A variant epidermal growth factor receptor exhibits altered type alpha transforming growth factor binding and transmembrane signaling

PET tracers in glioblastoma: Toward neurotheranostics as an individualized medicine approach

Over the past decade, theragnostic radiopharmaceuticals have been used in nuclear medicine for both diagnosis and treatment of various tumors. In this review, we carried out a literature search to investigate and explain the role of radiotracers in the theragnostic approach to glioblastoma multiform (GBM). We primarily focused on basic and rather common positron emotion tomography (PET) radiotracers in these tumors. Subsequently, we introduced and evaluated the preclinical and clinical results of theranostic-based biomarkers including integrin receptor family, prostate-specific membrane antigen (PSMA), fibroblast activated protein (FAP), somatostatin receptors (SRS), and chemokine receptor-4 (CXCR4) for patients with GBM to confer the benefit of personalized therapy. Moreover, promising research opportunities that could have a profound impact on the treatment of GBM over the next decade are also highlighted. Preliminary results showed the potential feasibility of the theragnostic approach using theses biomarkers in GBM patients.

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.

Lack of Association between Epidermal Growth Factor or Its Receptor and Reflux Esophagitis, Barrett’s Esophagus, and Esophageal Adenocarcinoma: A Case-Control Study

The epidermal growth factor (EGF) and its receptor (EGFR) gene-gene interactions were shown to increase the susceptibility to esophageal cancer. However, the role of the EGF/EGFR pathway in the development of gastroesophageal reflux disease (GERD) and its complications (reflux esophagitis (RE), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC)) remains unclear. This association study is aimed at investigating functional EGF and EGFR gene polymorphisms, their mRNA expression in esophageal tissues, and EGF plasma levels in relation to RE, BE, and EAC development in the Central European population. 301 patients with RE/BE/EAC (cases) as well as 98 patients with nonerosive reflux disease (NERD) and 8 healthy individuals (controls) were genotyped for +61 A>G EGF (rs4444903) and +142285 G>A EGFR (rs2227983) polymorphisms using the TaqMan quantitative polymerase chain reaction (qPCR). In random subgroups, the EGF and EGFR mRNA expressions were analyzed by reverse transcription qPCR in esophageal tissue with and without endoscopically visible pathological changes; and the EGF plasma levels were determined by enzyme-linked immunosorbent assay. None of the genotyped SNPs nor EGF-EGFR genotype interactions were associated with RE, BE, or EAC development (p > 0.05). Moreover, mRNA expression of neither EGF nor EGFR differed between samples of the esophageal tissue with and without endoscopically visible pathology (p > 0.05) nor between samples from patients with different diagnoses, i.e., RE, BE, or EAC (p > 0.05). Nevertheless, the lower EGF mRNA expression in carriers of combined genotypes AA +61 EGF (rs4444903) and GG +142285 EGFR (rs2227983; p < 0.05) suggests a possible direct/indirect effect of EGF-EGFR gene interactions on EGF gene expression. In conclusion, EGF and EGFR gene variants and their mRNA/protein expression were not associated with RE, BE or EAC development in the Central European population.

Predicting drug response and toxicity in metastatic colorectal cancer: the role of germline markers

INTRODUCTION

Despite the introduction of targeted agents leading to therapeutic advances, clinical management of patients with metastatic colorectal cancer (mCRC) is still challenged by significant interindividual variability in treatment outcomes, both in terms of toxicity and therapy efficacy. The study of germline genetic variants could help to personalize and optimize therapeutic approaches in mCRC.

AREAS COVERED

A systematic review of pharmacogenetic studies in mCRC patients published on PubMed between 2011 and 2021, evaluating the role of germline variants as predictive markers of toxicity and efficacy of drugs currently approved for treatment of mCRC, was perfomed.

EXPERT OPINION

Despite the large amount of pharmacogenetic data published to date, only a few genetic markers (i.e., DPYD and UGT1A1 variants) reached the clinical practice, mainly to prevent the toxic effects of chemotherapy. The large heterogeneity of available studies represents the major limitation in comparing results and identifying potential markers for clinical use, the role of which remains exploratory in most cases. However, the available published findings are an important starting point for future investigations. They highlighted new promising pharmacogenetic markers within the network of inflammatory and immune response signaling. In addition, the emerging role of previously overlooked rare variants has been pointed out.

Chronic arsenic increases cell migration in BEAS-2B cells by increasing cell speed, cell persistence, and cell protrusion length

There is a strong association between arsenic exposure and lung cancer development, however, the mechanism by which arsenic exposure leads to carcinogenesis is not clear. In our previous study, we observed that when BEAS-2B cells are chronically exposed to arsenic, there is an increase in secreted TGFα, as well as an increase in EGFR expression and activity. Further, these changes were broadly accompanied with an increase in cell migration. The overarching goal of this study was to acquire finer resolution of the arsenic-dependent changes in cell migration, as well as to understand the role of increased EGFR expression and activity levels in the underlying mechanisms of cell migration. To do this, we used a combination of biochemical and single cell assays, and observed chronic arsenic treatment enhancing cell migration by increasing cell speed, cell persistence and cell protrusion length. All three parameters were further increased by the addition of TGFα, indicating EGFR activity is sufficient to enhance those aspects of cell migration. In contrast, EGFR activity was necessary for the increase in cell speed, as it was reversed with an EGFR inhibitor, AG1478, but was not necessary to enhance persistence and protrusion length. From these data, we were able to isolate both EGFR-dependent and -independent features of cell migration that were enhanced by chronic arsenic exposure.

The Investigation of Associations between TP53 rs1042522, BBC3 rs2032809, CCND1 rs9344, EGFR rs2227983 Polymorphisms and Breast Cancer Phenotype and Prognosis

Breast cancer is one of the most common oncological diseases among women worldwide. Cell cycle and apoptosis-related genes TP53, BBC3, CCND1 and EGFR play an important role in the pathogenesis of breast cancer. However, the roles of single nucleotide polymorphisms (SNPs) in these genes have not been fully defined. Therefore, this study aimed to analyze the association between TP53 rs1042522, BBC3 rs2032809, CCND1 rs9344 and EGFR rs2227983 polymorphisms and breast cancer phenotype and prognosis. For the purpose of the analysis, 171 Lithuanian women were enrolled. Genomic DNA was extracted from peripheral blood; PCR-RFLP was used for SNPs analysis. The results showed that BBC3 rs2032809 was associated with age at the time of diagnosis, disease progression, metastasis and death. CCND1 rs9344 was associated with tumor size, however an association resulted in loss of significance after Bonferroni correction. In survival analysis, significant associations were observed between BBC3 rs2032809 and OS, PFS and MFS. EGFR rs2227983 also showed some associations with OS and PFS (univariate Cox regression analysis). However, the results were in loss of significance (multivariate Cox regression analysis). In conclusion, BBC3 rs2032809 polymorphism was associated with breast cancer phenotype and prognosis. Therefore, it could be applied as potential markers for breast cancer prognosis.

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

For non-small cell lung cancer (NSCLC), radiotherapy (RT) and platinum-based chemotherapy (CHT) are among the main treatment options. On the other hand, radioresistance and cytotoxic drug resistance are common causes of failure. The epidermal growth factor receptor (EGFR) plays an important role in radioresponse and therapy resistance. We hypothesized that single nucleotide polymorphisms (SNPs) in the EGFR gene might affect individual sensitivity to these treatments, and thus, therapy outcome and prognosis. The association between functional EGFR SNPs and overall (OS), locoregional recurrence-free (LFRS), and metastasis-free (MFS) survival was examined in 436 patients with unresectable NSCLC receiving RT and platinum-based CHTRT. In a multivariate analysis, the rs712830 CC homozygotes showed reduced OS in the whole group (p = 0.039) and in the curative treatment subset (p = 0.047). The rs712829 TT genotype was strongly associated with decreased LRFS (p = 0.006), and the T-C haplotype was a risk factor for locoregional recurrence in our patients (p = 0.003). The rs2227983 GG alone and in combination with rs712829 T was an indicator of unfavorable LRFS (p = 0.028 and 0.002, respectively). Moreover, significant independent effects of these SNPs on OS, LRFS, and MFS were observed. Our results demonstrate that inherited EGFR gene variants may predict clinical outcomes in NSCLC treated with DNA damage-inducing therapy.

Genetic variants of the EGFR ligand-binding domain and their association with structural alterations in Arab cancer patients

Objective

This study aimed to identify novel genetic variants in the CR2 extracellular domain of the epidermal growth factor receptor (EGFR) in healthy individuals and patients with six different types of adenocarcinoma, in Arabian peninsula populations. It also aimed to investigate the effects of these variants on the EGFR structure and their eventual relevance to tumorigenesis.

Results

We detected seven new EGFR genetic variants in 168 cancer patients and 114 controls. A SNP rs374670788 was more frequent in bladder cancer but not significantly associated to. However, a missense mutation (V550M) was significantly associated to colon, ovary, lung, bladder and thyroid cancer samples (p < 0.05). Three mutations (H590R, E602K and T605T) were found in the heterozygous form only in colon cancer patients. Genomic analysis of the synonymous mutation (G632G) showed that the T/A genotype could be associated to thyroid cancer in Arab patients (p < 0.05). An additional novel SNP rs571064657 was observed in control individuals. Computational analysis of the genetic variants revealed a reduction in the stabilization of the EGFR tethered form for both V550M and the common R521K variant with low energetic state (− ∆∆G). Molecular interactions analysis suggested that these mutations might affect the receptor’s function and promote tumorigenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05559-y.

Chronic and acute arsenic exposure enhance EGFR expression via distinct molecular mechanisms

The impacts of acute arsenic exposure (i.e. vomiting, diarrhea, and renal failure) are distinct from those brought about by sustained, low level exposure from environmental sources or drinking of contaminated well water. Chronic arsenic exposure is a risk factor for the development of pulmonary diseases, including lung cancer. How arsenic exposure leads to pulmonary disease is not fully understood. Both acute versus chronic arsenic exposure increase EGFR expression, but do so via distinct molecular mechanisms. BEAS-2B cells were exposed to either acute sodium arsenite (5 μM for 24 h) or chronic sodium arsenite (100 nM for 24 weeks). Cells treated with acute arsenic exhibited a decrease in viability, changes in morphology, and increased mRNA level of BTC. In contrast, during 24 weeks of arsenic exposure, the cells had increased EGFR expression and activity, and increased mRNA and protein levels of TGFα. Further, chronic arsenic treatment caused an increase in cell migration in the absence of exogenous ligand. Elevated TGFα and EGFR expression are features of many non-small cell lung cancers. We propose that lung epithelial cells chronically exposed to low level arsenic increases EGFR signaling via TGFα production to enhance ligand-independent cell migration.

The Association between Epidermal Growth Factor Receptor Single Nucleotide Polymorphisms and Radiochemotherapy Response in Cervical Cancer

Emerging data reveal that epidermal growth factor receptor (EGFR) single nucleotide polymorphisms (SNPs) can act as efficacy indicators for tumor treatment. Here, the association between EGFR R497K (rs11543848) and -216G/T (rs712829) SNPs and radiochemotherapy response in cervical cancer was investigated. EGFR R497K and -216G/T genotypes were analyzed by polymerase chain reaction-ligation detection reaction in 196 cervical cancer patients receiving radiotherapy alone, or in combination with chemotherapy. Compared with the 497G/G genotype, the A/A genotype significantly increased sensitivity to radiochemotherapy treatment (adjusted OR = 0.244, 95% CI = 0.087-0.680). Sensitivity to radiochemotherapy was not significantly different in carriers of the 'T' allele than that measured for the -216G/G genotype (adjusted OR = 2.412, 95% CI = 0.856-6.979). Additionally, the 497A/A genotype conferred a reduced risk of recurrence or metastasis than did the G/G genotype (adjusted OR = 0.248, 95% CI = 0.078-0.786, P < 0.05). Moreover, carriers of the 'T' allele did not have significantly modified risk of recurrence or metastasis compared with those with the -216G/G genotype (adjusted OR = 1.027, 95% CI = 0.324-3.253). Multivariate analysis revealed an association between clinical stage and treatment response (adjusted OR = 3.575, 95% CI = 1.662-7.692) and between age and the risk of recurrence or metastasis (adjusted OR = 0.319, 95% CI = 0.148-0.691). Our results show that, in patients with cervical cancer, the R497K polymorphism is correlated with treatment response and the risk of recurrence or metastasis. The R497K SNP might be a genetic marker for prediction of radiochemotherapy response and the risk of recurrence and/or metastasis in patients with cervical cancer.

Impact of single nucleotide polymorphisms on the efficacy and toxicity of EGFR tyrosine kinase inhibitors in advanced non-small cell lung cancer patients

EGFR tyrosine kinase inhibitors (EGFR-TKIs) are the treatment of choice for advanced-stage (IIIB-IV) NSCLC patients with mutations in EGFR. However, EGFR-TKIs clinical outcomes vary from person to person and these inter-individual differences may be due to genetic factors such as single nucleotide polymorphisms (SNPs). SNPs in genes involved in EGFR-TKIs pharmacodynamics, metabolism and mechanism of action have been demonstrated to be associated with response, survival and toxicity in advanced NSCLC patients treated with EGFR-TKIs. Here we review the influence of gene polymorphisms in the EGFR pathway on clinical outcome and toxicity to EGFR-TKIs in advanced NSCLC patients. The EGFR-216 polymorphism has reported a strong association between response and/or survival to EGFR-TKIs in Caucasian population. Similarly, the effect of EGFR-CA repeats polymorphisms on survival of advanced NSCLC patients treated with EGFR-TKIs have been confirmed both in Caucasian and Asian population. The influence on toxicity of the -216, -191, CA repeats, Arg497Lys and Asp994Asp polymorphisms in EGFR have also been confirmed. Polymorphisms in AKT (rs1130214 and rs1130233) and SMAD3 (rs6494633, rs11071938 and rs11632964) have been associated with survival in advanced NSCLC patients treated with EGFR-TKIs. However, data come from a limited number of studies and need to be confirmed. Finally, polymorphisms in genes coding proteins of the membrane transporters and cytochrome P450 enzymes have been less extensively investigated. There are few studies with small samples, which complicated the generalization of their role in EGFR-TKIs treatment.

Association of EGFR 1 Gene Alteration and their Association with Lung Adenocarcinoma Patients

Background: The epidermal growth factor receptor 1 (EGFR1) plays a significant role in cell proliferation and development. Its regulation in humans is very critical and incompletely understood in Non small cell lung cancer (NSCLC). Methods: 100 newly diagnosed NSCLC (lung adenocarcinoma) patients and 100 healthy controls were included and allele specific (AS) polymerase chain reaction (PCR) was used to genotype and expression was analyzed by quantitative real time PCR. Overall survival of patients was analyzed by Kaplan-Meier method and for prognostic significance ROC curve was plotted. Results: A statistically significant difference (p<0.0001) in CC, AA and CA genotypes distribution among patients and healthy controls was observed. Compared to the CC genotype as reference, OR was 30.40 (95%CI 1.75- 524.9, p=0.0002) and 3.97 (95%CI 1.49-10.52, p=0.003) for the homozygous AA and heterozygous CA genotypes respectively. Kaplan-Meier survival analysis was also performed to analyze the relationship of EGFR1 (-191C/A) genotypes with progression free median survival of NSCLC patients and the difference was found to be significantly (p=0.0002) associated with different genotypes. In the ROC curve with respect to TNM stage at optimal cut-off value of 9.88 fold increase in EGFR1 mRNA expression, sensitivity and specificity were 92.9%, 83.3% respectively (AUC=0.95, p<0.0001). ROC curve w.r.t. distant metastases at optimal cut-off value of 13.5 fold change EGFR1 mRNA expression, sensitivity and specificity were 68.2%, 71.4% respectively (AUC=0.81, p<0.0001). In ROC curve w.r.t to presence/ absence of pleural effusion at optimal cut-off value of 14.8 fold change EGFR1 mRNA expression sensitivity and specificity were 66.7%, 68.2% respectively (AUC=0.71, p=0.009). Conclusions: Study concluded EGFR1 promoter polymorphism could be a risk factor associated with disease and may be used as prognostic marker for patients’ survival and predictor for disease worseness.

Evaluation of the EGFR polymorphism R497K in two cohorts of neoadjuvantly treated breast cancer patients

Pathological response of breast cancer to neoadjuvant chemotherapy (NAC) presents great variability, and new prognostic biomarkers are needed. Our aim was to evaluate the association of the epidermal growth factor receptor gene (EGFR) polymorphism R497K (rs2227983) with prognostic features and clinical outcomes of breast cancer, including the pathological response to NAC and the recurrence-free survival (RFS). Tumoral complete response (tCR) was defined by no remaining invasive cancer in the excised breast, whereas pathological complete response (pCR) was defined by no remaining invasive cancer both in the excised breast and lymph nodes. Two independent cohorts were analyzed: one from Brazil (INCA, n = 288) and one from The Netherlands (NKI-AVL, n = 255). In the INCA cohort, the variant (Lys-containing) genotypes were significantly associated with lower proportion of tCR (ORadj = 0.92; 95%CI = 0.85-0.99), whereas in the NKI-AVL cohort they were associated with tumor grade 3 (p = 0.035) and with triple-negative subtype (p = 0.032), but not with clinical outcomes. Such distinct prognostic associations may have arisen due to different neoadjuvant protocols (p < 0.001), or to lower age at diagnosis (p < 0.001) and higher proportion of tumor grade 3 (p = 0.018) at the NKI-AVL cohort. Moreover, NKI-AVL patients achieved better proportion of pCR (21.2% vs 8.3%, p < 0.001) and better RFS (HRadj = 0.48; 95% adjCI = 0.26-0.86) than patients from INCA. In conclusion, large scale studies comprehending different populations are needed to evaluate the impact of genome variants on breast cancer outcomes.

Cetuximab Resistance in Head and Neck Cancer Is Mediated by EGFR-K521 Polymorphism

Head and neck squamous cell carcinomas (HNSCC) exhibiting resistance to the EGFR-targeting drug cetuximab poses a challenge to their effective clinical management. Here, we report a specific mechanism of resistance in this setting based upon the presence of a single nucleotide polymorphism encoding EGFR-K₅₂₁ (K-allele), which is expressed in >40% of HNSCC cases. Patients expressing the K-allele showed significantly shorter progression-free survival upon palliative treatment with cetuximab plus chemotherapy or radiation. In several EGFR-mediated cancer models, cetuximab failed to inhibit downstream signaling or to kill cells harboring a high K-allele frequency. Cetuximab affinity for EGFR-K₅₂₁ was reduced slightly, but ligand-mediated EGFR activation was intact. We found a lack of glycan sialyation on EGFR-K₅₂₁ that associated with reduced protein stability, suggesting a structural basis for reduced cetuximab efficacy. CetuGEX, an antibody with optimized Fc glycosylation targeting the same epitope as cetuximab, restored HNSCC sensitivity in a manner associated with antibody-dependent cellular cytotoxicity rather than EGFR pathway inhibition. Overall, our results highlight EGFR-K₅₂₁ expression as a key mechanism of cetuximab resistance to evaluate prospectively as a predictive biomarker in HNSCC patients. Further, they offer a preclinical rationale for the use of ADCC-optimized antibodies to treat tumors harboring this EGFR isoform. Cancer Res; 77(5); 1188-99. ©2016 AACR.

Simul-seq: combined DNA and RNA sequencing for whole-genome and transcriptome profiling

Paired DNA and RNA profiling is increasingly employed in genomics research to uncover molecular mechanisms of disease and to explore personal genotype and phenotype correlations. here, we introduce Simul-seq, a technique for the production of high-quality whole-genome and transcriptome sequencing libraries from small quantities of cells or tissues. We apply the method to laser-capture-microdissected esophageal adenocarcinoma tissue, revealing a highly aneuploid tumor genome with extensive blocks of increased homozygosity and corresponding increases in allele-specific expression. Among this widespread allele-specific expression, we identify germline polymorphisms that are associated with response to cancer therapies. We further leverage this integrative data to uncover expressed mutations in several known cancer genes as well as a recurrent mutation in the motor domain of KIF3B that significantly affects kinesin–microtubule interactions. Simul-seq provides a new streamlined approach for generating comprehensive genome and transcriptome profiles from limited quantities of clinically relevant samples.

Correlations between EGFR gene polymorphisms and pleural metastasis of lung adenocarcinoma

Proliferation, growth, and differentiation of cells are strictly controlled by the signal system of epidermal growth factor receptor (EGFR). If any link of the EGFR signals system is interfered with or damaged, the proliferation, growth, and differentiation of cells would become uncontrolled. EGFR is overexpressed in a variety of malignant tumors, such as non-small-cell lung cancer, colorectal cancer and breast cancer. Results of the study have proved that EGFR overexpression is closely associated with mutations and variants of the EGFR genes, whose mutations and variants are associated with occurrence, metastasis, and prognosis of different types of tumors, including lung cancer. This study is aimed at investigating whether the polymorphisms of CA simple sequence repeat in intron 1 (CA-SSR1), -216G/T, and R497K in the EGFR are able to induce EGFR activation and whether overexpression is associated with pleural metastasis of lung adenocarcinoma. A total of 432 lung adenocarcinoma patients with pleural metastasis (metastasis group) and 424 patients with lung adenocarcinoma but without pleural metastasis (nonmetastasis group) were enrolled in this study. For all patients, the CA-SSR1 genotypes were determined by capillary electrophoresis, polymerase chain reaction amplification, and direct DNA sequencing, and the R497K and -216G/T genotypes were determined by polymerase chain reaction amplification and direct DNA sequencing. EGFR expression was evaluated by immunohistochemical staining in primary tumor tissues with different -216G/T, R497K, and CA-SSR1 genotypes. Our results showed significant differences between pleural metastasis and nonmetastasis groups in the genotype and allele distribution of -216G/T, R497K, and CA-SSR1 polymorphisms of the EGFR gene. The -216T allele, Arg allele, and shorter CA-SSR1 (<17) had significantly increased risks of pleural metastasis compared with the -216G allele, Lys allele, and longer CA-SSR1 (≥17), respectively. The expression of EGFR was higher in patients with genotypes of -216T/T or -216G/T, Arg/Arg or Arg/Lys, and shorter CA-SSR1 (<17) than that in patients with genotypes of -216G/G, Lys/Lys, and longer CA-SSR1 (≥17), respectively. These results indicate that -216G/T, R497K, and CA-SSR1 polymorphisms are associated with the risk of pleural metastasis of lung adenocarcinoma, which may be related to the overexpression of EGFR protein induced by -216G/T, R497K, and CA-SSR1 polymorphisms.

EGFR and SYNE2 are associated with p21 expression and SYNE2 variants predict post-operative clinical outcomes in HBV-related hepatocellular carcinoma

This study was to explore the association between gene variants and p21 expression and investigate the TP53-independent p21 regulation in hepatitis B virus (HBV) related hepatocellular carcinoma (HCC) patients from Guangxi by genome-wide association study. 426 HBV-related HCC patients were enrolled. Results showed that, after quality control, a total of 21,643 SNPs were identified in 107 p21 positive and 298 p21 negative patients. The variants of epidermal growth factor receptor (EGFR; rs2227983 and rs6950826) and spectrin repeat containing, nuclear envelope 2 (SYNE2; rs8010699, rs4027405 and rs1890908) were associated with p21 expression. Moreover the haplotype block (rs2227983 and rs6950826, r² = 0.378) in EGFR and the haplotype block in SYNE2 (rs8010699 was in strong LD with rs4027405 and rs1890908 (r² = 0.91 and 0.70, respectively)) were identified, and the haplotype A-G of EGFR and haplotype G-A-A of SYNE2 were significantly associated with p21 expression (P < 0.01). rs4027405 and rs1890908 were significantly associated with overall survival, and patients with AG/GG genotypes of SYNE2 gene had a worse overall survival (P = 0.001, P = 0.002). Our findings indicate that variants of EGFR and SYNE2 play an important role in p21 regulation and are associated with the clinical outcome of HBV-related HCC in a TP53-indenpdent manner.

On the pharmacogenetics of non-small cell lung cancer treatment

Despite many clinical efforts, non-small-cell lung cancer (NSCLC) has a dismal 5-year survival rate of 16%, and high incidence of recurrence. The success of biologically targeted agents, as well as the activity of well-established chemotherapeutic regimens, has been limited by inherited/acquired resistance, and biomarkers to adapt the prescription of anticancer drugs to patients' features are urgently warranted. Areas covered. In oncology, pharmacogenetics should provide the way to select patients who may benefit from a specific therapy that best match the individual and tumor genetic profile, thus allowing maximum activity and minimal toxicity. The present review summarizes the main findings on NSCLC pharmacogenetics, critically reappraising the most important studies on polymorphisms correlated with outcome of pemetrexed and EGFR-inhibitors, and provides perspective on clinical application of genomic tests for treatment decision-making. Expert Opinion. A major challenge in NSCLC is the identification of subgroups of diseases/patients that will truly benefit from specific treatments. Ideally, convenient and minimally invasive tests to decipher biomarkers of chemosensitivity/resistance and toxicity should be developed alongside novel anticancer treatments. Integration with the latest generation of whole-genome analyses and liquid biopsies as well as prospective validation in large cohorts of patients will overcome the limitations of the traditional pharmacogenetic approaches.

Clinical Trials in Precision Oncology

BACKGROUND

Availability of genomic information used in the management of cancer treatment has outpaced both regulatory and reimbursement efforts. Many types of clinical trials are underway to validate the utility of emerging genome-based biomarkers for diagnostic, prognostic, and predictive applications. Clinical trials are a key source of evidence required for US Food and Drug Administration approval of therapies and companion diagnostics and for establishing the acceptance criteria for reimbursement.

CONTENT

Determining the eligibility of patients for molecular-based clinical trials and the interpretation of data emerging from clinical trials is significantly hampered by 2 primary factors: the lack of specific reporting standards for biomarkers in clinical trials and the lack of adherence to official gene and variant naming standards. Clinical trial registries need specifics on the mutation required for enrollment as opposed to allowing a generic mutation entry such as, "EGFR mutation." The use of clinical trials data in bioinformatics analysis and reporting is also gated by the lack of robust, state of the art programmatic access support. An initiative is needed to develop community standards for clinical trial descriptions and outcome reporting that are modeled after similar efforts in the genomics research community.

SUMMARY

Systematic implementation of reporting standards is needed to insure consistency and specificity of biomarker data, which will in turn enable better comparison and assessment of clinical trial outcomes across multiple studies. Reporting standards will facilitate improved identification of relevant clinical trials, aggregation and comparison of information across independent trials, and programmatic access to clinical trials databases.

MTHFR C677T Polymorphism is Associated with Tumor Response to Preoperative Chemoradiotherapy: A Result Based on Previous Reports

BACKGROUND

Preoperative chemoradiotherapy (pRCT) followed by surgery has been widely practiced in locally advanced rectal cancer, esophageal cancer, gastric cancer and other cancers. However, the therapy also exerts some severe adverse effects and some of the patients show poor or no response. It is very important to develop biomarkers (e.g., gene polymorphisms) to identify patients who have a higher likelihood of responding to pRCT. Recently, a series of reports have investigated the association of the genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and epidermal growth factor receptor (EGFR) genes with the tumor response to pRCT; however, the results were inconsistent and inconclusive.

MATERIAL AND METHODS

A systematic review and meta-analysis was performed by searching relevant studies about the association of MTHFR and EGFR polymorphisms with the tumor regression grade (TRG) in response to pRCT in databases of PubMed, EMBAS, Web of science, Chinese National Knowledge Infrastructure, and Wanfang database up to March 30, 2015. The pooled odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs) were calculated to assess the strength of the association under 5 genetic models.

RESULTS

A total of 11 eligible articles were included in the present meta-analysis, of which 8 studies were performed in rectal cancer and 3 studies were performed in esophageal cancer. We finally included 8 included studies containing 839 cases for MTHFR C677T, 5 studies involving 634 cases for MTHFR A1298C, 3 studies containing 340 cases for EGFR G497A, and 4 studies containing 396 cases for EGFR CA repeat. The pooled analysis results indicated that MTHFR C677T might be correlated with the tumor response to pRCT under the recessive model (CC vs. CTTT) in overall analysis (OR=1.426(1.074-1.894), P=0.014), rectal cancer (OR=1.483(1.102-1.996), P=0.009), and TRG 1-2 vs. 3-5 group (OR=1.423(1.046-1.936), P=0.025), while other polymorphism including MTHFR A1298C, EGFR G497A, and EGFR CA repeat polymorphisms exerted significant association under all genetic models in overall analysis or subgroup analysis.

CONCLUSIONS

MTHFR C677T might be correlated with the tumor response to pRCT. Further well-designed, larger-scale epidemiological studies are needed to validate our results.

Identification of epidermal growth factor receptor (EGFR) genetic variants that modify risk for head and neck squamous cell carcinoma

EGFR polymorphisms have not been thoroughly evaluated for association with head and neck squamous cell carcinoma (HNSCC) risk. We genotyped 578 HNSCC patients and 588 cancer-free controls for 60 EGFR single nucleotide polymorphisms (SNPs) and tested associations with HNSCC risk. EGFR intronic SNPs rs12535536, rs2075110, rs1253871, rs845561 and rs6970262 and synonymous SNP rs2072454 were associated with HNSCC risk among all subjects (p < 0.05). SNPs rs12538371, rs845561, and rs6970262 were significantly associated with HNSCC risk (p < 0.05) among never tobacco users. We identified EGFR variants that likely modify risk for HNSCC including three variants that contribute to tobacco-independent risk.

EGF and EGFR genetic polymorphisms predict prognosis in locally advanced pharyngolaryngeal squamous cell carcinoma patients receiving postoperative concurrent chemoradiotherapy

Background

Epidermal growth factor (EGF) and its receptor (EGFR) are part of an important signaling pathway that is involved in the pathogenesis of squamous cell carcinoma of the head and neck (SCCHN). We hypothesized that EGF/EGFR genetic polymorphisms might have a prognostic impact on disease-free survival and overall survival (OS) in locally advanced SCCHN.

Materials and methods

The patient group included a consecutive cohort of 180 patients with locally advanced SCCHN who underwent postoperative concurrent chemoradiotherapy between 2002 and 2010. DNA from formalin-fixed, paraffin-embedded tumor tissues was genotyped for the single nucleotide polymorphism (SNP) of EGF A61G A>G, EGFR R521K G>A and G-216T. The log-rank test was applied to evaluate the impact of SNPs on the outcomes. Survival was estimated using the Kaplan–Meier statistical method.

Results

We demonstrated that EGF/EGFR SNPs might predict prognosis in patients with primary pharyngolaryngeal tumors, but not in those with oral cavity tumors. In pharyngolaryngeal tumor subgroup, EGF61 G/G genotype led to worse 5 year OS rate when compared to G/A or A/A genotypes (13.3% versus 34.3% versus 50.0%, P=0.017). The 5 year OS of patients with EGFR R521K G/G (11.1%) and G/A (15.9%) were lower than the A/A (62.5%) genotype (P=0.054). Patients carrying one or two unfavorable alleles had worse 5 year OS than those without unfavorable allele (not available versus 20% versus 71.4%, P=0.002). Multivariate analysis revealed that the highest risk of death was associated with the coexistence of two unfavorable genotypes (hazard ratio 25.7, 95% confidence interval =3.4–193.4; P=0.002).

Conclusion

In this study, we were able to demonstrate that the EGF A61G and EGFR R521K genetic polymorphisms might be important prognostic factors in patients with locally advanced primary pharyngolaryngeal squamous cell carcinoma who underwent postoperative concurrent chemoradiotherapy.

A Meta-Analysis on the Relations between EGFR R521K Polymorphism and Risk of Cancer

The EGFR R521K polymorphism has been shown to reduce the activity of EGFR; however, the association between EGFR R521K polymorphism and the risk of cancer remains inconclusive; therefore we performed a meta-analysis to evaluate the relationship between EGFR R521K polymorphism and susceptibility to cancer. Our results suggest that the EGFR R521K polymorphism is not associated with risk of cancer, but the different chemosensitivity to anticancer drugs may need further investigation.

A pilot study on EGFR-targeted molecular imaging of PET/CT With 11C-PD153035 in human gliomas

11C-PD153035, a potent and specific ATP-competitive tyrosine kinase inhibitor (TKI) of the EGF receptor, has been developed for PET imaging of epidermal growth factor receptor (EGFR) in lung cancer. The objective of the present study was to investigate the relationship of the accumulation of 11C-PD153035 and the EGFR expression level in human gliomas and to explore whether 11C-PD153035 can be used in the molecular imaging of glioma with EGFR overexpression. Eleven patients with histopathologically proven gliomas underwent 11C-PD153035 PET/CT examination before surgery. Combining MRI with the 11C-PD153035 PET/CT image, 2 specimens from different C-PD153035 uptake regions of each tumor and adjacent normal brain tissue were selected as the biopsy targets through the stereotactic technique. The radioactivity concentrations were analyzed as the mathematical maximum standardized uptake value (SUVmax) in region of interest (ROI). The EGFR expression in the biopsied tissues was analyzed by immunohistochemical staining (IHC) and western blotting. The SUVmax/WM (11C-PD153035 uptake in the white matter of the contralateral normal hemisphere) ratio was used to indicate the EGFR expression level in the ROI in PET/CT, and it was correlated with the EGFR expression detected by IHC and western blot analysis. The results demonstrated that 6 of the 8 patients with glioblastoma (GBM) were obviously visualized by 11C-PD153035 PET/CT, whereas 2 patients with GBM, 1 with anaplastic astrocytoma, and 2 with oligodendroglioma did not show significant 11C-PD153035 uptake. There were positive correlations between the SUVmax/WM and the results of IHC (r = 0.955, P < 0.01) and western blotting(r = 0.889, P < 0.010). Our preliminary findings suggest that 11C-PD153035 PET/CT is a promising method for the EGFR-targeted molecular imaging of human GBM, which may be translated into the clinic to select the appropriate population of patients for EGFR-targeted therapy and to assess the early targeted therapeutic response of malignant gliomas.

Genetic variants of EGF and VEGF predict prognosis of patients with advanced esophageal squamous cell carcinoma

PURPOSE

To investigate the association between genetic polymorphisms of growth factor-related genes and prognosis in patients with advanced esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

A total of 334 ESCC patients with advanced tumor stages (stages IIB, III and IV) were enrolled in the study. The genotypes of 14 candidate single nucleotide polymorphisms (SNPs) involved in growth factor-related functions were analyzed using iPLEX Gold technology from the genomic DNA of peripheral leukocytes, and were correlated with the clinical outcome of patients. Serum levels of growth factors were examined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The genetic polymorphisms of EGF:rs4444903, EGF:rs2237051 and VEGF:rs2010963 showed significant associations with overall survival (OS) of advanced ESCC patients (A/A+ A/G vs. GG, [HR = 0.77, 95% CI = 0.60-0.99, P = 0.039 for rs4444903; A/G+ G/G vs. A/A, [HR = 0.74, 95% CI = 0.58-0.95, P = 0.019 for rs2237051; G/G+G/C vs. C/C, [HR] inves = 0.69, 95% CI = 0.50-0.95, P = 0.023 for rs2010963). EGFR:rs2227983 and 3 SNPs of PIK3CA also showed borderline significant correlation with OS of advanced ESCC patients (P = 0.058 for rs2227983; P = 0.069, 0.091 and 0.067 for rs6443624, rs7651265 and rs7621329 of PIK3CA respectively). According to cumulative effect analysis of multiple SNPs, patients carrying 4 unfavorable genotypes exhibited more than a 3-fold increased risk of mortality. Finally, both EGF and VEGF expression levels significantly associated with patient mortality.

CONCLUSION

The genetic variants and expression levels of EGF and VEGF can serve as prognostic predictors in patients with advanced ESCC, and thus provide more information for optimizing personalized therapies for patients with ESCC.

MUC5AC and inflammatory mediators associated with respiratory outcomes in the British 1946 birth cohort

Background and objective: Dysregulation of respiratory mucins, MUC5AC in particular, has been implicated in respiratory disease and MUC5AC expression is up-regulated in response to environmental challenges and inflammatory mediators. The aim of this study was to examine the effect of genetic variation on susceptibility to common respiratory conditions.

Methods: The association of MUC5AC and the closely linked genes MUC2 and MUC5B with respiratory outcomes was tested in the MRC National Survey of Health and Development, a longitudinal birth cohort of men and women born in 1946. Also examined were the functional variants of the genes encoding inflammatory mediators, IL13, IL1B, IL1RN, TNFA and ERBB1, for which there is a likely influence on MUC5AC expression and were explored potential gene-gene interactions with these inflammatory mediators.

Results: Statistically significant associations between the 3'ter MUC5AC simple nucleotide polymorphism (SNP) rs1132440 and various non-independent respiratory outcomes (bronchitis, wheeze, asthma, hay fever) were reported while the adjacent loci show slight (but largely non-statistically significant) differences, presumably reflective of linkage disequilibrium (allelic association) across the region. A novel association between bronchitis and a non-synonymous functional ERBB1 SNP, rs2227983 (aka epidermal growth factor receptor:R497K, R521K) is also reported and evidence presented of interaction between MUC5AC and ERBB1 and between MUC5AC and IL1RN with respect to bronchitis. The ERBB1 result suggests a clear mechanism for a biological interaction in which the allelic variants of epidermal growth factor receptor differentially affect mucin expression.

Conclusions: The MUC5AC association and the interactions with inflammatory mediators suggest that genetically determined differences in MUC5AC expression alter susceptibility to respiratory disease.

SUMMARY AT A GLANCE

This longitudinal cohort study shows occurrence of the common respiratory conditions bronchitis, wheeze, asthma and hay fever to be associated with genetic variation in a mucin gene, MUC5AC. Functional variation in the epidermal growth factor receptor (epidermal growth factor receptor encoded by ERBB1) is also associated with bronchitis and modulates the MUC5AC effect.

Epidermal growth factor receptor (EGFR) pathway genes and interstitial lung disease: an association study

The etiology and pathogenesis of idiopathic interstitial lung disease (ILD) remain incompletely understood. Genetic susceptibility to ILD has been demonstrated in previous studies. It is well known that EGFR inhibitors can induce ILD in human lung cancer patient with ethnic differences, which prompted us to hypothesize that genetic variation in EGFR pathway genes confer susceptibility to ILD. We aimed in this study to investigate whether functional polymorphisms of EGFR and its ligands genes (EGF and TGFA) were associated with ILD. Three EGFR [-216G/T (rs712830), -191A/C (rs712829), 497R > K(A/G) (rs2227983)], one EGF [61A/G, (rs4444903)] and one TGFA (rs3821262C/T) polymorphisms previously demonstrated to alter gene functions were genotyped in 229 sporadic idiopathic ILD patients and 693 normal healthy individuals. Allelic and genotypic association tests between these polymorphisms and ILD were performed. The EGF 61A/G polymorphism was significantly associated with elevated risk of ILD, with the frequency of G allele significantly increased in the ILD patient population (OR = 1.33, 95%CI = 1.07-1.66, P = 0.0099). None of the other polymorphisms were associated with risk of ILD. Our study suggested that the EGF 61A/G polymorphism may be associated with sporadic ILD. While a false positive finding cannot be excluded, independent studies are warranted to further validate this result.

The role of endogenous epidermal growth factor receptor ligands in mediating corneal epithelial homeostasis

PURPOSE

To provide a comprehensive study of the biological role and therapeutic potential of six endogenous epidermal growth factor receptor (EGFR) ligands in corneal epithelial homeostasis.

METHODS

Kinetic analysis and dose response curves were performed by using in vitro and in vivo wound-healing assays. Biochemical assays were used to determine receptor expression and activity. Human tears were collected and quantitatively analyzed by multianalyte profiling for endogenous EGFR ligands.

RESULTS

Epidermal growth factor receptor ligands improved wound closure and activated EGFR, but betacellulin (BTC) was the most efficacious promoter of wound healing in vitro. In contrast, only epidermal growth factor (EGF) promoted wound healing in vivo. Human tears from 25 healthy individuals showed EGFR ligands at these average concentrations: EGF at 2053 ± 312.4 pg/mL, BTC at 207 ± 39.4 pg/mL, heparin-binding EGF at 44 ± 5.8 pg/mL, amphiregulin at 509 ± 28.8 pg/mL, transforming growth factor-α at 84 ± 19 pg/mL, and epiregulin at 52 ± 15 pg/mL.

CONCLUSIONS

Under unwounded conditions, only EGF was present at concentrations near the ligand's Kd for the receptor, indicating it is the primary mediator of corneal epithelial homeostasis. Other ligands were present but at concentrations 11- to 7500-fold less their Kd, preventing significant ligand binding. Further, the high levels of EGF and its predicted binding preclude receptor occupancy by exogenous ligand and can explain the discrepancy between the in vitro and in vivo data. Therefore, therapeutic use of EGFR ligands may be unpredictable and impractical.

Epidermal growth factor receptor gene polymorphisms are associated with prognostic features of breast cancer

BACKGROUND

The epidermal growth factor receptor (EGFR) is differently expressed in breast cancer, and its presence may favor cancer progression. We hypothesized that two EGFR functional polymorphisms, a (CA)n repeat in intron 1, and a single nucleotide polymorphism, R497K, may affect EGFR expression and breast cancer clinical profile.

METHODS

The study population consisted of 508 Brazilian women with unilateral breast cancer, and no distant metastases. Patients were genotyped for the (CA)n and R497K polymorphisms, and the associations between (CA)n polymorphism and EGFR transcript levels (n = 129), or between either polymorphism and histopathological features (n = 505) were evaluated. The REMARK criteria of tumor marker evaluation were followed.

RESULTS

(CA)n lengths ranged from 14 to 24 repeats, comprehending 11 alleles and 37 genotypes. The most frequent allele was (CA)16 (0.43; 95% CI = 0.40-0.46), which was set as the cut-off length to define the Short allele. Variant (CA)n genotypes had no significant effect in tumoral EGFR mRNA levels, but patients with two (CA)n Long alleles showed lower chances of being negative for progesterone receptor (ORadjusted = 0.42; 95% CI = 0.19-0.91). The evaluation of R497K polymorphism indicated a frequency of 0.21 (95% CI = 0.19 - 0.24) for the variant (Lys) allele. Patients with variant R497K genotypes presented lower proportion of worse lymph node status (pN2 or pN3) when compared to the reference genotype Arg/Arg (ORadjusted = 0.32; 95% CI = 0.17-0.59), which resulted in lower tumor staging (ORadjusted = 0.34; 95% CI = 0.19-0.63), and lower estimated recurrence risk (OR = 0.50; 95% CI = 0.30-0.81). The combined presence of both EGFR polymorphisms (Lys allele of R497K and Long/Long (CA)n) resulted in lower TNM status (ORadjusted = 0.22; 95% CI = 0.07-0.75) and lower ERR (OR = 0.25; 95% CI = 0.09-0.71). When tumors were stratified according to biological classification, the favorable effects of variant EGFR polymorphisms were preserved for luminal A tumors, but not for other subtypes.

CONCLUSIONS

The data suggest that the presence of the variant forms of EGFR polymorphisms may lead to better prognosis in breast cancer, especially in patients with luminal A tumors.

Cell and molecular biology of epidermal growth factor receptor

The epidermal growth factor receptor (EGFR) has been one of the most intensely studied cell surface receptors due to its well-established roles in developmental biology, tissue homeostasis, and cancer biology. The EGFR has been critical for creating paradigms for numerous aspects of cell biology, such as ligand binding, signal transduction, and membrane trafficking. Despite this history of discovery, there is a continual stream of evidence that only the surface has been scratched. New ways of receptor regulation continue to be identified, each of which is a potential molecular target for manipulating EGFR signaling and the resultant changes in cell and tissue biology. This chapter is an update on EGFR-mediated signaling, and describes some recent developments in the regulation of receptor biology.

Intergenic polymorphisms in the amphiregulin gene region as biomarkers in metastatic colorectal cancer patients treated with anti-EGFR plus irinotecan

In the epidermal growth factor receptor (EGFR) pathway, polymorphisms in EGFR and its ligand EGF have been studied as biomarkers for anti-EGFR treatment. However, the potential pharmacogenetic role of other EGFR ligands such as amphiregulin (AREG) and epiregulin (EREG) has not been elucidated. We studied 74 KRAS and BRAF wild-type metastatic colorectal cancer patients treated with anti-EGFR plus irinotecan. Twenty-two genetic variants in EGFR, EGF, AREG and EREG genes were selected using HapMap database and literature resources. Three tagging single-nucleotide polymorphisms in the AREG gene region (rs11942466 C>A, rs13104811 A>G, and rs9996584 C>T) predicted disease control in the multivariate analyses. AREG rs11942466 C>A and rs9996584 C>T were also associated with overall survival (OS). The functional polymorphism, EGFR rs712829 G>T, was associated with progression-free and OS. Our findings support that intergenic polymorphisms in the AREG gene region might help to identify colorectal cancer patients that will benefit from irinotecan plus anti-EGFR therapy.

Allele Frequencies of the Epidermal Growth Factor Receptors Polymorphism R521K in Colorectal Cancer Patients and Healthy Subjects Indicate a Risk-Reducing Effect of K521 in Syrian Population

Background:

Colorectal cancer contributes heavily to cancer morbidity and mortality worldwide. Numerous therapies are currently in use, including monoclonal antibodies against cellular components involved in tumorigenesis such as epidermal growth factor receptors (EGFRs). Studies showed the polymorphism [R521K] GàA in the EGFR gene to be involved in both colorectal cancer susceptibility and clinical response to therapeutics (e.g., Cetuximab).

Aim:

We aimed at uncovering allele frequencies of this polymorphism among Syrian colorectal cancer patients and healthy individuals.

Materials and Methods:

Forty-seven patients with colorectal cancer were included in a case-control study along with 48 healthy subjects, all native Syrians. Individuals were genotyped using PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) and results were statistically analyzed to elucidate significant differences between the two groups.

Results:

Allele frequencies were 40.4% (G/G), 57.4% (G/A) and 2.1% (A/A) in colorectal cancer patients and 41.6% (G/G), 43.7% (G/A) and 14.5% (A/A) in healthy subjects. The A/A genotype was significantly lower in colorectal cancer patients than in the control group.

Conclusions:

Homozygosity for the A allele is linked to reducing the risk of developing colorectal cancer in Syrian patients. The lower prevalence of (A/A) locally may predict sub-optimal rates of clinical response to Cetuximab compared with populations with higher frequencies of the A allele. Larger scale investigations are needed for a stronger conclusion.

MTHFR Glu429Ala and ERCC5 His46His polymorphisms are associated with prognosis in colorectal cancer patients: analysis of two independent cohorts from Newfoundland

Introduction

In this study, 27 genetic polymorphisms that were previously reported to be associated with clinical outcomes in colorectal cancer patients were investigated in relation to overall survival (OS) and disease free survival (DFS) in colorectal cancer patients from Newfoundland.

Methods

The discovery and validation cohorts comprised of 532 and 252 patients, respectively. Genotypes of 27 polymorphisms were first obtained in the discovery cohort and survival analyses were performed assuming the co-dominant genetic model. Polymorphisms associated with disease outcomes in the discovery cohort were then investigated in the validation cohort.

Results

When adjusted for sex, age, tumor stage and microsatellite instability (MSI) status, four polymorphisms were independent predictors of OS in the discovery cohort MTHFR Glu429Ala (HR: 1.72, 95%CI: 1.04–2.84, p = 0.036), ERCC5 His46His (HR: 1.78, 95%CI: 1.15–2.76, p = 0.01), SERPINE1 −675indelG (HR: 0.52, 95%CI: 0.32–0.84, p = 0.008), and the homozygous deletion of GSTM1 gene (HR: 1.4, 95%CI: 1.03–1.92, p = 0.033). In the validation cohort, the MTHFR Glu429Ala polymorphism was associated with shorter OS (HR: 1.71, 95%CI: 1.18–2.49, p = 0.005), although with a different genotype than the discovery cohort (CC genotype in the discovery cohort and AC genotype in the validation cohort). When stratified based on treatment with 5-Fluorouracil (5-FU)-based regimens, this polymorphism was associated with reduced OS only in patients not treated with 5-FU. In the DFS analysis, when adjusted for other variables, the TT genotype of the ERCC5 His46His polymorphism was associated with shorter DFS in both cohorts (discovery cohort: HR: 1.54, 95%CI: 1.04–2.29, p = 0.032 and replication cohort: HR: 1.81, 95%CI: 1.11–2.94, p = 0.018).

Conclusions

In this study, associations of the MTHFR Glu429Ala polymorphism with OS and the ERCC5 His46His polymorphism with DFS were identified in two colorectal cancer patient cohorts. Our results also suggest that the MTHFR Glu429Ala polymorphism may be an adverse prognostic marker in patients not treated with 5-FU.

[Effects of EGFR gene polymorphisms on efficacy and prognosis in advanced non-small cell lung cancer treated with EGFR-TKIs]

表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor tyrosine kinase inhibitors, EGFR-TKIs）在晚期非小细胞肺癌患者（non-small cell lung cancer, NSCLC）中的应用越来越广泛，但患者的疗效存在明显差异。目前主要是根据EGFR基因突变来选择患者，然而，其检测常受到肿瘤组织来源困难、技术复杂、费用高等因素限制。因此，临床亟待寻求其他生物学标记物来预测EGFR-TKIs疗效。近来有诸多研究发现EGFR基因多态性与晚期NSCLC患者EGFR-TKIs疗效及预后也存在相关性，现将其研究进展作一综述。

Germline prognostic markers for urinary bladder cancer: obstacles and opportunities

Urinary bladder cancer is a heterogeneous disease with diverse genetic and environmental risk factors that can influence disease risk or clinical course for recurrence, progression, and survival. Therefore, identification of these factors is paramount for disease prevention and optimal clinical management of bladder cancer patients. Of particular interest is the need to identify molecular biomarkers that can give accurate assessment of tumor biological potential and to predict treatment response. Recent advances in molecular biology, cytogenetic, and genomic research have spurred discovery efforts for novel genetic, epigenetic, and proteomic biomarkers that are prognostic for cancer. This review focuses on some of the important germ line polymorphisms found to be correlated with clinical outcomes in bladder cancer. So far, most of the identified candidate loci were based on prior knowledge of pathogenesis and had not been validated for clinical applications. The future challenges are to analyze the wealth of information from whole-genome studies, to understand the underlying biological mechanisms of these associations, the network of gene-gene and gene-environment interactions, and to apply these markers for the identification of high-risk population for targeted, personalized therapy.

EGF receptor-targeted therapy in non-small-cell lung cancer: role of germline polymorphisms in outcome and toxicity

Conventional chemotherapeutic regimens have limited impact against most solid tumors and deal with significant toxicity. Over the last 10 years, novel anticancer treatments targeting specific molecules or genes involved in cancer progression have been developed to improve outcome and reduce side effects. In particular, the tyrosine kinase inhibitors gefitinib and erlotinib have been approved for the treatment of non-small-cell lung cancer. Their clinical activity has been related to different clinical and biological parameters, such as EGFR-activating mutations. However, not all clinical outcomes, including tolerability, are explained, and the identification/validation of novel biomarkers is a viable area of research. Germline polymorphisms can be easily assessed in blood samples, and candidate polymorphisms in EGFR and ABCG2 have been correlated with outcome and toxicity in non-small-cell lung cancer patients treated with gefitinib or erlotinib. However, differences in study population and design resulted in several controversial findings, while the prognostic versus predictive role of the polymorphisms still needs to be validated within larger prospective studies. More studies on the relationship of the genotype with drug pharmacokinetics and mechanism of action are also warranted. These future studies, as well as further development and application of novel technologies to decipher genetic alterations, might contribute to the validation of selected polymorphisms as molecular markers predictive of drug activity and help in the selection of tyrosine kinase inhibitors best suited to the individual patient.

Association of epidermal growth factor receptor gene polymorphisms with advanced endometriosis in a Korean population

OBJECTIVES

To determine if specific single nucleotide polymorphisms (SNPs) in the Epidermal Growth Factor Receptor (EGFR) gene were meaningful markers for the risk of advanced stage endometriosis in a Korean population.

STUDY DESIGN

Case-control study in a collective of 299 women with endometriosis and 285 controls. Three polymorphisms (151904 A>T [T628T] on exon 16 [rs 17337023], 162093 G>A [Q787Q] on exon 20 [rs 10251977], and 181946 C>T [D994D] on exon 25 [rs 2293347]) were assessed by a Minor Groove Binder (MGB) primer/probe Taqman assay. In-silico haplotypes were deduced using the Haploview (version 3.32) software package.

RESULTS

There were no statistically significant differences in the genotype or haplotype frequencies of the three EGFR polymorphisms between subjects with endometriosis versus the control group. Even when the endometriosis cases were subdivided into stage III and IV based on the ASRM criteria, no statistically significant differences in genotype distribution or haplotype frequencies were observed between the three groups.

CONCLUSIONS

Our results suggest that the 151904 A>T, 162093 G>A, and 181946 C>T polymorphisms in the EGFR gene are not associated with advanced stage endometriosis in a Korean population. Our results are in agreement with the results reported by Inagaki et al.

Can population differences in chemotherapy outcomes be inferred from differences in pharmacogenetic frequencies?

Inter-ethnic differences in drug handling and frequencies of pharmacogenetic variants are increasingly being characterized. In this study, we systematically assessed the feasibility of inferring ethnic trends in chemotherapy outcomes from inter-ethnic differences in pharmacogenetic variant frequencies. Frequencies of 51 variants and chemotherapy outcomes of East Asian and Caucasian colorectal cancer patients on standard chemotherapy regimens were summarized by meta-analyses, and variant frequencies were validated by MassARRAY analysis. Inferences of relative chemotherapy outcomes were made by considering minor allele function and population differences in their frequency. Significant population differences in genotype distributions were observed for 13/23 (60%) and 27/35 (77%) variants in the meta-analyses and validation series, respectively. Across chemotherapy regimens, East Asians had lower rates of grade 3/4 toxicity for diarrhea and stomatitis/mucositis than Caucasians, which was correctly inferred from 13/18 (72%, P=0.018) informative genetic variants. With appropriate variant selection, inferring relative population toxicity rates from population genotype differences may be relevant.

Prognostic and predictive biomarkers for epidermal growth factor receptor-targeted therapy in colorectal cancer: beyond KRAS mutations

The advent of the epidermal growth factor receptor (EGFR)-targeted monoclonal antibodies (mAbs), cetuximab and panitumumab has expanded the range of treatment options for metastatic colorectal cancer (CRC). Despite these agents have paved the way to individualized therapy, our understanding why some patients respond to treatment whereas others do not remain poor. The realization that detection of positive EGFR expression by IHC does not reliably predict clinical outcome of EGFR-targeted treatment has led to an intense search for alternative predictive biomarkers. Data derived from multiple phase III trials have indicated that KRAS mutations can be considered a highly specific negative biomarker of benefit to anti-EGFR mAbs. Oncologists are now facing emerging issues in the treatment of metastatic CRC, including the identification of additional genetic determinants of primary resistance to EGFR-targeted therapy for further improving selection of patients, the explanation of rare cases of patients carrying KRAS-mutated tumours who have been reported to respond to cetuximab and panitumumab and the discovery of mechanisms of secondary resistance to EGFR-targeted therapy. Current data suggest that, together with KRAS mutations, the evaluation of EGFR gene copy number (GCN), BRAF, NRAS, PIK3CA mutations or loss of PTEN expression could also be useful for selecting patients with reduced chance to benefit from anti-EGFR mAbs. This review aims to provide an updated of the most recent data on predictive and prognostic biomarkers within the EGFR pathway, the challenges this emerging field presents and the future role of these molecular markers in CRC treatment.

Epidermal growth factor receptor R521K polymorphism shows favorable outcomes in KRAS wild-type colorectal cancer patients treated with cetuximab-based chemotherapy

The R521K polymorphism of epidermal growth factor receptor has attenuated affinity in ligand binding and proto-oncogene induction, which may affect the efficacy of cetuximab. We analyzed the effect of this polymorphism on the outcome of 112 patients with KRAS wild-type metastatic colorectal carcinoma treated with first-line cetuximab plus FOLFOX-4. The associations of this polymorphism with vascular endothelial growth factor (VEGF) expression and clinicopathologic characteristics were also examined. The results showed that the frequencies of the G/G, G/A, and A/A genotypes were 32.1% (n = 36), 42.9% (n = 48), and 25.0% (n = 28), respectively. A marked decrease in VEGF expression levels (66.7% vs 28.9%, P < 0.01) was observed in patients with 521A allele variants (Arg/Lys or Lys/Lys), which were associated with a decreased tumor size (55.6% vs 31.6%, P = 0.02), good histological differentiation (63.9% vs 85.5%, P = 0.01), decreased lymphovascular invasion (69.4% vs 39.5%, P < 0.01), and a higher response rate to cetuximab plus FOLFOX treatment (55.6% vs 78.9%, P = 0.01). In addition, this polymorphism was associated with a longer progression-free period (P = 0.001) and overall survival (P = 0.001). By multivariate analysis, this polymorphism was also identified as an independent prognostic factor. These data suggest that the R521K polymorphism of epidermal growth factor receptor, by reducing its activation and a consequential downregulation of its target genes, including VEGF, could be a key determinant of an increased response to cetuximab-based chemotherapy and a longer survival for KRAS wild-type colorectal carcinoma patients.

Pharmacogenetic profiling and cetuximab outcome in patients with advanced colorectal cancer

Background

We analyzed the influence of 8 germinal polymorphisms of candidate genes potentially related to EGFR signalling (EGFR, EGF, CCND1) or antibody-directed cell cytotoxicity (FCGR2A and FCGR3A) on outcome of colorectal cancer (CRC) patients receiving cetuximab-based therapy.

Methods

Fifty-eight advanced CRC patients treated with cetuximab-irinotecan salvage therapy between 2001 and 2007 were analyzed (mean age 60; 50 PS 0-1). The following polymorphisms were analyzed on blood DNA: EGFR (CA repeats in intron 1, -216 G > T, -191C > A, R497K), EGF (A61G), CCND1 (A870G), FCGR2A (R131H), FCGR3A (F158V). Statistical analyses were conducted on the total population and on patients with wt KRas tumors. All SNPs were considered as ternary variables (wt/wt vs wt/mut vs mut/mut), with the exception of -191C > A EGFR polymorphism (AA patient merged with CA patients).

Results

Analysis of skin toxicity as a function of EGFR intron 1 polymorphism showed a tendency for higher toxicity in patients with a low number of CA-repeats (p = 0.058). CCND1 A870G polymorphism was significantly related to clinical response, both in the entire population and in KRas wt patients, with the G allele being associated with a lack of response. In wt KRas patients, time to progression (TTP) was significantly related to EGFR -191C > A polymorphism with a longer TTP in CC patients as compared to others, and to CCND1 A870G polymorphism with the G allele being associated with a shorter TTP; a multivariate analysis including these two polymorphisms only retained CCND1 polymorphism. Overall survival was significantly related to CCND1 polymorphism with a shorter survival in patients bearing the G allele, and to FCGR3A F158V polymorphism with a shorter survival in VV patients (in the entire population and in KRas wt patients). FCGR3A F158V and CCND1 A870G polymorphisms were significant independent predictors of overall survival.

Conclusions

Present original data obtained in wt KRas patients corresponding to the current cetuximab-treated population clearly suggest that CCND1 A870G polymorphism may be used as an additional marker for predicting cetuximab efficacy, TTP and overall survival. In addition, FCGR3A F158V polymorphism was a significant independent predictor of overall survival.