Polymorphisms in EGFR Gene Predict Clinical Outcome in Unresectable Non-Small Cell Lung Cancer Treated with Radiotherapy and Platinum-Based Chemoradiotherapy

Meta-analysis of EGFR gene polymorphisms and lung cancer risk

OBJECTIVE

This meta-analysis aims to systematically evaluate the associations of four specific Single Nucleotide Polymorphisms (SNPs)-rs712829, rs712830, rs11568315, and rs884225-located in the promoter, intronic, and 3' untranslated regions (3'UTR) of the EGFR gene, with lung cancer risk.

INTRODUCTION

The associations between EGFR gene polymorphisms and lung cancer risk is a topic of ongoing debate, which is still deemed controversial. Despite numerous studies, results are inconsistent.

METHODS

We conducted a comprehensive literature search across the PubMed, Science Direct, and Web of Science databases to identify relevant case-control studies examining the association between EGFR gene polymorphisms and lung cancer risk.

RESULTS

From an initial pool of 26,959 articles, 10 case-control studies were included, involving 2471 lung cancer patients and 4489 controls. A significant association between rs712829 and increased lung cancer risk was found across multiple genetic models. Under the allelic contrast model (G vs T), the OR was 1.31 (95% CI = [1.02; 1.68], p < 0.05), the dominant model (GG + GT vs TT) showed an OR of 1.69 (95% CI = [1.07; 2.67], p < 0.05), the homozygote model (GG vs TT) yielded an OR of 1.70 (95% CI = [1.00; 2.88], p < 0.05), and the heterozygote model (GT vs TT) had an OR of 1.64 (95% CI = [1.01; 2.66], p < 0.05). No significant associations were found for rs11568315, rs712830, and rs884225.

CONCLUSION

The findings from the current meta-analysis confirm that rs712829 within the EGFR gene is significantly associated with lung cancer risk according to the allele, dominant, homozygote and heterozygote models.

Effects of EGFR driver mutations on pathologic regression in resectable locally advanced non-small cell lung cancer treated with neoadjuvant chemoradiation and completion surgery

OBJECTIVE

We hypothesized that driver mutations in epidermal growth factor receptor (EGFR) are associated with decreased pathologic response to neoadjuvant chemoradiation (NA-ChRT) in locally advanced non-small cell lung cancer (LA-NSCLC).

METHODS

Patients with Stage IIB-IIIA NSCLC treated with NA-ChRT, completion surgery, and underwent molecular profile testing were identified in a lung cancer database. Pathologic response was quantified using: (i) major pathologic response (MPR), (ii) complete pathologic response (pCR), and (iii) mean residual viable tumor cells (MRTC). Two groups were formed based on the presence or absence of driver mutations. Clinical and pathological correlations between the groups were studied.

RESULTS

Forty-seven patients underwent tumor molecular profile testing, NA-ChRT, and completion surgery. Compared to the no-driver mutation group, the driver mutation group had lower MPR (23% vs 71%, p = 0.003), pCR (0% vs 26%, p = 0.02), and higher MRTC (43.4% vs 15.8%, p = 0.009). Univariate analysis showed an increased MPR rate for smokers, squamous cell histology, ChRT-surgery interval >65 days, and no-driver mutations. Multivariate analysis showed that only no-driver mutations (OR 0.39, p = 0.02) remained significant for MPR. PD-L1 status did not affect MPR. At 2 years, the driver mutation group had lower rates of local control (Hazard ration [HR] 0.67, p = 0.17) and disease-free survival (HR 0.5, p = 0.001). Overall survival was similar for both groups (HR = 1.04, p = 0.86).

CONCLUSION

Following 60 Gray NA-ChRT, tumors with a driver mutation had lower MPR and pCR rates than tumors without a driver mutation. PD-L1 was not associated with tumor regression.

ADVANCES IN KNOWLEDGE

Patients with resectable LA-NSCLC and an EGFR driver mutation treated with neoadjuvant-ChRT and completion surgery have reduced pathologic regression, lower local control rates, and shorter disease-free survival than patients without a driver mutation. Evaluation of molecular testing should be introduced in LA-NSCLC intended for prognostication and treatment decisions.

Review: Mechanisms and perspective treatment of radioresistance in non-small cell lung cancer

Radiotherapy is the major treatment of non-small cell lung cancer (NSCLC). The radioresistance and toxicity are the main obstacles that leading to therapeutic failure and poor prognosis. Oncogenic mutation, cancer stem cells (CSCs), tumor hypoxia, DNA damage repair, epithelial-mesenchymal transition (EMT), and tumor microenvironment (TME) may dominate the occurrence of radioresistance at different stages of radiotherapy. Chemotherapy drugs, targeted drugs, and immune checkpoint inhibitors are combined with radiotherapy to treat NSCLC to improve the efficacy. This article reviews the potential mechanism of radioresistance in NSCLC, and discusses the current drug research to overcome radioresistance and the advantages of Traditional Chinese medicine (TCM) in improving the efficacy and reducing the toxicity of radiotherapy.

A two-stage genome-wide association study identifies novel germline genetic variations in CACNA2D3 associated with radiotherapy response in nasopharyngeal carcinoma

BACKGROUND

Radiotherapy (RT) is the standard treatment for nasopharyngeal carcinoma (NPC). However, due to individual differences in radiosensitivity, biomarkers are needed to tailored radiotherapy to cancer patients. However, comprehensive genome-wide radiogenomic studies on them are still lacking. The aim of this study was to identify genetic variants associated with radiotherapy response in patients with NPC.

METHODS

This was a large‑scale genome-wide association analysis (GWAS) including a total of 981 patients. 319 individuals in the discovery stage were genotyped for 688,783 SNPs using whole genome-wide screening microarray. Significant loci were further genotyped using MassARRAY system and TaqMan SNP assays in the validation stages of 847 patients. This study used logistic regression analysis and multiple bioinformatics tools such as PLINK, LocusZoom, LDBlockShow, GTEx, Pancan-meQTL and FUMA to examine genetic variants associated with radiotherapy efficacy in NPC.

RESULTS

After genome-wide level analysis, 19 SNPs entered the validation stage (P < 1 × 10^- 6), and rs11130424 ultimately showed statistical significance among these SNPs. The efficacy was better in minor allele carriers of rs11130424 than in major allele carriers. Further stratified analysis showed that the association existed in patients in the EBV-positive, smoking, and late-stage (III and IV) subgroups and in patients who underwent both concurrent chemoradiotherapy and induction/adjuvant chemotherapy.

CONCLUSION

Our study showed that rs11130424 in the CACNA2D3 gene was associated with sensitivity to radiotherapy in NPC patients.

TRIAL REGISTRATION NUMBER

Effect of genetic polymorphism on nasopharyngeal carcinoma chemoradiotherapy reaction, ChiCTR-OPC-14005257, Registered 18 September 2014, http://www.chictr.org.cn/showproj.aspx?proj=9546 .

Two independent variants of epidermal growth factor receptor associated with risk of glioma in a Korean population

Gliomas are the most common primary tumors in the brain and spinal cord. In previous GWASs, SNPs in epidermal growth factor receptor (EGFR) have been reported as risk loci for gliomas. However, EGFR variants associated with gliomas in the Korean population remain unstudied. This study explored the association of EGFR SNPs with the risk of glioma. We genotyped 13 EGFR exon SNPs in a case-control study that included 324 Korean patients diagnosed with glioma and 480 population-based controls. Statistical analyses of the association between EGFR SNPs and glioma risk were conducted using logistic regression. Both stepwise analysis and conditional logistic analysis were performed to identify independent associations among genotyped variants. We confirmed that two SNPs (rs2227983, rs1050171) were significantly associated with glioma (rs2227983: odds ratio = 1.42, P^corr = 0.009; rs1050171: odds ratio = 1.68, P^corr = 0.005). Additionally, the stepwise analysis and conditional logistic analysis indicated that both SNPs created variants with independent genetic effects. This study is the first to show evidence that functional variants of EGFR, namely, rs2227983 (K521R) and rs1050171 (Q787Q), are associated with an increased risk of glioma in the Korean population. Future work should confirm the functional association between EGFR variants and glioma.

Two missense variants of the epidermal growth factor receptor gene are associated with non small cell lung carcinoma in the subjects from Iraq

BACKGROUND

Lung carcinoma is a foremost cause of cancer-related mortality worldwide. Variable genetic factors are associated with the development of lung cancer. This study was performed to evaluate the possible association of epidermal growth factor receptor (EGFR) gene polymorphisms with non small cell lung carcinoma (NSCLC) in Iraqi population.

METHODS

DNA samples were extracted from 100 patients and 100 controls. Four PCR fragments were designed to amplify four high-frequency variants within EGFR, namely rs1050171, rs2072454, rs2227984, and rs2227983. The PCR fragments were genotyped by single-strand conformation polymorphism (SSCP) method, and each genotype was subjected to direct sequencing.

RESULTS

Genotyping experiments confirmed the variability of three targeted variants, and logistic regression analysis showed that two of these variants (rs1050171 and rs2227983) tend to exhibit a significant association with NSCLC. Individuals with rs1050171:GA genotype showed a possible association with the increased risk of NSCLC (P = 0.0110; OD 5.2636; Cl_95% 1.4630 to 18.9371). Individuals with rs2227983:GG genotype exhibited a potential association with NSCLC (P = 0.0037; OD 5.2683; Cl_95% 1.7141 to 16.1919). Linkage disequilibrium analysis showed that the effects of the investigated variants seem to take independent actions, and no haplotype was found to be associated with the high prevalence of NSCLC.

CONCLUSIONS

Our collective data indicated that EGFR-rs1050171G/A and EGFR-rs2227983G/G SNPs tend to exert significant and separate associations with the increased risk of NSCLC. However, this study recommends using a broader spectrum of the investigated samples to get further details of both SNPs in terms of their association with the susceptibility to NSCLC.

Based on the Development and Verification of a Risk Stratification Nomogram: Predicting the Risk of Lung Cancer-Specific Mortality in Stage IIIA-N2 Unresectable Large Cell Lung Neuroendocrine Cancer Compared With Lung Squamous Cell Cancer and Lung Adenocarcinoma

Background

The purpose of this study is to predict overall survival (OS) and lung cancer-specific survival (LCSS) in patients with stage IIIA-N2 unresectable lung squamous cell cancer (LUSC), lung adenocarcinoma (LUAD), and large cell neuroendocrine cancer (LCNEC) by constructing nomograms and to compare risk and prognostic factors affecting survival outcomes in different histological subtypes.

Methods

We included 11,505 unresectable NSCLC patients at stage IIIA-N2 between 2010 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. Moreover, competition models and nomograms were developed to predict prognostic factors for OS and LCSS.

Results

Analysis of the SEER database identified 11,505 NSCLC patients, of whom 5,559 (48.3%) have LUAD, 5,842 (50.8%) have LUSC, and 104 (0.9%) have LCNEC. Overall, both OS and LCSS were significantly better in stage IIIA-N2 unresectable LUAD than in LCNEC, while there was no statistically significant difference between LUSC and LCNEC. Age, gender, T stage, chemotherapy, and radiotherapy were significantly associated with OS rates in LUAD and LUSC. However, chemotherapy was the only independent factor for LCNEC (p < 0.01).From competitive risk models, we found that older age, larger tumors, non-chemotherapy and non-radiotherapy were associated with a increased risk of death from LUAD and LUSC. Unlike prognostic factors for OS, our study showed that both chemotherapy and radiotherapy were all LCNEC-specific survival factors for both LCSS and non-LCSS LCNEC.

Conclusion

Our study reports that unresectable patients with stage IIIA-N2 LCNEC and LUSC have worse LCSS than LUAD. The study’s first prognostic nomogram constructed for patients with unresectable stage IIIA-N2 NSCLC can accurately predict the survival of different histological types, which may provide a practical tool to help clinicians assess prognosis and stratify these prognostic risks to determine which patients should be given an optimized individual treatment strategy based on histology.