Use of thyroid transcription factor 1 and napsin A to predict local failure and survival after Gamma Knife radiosurgery in patients with brain metastases from lung adenocarcinoma

OBJECTIVE

Stereotactic radiosurgery (SRS), combined with contemporary targeted therapies and immunotherapies, has improved the overall survival of patients with lung adenocarcinoma (ADC). Given that histological subtypes reflect prognosis in patients with primary ADC, it is important to integrate pathological biomarkers to predict clinical outcomes after SRS in patients with brain metastases from lung ADC. Therefore, the authors investigated the prognostic relevance of various biomarkers of primary lung ADC for clinical outcomes after SRS.

METHODS

A total of 95 patients with 136 brain metastases (1-4 oligometastases) who were treated with Gamma Knife radiosurgery between January 2017 and December 2020 were included. The Kaplan-Meier method and univariate and multivariate analyses using Cox proportional hazard regression models were used to identify prognostic factors for local control, survival, and distant brain control.

RESULTS

Multivariate analysis revealed thyroid transcription factor 1 as an independent prognostic factor for local control (HR 0.098, 95% CI 0.014-0.698, p = 0.0203) and napsin A as a significant predictor of overall survival after SRS (HR 0.080, 95% CI 0.017-0.386, p < 0.01). In a subset analysis of epidermal growth factor receptor (EGFR) mutation, patients with EGFR exon 19 mutations showed better distant brain control than those with EGFR exon 21 mutations (p < 0.01).

CONCLUSIONS

Pathological biomarkers of primary cancer should be considered to predict clinical outcomes after SRS in patients with lung ADC. Use of such biomarkers may help to provide personalized treatment to each patient, improving clinical outcomes after SRS.

Osimertinib and anti-HER3 combination therapy engages immune dependent tumor toxicity via STING activation in trans

Over the past decade, immunotherapy delivered novel treatments for many cancer types. However, lung cancer still leads cancer mortality, and non-small-cell lung carcinoma patients with mutant EGFR cannot benefit from checkpoint inhibitors due to toxicity, relying only on palliative chemotherapy and the third-generation tyrosine kinase inhibitor (TKI) osimertinib. This new drug extends lifespan by 9-months vs. second-generation TKIs, but unfortunately, cancers relapse due to resistance mechanisms and the lack of antitumor immune responses. Here we explored the combination of osimertinib with anti-HER3 monoclonal antibodies and observed that the immune system contributed to eliminate tumor cells in mice and co-culture experiments using bone marrow-derived macrophages and human PBMCs. Osimertinib led to apoptosis of tumors but simultaneously, it triggered inositol-requiring-enzyme (IRE1α)-dependent HER3 upregulation, increased macrophage infiltration, and activated cGAS in cancer cells to produce cGAMP (detected by a lentivirally transduced STING activity biosensor), transactivating STING in macrophages. We sought to target osimertinib-induced HER3 upregulation with monoclonal antibodies, which engaged Fc receptor-dependent tumor elimination by macrophages, and STING agonists enhanced macrophage-mediated tumor elimination further. Thus, by engaging a tumor non-autonomous mechanism involving cGAS-STING and innate immunity, the combination of osimertinib and anti-HER3 antibodies could improve the limited therapeutic and stratification options for advanced stage lung cancer patients with mutant EGFR.

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 Frequency of Epidermal Growth Factor Receptor (EGFR) mutations in Iraqi patients with Non-Small Cell Lung Cancer (NSCLC)

Objective:

Non-Small Cell Lung Cancer (NSCLC) Carcinogenesis could be caused by numerous genetic mutations, one of the most common is the mutation in the Epidermal Growth Factor Receptor (EGFR) which was used in the advanced stages of the disease as a therapeutic goal. This study aims to estimate the frequency of Epidermal Growth Factor Receptor mutations in Iraqi patients with Non-Small Cell Lung Cancer.

Methods:

One hundred thirty-eight patients confirmed with NSCLC have participated in this study, patients were sent for EGFR testing by different oncology centers in Iraq. Data and samples were collected. The Mutation was detected using COBAS^® DNA Sample Preparation Kit that designed to detect the following mutations: Exon 19: deletions and complex mutations; Exon 21: L861Q and L858R; Exon 18 mutation: G719X (G719A, G719C, and G719S); Exon 20: S768I, T790M, and insertions, this kit utilizes the technology of the real time Polymerase Chain Reaction.

Results:

This study was included 79 males and 59 females, with a mean age of 60.1±12.4 years. A positive EGFR mutations were found in 38 (27.53%) of samples. Exon 19 deletions (25/38, 65.8%) and substitution L858R in exon 21 10/38 (26.3%) were the most common mutations. Multiple mutations (Exon 20 and 19 combined together) were founded in 2/38 (5.3%), and 1/38 (2.6%) ALK mutation. Non-significant differences among age groups and gender in the incidence of mutations were found.

Conclusion:

The current study represents the first epidemiological study in Iraq to find EGFR mutations frequency among NSCLC patients that reveals the incidence rate of 27.53%, which is between the higher prevalence rate in Asian populations and lower rates in western countries. These results explain the genetic differences of NSCLC in the world due to ethnic differences of the population, more studies are needed in Arab countries to study the EGFR mutations, find the effect of ethnicity and environmental factors for lung cancer, and the subsequent therapy.

EGFR mutations are significantly associated with visceral pleural invasion development in non-small-cell lung cancer patients

OBJECTIVES

A retrospective study was performed to investigate the association between EGFR mutations and visceral pleural invasion (VPI), and evaluate the prognostic value of EGFR in resected non-small-cell lung cancer (NSCLC) patients with VPI.

MATERIALS AND METHODS

Clinicopathological characteristics and follow-up information were collected from 508 consecutive patients with surgically resected stage I-III NSCLC, and EGFR mutations were detected based on real-time PCR technology. Significant results (P<0.05) from univariate logistic regression analysis were involved as covariates to adjust confounding factors in the analysis of independent factors.

RESULTS

VPI and EGFR mutations were detected in 229 (45.1%) and 243 (47.8%) cases in NSCLC, respectively. There was a significant association between EGFR mutations and VPI development. Both 19-del (adjusted OR =2.13, 95%CI =1.13-3.99, P=0.019) and L858R (adjusted OR =2.89, 95%CI =1.59-5.29, P=0.001) could significantly increase the risk of VPI development compared with EGFR wild-type. Higher frequency of L858R (adjusted OR =2.63, 95%CI =1.42-4.88, P=0.002) was detected in VPI patients compared with non-VPI patients. 19-del (adjusted HR =0.31, 95%CI =0.12-0.80, P=0.015) was an independent prognostic factor for a better disease-free survival (DFS) in non-VPI patients. No significant association was shown between EGFR mutations and DFS in VPI patients.

CONCLUSION

EGFR mutations were significantly associated with VPI development in NSCLC, but no significant association was observed between EGFR mutations and DFS in the patients with VPI. 19-del was a favorable prognostic factor for DFS in non-VPI patients.

Efficacy of gefitinib in epidermal growth factor receptor-activating mutation-positive nonsmall cell lung cancer: Does exon 19 deletion differ from exon 21 mutation?

BACKGROUND

This study was designed to evaluate the differential effect of epidermal growth factor receptor (EGFR) mutation status (exon 19 vs. 21) on progression-free survival (PFS) and overall survival (OS) in treatment-naïve advanced EGFR mutation-positive nonsmall cell lung cancer (NSCLC) treated with gefitinib as first-line agent.

METHODS

This was a post hoc analysis of EGFR-mutated (exon 19 and 21) advanced-stage (Stage IIIB or IV), chemotherapy-naive NSCLC patients treated with gefitinib as first line in a phase 3 randomized study. Patients were treated with gefitinib 250 mg daily. Patients underwent axial imaging for response assessment on D42, D84, D126, and subsequently every 2 months till progression. Responding or stable patients were treated until progression or unacceptable toxicity. SPSS was used for statistical analysis. Kaplan-Meier method was used for survival estimation and log-rank test for comparison. Cox proportion hazard model was used for multivariate analysis.

RESULTS

One hundred and forty-one patients were eligible for analysis, of which 78 were males and 63 were females. A total of 127 patients (90.1%) were ECOG 0-1 while 14 patients (9.1%) were ECOG >1. Exon 21 mutation was present in 65 patients (46.1%) and exon 19 mutation in 76 patients (53.9%). One hundred and thirty-three of 141 patients were evaluable for response. Response rate of patients having exon 19 mutation was 72.9% (51 patients, n = 70) while it was 55.6% in patients having exon 21 mutation (35 patients, n = 63) (P = 0.046). Median PFS in exon 19-mutated patients was 9.3 months (95% confidence interval [CI] 6.832-11.768) compared to 7.8 months (95% CI 5.543-10.0) (P = 0.699) in exon 21-mutated patients. The median OS in exon 19-mutated patients was 19.8 months (95% CI 16.8-22.7), and it was 16.5 months (95% CI 10.9-22.1) in exon 21-mutated patients (P = 0.215).

CONCLUSION

There were no differential outcomes in the Indian patients of advanced-stage NSCLC with exon 19 and 21 EGFR mutations treated with gefitinib.

Efficacy of Second-Line Pemetrexed-Carboplatin in EGFR-Activating Mutation-Positive NSCLC: Does Exon 19 Deletion Differ from Exon 21 Mutation?

Background

It is unknown whether the outcomes of second-line pemetrexed-carboplatin chemotherapy administered after progression on gefitinib are dependent on type of EGFR mutation present at baseline.

Method

Adult non-small-cell lung cancer patients, with exon 19 deletion or exon 21 L858R mutation, who progressed on gefitinib and received pemetrexed-carboplatin chemotherapy were selected for this analysis.

Result

55 patients received pemetrexed-carboplatin as second-line treatment. Response rates in evaluable patients were 39.3% in exon 19 patients (n = 28) and 33.3% in exon 21 patients (n = 15) (p = 0.752, Fisher's exact 2-sided p value). The median PFS in exon 19 and 21 cohorts was 5.900 months (95% CI: 4.274–7.526) and 4.767 months (95% CI: 1.374–8.159), respectively. The median overall survival in exon 19 patients was (11.8 months, 95% CI: 9.916–13.684 months) significantly better than that seen in exon 21 mutation patients (6.2 months, 95% CI: 4.215–8.118 months, p = 0.024) on univariate analysis; however, on multivariate analysis, this association was not confirmed (HR = 0.361, 95% CI: 0.090–1.439, p = 0.149).

Conclusion

Exon 19 deletion has no impact on PFS and OS in EGFR-mutated patients treated with second-line pemetrexed-carboplatin.

Impact of exon 19 versus exon 21 EGFR-activating mutation on outcomes with upfront pemetrexed-carboplatin chemotherapy

BACKGROUND

EGFR mutation subtype is a recognised factor impacting outcomes of patients receiving oral tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancer (NSCLC). Evidence for the effect of this factor on outcomes in patients receiving pemetrexed is limited.

METHODS

We completed a study comparing pemetrexed-platinum combination versus oral TKI in EGFR mutation-positive patients in lung cancer. We analysed the impact of EGFR mutation subtype, specifically, exon 19 and 21 on the PFS and OS of patients treated with pemetrexed (500 mg/m2 on day 1) and carboplatin (AUC 5 on day 1) as first-line therapy. Patients underwent axial imaging for response assessment on D42, D84, D126 and subsequently every two months till progression. Patients post-progression were treated with gefitinib.

RESULTS

Fifty-one patients (36%) had exon 21 mutation, while 92 patients (64%) had exon 19 mutation. Response rates in evaluable patients was 47.7% in exon 19 patients (41 patients, n = 86) and 42.9 % in exon 21 patients (18 patients, n = 42). There was a significant increase in median overall survival for patients with exon 19 mutations (24.5 months, 95% CI: 21.3-27.7 months ) over the exon 21-mutated patients (18.1 months, 95% Cl: 13.5-22.6 months, p = 0.002). This differential impact was due to second-line gefitinib having a differential outcome on these mutations.

CONCLUSION

Pemetrexed-based chemotherapy does not have a differential impact on exon 19- or exon 21-mutated patients. However, second-line treatment with gefitinib has a favourable response and outcome in exon 19-mutated patients.

Correlation between EGFR mutation status and the incidence of brain metastases in patients with non-small cell lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer-related death worldwide. Numerous studies have been performed to investigate the correlation between epidermal growth factor receptor (EGFR) mutation status and the incidence of brain metastases (BMs) in patients with non-small cell lung cancer (NSCLC), however, the outcomes were inconsistent. Thus, we performed this study to establish the role of EGFR mutation status in BMs.

METHODS

Electronic databases PubMed, Embase, Cochrane Library, CBM, WanFang, CNKI were searched to identify relevant trials. The primary endpoint was the incidence of BMs in EGFR mutations or wild type NSCLC and the secondary endpoint was overall survival calculated from the BMs emerging (BMOS).

RESULTS

Twenty-two studies incorporating 8,152 participants were eligible. EGFR mutations group possessed a significantly higher risk of BMs (OR =1.99; 95% CI, 1.59-2.48; P=0.000) than EGFR wild type group. In the stratified analysis, compared with EGFR wild type group, EGFR mutations group had a significant higher incidence (OR =2.01; 95% CI, 1.56-2.59; P=0.000) of subsequent BMs while only a trend of increasing the incidence of initial BMs (OR =1.38; 95% CI, 0.98-1.94; P=0.066). Moreover, exon 19 deletion had a trend of increasing the incidence of BMs than exon 21 mutation (OR =1.44; 95% CI, 0.77-2.68; P=0.252). Compared with EGFR wild type group, EGFR mutations group possessed a prolonged overall BMOS (HR =0.68; 95% CI, 0.47-0.98; P=0.038) and a longer BMOS in initial BMs (HR =0.50; 95% CI, 0.31-0.80; P=0.004) but no significant difference in NSCLC with subsequent BMs (HR =0.95; 95% CI, 0.42-2.15; P=0.901).

CONCLUSIONS

Patients with EGFR mutations were more susceptible to develop into BMs than those with EGFR wild type, especially during the course of disease.

Clinicopathological features of Chinese lung cancer patients with epidermal growth factor receptor mutation

BACKGROUND

Epidermal growth factor receptor (EGFR) gene was the major causative gene of lung cancer and also the specific treatment target. It is necessary to analyze the genotype and phenotype characters of patients.

METHODS

We investigated 1,034 lung cancer patients in this study. The collected clinicopathological parameters included gender, age at diagnosis, smoking status, pathological TNM stage, tumor morphology and location, visceral pleural invasion as well as histological type.

RESULTS

Almost 50% participants had EGFR mutations. L858R in exon 21 was the most common type. Concomitant mutation, 19 del and L858R, were detected in 20 patients. Compared to patients with exon 19 del or L858R mutations solely, they were inclined to have small size adenocarcinomas which occurred in bilateral and invaded the visceral pleura. The tyrosine kinases inhibitors (TKIs)-resistant mutation, insertions in exon 20, was detected in 11 patients.

CONCLUSIONS

The summarized clinicopathological features will help clinicians to implement the feasible treatment plan.

Targeted Therapy Management in NSCLC Patients Using Cytology: Experience from a Tertiary Care Cancer Center

BACKGROUND

Although biopsy is the gold standard for diagnosis, cytological material has often been used to assist in making a pathologic diagnosis as well as for molecular testing in certain cancers such as in the lung, cervix, and head/neck.

OBJECTIVE

Our objective is to share experience from our institution in the use of cytological material in screening for epidermal growth factor receptor (EGFR) mutations in a subset of patients with non-small cell lung cancer (NSCLC).

METHODS

Fine needle aspirates, pleural effusion, cell blocks of 223 NSCLC patients, where cytology suggested malignancy were screened for EGFR mutation in exons 18-21 using Scorpion(®) ARMS real-time polymerase chain reaction (PCR) technology.

RESULTS

Overall, EGFR mutation was seen in 43.5 % of study samples. Deletions were highest in exon 19 (27.2 %), followed by exon 21 (15.5 %), exon 18 (5.3 %), and exon 20 (1.9 %). Chi-squared analysis revealed a significant correlation for mutation status in women compared with men (χ (2) = 5.88, p = 0.02), with exon 19 mutation predominating (χ (2) = 5.66, p = 0.02).

CONCLUSION

Our results demonstrate the successful use of cytology material for molecular testing in a subset of NSCLC patients to direct their treatment.

Screening for major driver oncogene alterations in adenosquamous lung carcinoma using PCR coupled with next-generation and Sanger sequencing methods

We investigated the frequency of major driver oncogenes in lung adenosquamous cell carcinoma (ASC) cases. Frequency of EGFR, K-Ras, B-Raf, PIK3CA, DDR2, ALK, and PDGFRA gene mutations was examined in 56 patients using next-generation sequencing, polymerase chain reaction, and Sanger sequencing. Macrodissection or microdissection was performed in 37 cases to separate the adenomatous and squamous components of ASC. The overall mutation rate was 64.29%, including 55.36%, 7.14%, and 1.79% for EGFR, K-Ras, and B-Raf mutations, respectively. PIK3CA mutation was detected in three cases; all involved coexisting EGFR mutations. Of the 37 cases, 34 were convergent in two components, while three showed EGFR mutations in the glandular components and three showed PIK3CA mutations in the squamous components. With respect to EGFR mutations, the number of young female patients, nonsmokers, and those with positive pleural invasion was higher in the mutation-positive group than that in the mutation-negative. K-Ras mutation was significantly associated with smoking. Overall survival in the different EGFR mutation groups differed significantly. The frequency and clinicopathological characteristics of EGFR- and K-Ras-mutated adenosquamous lung carcinoma were similar to that noted in Asian adenocarcinomas patients. The high convergence mutation rate in both adenomatous and squamous components suggests monoclonality in ASC.

Mutation analysis of EGFR and its correlation with the HPV in Indian cervical cancer patients

Cervical cancer is a major cause of morbidity and mortality particularly in developing countries. Somatic mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene is associated with increased sensitivity to tyrosine kinase inhibitors (TKIs). In this study, the presence of EGFR mutations in cervical cancer and its correlation with HPV were identified. EGFR mutations were found in 31 out of 95 patients (32.63 %). Results showed the presence of EGFR mutations in 5.263 % of patients in exon 19. In exon 20, mutations were predominant in 25.26 % patients. While in exon 21, 8.421 % of patients had mutations. HPV, which is associated with cervical cancer development, was found in 95.78 % (HPVL1), 92.63 % (HPV16), and 3.15 % (HPV18) of patients. No correlation was found between HPV16 and EGFR mutations (p = 0.0616). Overall, mutations like V742R, Q787Q, Q849H, E866E, T854A, L858R, E872Q, and E688Q were found. Next, impact of TKI inhibitor (gefitinib) was checked with respect to presence or absence of mutation considering Q787Q mutation in exon 20 (G/A genotype) which is present in 25.2 % patients. Mutated cervical cancer cell lines showed higher sensitivity to gefitinib. Overall, this study suggests the importance of mutations in EGFR gene and indicates their relevance with respect to TKIs treatment in Indian cervical cancer patients.

Concomitance of P-gp/LRP Expression with EGFR Mutations in Exons 19 and 21 in Non-Small Cell Lung Cancers

PURPOSE

Traditional chemotherapy is the main adjuvant therapy for the treatment of non-small cell lung cancer (NSCLC). However, the emergence of multi-drug resistance (MDR) has greatly restricted the curative effect of chemotherapy. Therefore, it is necessary to find a method to treat MDR NSCLC clinically. It is worth investigating whether NSCLCs that are resistant to traditional chemotherapy can be effectively treated with tyrosine kinase inhibitors targeting epidermal growth factor receptor (EGFR).

MATERIALS AND METHODS

The expression of P-glycoprotein (P-gp) and lung resistance-related protein (LRP) was detected by immunohistochemistry, and mutations in EGFR (exons 19 and 21) and Kirsten rat sarcoma viral oncogene homolog (KRAS) (exon 2) were detected by high-resolution melting analysis (HRMA) of surgical NSCLC specimens from 127 patients who did not undergo traditional chemotherapy or radiotherapy. A Pearson chi-square test was performed to analyze the correlations between the expression of P-gp and LRP and mutations in EGFR and KRAS.

RESULTS

The expression frequencies of P-gp and LRP were significantly higher in adenocarcinomas from non-smoking patients; the expression frequency of LRP was significantly higher in cancer tissue from female patients. The frequency of EGFR mutations was significantly higher in well to moderately differentiated adenocarcinomas from non-smoking female patients. The frequency of EGFR mutations in the cancers that expressed P-gp, LRP, or both P-gp and LRP was significantly higher than that in cancers that did not express P-gp or LRP.

CONCLUSION

NSCLCs expressing P-gp/LRP bear the EGFR mutation in exon 19 or 21 easily.

Association between a p73 gene polymorphism and genetic susceptibility to non-small cell lung cancer in the South of China

BACKGROUND

This study aimed to identify any association between the p73 gene G4C14-to-A4T14 polymorphism and risk of non-small cell lung cancer (NSCLC) in the south of China.

MATERIALS AND METHODS

We genotyped the p73 gene polymorphism of peripheral blood DNA from 168 patients with NSCLC and 195 normal controls using HRM (high resolution melting) and PCR-CTPP (polymerase chain reaction with confronting two-pair primers).

RESULTS

The results of genotyping by HRM and PCR-CTPP were consistent with direct sequencing, the p73 genotype distribution in 168 lung cancer patients being as follows: GC/GC 101 cases (60.1%), GC/ AT 59 cases (35.1%), AT/AT 8 cases (4.8%). The carriers of AT/AT genotype had a significantly reduced risk of NSCLC (OR=0.370; 95%CI: 0.170-0.806; p=0.010) as compared with non-carriers. However, we found no relations between p73 genotypes and histological type (p=0.798, x2=0.452), tumor stage (p=0.806, x2=0.806), or lymph node metastasis (p=0.578, x2=1.098).

CONCLUSIONS

Our findings suggest that the p73 G4C14-to-A4T14 polymorphism may be a modifier of NSCLC susceptibility in the Chinese population.

[Clinical characteristics and outcomes of lung cancer patients with EGFR mutations in exons 19 and 21]

背景与目的

近年来，通过对表皮生长因子受体（epidermal growth factor receptor, EGFR）等相关信号通路的研究及对EGFR酪氨酸激酶抑制剂（EGFR-tyrosine kinase inhibitors, EGFR-TKIs）疗效及安全性的探索，证实了靶向治疗已成为肺癌的重要治疗手段之一。然而，在各中心试验中EGFR-TKIs应用于不同EGFR突变亚型患者的效果不尽相同，其原因尚有争议。因此，本研究通过对比EGFR 19和21外显子突变肺癌患者的临床特点和预后分析，以明确不同EGFR突变亚型肺癌患者的临床病理生理特征的差异，并为TKIs应用于EGFR不同突变亚型疗效差异的研究提供理论依据。

方法

研究对象为EGFR外显子19或21突变阳性肺癌患者共113例。其中47例患者采用Real-time PCR或测序分析EGFR突变状况，余66例患者则是采用x-TAG液相芯片技术进行分析。收集临床资料，同时定期随访，以死亡作为患者终点事件，并应用SPSS 19.0软件进行统计学分析。

结果

在本研究中，EGFR外显子突变阳性患者共113例。其中，19外显子突变患者56例，平均年龄为（57.02±11.31）岁；21外显子突变患者57例，平均年龄为（62.25±7.76）岁，两组患者在年龄分布上存在明显差异（P＜0.05）；EGFR外显子突变阳性患者以女性（61.9%）、非吸烟（72.6%）、腺癌（84.1%）多见，但两组患者在性别、吸烟状况、组织类型、分化程度及TNM分期等临床特征方面均无明显差异（P＞0.05）。进一步分析发现，19外显子突变患者相对21外显子突变患者多好发于右侧（P＜0.05）。对所有具有完整随访资料的91例（80.53%, 91/113）患者预后分析发现，两组患者总生存期无统计学差异（中位生存期19外显子组和21外显子组分别为1, 051 vs 1, 076天，P=0.566）。进一步分析发现，在年龄＞61岁、男性、吸烟、Ⅳ期肺癌患者中，19外显子突变组患者均表现出相对较好的预后，但均无统计学差异。

结论

EGFR 19外显子突变肺癌患者相对21外显子突变肺癌患者年龄较小，且右侧原发较为多见。两者在性别、吸烟状况、组织类型、分期及分化程度上无明显差别。两者总生存时间无差异，但仍然需要进一步研究论证。

Lack of mutations in protein tyrosine kinase domain coding exons 19 and 21 of the EGFR gene in oral squamous cell carcinomas

BACKGROUND

The epidermal growth factor receptor (EGFR) plays a vital role in the activation and inactivation of receptor tyrosine kinases. Mutations in exons 19 and 21 of EGFR are commonly found to be associated with non small cell lung carcinoma and triple negative breast cancer, enhancing sensitivity to EGFR targeting chemotherapeutic agents. Since amplification and prolonged activation of EGFR molecules have been identified in oral squamous cell carcinomas (OSCC), we investigated whether OSCCs carried mutations in exons 19 and 21 of EGFR to their incidence.

MATERIALS AND METHODS

Tumor chromosomal DNA isolated from forty surgically excised oral squamous cell carcinoma tissues was subjected to PCR amplification with intronic primers flanking exons 19 and 21 of the EGFR gene. The PCR amplicons were subsequently subjected to direct sequencing to elucidate the mutation status.

RESULTS

Data analysis of the EGFR exon 19 and 21 coding sequences did not show any mutations in the forty OSCC samples that were analyzed.

CONCLUSIONS

To the best of our knowledge, this is the first study to have investigated the genetic status of exons 19 and 21 of EGFR in Indian OSCCs and identified that mutation in EGFR exon 19 and 21 may not contribute towards their genesis. The absence of mutations also indicates that oral cancerous lesions may not be as sensitive as other cancers to chemotherapeutic agents targeting EGFR.

Genotyping Accuracy of High-Resolution DNA Melting Instruments

BACKGROUND

High-resolution DNA melting is a closed-tube method for genotyping and variant scanning that depends on the thermal stability of PCR-generated products. Instruments vary in thermal precision, sample format, melting rates, acquisition, and software. Instrument genotyping accuracy has not been assessed.

METHODS

Each genotype of the single nucleotide variant (SNV) (c.3405–29A&gt;T) of CPS1 (carbamoyl-phosphate synthase 1, mitochondrial) was amplified by PCR in the presence of LCGreen Plus with 4 PCR product lengths. After blinding and genotype randomization, samples were melted in 10 instrument configurations under conditions recommended by the manufacturer. For each configuration and PCR product length, we analyzed 32–96 samples (depending on batch size) with both commercial and custom software. We assessed the accuracy of heterozygote detection and homozygote differentiation of a difficult, nearest-neighbor symmetric, class 4 variant with predicted ΔTm of 0.00 °C.

RESULTS

Overall, the heterozygote accuracy was 99.7% (n = 2141), whereas homozygote accuracy was 70.3% (n = 4441). Instruments with single sample detection as opposed to full-plate imaging better distinguished homozygotes (78.1% and 61.8%, respectively, χ2P &lt; 0.0005). Custom software improved accuracy over commercial software (P &lt; 0.002), although melting protocols recommended by manufacturers were better than a constant ramp rate of 0.1 °C with an oil overlay. PCR products of 51, 100, 272, and 547 bp had accuracies of 72.3%, 83.1%, 59.8%, and 65.9%, respectively (P &lt; 0.0005).

CONCLUSIONS

High-resolution melting detects heterozygotes with excellent accuracy, but homozygote accuracy is dependent on detection mode, analysis software, and PCR product size, as well as melting temperature differences between, and variation within, homozygotes.

Relationship between epidermal growth factor receptor gene mutations and clinicopathological features in patients with non-small cell lung cancer in western Turkey

BACKGROUND

To investigate epidermal growth factor receptor (EGFR) gene mutations in patients with non- small cell lung cancer (NSCLC) and to analyze any relationship with clinicopathological features and prognosis.

MATERIALS AND METHODS

EGFR gene exons 18-21 in 48 specimens of paraffin-embedded tumor tissue from NSCLC patients were amplified by PCR, followed by direct sequencing and analysis of links to clinicopathological features and prognosis.

RESULTS

EGFR mutations were detected in 18 of 48 (42.6%) patients with NSCLC. There were 9 cases of mutations in exon 20, 7 in exon 19 and 2 in exon 21. Mutations were more frequently observed in women (5/7 pts, 71.4%) than in men (13/41 pts, 31.7%) (p=0.086) and in non-smokers (5/5 pts, 100%) than smokers (13/43 pts, 30.2%). There was negative correlation of EGFR mutations with smoking status (p=0.005). EGFR mutations were more frequently observed with adenocarcinoma histology (13/32 pts, 40.6%) than in other types (5/16 pts, 31.3%) (p=0.527). The patients with EGFR mutations had better survival than those with wild- type EGFR (p=0.08). There was no association of EGFR mutations with metastatic spread.

CONCLUSIONS

EGFR mutations in NSCLC were here demonstrated more frequently in females, non-smokers and adenocarcinoma histology in the western region of Turkey. Patients with EGFR mutations have a better prognosis.

Expression of the mismatch repair gene hMLH1 is enhanced in non-small cell lung cancer with EGFR mutations

Mismatch repair (MMR) plays a pivotal role in keeping the genome stable. MMR dysfunction can lead to carcinogenesis by gene mutation accumulation. HMSH2 and hMLH1 are two key components of MMR. High or low expression of them often mark the status of MMR function. Mutations (EGFR, KRAS, etc) are common in non-small cell lung cancer (NSCLC). However, it is not clear what role MMR plays in NSCLC gene mutations. The expression of MMR proteins hMSH2 and hMLH1, and the proliferation markers PCNA and Ki67 were measured by immunohistochemistry in 181 NSCLCs. EGFR and KRAS mutations were identified by high resolution melting analysis. Stronger hMLH1 expression correlated to a higher frequency of EGFR mutations in exon 19 and 21 (p<0.0005). Overexpression of hMLH1 and the adenocarcinoma subtype were both independent factors that related to EGFR mutations in NSCLCs (p=0.013 and p<0.0005). The expression of hMLH1, hMSH2 and PCNA increased, while Ki67 expression significantly decreased (p=0.030) in NSCLCs with EGFR mutations. Overexpression of hMLH1 could be a new molecular marker to predict the response to EGFR-TKIs in NSCLCs. Furthermore, EGFR mutations might be an early event of NSCLC that occur before MMR dysfunction.

Frequency of EGFR mutations in 907 lung adenocarcioma patients of Indian ethnicity

BACKGROUND

During the past decade, the incidence of EGFR mutation has been shown to vary across different ethnicities. It occurs at the rate of 10-15% in North Americans and Europeans, 19% in African-Americans, 20-30% in various East Asian series including Chinese, Koreans, and Japanese. Frequency of EGFR mutations in India however remains sparsely explored.

METHODOLOGY/PRINCIPAL FINDINGS

We report 23% incidence of Epidermal growth factor receptor (EGFR) mutations in 907 Non small cell lung cancer (NSCLC) patients of Indian ethnicity, in contrast to 10-15% known in Caucasians and 27-62% among East Asians. In this study, EGFR mutations were found to be more common in never-smokers 29.4% as compared to smokers 15.3%. Consistent with other populations, mutation rates among adenocarcinoma-males were predominantly lower than females with 32% incidence. However unlike Caucasians, EGFR mutation rate among adenocarcinoma-never-smoker females were comparable to males suggesting lack of gender bias among never smokers likely to benefit from EGFR targeted therapy.

CONCLUSIONS/SIGNIFICANCE

This study has an overall implication for establishing relevance for routine EGFR mutation diagnostics for NSCLC patients in clinics and emphasizes effectiveness for adoption of EGFR inhibitors as the first line treatment among Indian population. The intermediate frequency of EGFR mutation among Indian population compared to Caucasians and East Asians is reminiscent of an ancestral admixture of genetic influence from Middle Easterners, Central Asians, and Europeans on modern- Indian population that may confer differential susceptibility to somatic mutations in EGFR.

Epidermal growth factor receptor mutation subtypes and geographical distribution among Indian non-small cell lung cancer patients

BACKGROUND

The Medical Oncology Department at Tata Memorial Hospital, the single largest tertiary cancer care center in Asia, receives in-house registered and referral patient samples from all parts of the country. Our recent studies establish 23% EGFR mutation frequency among Indian population. Here, we extend our study and report further analysis of distribution of different types of EGFR mutations in 1018 non small cell lung cancer patient, and its co-relation with clinical parameters and geographical variations across the country.

MATERIAL AND METHODS

This study is a retrospective analysis on all the patients who were referred for EFGR testing as a routine service over a 1.5 year period. This was part of standard care. EGFR kinase domain mutations in exon 18-21 were probed by TaqMan probe-based assays in 1018 NSCLC patients.

RESULTS AND DISCUSSION

While EGFR exon 19 mutations, the most frequent EGFR mutation, were found be higher among non smokers females, we find surprisingly higher incidence of exon 21 mutations among EGFR mutation positive male smokers of Indian ethnicity. Furthermore, as Indian population is known to be composed of a gradient admixture of Ancestral North Indian (with genetic influence from Middle Easterners, Central Asians, and Europeans harboring variant EGFR mutation frequency) and Ancestral South Indians, as a paradox our study indicates comparable EGFR mutation frequency across different geographical locations within India

CONCLUSION

Geographically there is uniform distribution in the EGFR mutation frequency within India. Further more, while exon 19 mutations are predominant among non smokers, higher incidence of exon 21 mutations exists among EGFR mutation positive male smokers of Indian ethnicity.

Biomarkers and molecular testing for early detection, diagnosis, and therapeutic prediction of lung cancer

The search for biomarkers in the management of lung cancer involves the use of multiple platforms to examine changes in gene, protein, and microRNA expression. Multiple studies have been published in an attempt to describe early detection, diagnostic, prognostic, and predictive biomarkers using chiefly tissues and blood elements. Studies are characterized by a lack of commonality of specific biomarkers, and a lack of validated, clinically useful markers. The future of biomarker discovery as a means of tailoring therapy for patients with lung cancer will involve next-generation sequencing along with collaborative efforts to integrate and validate candidate markers.