Liquid biopsy and tissue biopsy for the detection of EGFR mutations in patients with stage III non-small-cell lung cancer: an observational real-world study

BackgroundNon-surgical cytological specimens are adequate not only for accurate histological subtyping but also for molecular profiling. A modified amplification refractory mutation system polymerase chain reaction (ARMS PCR), known as SuperARMS PCR, was improved by optimizing the primers designation, which provides a higher sensitivity and specificity approach for free plasma DNA detection. It is unclear whether SuperARMS PCR detects epidermal growth factor receptor (EGFR) mutations in cytology samples. The aim of this study was to compare the EGFR mutations detected by ARMS PCR and SuperARMS PCR in cytology samples derived from advanced non-small cell lung cancer (NSCLC) patients.MethodsFrom March 2016 to March 2018, a total of 234 cytological samples were obtained from primary or metastatic lesions of NSCLC, including 144 fine-needle aspirations (FNAs), 36 endobroncheal ultrasonography (EBUS) FNAs, 36 transbronchial needle aspirations (TBNAs) and 18 pleural effusion (PLEs). EGFR mutations were simultaneously detected using an ADx-ARMS EGFR kit (Amoy Diagnostics CO., ltd., Xiamen, China) and an ADx-SuperARMS EGFR kit (Amoy Diagnostics CO., ltd., Xiamen, China). Digital droplet PCR (ddPCR) and next-generation sequencing (NGS) were further used to verify the EGFR mutant inconsistent samples.ResultsAll of the 234 patients with advanced or recurrent NSCLC were diagnosed and assessed by two cytopathologists, and their EGFR mutation statuses were successfully detected by ARMS and SuperARMS. Importantly, the SuperARMS and ARMS methods showed a highly concordant result of 94.0% (220/234) (95%CI: 85.0, 95.0%). The positive rate of the SuperARMS was higher than the ARMS in the cytology samples for EGFR detection (46.2% vs. 40.2%). The specific EGFR mutation sites in 16 samples (6.8%) were not completely consistent between the SuperARMS and ARMS. A total of 14 patients showed EGFR mutations when detected by SuperARMS, but by ARMS there were EGFR wild-type. Two patients were detected as having one more EGFR mutation site by SuperARMS than by ARMS. ddPCR and NGS were used to further confirm the EGFR mutations in these inconsistent samples. Eight samples had the same mutation results as the SuperARMS, and 6 samples were not verified because the remaining DNA was insufficient. A total of 78 EGFR mutation patients received Tyrosine Kinase Inhibitor (TKI) treatment. The overall objective response rate (ORR) was 88.5% (69/78) for EGFR TKI treatment.ConclusionSuperARMS showed a high sensitivity and specificity for EGFR detection and thus, is expected to become a routine test in the clinic to be used as a widely available, easy-to-operate and sensitive method for EGFR mutation detection in liquid-based cytology samples.

The validity of epidermal growth factor receptor (EGFR) mutation in serum and plasma DNA as a surrogate of tumor tissue has been comprehensively explored. However, the concordance between peripheral blood and tumor tissue samples in EGFR mutation detection remains variable. The question as to whether real-time samples for EGFR mutation analysis are required before epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy remains unanswered. This study included two cohorts:(i) 822 non-small cell lung cancer (NSCLC) patients with primary tumor tissue and matched plasma samples at initial diagnosis; and (ii) 207 patients with advanced NSCLC who had plasma samples taken immediately before EGFR-TKI therapy, in which 157 cases had matched tumor tissues. Denaturing High-Performance Liquid Chromatography (DHPLC) determined EGFR mutation status. Among a total of 822 patients with matched samples, the EGFR mutation rates were 36.3% and 32.1% in tissue and plasma samples, respectively. Concordance of EGFR mutation between two kinds of samples was 77.0% (631/822),with 63.5% (188/296) of accuracy of EGFR mutation in plasma DNA. In 207 advanced NSCLC patients who had plasma samples taken immediately before EGFR-TKI therapy, the objective response rate (ORR) after EGFR-TKI therapy was significantly higher in EGFR mutant patients than those in EGFR wild-type patients (51.4% vs. 22.6%, P < 0.001), regardless of the treatment lines of EGFR-TKI. In patients with two or more lines of EGFR-TKI therapy, EGFR mutation status in plasma samples, but not in tissues, was a predictor for progression-free survival (PFS) after EGFR-TKI therapy (mutant vs. wild-type: 10.1 months vs. 3.7 months, P = 0.038). An EGFR mutation test using plasma DNA samples was validated and reproducible. Obtaining real-time samples for EGFR mutation detection is critical in order to predict the outcomes of EGFR-TKI.

Much evidence has accumulated that the epidermal growth factor receptor (EGFR) and its family members are strongly implicated in the development and progression of lung cancers. Somatic mutations of the EGFR gene were found in about 25-40% of Japanese lung cancer patients. More recently, erbB2 mutations are found in about 4% of European-derived lung cancer patients. We have investigated EGFR and erbB2 mutation status in 95 surgically treated nonsmall cell lung cancer (NSCLC) cases from Nagoya City University Hospital. Seventy-five adenocarcinoma cases were included. The presence or absence of EGFR and ernB2 mutations of kinase domains were analyzed by reverse transcription polymerase chain reaction (RT-PCR) amplifications and direct sequences. We have also investigated erbB2 mutation status in 27 surgically treated NSCLC cases followed by treatment with gefitinib from Kinki-chuo Chest Medical Center. EGFR mutations (CTG-->CGG; L858R) were found from 14 of 95 lung cancer patients. We also detected the deletion 1a-type mutations from 9 patients and deletion 4-type mutations from 6 patients in exon 19. In exon 20, 4 mutations including 2 novel mutations were found. Total EGFR mutations were present in 35 patients (36.8%). These mutation statuses were significantly correlated with gender (women 73.3% vs. men 20%, p < 0.0001), smoking status (never smoker 69.4% vs. smoker 16.9%, p < 0.0001), pathologic subtypes (adenocarcinoma 45.1% vs. nonadenocarcinoma 12.5%, p = 0.0089) and differentiation status of the lung cancers (well 51% vs. moderately or poorly 18.4%, p = 0.0021). On the other hand, erbB2 mutation was only found from 1 of 95 patients, at exon 20. This patient was female and a never smoker with adenocarcinoma. This 12 nucleotide insertion mutation (2324-2325 ins ATACGTGATGGC) was located in the exon 20 at kinase domain (775-776 ins YVMA). There was no erbB2 mutation in 27 gefitinib-treated NSCLC patients. In total, we have found only 1 erbB2 mutation from 122 (0.8%) Japanese NSCLC patients. There was a significantly higher erbB2 positive (2+/3+) ratio in EGFR mutant patients (13/25, 52.0%) compared to EGFR wild-type patients (10/62, 16.1%; p = 0.0247). The NSCLC specimen with erbB2 mutation showed 1+ immunoreactivity. The EGFR mutation status might correlate with the clinicopathologic features related to good response to gefitinib, such as gender, smoking history and pathologic subtypes of lung cancers. However, erbB2 mutation is rare from Japanese lung cancer and is of limited value for molecular target therapy.

10527 Background: Epidermal growth factor receptor (EGFR) mutation or anaplastic lymphoma kinase (ALK) rearrangement was found not only predict the efficacy of targeted drugs, but also associate with the efficacy of chemotherapy drugs in non-small cell lung cancer (NSCLC) patients. We investigated the relationship of EGFR mutation status or ALK rearrangement and DNA repair or synthesis genes, such as excision repair cross-complementing 1 (ERCC1), ribonucleotide reductase subunit M1 (RRM1), thymidylate synthetase (TS) and breast cancer gene one (BRCA1) gene expression, as a potential explanation for these observations. Methods: In this surgical series, 104 resected lung adenocarcinomas from nonsmoker females were analyzed concurrently for the EGFR mutation, ALK rearrangement status and mRNA expression of ERCC1, RRM1, TS and BRCA1 genes. EGFR mutation detection was performed by the method of ADx-ARMS, ALK rearrangement was detected by PCR and the mRNA expression of different genes were tested using the method of real-time PCR. Results: 73 (70.2%) patients harbored EGFR mutations and 10 (9.6%) had ALK rearrangement. The ERCC1 mRNA level in patients with EGFR mutation was 3.44±1.94×10-3 , which is significantly lower than in the patients with ALK positive and both negative(4.60±1.95×10-3 and 4.95±2.33×10-3 respectively, P=0.010). While the TS mRNA levels were significantly lower in the patients with EGFR mutation(1.15±1.38×10-3 VS 2.69±3.97×10-3, P=0.006) or ALK positive (1.21±0.78×10-3VS 2.69±3.97×10-3, P=0.020) than in patients with both negative. Conclusions: NSCLC specimens harboring activating EGFR mutations are more likely to express low ERCC1 and TS mRNA levels, while NSCLC patients with ALK rearrangement are more likely to express low TS mRNA levels, which could be helpful to select a proper chemotherapy regimen for NSCLC patients with known EGFR mutation or ALK fusion status.

BackgroundThis study aimed to determine the effectiveness of liquid biopsy in detecting epidermal growth factor receptor (EGFR) mutations at diagnosis, disease progression, and intermediate stages.MethodsThis prospective, multicenter, observational study included 30 patients with non-small cell lung cancer treated with afatinib, harboring a major EGFR mutation confirmed by tumor tissue biopsy. We collected blood samples for liquid biopsy at diagnosis, intermediate stage, and progressive disease. Tissue and liquid biopsies were examined using Cobas ® EGFR Mutation Test v2.ResultsLiquid biopsy detected EGFR mutations in 63.6% of the patients at diagnosis. The presence of metastasis in the extrathoracic, brain, and adrenal glands correlated positively with the detection of EGFR mutations. Patients with positive EGFR mutations at diagnosis had significantly shorter overall and progression-free survival than patients with negative EGFR mutations. Four of the 18 patients (22.2%) who reached progressive disease had positive EGFR T790M mutations. Three of 10 patients (30.0%) with progressive disease were positive and negative for T790M using tumor re-biopsy and liquid biopsy, respectively. The results of EGFR mutation by tissue re-biopsy were the same as those of liquid biopsy in the three patients who were positive for significant EGFR mutations but negative for the T790M mutation using liquid biopsy at progressing disease. Only two patients were positive for major EGFR mutations at intermediate levels.ConclusionsLiquid biopsy can be a prognostic factor in EGFR-tyrosine kinase inhibitor treatments at diagnosis. Tumor re-biopsy can be omitted in patients with positive EGFR mutations by liquid biopsy at PD.

Commentary: Another win for immunotherapy

Background. Although epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are effective in patients with nonsmall cell lung cancer with epidermal growth factor receptor (EGFR) mutation, EGFR-TKIs have a risk of inducing fatal interstitial lung disease (ILD). The selection of chemotherapy based on the EGFR mutation status is recommended, however, the frequency of EGFR mutation in patients with ILD and the efficacy and safety of EGFR-TKI in patients with ILD and EGFR mutation are unknown. Methods. We retrospectively reviewed the association of the EGFR mutation status of nonsmall cell lung cancer and pulmonary diseases. Based on high-resolution computed tomography (HRCT) performed at diagnosis of lung cancer, patients were categorized into three groups: normal, emphysema, and fibrosis. Results. Of 198 patients with nonsmall cell lung cancer, we identified 52 (26.3%) patients with an EGFR mutation. EGFR mutations were identified in 43 (35.2%) of 122 patients with normal lungs, 8 (13.6%) of 59 with emphysema, and 1 (5.9%) of 17 with pulmonary fibrosis. Of the 52 patients with EGFR mutation, 43 patients received gefitinib. One patient with an EGFR mutation and fibrosis developed fatal ILD. There was not a significant difference in median overall survival from gefitinib treatment between never-smokers and smokers (797 days versus not reached; P = 0.96). Conclusions. Patients with sensitive EGFR mutation and normal lungs may benefit from an EGFR-TKI treatment even if they have smoking history.

Epidermal growth factor receptor (EGFR) mutation is the key predictor of EGFR tyrosine kinase inhibitors (TKIs) efficacy in non-small cell lung cancer (NSCLC). We conducted this study to verify the feasibility of EGFR mutation analysis in cytological specimens and investigate the responsiveness to gefitinib treatment in patients carrying EGFR mutations. A total of 210 cytological specimens were collected for EGFR mutation detection by both direct sequencing and amplification refractory mutation system (ARMS). We analyzed EGFR mutation status by both methods and evaluated the responsiveness to gefitinib treatment in patients harboring EGFR mutations by overall response rate (ORR), disease control rate (DCR) and progression free survival (PFS). Of all patients, EGFR mutation rate was 28.6% (60/210) by direct sequencing and 45.2% (95/210) by ARMS (P<0.001) respectively. Among the EGFR wild type patients tested by direct sequencing, 26.7% of them were positive by ARMS. For the 72 EGFR mutation positive patients treated with gefitinib, the ORR, DCR and median PFS were 69.4%, 90.2% and 9.3 months respectively. The patients whose EGFR mutation status was negative by direct sequencing but positive by ARMS had lower ORR (48.0% vs. 80.9%, P=0.004) and shorter median PFS (7.4 vs. 10.5 months, P=0.009) as compared with that of EGFR mutation positive patients by both detection methods. Our study verified the feasibility of EGFR analysis in cytological specimens in advanced NSCLC. ARMS is more sensitive than direct sequencing in EGFR mutation detection. EGFR Mutation status tested on cytological samples is applicable for predicting the response to gefitinib. Abundance of EGFR mutations might have an influence on TKIs efficacy.

7034 Background: Epidermal growth factor receptor (EGFR) mutation is reported to be associated with radiosensitivity of non-small cell lung cancer (NSCLC) in vitro. The aim of this study is to analyze the association of clinical outcome to neoadjuvant concurrent chemoradiotherapy (CCRT) with EGFR mutation status in N2(+) NSCLC patients. Methods: We retrospectively identified 161 patients with mediastinoscopy-proven N2(+) NSCLC who were treated with platinum-based neoadjuvant concurrent chemoradiotherapy at Samsung Medical Center between 1998 and 2006. In 98 patients with remaining tumor tissue, EGFR mutation was assessed by both peptide nucleic acid (PNA)-mediated PCR clamping method and sequencing simultaneously. 88 patients were finally included in analysis, excluding 4 patients with indeterminate EGFR mutation results and 6 patients who didn’t proceed to operation by reason of other than disease progression. Results: Among 88 patients, EGFR mutation (exon 19 deletions or L858R) was detected in 13 patients (14.8%), and KRAS mutation in 2 patients (2.3%). After neoadjuvant concurrent chemotherapy, 5 patients showed progressive disease, pathologic downstaging of lymph nodes (LN) to N0 or N1 was achieved in 44 patients (50%), and pathologic CR in 13 patients (14.8%). Achievement of pathologic CR or pathologic downstaging of LNs were not associated with EGFR mutation status. With a median follow-up of 73.8 months, there were no significant difference in overall survival or progession free survival between EGFR mutation and negative patients (28.2 months vs 33.6 months, p=0.125; 15.2 months vs. 18.0 months, p=0.631), respectively. Conclusions: In N2-positive NSCLC patient, EGFR mutation didn’t show any significant clinical benefit to neoadjuvant CCRT in terms of response rate, PFS or OS. Further study should be needed to confirm and elucidate the association between EGFR mutation status and radiosensitivity in NSCLC patients.

INTRODUCTION: Epidermal growth factor receptor (EGFR) mutations are a strong determinant factor of response to EGFR tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC). Now some methods have been used to detect EGFR mutations and they have approximately the same sensitivity and specificity. In a case, we experienced unmatched results from two methods of detecting EGFR mutations. In this study, we compared data from three methods of detecting mutations. METHODS: We obtained 30 samples of operation, transbronchial lung biopsy, bronchoscopic brushing, pleural effusion and lymph nodes from NSCLC patients. EGFR mutation status was determined by two or three methods (mutant-enriched PCR method, PNA-LNA PCR Clamp method and PCR invader method). RESULTS:method (n=31)mutation positive2 method (n=20)m.e./Clamp (n=10)4/4 m.e./invader (n=2)1/0 Clamp/invader (n=8)4/33 method (n=10)m.e./Clamp/invader (n=10)3/2/3m.e.: mutant-enriched PCR, Clamp: PNA-LNA PCR Clamp, invader: PCR invader EGFR mutations were detected in 12 samples. Mutation statuses of two or three methods were matched in 9 samples, but 3 samples were unmatched. CONCLUSIONS: EGFR mutation statuses were unmatched in same samples. EGFR gene status is essential information for NSCLC patients. We need to take false negative into consideration in the clinical setting and need father deliberation about detecting methods of EGFR mutations. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2110.

BackgroundThe purpose of this research was to investigate the relationship between epidermal growth factor receptor (EGFR) mutations and the response to first-line chemotherapy in patients with advanced non-small cell lung cancer (NSCLC).MethodsA total of 266 patients with stage IIIB or IV NSCLC who received platinum-based doublet therapies as first-line chemotherapy were investigated retrospectively, and their clinical data were assessed according to EGFR mutation.ResultsEGFR mutations were identified in 45.5% of patients. There was no significant difference in response rate between EGFR mutation carriers and EGFR wild-type carriers (P=0.484). Among the patients with Kirsten rat sarcoma viral oncogene homolog (KRAS) wild-type, however, those with EGFR mutations responded better to treatment than EGFR wild-type patients (46.2% versus 20.8%, P=0.043). The disease control rate associated with pemetrexed-based treatments was higher than for vinorelbine-based therapies in EGFR mutation patients (P=0.001). EGFR mutation was found in patients with longer progression-free survival and median survival time, and improved 1-year and 2-year overall survival when compared with EGFR wild-type patients (6.1 versus 5.0 months, P=0.004; 18.9 versus 13.8 months, P=0.001; 81.0% versus 63.4%, P=0.002; and 33.9% versus 22.8% P=0.044, respectively). Patients with the EGFR exon 19 mutation had longer progression-free survival than those with EGFR exon 21 mutation (P=0.007). Multivariate analysis showed that the response to first-line chemotherapy and the presence of EGFR mutations were independent prognostic factors in patients with advanced NSCLC.ConclusionOur data showed that the presence of EGFR mutations meant longer survival times for patients with advanced NSCLC who received platinum-based doublet first-line chemotherapy, especially in those with the exon 19 deletion mutation. Among KRAS wild-type patients, those with EGFR mutation responded better to first-line chemotherapy than EGFR wild-type patients.

Epidermal growth factor receptor (EGFR) mutations are potential markers driving carcinogenesis, and may alter the response to EGFR tyrosine kinase inhibitors in patients with non-small cell lung cancer (NSCLC). The frequency of EGFR mutations in patients with NSCLC differs according to sex, smoking habits and regional-based ethnicity differences. The aim of the present study was to determine the frequency of EGFR mutations in Turkish patients with NSCLC to highlight the importance of regional differences, and their associations with patient characteristics. Genomic DNA was extracted from formalin-fixed and paraffin-embedded tumor tissue sections of 409 NSCLC patients. The most common EGFR mutations in exons 18, 19, 20 and 21 were detected using BioFilmChip-based microarray assay. The overall EGFR mutation frequency was 16.6%, and the highest mutation frequencies were observed in exon 19 (6.4%) and exon 21 (7.3%). There was a higher frequency of EGFR mutations in females compared with males and in never-smokers compared with smokers (both P≤0.05). These results were similar to other European population-based studies, but not consistent Middle-Eastern based studies. The present study may contribute to understanding the gradient frequency of EGFR mutation across different ethnicities, and in designing genome wide-based collaborations that may reveal novel decision making and susceptibility mutations in EGFR in patients with NSCLC.

Simple SummaryThe present study showed the comprehensive analysis of disease characteristics and treatment patterns in uncommon EGFR mutation-positive NSCLC at a major cancer center. This study showed the efficacy of 1G or 2G EGFR-TKIs as the 1L treatment, and subsequent therapy including 3G EGFR-TKIs in the real-world setting.Approximately 10% of the epidermal growth factor receptor (EGFR) mutations in non-small-cell lung cancer (NSCLC) are uncommon EGFR mutations. Although the efficacy of second (2G) or third generation (3G) EGFR tyrosine kinase inhibitors (EGFR-TKIs) in the patients with uncommon EGFR mutation has been proven, further studies are warranted to define the optimal treatment approach for uncommon EGFR mutation-positive NSCLC. This study retrospectively investigated the treatment patterns and outcomes of patients with uncommon EGFR mutation-positive NSCLC from January 2011 to December 2019 at the Samsung Medical Center, Seoul, Korea. During the study, 2121 patients with EGFR mutation-positive NSCLC received first-generation (1G, gefitinib or erlotinib) or 2G EGFR-TKI (afatinib) as the first-line (1L) systemic therapy. Of this, 135 (6.4%) patients harbored uncommon EGFR mutations. Of 135, 54 (40%, 54/135) patients had overlapping mutations with major EGFR mutations. The objective response rate (ORR) for the 1L EGFR-TKI was 63.3%. The median progression-free survivals (PFSs) were 8.6 months (95% CI: 3.8–13.5), 11.7 months (95% CI: 6.6–16.7), 7.7 months (95% CI: 4.9–17.4), and 5.0 months (95% CI: 3.7–6.1) for major uncommon EGFR mutation (G719X, L861Q), compound mutation with major EGFR mutation (Del 19 or EGFR exon 21 p.L858R), other compound mutation, and other uncommon mutations, respectively. The median overall survivals (OSs) were 25.6 months (16.9–34.2), 28.8 (95% CI: 24.4–33.4), 13.5 months (95% CI: 7.4–27.8), and 9.4 months (95% CI: 3.4–10.5) for major uncommon EGFR mutation (G719X), compound mutation with major EGFR mutation (Del 19 or EGFR exon 21 p.L858R), other compound mutation, and other uncommon mutations, respectively. The response rate, median PFS, and OS were 63.3%, 16.3 months (95% CI: 15.6–16.9), and 37.5 months (95% CI: 35.4–39.6) for common EGFR mutation-positive NSCLC. After failing 1L EGFR-TKI, repeated tissue or liquid biopsy were carried out on 44.9% (35/78) of patients with T790M detected in 10/35 (28.6%) patients. With subsequent 3G EGFR-TKI after failing the first-line EGFR-TKI, the ORR and PFS for 3G EGFR-TKI were 80% and 8.9 months (95% CI: 8.0–9.8). These patients showed a median OS of 34.6 months (95% CI: 29.8–39.4). The ORR, PFS and OS were poorer in patients with uncommon (especially other compound and other uncommon mutation) than those with common EGFR mutations. T790M was detected in 28.6% of the uncommon EGFR mutation-positive patients for whom prior 1G/2G EGFR-TKIs failed and underwent repeat biopsy at the time of progression.

The Diagnostic Accuracy of Liquid Biopsy in EGFR-Mutated NSCLC: A Systematic Review and Meta-Analysis of 40 Studies.

JCES01.04 Liquid Biopsy in Monitoring Dynamic Changes of Driver Genes in Advanced NSCLC