Suitability of surgical tumor tissues, biopsy, or cytology samples for epidermal growth factor receptor mutation testing in non-small cell lung carcinoma based on chinese population

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

Background

Identification 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.

Methods

Embase^® 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.

Results

Of 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]).

Conclusions

Although 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 Information

The online version contains supplementary material available at 10.1007/s40291-021-00563-1.

High-resolution computed tomography findings independently predict epidermal growth factor receptor mutation status in ground-glass nodular lung adenocarcinoma

BACKGROUND

For lung adenocarcinoma with epidermal growth factor receptor (EGFR) gene mutation, small molecule tyrosine kinase inhibitors are more effective. Some patients could not obtain enough histological specimens for EGFR gene mutation detection. Specific imaging features can predict EGFR mutation status to a certain extent.

AIM

To assess the associations of EGFR mutations with high-resolution computerized tomography (HRCT) features in ground-glass nodular lung adenocarcinoma.

METHODS

This study retrospectively assessed patients with ground-glass nodular lung adenocarcinoma diagnosed between January 2011 and March 2017. EGFR gene mutations in exons 18-21 were detected. The patients were classified into mutant EGFR and wild-type groups, and general data and HRCT image characteristics were assessed.

RESULTS

Among 98 patients, 31 (31.6%) and 67 (68.4%) had mutated and wild-type EGFR in exons 18-21, respectively. Gender, age, smoking history, location of lesions, morphology, edges, borders, pleural indentations, and associations of nodules with bronchus and blood vessels were comparable in both groups (all P > 0.05). Patients with mutant EGFR had larger nodules than those with the wild-type (17.19 ± 6.79 and 14.37 ± 6.30 mm, respectively; P = 0.047). Meanwhile, the vacuole/honeycomb sign was more frequent in the mutant EGFR group (P = 0.011). The logistic regression prediction model included the combination of nodule size and vacuole/honeycomb sign (OR = 1.120, 95%CI: 1.023-1.227, P = 0.014) revealed a sensitivity of 83.9%, a specificity of 52.2% and an AUC of 0.698 (95%CI: 0.589-0.806; P = 0.002).

CONCLUSION

Nodule size and vacuole/honeycomb features could independently predict EGFR mutation status in ground-glass nodular lung adenocarcinoma.

Driver and novel genes correlated with metastasis of non-small cell lung cancer: A comprehensive analysis

Although mutations of genes are crucial events in tumorigenesis and development, the association between gene mutations and lung cancer metastasis is still largely unknown. The goal of this study is to identify driver and novel genes associated with non-small cell lung cancer (NSCLC) metastasis. Candidate genes were identified using a novel comprehensive analysis, which was based on bioinformatics technology and meta-analysis. Firstly, EGFR, KRAS, ALK, TP53, BRAF and PIK3CA were identified as candidate driver genes. Further meta-analysis identified that EGFR (Pooled OR 1.33, 95% CI 1.19, 1.50; P < .001) and ALK (Pooled OR 1.52, 95% CI 1.22, 1.89; P < .001) mutations were associated with distant metastasis of NSCLC. Besides, ALK (Pooled OR 2.40, 95% CI 1.71, 3.38; P < .001) mutation was associated with lymph node metastasis of NSCLC. In addition, thirteen novel gene mutations were identified to be correlated with NSCLC metastasis, including SMARCA1, GGCX, KIF24, LRRK1, LILRA4, OR2T10, EDNRB, NR1H4, ARID4A, PRKCI, PABPC5, ACAN and TLN1. Furthermore, elevated mRNA expression level of SMARCA1 and EDNRB was associated with poor overall survival in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), respectively. Additionally, pathway and protein-protein interactions network analyses found the two genes were correlated with epithelial-mesenchymal transition process. In conclusion, mutations of EGFR and ALK were significantly correlated with NSCLC metastasis. In addition, thirteen novel genes were identified to be associated with NSCLC metastasis, especially SMARCA1 in LUAD and EDNRB in LUSC.

The expression of circulating miR-504 in plasma is associated with EGFR mutation status in non-small-cell lung carcinoma patients

MicroRNAs (miRNAs), key regulators of gene expression at the post-transcriptional level, are grossly misregulated in some human cancers, including non-small-cell lung carcinoma (NSCLC). The aberrant expression of specific miRNAs results in the abnormal regulation of key components of signalling pathways in tumour cells. MiRNA levels and the activity of the gene targets, including oncogenes and tumour suppressors, produce feedback that changes miRNA expression levels and indicates the cell's genetic activity. In this study, we measured the expression of five circulating miRNAs (miR-195, miR-504, miR-122, miR-10b and miR-21) and evaluated their association with EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) mutation status in 66 NSCLC patients. Moreover, we examined the discriminative power of circulating miRNAs for EGFR mutant-positive and -negative NSCLC patients using two different data normalisation approaches. We extracted total RNA from the plasma of 66 non-squamous NSCLC patients (31 of whom had tumours with EGFR mutations) and measured circulating miRNA levels using quantitative reverse transcription polymerase chain reaction (RT-qPCR). The miRNA expression levels were normalised using two endogenous controls: miR-191 and miR-16. We found significant associations between the expression of circulating miR-504 and EGFR-activating mutations in NSCLC patients regardless of the normalisation approach used (p = 0.0072 and 0.0236 for miR-16 and miR-191 normalisation, respectively). The greatest discriminative power of circulating miR-504 was observed in patients with EGFR exon 19 deletions versus wild-type EGFR normalised to miR-191 (area under the curve (AUC) = 0.81, p < 0.0001). Interestingly, circulating miR-504 levels were significantly reduced in the v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutated subgroup compared to EGFR-mutated patients (p < 0.0030) and those with EGFR/KRAS wild-type tumours (p < 0.0359). Our study demonstrated the feasibility and potential diagnostic value of plasma miR-504 expression analysis to distinguish between EGFR-mutated and wild-type NSCLC patients. However, quality control and normalisation strategies are very important and have a major impact on the outcomes of circulating miRNA analyses.

[Relationship between EGFR Mutations and Pathological Classification and Specimen of Lung Adenocarcinoma]

背景与目的

随着基因突变技术及靶向药物治疗如火如荼的开展，对肺腺癌的精准治疗越来越受到关注，目前肺腺癌中研究最多的是表皮生长因子受体（epidermal growth factor receptor, EGFR）。对于EGFR突变和病理分型的关系在不同标本中是否一致，目前不甚明了。本研究比较肺腺癌活检标本和手术切除标本中EGFR基因突变与病理分型的关系是否一致，探讨EGFR基因突变与肺腺癌病理分型的关系以及标本类型对EGFR基因检测的影响。

方法

收集肺腺癌手术切除标本（楔形肺切除、肺叶切除标本）163例，肺腺癌活检[粘膜活检、肺穿刺、支气管内超声引导针吸活检术（endobronchial ultrasound-guided transbronchial needle aspiration, EBUS-TBNA）标本]173例，按照2015年世界卫生组织（World Health Organization, WHO）肺腺癌分型标准对其主要组织学分型确认（贴壁型、腺泡型、乳头型、微乳头型、实体型），行EGFR基因检测[基因测序法及突变扩增阻滞系统（amplification refractory mutation system, ARMS）]。分别对活检标本和手术切除标本进行统计。

结果

163例的肺腺癌手术切除标本中，102例EGFR基因突变，突变率为62.58%，173例的活检标本中，114例EGFR基因突变，突变率为65.9%。两组标本中EGFR突变率没有统计学差异（P > 0.05）。两组标本中女性的EGFR突变率均明显高于男性（P < 0.05）。手术切除标本中60岁以上患者的EGFR突变率明显低于60岁以下（P < 0.05），而活检标本中EGFR突变与年龄无关（P > 0.05）。在EGFR突变的两组标本中病理分型构成比不同（χ²=8.040, P < 0.05）。手术切除标本肺腺癌中EGFR突变的102例中，腺泡型占54.9%（56例），贴壁型占23.53%（24例），乳头型占17.65%（18例），实体型占3.9%（4例），其中腺泡型所占比例最高，其次是贴壁型和乳头型，实体型则比例最少。19、21外显子单独突变最多，21外显子突变在贴壁型较其他两型高（P < 0.05），19外显子突变在乳头型较贴壁型高（P < 0.05）。腺泡型和乳头型比较，19、21外显子突变无统计学意义。活检标本肺腺癌中EGFR突变的114例中腺泡型占48.25%（55例），贴壁型占26.32%（30例），乳头型占11.4%（13例），微乳头型占4.39%（5例），实体型占9.65%（11例）。腺泡型所占比例最高，其次是贴壁型，乳头状、微乳头状和实体型最少。同样是19、21外显子单独突变最多，但不同病理分型中，19、21外显子突变均无显著差异（P > 0.05）。

结论

肺腺癌中手术切除标本和活检标本EGFR突变率没有差异，且突变与性别有关，均为女性突变率高于男性。手术切除标本中EGFR突变与年龄有关，年龄越大突变率越低，而在活检标本中则与年龄无关。两组标本的病理分型构成比不同。19、21外显子单独突变最多。手术切除标本中EGFR突变类型与主要病理分型有关，21外显子单独突变中贴壁型最多，19外显子单独突变中乳头型最多。EGFR突变活检标本中，19、21外显子单独突变与主要病理分型无明显相关。

Analysis of EGFR mutation status in tissue and plasma for predicting response to EGFR-TKIs in advanced non-small-cell lung cancer

The detection of mutations in the epidermal growth factor receptor (EGFR) gene in tumor tissues has been established as the gold standard for predicting the efficacy of treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKIs) in advanced non-small-cell lung cancer (NSCLC). The current study aimed to investigate whether the presence of co-existing EGFR mutations in tumor tissue and in cell-free tumor DNA (ctDNA) in the plasma predicts a more favorable outcome of EGFR-TKI treatment in advanced NSCLC. A total of 287 NSCLC patients who had undergone EGFR-TKI treatment were enrolled and stratified into four subgroups: Wild-type EGFR in plasma and tissue specimens (B-/T-); mutated EGFR in plasma and tissue specimens (B+/T+); mutated EGFR in only in plasma samples (B+/T-); or mutated EGFR in only tissue specimens (B-/T+). EGFR mutations were tested using denaturing high-performance liquid chromatography and confirmed by amplification-refractory mutation system analysis. Of the 287 patients, 101 had mutations in both tissue and plasma samples and 103 had mutation in either tissue (n=65) or plasma (n=38). The median progression-free survival (mPFS) times were 9.2 and 2.0 months in the B+/T+ and B-/T- groups, respectively. The mPFS times were 7.9 months in the B-/T+ group and 11.9 months in the B+/T-group (P=0.001). Among the 187 patients with available pre-EGFR-TKI plasma samples, 70 received first-line EGFR-TKI treatment, and the mPFS in the B+/T+ group was longer than in the B-/T+ or B+/T- groups (18.8 vs. 9.4 vs. 6.9 months; P=0.003). In second-line setting of EGFR-TKI therapy, the groups of patients with EGFR mutation in ctDNA, regardless of the mutation status in the tissues, exhibited longer mPFS times compared with the B-/T+ group (10.0 vs. 5.8 months; P=0.044). The results suggest that co-existence of EGFR mutations in tissue and ctDNA predict longer PFS times for NSCLC patients who receive first-line EGFR-TKI therapy. In addition, real-time detection in ctDNA is an excellent predictor for the efficacy of second- or higher line EGFR-TKI therapy.

High-fidelity of non-small cell lung cancer xenograft models derived from bronchoscopy-guided biopsies

BACKGROUND

At present, there are two main types of lung cancer xenograft models: those derived from stable cell lines, and patient-derived xenograft models established by surgically resected tissues. However, these animal models may not reflect the biological and genetic characteristics of advanced non-small cell lung cancer (NSCLC). We utilized bronchoscopy-guided biopsy tissues of NSCLC patients to establish xenograft models and analyzed their histopathologic and genotypic fidelity with parental tumors.

METHODS

Tumor tissues of NSCLC patients taken via bronchoscope were subcutaneously implanted into mice with non-obese diabetic-severe combined immunodeficiency disease for model establishment and serial passage. The histopathology and genotype of the samples from bronchoscopy-guided biopsy-derived xenograft (BDX) models and their parental tumors were detected.

RESULTS

Thirty BDXs out of 114 NSCLC patients (26.32%) were successfully established. Smoking status significantly affected the success rate of NSCLC BDX establishment (P = 0.010). The BDX establishment success rate in squamous cell cancer was higher than in adenocarcinoma, with no significant difference (32.00% vs. 16.21%, P = 0.112). However, the growth rate of passage 1 BDX was slower than that of passages 2 and 3. Almost all NSCLC BDXs maintained similarity to their parental tumor tissues in regard to histologic characteristics, pathological markers, and driver-gene mutations. Only one BDX model lost the epidermal growth factor receptor mutation contained in tumor parental tissue, as a result of heterogeneity.

CONCLUSIONS

NSCLC BDXs maintained high fidelity of histopathology and genotype with their original tumors. NSCLC BDXs that possess the actual status of advanced lung carcinoma should be used in preclinical research.

Epidermal growth factor receptor mutation analysis in cytological specimens and responsiveness to gefitinib in advanced non-small cell lung cancer patients

BACKGROUND

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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.