by Parsortix™ (ANGLE plc, UK).Quality control steps were followed both at the preanalytical and analytical level. Results: Direct comparison between cdPCR and cobas® revealed high concordance rates forall EGFR mutations; however, in case of T790M, cdPCR proved to be more sensitive. Patients with higher %MAFs at PD presented significantly lower PFS compared to those with lower levels or without EGFR mutations. Direct comparison of EGFR genotyping between primary tissue and baseline plasma cfDNA samples revealed high concordance rates, too. During EGFR mutation analysis in paired CTC-derived gDNA, 11 samples were found positive for EGFR mutations with %MAF ranging from 0.2 to 2.25%. Conclusions: Crystal dPCR combines the unique benefits of sensitivity and accuracy with the multiplexing capacity for the detection of multiple EGFR mutations in plasma cfDNA samples and CTCs. High concordance rates were observed between cdPCR and cobas® assay. For the first time, cdPCR was applied to detect EGFR mutations in CTC-derived gDNA of NSCLC patients under osimertinib. Discordance between plasma and CTC-fractions might be indicative of tumor heterogeneity and predictive for acquired resistance. Acknowledgements-The research presented was carried out within the framework of a Stavros NiarchosFoundation grant to the National and Kapodistrian University of Athens-The authors would like to thank Larry Ba (Stilla Technologies, France) and Daniel Henaff(ID-solutions, France) for kindly providing the naica® digital PCR system and the ID-solutionskits, respectively. Citation Format: Aliki Ntzifa, Athanasios Kotsakis, Vassilis Georgoulias, Evi Lianidou. Detection of EGFR mutations in plasma cfDNA and paired CTCs of NSCLC patients before and after osimertinib therapy using crystal digital PCR [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5158.

Analysis of frequency ofgenotypes and alleles of rs2227983 polymorphism of &lt;i&gt;EGFR&lt;/i&gt; gene among patients with allergic bronchial asthma with various levels of control

The objective: exploring the frequency of circulation of genotypes and alleles of rs2227983 polymorphism of EGFR gene among patients with allergic bronchial asthma with various levels of control.Subjects and Methods. The study includes adult individuals (n = 396) divided into two groups: Group 1 (main) – individuals with allergic bronchial asthma (ABA), Group 2 is a control one. ABA Group consisted of 179individuals (118 women и 61 men) aged 37.4 ± 14.2 years. Control Group consisted of 217 individuals (110 women и 107 men) aged 30.0±9.1years. All subject included in ABA Group and Control Group underwent molecular genetic tests for rs2227983 polymorphism of EGFR gene using polymerase chain reaction.Results. The comparison of distribution of gene EGFR genotypes showed statistically significant predominance of genotype AGcarriers in the group of patients with ABA (48.6%), versus Control Group (36.9%); p &lt; 0.05. Besides that, there is a predominance of number of carriers of heterozygote genotype АG of EGFR gene among patients with ABA (57.7%) with a controlled course of the disease versus Control Group (36.9%); p &lt; 0.05. Also, it has been found out that rs2227983 genotype of EGFR gene was more frequent in women with controlled ABA (67.4%) compared to women from Control Group (32.7%); p &lt; 0.05.Conclusion. The results of the conducted study allowed analyzing the connection of single nucleotide rs2227983 polymorphism ofEGFR gene with ABA including various levels of control of the course of the disease. Genotype АG of single nucleotide polymorphism rs2227983 of EGFR gene increases the risk of developing ABA. Alongside this, АG genotype of EGFR gene is correlated with the controlled course of ABA.

Extracellular Vesicle-Based Bronchoalveolar Lavage Fluid Liquid Biopsy for EGFR Mutation Testing in Advanced Non-Squamous NSCLC.

Simple SummaryTissue biopsy is the gold standard for molecular genotyping in lung cancer. However, obtaining tumor tissue is challenging due to its invasiveness, inadequate amount of tissue, or complications. To overcome the limitations of tissue biopsy, plasma liquid biopsy using cfDNA has been investigated extensively; however, its low sensitivity limits the clinical application. Therefore, we used the tumor-specific DNA of extracellular vesicles (EVs) in bronchoalveolar lavage fluid (BALF) as DNA source for EGFR genotyping. As a result, we demonstrated that EV-based BALF EGFR testing in advanced lung NSCLC is a highly accurate rapid method overcoming low sensitivity of plasma cfDNA-based EGFR genotyping. It can be used as an adjuvant or alternative method for lung biopsy in cases where obtaining an adequate amount of tissue is difficult.To overcome the limitations of the tissue biopsy and plasma cfDNA liquid biopsy, we performed the EV-based BALF liquid biopsy of 224 newly diagnosed stage III-IV NSCLC patients and compared it with tissue genotyping and 110 plasma liquid biopsies. Isolation of EVs from BALF was performed by ultracentrifugation. EGFR genotyping was performed through peptide nucleic acid clamping-assisted fluorescence melting curve analysis. Compared with tissue-based genotyping, BALF liquid biopsy demonstrated a sensitivity, specificity, and concordance rates of 97.8%, 96.9%, and 97.7%, respectively. The performance of BALF liquid biopsy was almost identical to that of standard tissue-based genotyping. In contrast, plasma cfDNA-based liquid biopsy (n = 110) demonstrated sensitivity, specificity, and concordance rates of 48.5%, 86.3%, and 63.6%, respectively. The mean turn-around time of BALF liquid biopsy was significantly shorter (2.6 days) than that of tissue-based genotyping (13.9 days; p < 0.001). Therefore, the use of EV-based BALF shortens the time for confirmation of EGFR mutation status for starting EGFR-TKI treatment and can hence potentially improve clinical outcomes. As a result, we suggest that EV-based BALF EGFR testing in advanced lung NSCLC is a highly accurate rapid method and can be used as an alternative method for lung tissue biopsy.

EGFRdetection by liquid biopsy: ripe for clinical usage.

Introduction: With the International Association for the Study of Lung Cancer (IASLC)recommendations promoting liquid biopsy as a primary detection tool, a new era of research has begun. The authors aimed to study the concordance of plasma genotyping platforms against the tissue gold standard. Methods: 184 patients with non-small cell lung cancerunderwent EGFRgenotyping using Cobas, droplet digital polymerase chain reaction (ddPCR)and Therascreen assays from 2019-2020. Results: Of 184 cases, 70 were positive by Cobas, 51 by ddPCR and 69 by Therascreen. The sensitivity of Cobas was 97.1% and thesensitivityof ddPCR was 71%. Receiver operating characteristic analysis showed an area under the curveof 0.977 for Cobas and 0.846 for ddPCR. Conclusion: In line with the FLAURA trial of osimertinib making its way to first-lineand giventheIASLC recommendations, it is important to understand the attributes of these teststo initiate appropriate treatment.

Multiple genetic variants predict the progression-free survival of bevacizumab plus chemotherapy in advanced ovarian cancer: A retrospective study.

Bevacizumab (BV) plus chemotherapy is broadly used in advanced ovarian cancer (OC). However, the efficacy of BV-based regimens for advanced OC patients is not satisfactory. Therefore, it is urgent to explore the predictive genetic biomarkers for BV.Tumor tissues from advanced OC patients receiving BV-based regimens were analyzed with a 150-gene targeted panel for next generation sequencing. The associations between gene alterations or clinicopathology features and progression-free survival (PFS) were analyzed by Kaplan–Meier curves or Cox regression. The association of the genetic alteration in potential predictive genes and expressions of 11 vascular endothelial growth factor-related genes were analyzed in The Cancer Genome Atlas cohort using 292 OC cases.Sixty two Chinese advanced OC patients treated with BV-based therapy were included. The median PFS of was 6.9 months, and objective response rate was 14.5%. In multivariate Cox regression analysis, the status of endothelial growth factor receptor (EGFR) (hazard ratio = 6.39, 95% confidence interval [CI] 2.25–18.13, P < .001) and human epidermal growth factor receptor 2 (HER2) (hazard ratio = 3.58, 95% CI 1.27–10.08, P = .016) were significantly correlated with PFS. MYC Proto-Oncogene amplification seemed to have a positive trend (hazard ratio = 0.21, 95% CI 0.05–1.02, P = .052). Moreover, EGFR and HER2 alterations were not prognostic factors of overall survival for OC in The Cancer Genome Atlas OC cohort. The vascular endothelial growth factor-related signature analysis indicated vascular endothelial factor A expression was upregulated with EGFR alterations (P = .034) which may be involved in BV resistance, and HER2 alterations were associated with hypoxia inducible factor 1 subunit alpha overexpression significantly (P = .029).EGFR or HER2 alterations are negative predictors of PFS for OC patient treated with BV plus chemotherapy. Therefore, the clinicians may consider to use alternative regimens such as anti-EGFR or anti-HER2 targeted therapy instead of BV-based regimens on these patients when standard care fail.

Abstract 1196: BALF liquid biopsy provides a novel platform for speedy and accurate EGFR mutation testing in advanced NSCLC patients

Abstract Background EGFR mutation testing is an essential step for the therapeutic decision in newly diagnosed advanced NSCLC patients and usually performed by using DNA extracted from biopsied tumor tissue with a turnaround time(TAT) of 2-3 weeks. Plasma liquid biopsy using ctDNA is minimally invasive and less time-consuming, but shows limited usefulness due to low sensitivity. We conducted a prospective study to demonstrate clinical usefulness of bronchoalveolar lavage fluid (BALF) liquid biopsy using extracellular vesicle(EV)-derived DNA in advanced NSCLC patients by comparing the sensitivity and TAT with conventional tissue biopsy and plasma liquid biopsy Methods The analysis set for liquid EGFR genotyping is 224 BALF samples and 110 plasma samples obtained from newly diagnosed 224 advanced non-squamous NSCLC patients. EGFR genotyping was done through peptide nucleic acid(PNA)-mediated real-time PCR after extracting BALF EV DNA and plasma cfDNA separately. The sensitivity, specificity, and concordance rate of BALF liquid biopsy were calculated in comparison to matched tissue genotyping and plasma liquid biopsy. In addition, TAT was compared between BALF liquid biopsy and tissue genotyping. Results Tissue genotyping revealed 93 EGFR mutant cases (41.5%) and 131 wild-type cases (58.5%). The sensitivity, specificity, positive predictive value, negative predictive value, and concordance rate of BALF liquid biopsy to tissue genotyping were 97.8%, 96.9%, 96.8%, 98.4%, and 97.7%, respectively. BALF liquid biopsy showed almost identical performance with standard tissue genotyping, while only 5 cases were mismatched each other. On the other hand, plasma liquid biopsy using cfDNA (n=110) revealed 48.5% sensitivity, 86.3% specificity, and 63.6% concordance rate in comparison to tissue genotyping. The mean turnaround times of BALF liquid biopsy was significantly shortened to 2.6±2.0 days in contrast to 13.9±12.4 days of tissue genotyping. (p&amp;lt;0.001). Conclusion BALF liquid biopsy can be developed as a novel platform for EGFR mutation testing in advanced NSCLC with almost identical performance with conventional tissue genotyping and significantly shorten TAT to 1-2 days. Citation Format: In Ae Kim, Jae Young Hur, Hee Joung Kim, Wan Seop Kim, Kye Young Lee. BALF liquid biopsy provides a novel platform for speedy and accurate EGFR mutation testing in advanced NSCLC patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1196.

P76.53 Impact of Neutrophil-to-Lymphocyte Ratio in Patients with EGFR-Mutant NSCLC Treated with Tyrosine Kinase Inhibitors

We previously reported that a patient’s smoking status was an independent predictor of progression-free survival (PFS) in gefitinib and erlotinib therapy for patients with non-small cell lung cancer (NSCLC) harboring EGFR mutations. However, other indicators that can elaborate on the clinical efficacy to the EGFR-TKI therapy remain understudied. The inflammatory indicator neutrophil-to-lymphocyte ratio (NLR) in peripheral blood serves as a predictive factor for NSCLC patients treated with anti-cancer agents such as cytotoxic drugs and PD-1 inhibitors. Here, we aimed to evaluate the correlation between NLR and clinical efficacy of EGFR-TKIs in NSCLC patients harboring EGFR mutations. We retrospectively collected information of 205 patients with advanced NSCLC harboring exon 19 deletion or L858R point mutation and receiving gefitinib or erlotinib, between March 2009 and June 2016, were enrolled. The date cut-off date was March 2019. The clinical outcomes in the NSCLC patients were evaluated based on NLR level before EGFR-TKI therapy. Variables (including gender, age, performance status [PS], NLR, EGFR genotype, smoking status, clinical stage prior to EGFR-TKI treatment [Stage IV vs. postoperative recurrence], the presence or absence of brain metastases, type of EGFR-TKI [gefitinib vs. erlotinib]) were entered into a Cox proportional hazards regression model to estimate the hazards ratios for PFS and overall survival (OS). We used PFS longer or shorter than 10 months as the binary variables for ROC curves. The patient cohort comprised of 60% women, with 70 years median age, and 65% of good PS. An optimal cut-off value of 3.55 was chosen for NLR, with an area under the curve (AUC) value of 0.67 [95% confidence interval (CI): 0.59–0.74, P < 0.0001]. The response rates in the low-NLR and high-NLR groups were 69.2% (95% CI: 60.3–78.1%) and 51.5% (95% CI: 41.8–61.2%). In addition, the mean values of NLR in responders (patients with partial response) and non-responders (patients with stable disease or progressive disease) were 4.8 and 11.3 respectively, indicating a significant difference (P = 0.021). A median follow-up period for the survival analysis was 25.2 months. The median PFS and OS of all the patients together were 10.8 months (95% CI: 8.8– 12.8 months) and 28.0 months (95% CI: 23.5– 32.5 months). The median PFS in the low-NLR and high-NLR groups were 15.7 months (95% CI: 12.7–18.7 months) and 6.7 months (95% CI: 4.6–8.8 months). The median OS in the low-NLR and high-NLR groups were 37.6 months (95% CI: 30.3–44.9 months) and 19.2 months (95% CI: 10.6–27.8 months). The multivariate analysis identified PS, NLR, stage, and smoking status as independent predictors of PFS. Moreover, the PS and NLR were identified as independent predictors of OS. NLR was a significant predictor of clinical efficacy in NSCLC patients harboring EGFR mutations treated with gefitinib or erlotinib.

Does histological assessment accurately distinguish separate primary lung adenocarcinomas from intrapulmonary metastases? A study of paired resected lung nodules in 32 patients using a routine next-generation sequencing panel for driver mutations

AimVarious approaches have been reported for distinguishing separate primary lung adenocarcinomas from intrapulmonary metastases in patients with two lung nodules. The aim of this study was to determine whether histological...

Implication of podocin promoter variant haplotype in south Indian diabetic kidney patients

Type 2 diabetes (T2D) is a global epidemic, 40% of T2D individuals are associated with diabetic kidney disease (DKD) a major microvascular complication leading to end stage renal disease (ESRD). We aimed to screen for three podocin (NPHS2) gene promoter variants -535ins/del (CTTTTTTT)2, rs1079291(C > T) and rs12406197 (G > T) in T2D and DKD patients of south India to explore their role in the propensity to DKD. The present study enrolled a total of 200 T2D patients comprising an equal number of T2D and DKD patients and performed genotyping using PCR followed by Sanger sequencing. Individual genotype analysis performed for three podocin promoter variants yielded different results. -535 ins/del (CTTTTTT)2 and rs1079291(C > T) gene variants showed lack of association. However, the GG vs. GT + TT genotype of rs12406197(G > T) exhibited protective effect (OR = 0.51; 95% CI = 0.28–0.92; p = 0.03). A genotype dependent variation was noted with respect to rs1079291 mutant genotype for serum albumin, serum creatinine, eGFR and rs12406197 risk genotypes for HbA1c, serum albumin and serum creatinine within the DKD group. Haplotype block 2TT found to be a risk haplotype towards DKD (OR = 2.43; 95% CI = 1.17–5.03; p = 0.017). Diabetic individuals carrying mutant allele and the elevated levels of kidney functioning markers are vulnerable to nephropathy. Further 2TT promoter haplotype appears to play a role in the genetic susceptibility to DKD in south Indian patients suggesting that the low production/depletion of podocin may hinder the regeneration and replacement of podocytes. As the sample size of the present study is limited in order to test our contention large studies are warranted.

18F-FDG PET/CT SUVmax and serum CEA levels as predictors for EGFR mutation state in Chinese patients with non-small cell lung cancer.

The epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) contribute to an increased response rate, compared with chemotherapy, in patients with inhibitor-sensitive EGFR mutations. The present study evaluated the association between the maximum standardized uptake value (SUVmax) of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT), as well as serum carcinoembryonic antigen (CEA) levels and EGFR mutations prior to treatment, in patients with non-small cell lung cancer (NSCLC). Patients with histologically confirmed NSCLC (n=167), who underwent an 18F-FDG PET/CT scan, EGFR mutation analysis and a serum CEA test participated in the present study. Multivariate logistic regression analysis was used to analyze predictors of EGFR mutations. Receiver-operating characteristic (ROC) curve analysis was performed to determine the efficient cut-off value. Survival rate analysis was evaluated according to SUVmax and EGFR mutation status. A decreased SUVmax and an increased CEA level was observed in patients with EGFR-mutations, compared with patients with wild-type primary lesions and metastatic lymph nodes. The exon 19 EGFR mutation was associated with increased SUVmax, compared with the exon 21 L858R mutation. The ROC analysis indicated that an 18F-FDG PET/CT uptake SUVmax >11.5 may be a predictor of the wild-type EGFR genotype and increased CEA levels (CEA >9.4 ng/ml) were associated with EGFR mutations. Furthermore, patients with no smoking history, low SUVmax of the primary tumor, metastatic lymph nodes and a high CEA level were significantly associated with EGFR mutation status. The results of the present study indicated that patients with advanced NSCLC, particularly Chinese patients, with decreased SUVmax and increased CEA levels are associated with EGFR mutations, which may serve as predictors for the EGFR-TKI therapeutic response.

EGFR mutation genotypes affect efficacy and resistance mechanisms of osimertinib in T790M-positive NSCLC patients.

BackgroundOsimertinib is a potent third-generation EGFR tyrosine kinase inhibitor (TKI) with robust activity in advanced EGFR-mutant non-small cell lung cancer (NSCLC), including those with T790M resistance mutation. However, a broad interpatient variability was observed. This study aimed to evaluate whether EGFR-mutant genotypes affect the clinical outcomes and resistance mechanisms in T790M-positive NSCLC patients receiving osimertinib therapy.MethodsAll NSCLC patients treated with osimertinib in our institute were screened. We included those with known EGFR-mutant genotypes and T790M positivity. Clinical outcomes including objective response rate (ORR), clinical benefit rate (CBR), progression-free survival (PFS), and overall survival (OS), were evaluated and compared between different EGFR genotypes. Patients with next-generation sequencing testing or tumor rebiopsy after osimertinib treatment were analyzed for resistance mechanisms.ResultsORR, CBR, PFS, and OS were all non-significantly different among patients harboring EGFR exon 19 deletion (19Del, n=136), L858R (n=93), and uncommon mutations (n=6). However, a subset of tumors with deletion starting at E746 (ΔE746, n=98), but not non-ΔE746 tumors (n=38), had better clinical outcomes than L858R tumors (n=93). Frequencies of T790M loss and C797S acquisition after osimertinib treatment were similar between 19Del (n=56) and L858R tumors (n=33). However, compared with L858R tumors (n=33), those with 19Del ΔE746 subtype (n=40) had a higher whereas non-ΔE746 subtype (n=16) had a similar frequency of acquired C797S mutation. Combined analysis of our cohort and public cohort confirmed these findings.ConclusionsOur findings indicate that the EGFR 19Del subtypes affect the clinical outcomes and resistance mechanisms to osimertinib in T790M-positive patients. Identifying patients with relatively worse treatment outcomes may be informative for establishing new therapies for these patients.

SO092REDUCED QUALITY OF LIFE IN ADPKD PATIENTS WITH CKD STAGE 1-3: THE CYSTIC I QUALITY OF LIFE STUDY

Abstract Background and Aims ADPKD is the most common inherited kidney disease in man, a major cause of end-stage renal disease and is a significant medical and economic burden across Europe. However the impact of this major disease on the quality of life of patients with preserved kidney function has not been systematically explored. Method The CYSTic 1 study was an academic prospective study designed to study the natural history of ADPKD, the impact of the disease on individual patients and the health economic costs on care systems across Europe in adult patients with preserved kidney function (eGFR ≥30 mls/min). Around 400 patients were recruited from 6 expert centres across Europe (Belgium, France, Italy, Netherlands, Spain, UK) with baseline clinical data recorded including HR-QOL (Health-Related Quality of Life) incorporating a Kidney Disease QOL short form (KDQOL-SF v1.3 questionnaire), renal MRI for TKV (Total Kidney Volume) and DNA for genotyping. Here we report initial results based on baseline HR-QOL data in the UK patients. Results Detailed analysis was conducted on 76 patients recruited from a single centre (UK) whose mean age was 43 years, 53.9% were female with a mean eGFR-EPI of 69ml/min/1.73m2 and mean height-adjusted TKV (Ht-TKV) of 664ml/m. The cohort was subdivided by groups based on eGFR stage (I, II, III), Ht-TKV (&amp;lt;&amp;gt;750ml/m) and genotype (PKD1 v PKD2/NMD) and correlated with HR-QOL scores. As expected, age, hypertension and Ht-TKV were significantly associated with eGFR stage. Of interest, flank pain was more frequently reported in patients with smaller kidneys (Ht-TKV&amp;lt;750) and patients with PKD1 more likely to be hypertensive. All QOL scores (SF36) were significantly lower in patients with progressively lower eGFR except for emotional well-being whereas Symptom/problem (p=0.043) and Sleep (p=0.021) (KDQOL-SF1.3) were significantly worse in patients with lower kidney function. SF36 scores for Physical functioning (p=0.001), General health (p=0.026) and physical component summary (PCS) (P=0.019) decreased in patients with more advanced disease defined by larger kidneys (ht-TKV&amp;gt;750). Conclusion In ADPKD patients with stage 1-3 chronic kidney disease (CKD), stepwise lower QOL scores were consistently found and significantly associated with decreasing eGFR. A notable reported item was disturbed sleep. Unexpectedly, patients with smaller kidneys reported significantly more flank pain. PKD1 patients and those with large kidneys were more likely to be hypertensive. Our results suggest that the impact of ADPKD on patients with stage 1-3 CKD is underestimated. Future work will investigate possible national differences and the relationship of HR-QOL with markers of disease within the entire cohort.