Epidermal Growth Factor Receptor Mutation Analysis Research Articles

Detection of Circulating Tumor Cells and EGFR Mutation in Pulmonary Vein and Arterial Blood of Lung Cancer Patients Using a Newly Developed Immunocytology-Based Platform.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors are powerful molecular targeted therapeutic agents for lung cancer. We recently developed an original immunocytology and glass slide-based circulating tumor cell (CTC) detection platform for both CTC enumeration and EGFR mutation analysis with DNA extracted from CTCs. Using this platform, we conducted a pilot clinical study for CTC enumeration in peripheral blood (PB), pulmonary arterial blood (PA), and pulmonary venous blood (PV) from 33 patients with lung cancer (Stage I-III) who underwent surgery, followed by digital PCR-based EGFR mutation analysis of CTCs in PV from 12 patients. The results showed that CTC levels were significantly higher in PV and PA than in PB (p < 0.05, p < 0.01. respectively), with a notably greater number of small and large CTC clusters (p < 0.01). Genetic analysis of EGFR mutations of CTCs from PV (n = 12) revealed six mutations, including three Exon19del and three L856R, in CTCs and eight EGFR mutations, including five Exon19del and three L856R, in lung tumor tissue. CTC mutation status matched that of tissue samples in nine patients, was unmatched in two patients, and controversial in one patient, indicating a sensitivity of 0.75 (6/8) and specificity of 1.0 (4/4) with some false-negative results for the mutation analysis of CTCs. This immunocytology-based CTC detection platform is a convenient method for detecting both CTC number and EGFR mutation status under microscopy, suggesting its potential as a liquid biopsy tool in the hospital for patients with lung cancer in some clinical settings.

The Comparison of Real-Time PCR and Mutation-Specific Immunohistochemistry in EGFR Mutation Analysis of Non-Small Cell Lung Carcinomas

Objective: This study aims to identify activating mutations in the epidermal growth factor receptor (EGFR) gene in patients with non-small cell lung cancer (NSCLC) and to evaluate their correlation with responses to EGFR-tyrosine kinase inhibitors (TKI) treatment. This study aims to identify activating mutations in the epidermal growth factor receptor (EGFR) gene in patients with non-small cell lung cancer (NSCLC) and to evaluate their correlation with responses to EGFR-tyrosine kinase inhibitors (TKI) treatment. We conducted a comparative analysis of Real-Time PCR and immunohistochemistry to detect EGFR mutation status in non-small cell lung cancer patients, focusing on the sensitivity, specificity, and predictive values of immunohistochemistry. Material and Method: We evaluated 788 non-small cell lung cancer samples which were analyzed for EGFR mutation status by RT-PCR. We detected 126 EGFR mutated cases among these patients. We evaluated mutation-specific EGFR immunohistochemistry directed towards the exon 19 deletions (15 bp E746-A750) and exon 21 point mutation (L858R) to the 47 EGFR mutated patients histologic material and cell blocks of cytologic specimens. Results: 32 of the 47 cases (68%) had exon 19 deletion, 14 of them (30%) had point mutation in exon 21, and one of them (2%) showed exon 18 mutation. EGFR exon 19 (15 bp E746-A750 deletion) antibody showed a sensitivity of 100%, specificity of 40%, negative predictive value of 100%, and positive predictive value of 78%. The sensitivity of the exon 21 (L858R point mutation) antibody was 93%, specificity was 91%, negative predictive value was 97% and positive predictive value was 82%. Conclusion: Our investigation indicates that mutation-specific EGFR immunohistochemistry has demonstrated a notable sensitivity and specificity for exon 21. However, while sensitive, the exon 19 (15 bp E746-A750 deletion) antibody lacked specificity. While positive immunohistochemical staining may suggest the presence of an EGFR mutation, making the patient potentially eligible for TKI treatment, it should not be the sole determinant. If immunohistochemistry results are negative, it is essential to resort to molecular tests to ensure accurate diagnosis and appropriate therapeutic guidance. With evolving diagnostic landscapes, it is crucial to harness both IHC and molecular techniques judiciously for optimal patient care.

Characteristics, treatment patterns, and prognostic factors in small cell lung cancer transformation of advanced non-small cell lung cancer with epidermal growth factor receptor mutation after tyrosine kinase inhibitor therapy.

e20569 Background: Small cell lung cancer transformation in advanced non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation following tyrosine kinase inhibitor (TKI) therapy poses a challenging clinical scenario. This study aims to explore the characteristics, treatment patterns, and prognostic factors associated with this transformation. Methods: A total of 41 patients with transformed SCLC (tSCLC) were included. Patient characteristics, treatment details, and laboratory data were collected. Re-biopsy specimens and subsequent treatments were analyzed. Statistical analyses were conducted to identify factors associated with treatment response and survival outcomes. Results: The median age of the patients was 61.7 years old, with a median time from TKI treatment to small cell transformation of 22.2 months. The majority were female (58.5%), never smokers (80.5%), with 53.7% having stage IVB disease prior to EGFR-TKI treatment. The most prevalent initial EGFR mutation was exon 19 deletion (56.1%), and afatinib (46.3%) was the most commonly used EGFR-TKI. EGFR mutation analysis was performed in 68.3% of the tSCLC specimen, and acquired T790M was detected in 7.1% of the patients. Treatment patterns after transformation included various systemic therapies, with the most (63.4%) receiving etoposide plus platinum (EP) based chemotherapy in the first line setting. Among all the patients, 56.1% received EGFR-TKI and 22% received immune checkpoint inhibitors (ICI) throughout the post-transformation treatment course. Anemia (Hgb &lt; 10g/dL) and ever use of EP were significant factors associated with post-transformation survival. The median progression-free survival (PFS) of the first line treatment was 3.27 months, and the overall survival (OS) was 10.43 months post transformation. Conclusions: Small cell lung cancer transformation in advanced NSCLC with EGFR mutation after TKI therapy is associated with diverse clinical characteristics and dismal outcomes. We presented the complexity of managing these cases in real-world practice. Anemia and ever use of EP affected post-transformation survival. Further research is warranted to optimize therapeutic strategies for this unique subset of patients.

Immunohistochemical analysis of epidermal growth factor receptor as a predictive biomarker in lung adenocarcinoma – A cross-sectional study of 33 cases on computed tomography-guided core needle biopsy specimens

Background: Lung cancer is the second most common cause of cancer in all ages and both genders and is the leading cause of cancer death. Two major groups of lung cancers are – small cell lung carcinoma (SCLC) and non-SCLC (NSCLC). Due to discovery of driver mutation such as epidermal growth factor receptor (EGFR) mutation in NSCLC, the paradigm of lung cancer therapy has shifted from cytotoxic platinum based therapy to tyrosine kinase inhibitor (TKI) therapy. In this study, we have analyzed EGFR expression in NSCLC by immunohistochemistry (IHC) and studied the response to TKI therapy in terms of progression free survival (PFS) and overall survival (OS). Aims and Objectives: In this study, we have retrospectively analyzed the EGFR overexpression in adenocarcinoma of lung in core needle biopsy (CNB) specimen by IHC analysis and correlated with the therapeutic response and survival rate (OS and PFS) in lung carcinoma patients. Materials and Methods: We have analyzed retrospectively EGFR expression in lung adenocarcinoma cases (computed tomography-guided CNB specimen) by IHC. In our study, we have used monoclonal primary antibodies against two most common EGFR mutations, that is, L858R point mutation and E 746–A 750 deletion. Results: Out of 33 cases, EGFR expression was seen in 28 cases. For EGFR expression assessment by IHC, both cytoplasmic and/or membranous staining taken into consideration. EGFR positivity was interpreted only when &gt;10% tumor cells having 2+ or more intensely staining pattern. The response to TKI therapy in terms of PFS and OS was also studied. Conclusion: IHC analysis of EGFR mutation using specific antibodies has extremely high specificity with good sensitivity. Use of targeted therapy in the form of TKI in EGFR positive lung adenocarcinoma has high response rate and long duration of survival (PFS and OS) with acceptable toxicity profile in contrast to the conventional therapy.

Clinical, Genomic, and Transcriptomic Featurses of Lung Adenocarcinoma With Uncommon EGFR Mutation

PurposeThe purpose of this study is to identify the clinical, genomic, and transcriptomic features of patients with lung adenocarcinoma (LUAD) harboring uncommon epidermal growth factor receptor (EGFR) mutations (UCM) compared with common EGFR mutations (CM). Materials and MethodsIn this multicenter retrospective cohort study, clinicopathological data were collected from 1047 consecutive patients who underwent complete surgical resection for LUAD, as well as EGFR mutation analysis, between 2005 and 2012 at 4 institutions. Differences in postoperative overall survival (OS) and recurrence-free survival (RFS) according to EGFR mutation status were evaluated. For the genomic and transcriptomic analyses, 5 cohorts from public databases were evaluated. ResultsOf 466 eligible patients, 415 (89.1%) and 51 (10.9%) had CM and UCM, respectively. The 5-year OS and RFS rates in the CM/UCM groups were 86.8%/77.0% and 74.8%/59.0%, respectively. OS and RFS were significantly shorter in the UCM than CM group (both P < .01). Multivariable analysis of OS showed that UCM was an independent prognostic factor (hazard ratio 1.72, 95% confidential interval 1.01-2.93). According to the genomic analysis, tumors with UCM had a significantly higher tumor mutation burden and TP53 mutation frequency. Transcriptomic analysis showed that the T-cell-inflamed gene signature, a biomarker of the treatment for immunotherapy, was significantly associated with tumors with UCM. ConclusionUCM were associated with a poor prognosis in patients with surgically resected EGFR-mutated LUAD. Tumors with UCM had unique genomic and transcriptomic features suggestive of a tumor microenvironment responsive to immunotherapy.

Comparison of Confirmed Cytology Smears and Cell Blocks for Epidermal Growth Factor Receptor Mutation Testing in Non-Small Cell Lung Cancer.

Various cytologic specimens have been used to diagnose epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer (NSCLC). However, insufficient samples and lengthy DNA extraction procedures have led to inconsistent diagnostic results. To reduce manipulation losses and improve DNA extraction quality, we provide an improved procedure for DNA extraction from smear samples containing rare tumor cells in NSCLC. The effectiveness of this new method for DNA extraction and diagnosis was validated in 8 patients with pleural effusion smears and formalin-fixed paraffin-embedded cell blocks, and another with 2 smears. Smear samples with <5% tumor cells were collected, and visible particles were selected for DNA extraction after centrifugation. Qiagen formalin-fixed paraffin-embedded DNA extraction kit (Qiagen) was used for DNA extraction and the procedure was modified. The EGFR mutation analysis in both types of material used the EGFR mutation analysis kit (Therascreen EGFR RGQ PCR) and real-time polymerase chain reaction (Rotor-Gene Q). The DNA extraction amount of the smear was 2.6 to 258.8 ng/μL, and that of the cell block was 1.4 to 139.9 ng/μL. The DNA quantity and purity of DNA extracts isolated from both sample sources were sufficient for subsequent EGFR mutation detection, where mutation rates were similar and diagnostic results were consistent when smears or cell blocks were used. This improved method demonstrates that cytology smears can be used as a test material for the detection of EGFR mutations in patients with NSCLC with sparse cells.

Monitoring of Plasma EGFR Mutations during Osimertinib Treatment for NSCLC Patients with Acquired T790M Mutation.

Osimertinib was first approved for the treatment of non-small cell lung cancer (NSCLC) in patients who have developed the epidermal growth factor receptor (EGFR) T790M mutation after treatment with EGFR tyrosine kinase inhibitors (TKIs). We routinely evaluated the plasma of NSCLC patients with the T790M mutation to more rapidly detect an increase in disease activity and resistance to treatment. Eligible patients received osimertinib after resistance to the first- or second-generation of EGFR-TKIs in NSCLC harboring T790M mutation detectable in tumor tissue or plasma. Plasma samples were collected every 8 weeks during osimertinib treatment. The plasma analysis was performed using an improved PNA-LNA PCR clamp method. We tested samples for a resistance mechanism, including EGFR-activating, T790M, and C797S mutations, and assessed the association between the mutations and osimertinib treatment. Of the 60 patients enrolled in the study, 58 were eligible for this analysis. In plasma collected before osimertinib treatment, activating mutations were detected in 47 of 58 patients (81.0%) and T790M was detected in 44 patients (75.9%). Activating mutations were cleared in 60.9% (28/46) and T790M was cleared in 93.0% (40/43). Of these, 71.4% (20/28) of activating mutations and 87.5% (35/40) of T790M mutation were cleared within 8 weeks of treatment. The total response rate (RR) was 53.4% (31/58). The median duration of treatment was 259 days, with a trend toward longer treatment duration in patients who experienced the clearance of activating mutations with osimertinib. At the time of disease progression during osimertinib treatment, C797S was detected in 3 of 37 patients (8.1%). Plasma EGFR mutation analysis was effective in predicting the effect of osimertinib treatment.

Possible False Results With cobas® EGFR Mutation Test v2 and Oncomine Dx Target Test for EGFR Mutation.

Disparities in the results of next-generation sequencing-based multiplex gene panel tests and those of single-gene tests when detecting epidermal growth factor receptor (EGFR) mutations in non-small-cell lung cancer (NSCLC) have been reported. However, the possible underlying causes have not been investigated. The aim of this study was to explore the possibilities and causes of false results obtained using cobas® EGFR Mutation Test v2 (cobas® EGFR) and Oncomine Dx Target Test (ODxTT). The data of patients with NSCLC who underwent gene assessment using both cobas® EGFR and ODxTT between April 2021 and May 2022 were retrospectively reviewed. Disparate results of EGFR mutation analyses were then reviewed. One hundred and sixteen patients were included in the analysis. The results of six samples were inconsistent. In four samples, exon 20 insertion mutations were detected using cobas® EGFR, but not identified using ODxTT. A fragment analysis was performed on three of the four samples, and all showed negative results for exon 20 insertion. Furthermore, one false negative result was obtained in the ODxTT for both exon 19 deletion and L858R mutations. For exon 19 deletion mutation, a single nucleotide variant from adenine to thymine was identified close to the mutation site. False positives for exon 20 insertion may occur when using cobas® EGFR, and false negatives for exon 19 deletion and L858R mutations may occur when using ODxTT.

Performance of Ultra-Rapid Idylla™ EGFR Mutation Test in Non-Small-Cell Lung Cancer and Its Potential at Clinical Molecular Screening.

The Idylla™ EGFR Mutation Test is an ultra-rapid single-gene test that detects epidermal growth factor receptor (EGFR) mutations using formalin-fixed paraffin-embedded specimens. Here, we compared the performance of the Idylla EGFR Mutation Test with the Cobas® EGFR Mutation Test v2. Surgically resected NSCLC specimens obtained at two Japanese institutions (N = 170) were examined. The Idylla EGFR Mutation Test and the Cobas EGFR Mutation Test v2 were performed independently and the results were compared. For discordant cases, the Ion AmpliSeq Colon and Lung Cancer Research Panel V2 was performed. After the exclusion of five inadequate/invalid samples, 165 cases were evaluated. EGFR mutation analysis revealed 52 were positive and 107 were negative for EGFR mutation in both assays (overall concordance rate: 96.4%). Analyses of the six discordant cases revealed that the Idylla EGFR Mutation Test was correct in four and the Cobas EGFR Mutation Test v2 was correct in two. In a trial calculation, the combination of the Idylla EGFR Mutation Test followed by a multi-gene panel test will reduce molecular screening expenses if applied to a cohort with EGFR mutation frequency >17.9%. We demonstrated the accuracy and potential clinical utility of the Idylla EGFR Mutation Test as a molecular screening platform in terms of turnaround time and molecular testing cost if applied to a cohort with a high EGFR mutation incidence (>17.9%).

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.

Molecular epidemiology and clinical characteristics of epidermal growth factor receptor mutations in NSCLC: A single-center experience from India.

The genetic profiling of non-small cell lung cancer (NSCLC) has contributed to the discovery of actionable targetable mutations, which have significantly improved outcomes in disease with poor prognosis. Molecular epidemiological data of driver mutations in Indian populations have not been extensively elaborated compared to western and eastern Asian NSCLC populations. This study assessed the prevalence and clinical outcomes of EGFR (epidermal growth factor receptor) mutations among the Indian NSCLC cohort in South India. Retrospective analysis of 2,003 NSCLC patients who had undergone EGFR mutational analysis from 2013 to 2020 was performed. Clinical analysis was performed for 141 patients from 2013 to 2017 using Kaplan-Meier and Chi-square methods. Descriptive and survival statistics were performed using IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp. EGFR-sensitizing mutations were detected in 41.6% (834/2003) in the study cohort with compound mutations detected in 7.55% (63/834) of EGFR-positive cases. A significant relationship with regard to female gender and EGFR mutation status (P <.001) was observed. Exon 18 G719X (8.7%) mutations and exon 20 T790M point mutation (3.1%) were the most frequently isolated uncommon EGFR mutations. In the clinical cohort, EGFR mutations were detected at a significantly higher prevalence in females (P =0.002) and never-smokers (P < 0.001). EGFR mutation demonstrated a significant relationship with regard to brain metastasis (P = 0.011). EGFR mutated individuals had significantly longer median overall survival compared to EGFR wild type (26 months vs. 12 months, P = 0.044). We reports the highest number of EGFR mutation analysis performed from India and mutational analysis indicated a loco-regional variation in India with regard to EGFR mutation frequency and its subtypes.

Phenotypic and Genotypic Appraisal of Pulmonary Mucinous Adenocarcinoma: A Retrospective Study

Introduction: Lung cancer is the second most common cancer diagnosed in the world. According to GLOBOCAN 2020, it is approximately 11.4% of all malignancies and accounts for one in five cancer deaths worldwide. Several driver gene mutations are known in lung adenocarcinoma including Epidermal Growth Factor Receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog(KRAS), v-raf murine sarcoma viral oncogene homolog B1(BRAF), Human epidermal growth factor receptor2 (HER 2), anaplastic lymphoma kinase (ALK), Ros Protooncogene 1, Receptor Tyrosine Kinase (ROS1) and rearranged during transfection (RET). Among these, KRAS mutation has been classically defined as bearing a negative prognostic factor. They are described to have unfavourable survival rates as compared with KRAS wild- type tumours. However, its real significance remains controversial due to heterogeneity amongst studies. Aim: The aim of this study was to assess the histomorphology, immunophenotype, EGFR and KRAS mutation profile in invasive mucinous and mixed mucinous/non mucinous type lung carcinoma. Materials and Methods: This retrospective study was done at a tertiary cancer centre in the state of Kerala, South India to identify the frequency of EGFR and KRAS mutations in invasive mucinous or mixed mucinous/non mucinous type lung carcinoma diagnosed during the period June 2017 to March 2019. Immunohistochemical assays for CK7, CK20, TTF-1, Napsin-A, CDX-2 and p63 were done on all cases. EGFR mutation analysis for exons 18, 19, 20, 21 were done using ARMS PCR and KRAS mutation analysis for codons 12, 13, 61, 146 by Sanger sequencer. Descriptive statistics was used wherever applicable. Results: Out of a total of 290 patients of pulmonary adenocarcinoma during the two year study period, twelve cases (4.1%) were diagnosed as invasive mucinous or mixed mucinous/non mucinous types based on histomorphology and immunophenotype, on both lung tissue biopsies as well as material from metastatic sites. Of the twelve, nine (75%) were pure mucinous and three (25%) were mixed mucinous and non mucinous. All the twelve cases were subjected to molecular testing for both EGFR and KRAS. Three cases (25%) showed KRAS mutations in codon 12. EGFR mutation (TKI resistant T790M mutation) was found only in a single case which had a histology of mixed mucinous and non mucinous carcinoma and a coexistent mutation in KRAS (c12 G&gt;C) gene. Conclusions: Our study corroborates the described fact that pulmonary mucinous carcinoma differ from the conventional adenocarcinoma in terms of its histology, immunoprofile and molecular profile. KRAS mutation appears to be the main pathogenetic factor in this variant. In the current day practice, there is no demonstrable effective therapy for KRAS mutant lung adenocarcinoma and more trials are needed to identify newer mutations that can modify treatment outcomes.

Mutational Analysis of EGFR Mutations in Non-Small Cell Lung Carcinoma—An Indian Perspective of 212 Patients

Lung cancer is the world's leading cause of cancer-related deaths. Epidermal growth factor receptor (EGFR) is one of the critical oncogenes and plays a significant role in tumor proliferation and metastasis. Patients with sensitizing mutations in the EGFR gene have better clinical outcomes when treated with tyrosine kinase inhibitors (TKI). This study expands our knowledge of the spectrum of EGFR mutations among lung cancer patients in the Indian scenario. This is a retrospective descriptive study of all newly diagnosed patients with lung cancer in tertiary care hospital in India. All the samples were subjected to real-time PCR (q-PCR) analysis and confirmation of rare novel mutations was done using Sanger sequencing. Clinicopathological characteristics, mutational EGFR status, and location on the exon and metastatic sites were evaluated. An analysis of total 212 samples showed mutations in 38.67% of cases. Among these, five (5.9%) samples had mutations in exon 18, 41 (48.8%) samples had mutations in exon 19, 12 (14.28%) samples had mutations in exon 20, and 26 (30.95%) samples had mutations in exon 21. Eleven (13.41%) were found to be uncommon EGFR mutations. Additionally, six (21.4%) samples that had EGFR mutations were also positive for brain metastasis. Future testing on bigger panels will help to characterize the incidence of genetic mutations and to determine the appropriate targeted treatment choices for NSCLC patients.

Correlation Analysis of Ki67 Expression and EGFR Mutation on the Risk of Recurrence and Metastasis in Postoperative Patients with Stage I Lung Adenocarcinoma

The prognosis of stage I non-small cell lung cancer (NSCLC) is generally good. However, some of the stage I NSCLC patients still may have early recurrence and metastasis, and there is no standard method to screen this part of the population. The aim of this study is to investigate the relationship between Ki67 expression as well as epidermal growth factor receptor (EGFR) mutation and the risk of recurrence in postoperative patients with stage I lung adenocarcinoma. We retrospectively enrolled 118 postoperative patients with stage I lung adenocarcinoma. EGFR mutation was tested using amplification refractory mutation system polymerase chain reaction (ARMS-PCR) , and Ki67 level was detected by immunohistochemistry (IHC), followed by the collection of the patients' clinical characteristics. Kaplan-Meier method, Log-rank test, and Cox proportional hazards regression model were used for the prognostic statistical analysis. Among the 118 patients, the rate of high Ki67 expression was 43.22% (51/118), which is related to gender, smoking status, surgical method, differentiation degree, and postoperative stage (P<0.05). Meanwhile, EGFR mutation rate was 61.02% (72/118), of which EGFR exon 19 deletion mutation rate was 19.49% (23/118), and the EGFR exon 21 L858R mutation rate was 41.53% (49/118). However, Ki67 expression was not associated with EGFR mutation status (χ2=1.412, P=0.235). Survival analysis showed that high Ki67 expression was inversely associated with disease-free survival (DFS) and overall survival (OS) in stage I lung adenocarcinoma (P<0.05), but EGFR mutation status was not significantly associated with DFS and OS (P>0.05). In the subgroup analysis, the DFS of the EGFR exon 19 deletion group was significantly decreased compared with the EGFR exon 21 L858R mutation group (P=0.031), but there was no significant difference in OS (P=0.308). Multivariate analysis showed that there was statistical significance between Ki67 expression (P=0.001) and DFS in stage I lung adenocarcinoma; Ki67 expression (P=0.03) and gender (P=0.015) were associated with OS in stage I lung adenocarcinoma. Ki67 expression is an independent influencing factor for postoperative recurrence and OS of stage I lung adenocarcinoma and it is not significantly associated with EGFR mutation. There is no significant difference between EGFR mutation status and the prognostis of stage I lung adenocarcinoma. However, the prognosis differed in EGFR mutation types; the patients with EGFR exon 19 deletion are at higher risk of recurrence than EGFR exon 21 L858R mutation.

59P Clinical utility of plasma cell-free DNA EGFR mutation analysis in treatment-naïve stage IV non-small cell lung cancer patients

Plasma cell-free DNA epidermal growth factor receptor (EGFR) mutation tests are widely used at initial diagnosis and at progression in stage IV non-small cell lung cancer (NSCLC). We analyzed the factors associated with plasma EGFR mutation detection and the effect of plasma EGFR genotyping on the clinical outcomes of the patients with treatment-naïve stage IV NSCLC. In this retrospective cohort study, we included subjects with treatment-naïve stage IV NSCLC who underwent plasma EGFR genotyping between 2018 and 2020. The presence of plasma EGFR mutation was determined by real-time polymeric chain reaction. The prevalence of EGFR mutation in this cohort was 52.7% (164/311). Among 164 EGFR mutant subjects, 34 (20.7%) were positive for the plasma EGFR mutation assay only. The diagnostic sensitivity of the plasma EGFR mutation assay (80.5%) was similar to that of the tissue EGFR mutation assay (79.3%, p = 0.787). In multivariable analysis, the detection of plasma EGFR mutation was significantly related to higher serum carcinoembryonic antigen levels, never-smoker status, N3 stage, and brain or intrathoracic metastasis. The time to treatment initiation (TTI) of the plasma EGFR mutation-positive group (14 days) was shorter than that of the plasma EGFR mutation-negative group (21 days, p < 0.001). More patients received the 1st line EGFR-TKI in the plasma positive group compared with the tissue positive group. Smoking status and the factors reflecting tumor burden were associated with detection of plasma EGFR mutation. The plasma EGFR mutation assay can shorten the TTI, and facilitate the 1st line EGFR-TKI therapy for patients with treatment-naïve stage IV NSCLC, especially in the region of high-prevalence of EGFR mutation.

Characteristics of EGFR Mutations in Plasma Samples in Non-Small Cell Lung Cancer Patients after Treatment with 1st and 2nd Generation of TKI at Bach Mai Hospital

This study aims to describe EGFR mutation status detected in plasma samples and analyze some related factors in non-small cell lung cancer patients after treatment with the generation I and II Tyrosine Kinase inhibitors at Bach Mai Hospital. Patients and methods: A retrospective descriptive study on 75 patients with non-small cell lung cancer tested for EGFR mutations in plasma after treatment with 1st or 2nd EGFR-TKIs in 2019-2020. Results: EGFR mutations were detected in 97.3% plasma samples; the T790M mutation accounted for 37.3% and is accompanied by a sensitive mutation TKI; The T790M mutations ratio after treatment was higher than before treatment with TKIs (p &lt; 0.001); the median total duration of EGFR-TKI treatment was significantly longer in patients with T790M mutation than in those without (16.8 months vs 12.5 months, p = 0.005); the T790M mutation ratio was higher in patients with a deletion on exon 19 than in L858R mutation on exon 21 (p=0.028), in Erlotinib treatment group higher than in Gefitinib and Afatinib treatment group (51.4% vs. with 20.0% and 33.3%, p=0.039). Conclusions: EGFR mutation plasma test helps to monitor disease progression and detect resistance mutations T790M in NSCLC patients after TKI generation I and II.&#x0D; Keywords: non-small cell lung cancer, EGFR mutations, T790M mutations, TKIs..&#x0D; References&#x0D; [1] H. Sung et al., Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers In 185 Countries, CA: A Cancer Journal for Clinicians. Vol. 71, No. 3, 2021, pp. 209-249, https://doi.org/10.3322/caac.21660.[2] N. V. Hieu, Oncology, Medical Publisher, 2015.[3] P. N. Ding et al., Plasma Pre-treatment T790M Relative Allelic Frequency in Patients with Advanced EGFR-mutated Non-small Cell Lung Cancer Predicts Treatment Response to Subsequent-Line Osimertinib, Translational Lung Cancer Research, Vol. 10, No. 4, 2021, pp. 1623-1634, https://doi.org/10.1186/s40169-020-0269-y.[4] N. Yamamoto et al., Erlotinib Plus Bevacizumab Vs Erlotinib Monotherapy as First-line Treatment for Advanced EGFR Mutation-positive Non-squamous Non-small-cell Lung Cancer: Survival Follow-up Results of the Randomized JO25567 Study, Lung Cancer, Vol. 151, 2021, pp.20-24, https://doi.org/10.1016/j.lungcan.2020.11.020.[5] D. S. Ettinger et al., NCCN Guidelines Insights: Non–Small Cell Lung Cancer, Version 2, 2021: Featured Updates to the NCCN Guidelines", Journal of the National Comprehensive Cancer Network, Vol. 19, No. 3, 2021, pp. 254-266, https://doi.org/10.6004/jnccn.2021.0013.[6] K. Usui et al., Plasma ctDNA Monitoring During Epidermal Growth Factor Receptor (EGFR)-Tyrosine Kinase Inhibitor Treatment in Patients With EGFR-mutant Non-small Cell Lung Cancer (JP-CLEAR trial), Japanese Journal of Clinical Oncology, Vol. 49, No. 6, 2021, pp. 554-558, https://doi.org/10.1093/jjco/hyz023.[7] M. Nagasaka et al., Liquid Biopsy for Therapy Monitoring in Early-stage Non-small Cell Lung Cancer, Molecular Cancer, Vol. 20, No. 1, 2021, pp. 82, https://doi.org/10.1186/s12943-021-01371-1.[8] M. D. Re et al., Incidence of T790M in Patients with NSCLC Progressed to Gefitinib, Erlotinib, and Afatinib: A Study on Circulating Cell-free DNA, Clinical Lung Cancer, Vol. 21, No. 3, 2020, pp. 232-237, https://doi.org/10.1016/j.cllc.2019.10.003.[9] S. Jenkins et al., Plasma ctDNA Analysis for Detection of the EGFR T790M Mutation in Patients with Advanced Non–small Cell Lung Cancer", Journal of Thoracic Oncology, Vol. 12, No. 7, 2017, pp. 1061-1070, https://doi.org/10.1016/j.jtho.2017.04.003.[10] R. Ko et al., Frequency of EGFR T790M Mutation and Multimutational Profiles of Rebiopsy Samples from Non-small Cell Lung Cancer Developing Acquired Resistance to EGFR Tyrosine Kinase Inhibitors in Japanese Patients, BMC Cancer, Vol. 16, No. 1, 2016, pp. 864, https://doi.org/10.1186/s12885-016-2902-0.[11] N. Matsuo et al., Association of EGFR Exon 19 Deletion and EGFR-TKI Treatment Duration with Frequency of T790M Mutation in EGFR-Mutant Lung Cancer Patients, Scientific Reports, Vol. 6, No. 1, 2016, pp. 36458 , https://doi.org/10.1038/srep36458.[12] W. Fanget al., EGFR Exon 20 Insertion Mutations and Response to Osimertinib in Non-small-cell Lung Cancer, BMC Cancer, Vol. 19, No. 1, 2019, pp. 1-9, https://doi.org/10.1186/s12885-019-5820-0.[13] D. T. Hien, P. C. Phuong, Analysis of EGFR Mutations in Paraffin-covered Tissue Samples and some Related Factors from Non-small Cell Lung Cancer Patients Over 60 Years Old, Science and Technology Vietnam, Vol. 62, No. 7, 2020, pp. 1-5[14] S. Hong et al., Concomitant Genetic Alterations with Response to Treatment and Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Patients with EGFR-Mutant Advanced Non–small Cell Lung Cancer, JAMA Oncology, Vol. 4, No. 5, 2018, pp. 739-742, https://doi.org/10.1001/jamaoncol.2018.0049.

Combination of epidermal growth factor receptor mutation and the presence of high-grade patterns is associated with recurrence in resected stage I lung adenocarcinoma.

OBJECTIVESThis study aimed to evaluate the prognostic impact of the combination of epidermal growth factor receptor (EGFR) mutation and the presence of high-grade patterns (solid or micropapillary component) in resected stage I lung adenocarcinoma.METHODSPatients who underwent curative resection for pathological stage I lung adenocarcinoma and EGFR mutation analysis were included in this study. The impact of the combination of EGFR mutation and the presence of >5% high-grade patterns on recurrence-free survival (RFS) was retrospectively analysed using Cox proportional hazards model and propensity score-matched analysis.RESULTSAmong the included 721 patients, EGFR mutations were positive in 380 (52.7%). In the EGFR-mutated group, cases with high-grade patterns showed poorer RFS than those without (5-year RFS, 77.7% vs 92.5%, P < 0.001), whereas there were no significant prognostic differences in the EGFR wild-type group (5-year RFS, 89.8% vs 88.2%, P = 0.807). Multivariable analyses revealed that the combination of EGFR mutations and the presence of high-grade patterns was associated with poor RFS (hazard ratio = 1.655, P = 0.035). Furthermore, EGFR mutation was associated with poor RFS in the group with high-grade patterns (hazard ratio = 2.108, P = 0.008). After propensity score matching, EGFR-mutated cases with high-grade patterns showed poorer RFS (P = 0.028).CONCLUSIONSThe combination of EGFR mutation and the presence of high-grade patterns was associated with recurrence in resected stage I lung adenocarcinoma. Histological subtypes, including minor components, should be considered when evaluating the risk of recurrence in patients with EGFR-mutated lung adenocarcinoma.

Clinical Utility of Plasma Cell-Free DNA EGFR Mutation Analysis in Treatment-Naïve Stage IV Non-Small Cell Lung Cancer Patients.

Background: Plasma cell-free Deoxyribo nucleic acid epidermal growth factor receptor (EGFR) mutation tests are widely used at initial diagnosis and at progression in stage IV non-small cell lung cancer (NSCLC). We analyzed the factors associated with plasma EGFR mutation detection and the effect of plasma EGFR genotyping on the clinical outcomes of the patients with treatment-naïve stage IV NSCLC. Methods: In this retrospective cohort study, we included subjects with treatment-naïve stage IV NSCLC who underwent plasma EGFR genotyping between 2018 and 2020. The presence of plasma EGFR mutation was determined by real-time polymeric chain reaction. Results: The prevalence of EGFR mutation in this cohort was 52.7% (164/311). Among 164 EGFR mutant subjects, 34 (20.7%) were positive for the plasma EGFR mutation assay only. In multivariable analysis, the detection of plasma EGFR mutation was significantly related to higher serum carcinoembryonic antigen levels, never-smoker status, N3 stage, and brain or intrathoracic metastasis. The time to treatment initiation (TTI) of the plasma EGFR mutation-positive group (14 days) was shorter than that of the plasma EGFR mutation-negative group (21 days, p < 0.001). More patients received the 1st line EGFR-TKI in the plasma positive group compared with the tissue positive group. Conclusion: Smoking status and the factors reflecting tumor burden were associated with the detection of plasma EGFR mutation. The plasma EGFR mutation assay can shorten the TTI, and facilitate the 1st line EGFR-TKI therapy for patients with treatment-naïve stage IV NSCLC, especially in the region of high-prevalence of EGFR mutation.

A Hospital-Based Study of EGFR and ALK Mutations in Patients with Lung Adenocarcinoma in Odisha

Background: Patients with advanced non-small cell lung cancer (NSCLC) have considerably benefited from the molecular identification of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) mutations and subsequent targeted therapy against these biomarkers. Few studies have been undertaken in the Indian population on the analysis of both EGFR and ALK mutations in lung adenocarcinoma cases. Aim and Objectives: The aim of this study was to determine the prevalence of EGFR and ALK mutations in lung adenocarcinoma patients, as well as to link mutational status with age, sex, and smoking history. Materials and Methods: This single hospital-based retrospective study was conducted at the Department of Medical Oncology, Acharya Harihar Post Graduate Institute of Cancer, Cuttack, on histologically proven lung adenocarcinoma cases over a duration of two years from 01.08.2019 to 31.07.2021. Results: Out of a total of 164 cases, males comprised 89 (54.26%) of the 164 lung adenocarcinoma cases, while females comprised 75 (45.73%). EGFR mutations were found in 42 (26.75%) of the patients. In 9 cases, the ALK gene rearrangement was also determined to be positive (5.66%). In terms of EGFR and ALK mutations, there was no statistically significant relationship between patient age and gender. (P-value &lt; 0.05). In our research, we found a link between nonsmokers and EGFR and ALK mutations. (P-value &lt;0.05). The deletion of exon 19 (76.19%) was the most prevalent mutation, followed by the exon 21 L858R mutation (14.28%). Conclusion: This study was found to have a significantly higher rate of EGFR and ALK mutation in the Indian population with adenocarcinoma of lung compared to Western populations. To get the maximum benefit from targeted therapies, all patients of adenocarcinoma of the lung should have mutational testing for EGFR and ALK as part of a broad molecular pannel.

Worldwide Prevalence of Epidermal Growth Factor Receptor Mutations in Non-Small Cell Lung Cancer: A Meta-Analysis.

BackgroundIdentification of variable epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer (NSCLC) is important for the selection of appropriate targeted therapies. This meta-analysis was conducted to provide a worldwide overview of EGFR mutation and submutation (specifically exon 19 deletions, exon 21 L858R substitutions, and others) prevalence, and identify important covariates that influence EGFR mutation status in patients with advanced NSCLC to address this clinical data gap.MethodsEmbase® and MEDLINE® in Ovid were searched for studies published between 2004 and 2019 with cohorts of ≥ 50 adults with EGFR mutations, focusing on stage III/IV NSCLC (≤ 20% of patients with stage I/II NSCLC). Linear mixed-effects models were fitted to EGFR mutation endpoints using logistic transformation (logit), assuming a binomial distribution. The model included terms for an intercept reflecting European studies and further additive terms for other continents. EGFR submutations examined were exon 19 deletions, exon 21 L858R substitutions, and others.ResultsOf 3969 abstracts screened, 57 studies were included in the overall EGFR mutation analysis and 74 were included in the submutation analysis relative to the overall EGFR mutation population (Europe, n = 12; Asia, n = 51; North America, n = 5; Central America, n = 1; South America, n = 1; Oceania, n = 1; Global, n = 3). The final overall EGFR mutations model estimated Asian and European prevalence of 49.1% and 12.8%, respectively, and included an additive covariate for the proportion of male patients in a study. There were no significant covariates in the submutation analyses. Most submutations were actionable: exon 19 deletions (49.2% [Asia]; 48.4% [Europe]); exon 21 L858R substitutions (41.1% [Asia]; 29.9% [Europe]).ConclusionsAlthough EGFR mutation prevalence was higher in Asian than Western countries, data support worldwide testing for EGFR overall and submutations to inform appropriate targeted treatment decisions.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40291-021-00563-1.