Genotypes and haplotypes of the VEGF gene and survival in locally advanced non-small cell lung cancer patients treated with chemoradiotherapy

VEGF single nucleotide polymorphisms predict improved outcome in advanced non-small cell lung cancer patients treated with platinum-based chemotherapy

We aimed to investigate the prognostic role of genetic variants of VEGF in advanced NSCLC patients treated with platinum-based chemotherapy. A total of 196 patients with advanced NSCLC treated with first-line platinum-based chemotherapy were enrolled. We evaluated the relationship between VEGF polymorphisms and efficacy outcomes and chemotherapy toxicity. We found that rs699947, rs833061 and rs1005230 were in full linkage disequilibrium. Patients with CC genotype of rs833061 had a significant longer PFS than TT genotype (CC vs TT, HR = 1.67, 95%CI = 1.01-2.76, P = 0.043). Patients harbouring CC genotype had longer PFS compared with CT genotype (P < 0.001). Moreover, CC genotypes conferred a significantly increased PFS compared to CT and TT genotype in dominant model (CC vs CT + TT, HR = 1.95, 95%CI = 1.23-3.10, P = 0.005). Patients carrying TT genotype of rs833061 had improved both ORR (HR = 0.54, 95%CI = 0.30-0.98, P = 0.041) and DCR (HR = 0.37, 95%CI = 0.20-0.66, P = 0.001) than non-TT patients. Furthermore, no association was found between any rs833061 alleles and adverse events (P = 0.425), but patients carrying rs1570360 AA genotype were more likely to experience grade 3-4 toxicities (P = 0.004) (GG vs AA, HR = 3.16, 95%CI = 1.26-7.94, P = 0.015). In conclusion, the variant homozygote CC of rs833061 exhibited a better prognosis based on association analysis. The present study provides reference for the future study of platinum-based chemotherapy response and toxicity.

Prospective Exploratory Analysis of Angiogenic Biomarkers in Peripheral Blood in Advanced NSCLC Patients Treated With Bevacizumab Plus Chemotherapy: The ANGIOMET Study

Finding angiogenic prognostic markers in advanced non-small-cell lung cancer is still an unmet medical need. We explored a set of genetic variants in the VEGF-pathway as potential biomarkers to predict clinical outcomes of patients with non-small-cell lung cancer treated with chemotherapy plus bevacizumab. We prospectively analyzed the relationship between VEGF-pathway components with both pathological and prognostic variables in response to chemotherapy plus bevacizumab in 168 patients with non-squamous non-small-cell lung cancer. Circulating levels of VEGF and VEGFR2 and expression of specific endothelial surface markers and single-nucleotide polymorphisms in VEGF-pathway genes were analyzed. The primary clinical endpoint was progression-free survival. Secondary endpoints included overall survival and objective tumor response. VEGFR-1 rs9582036 variants AA/AC were associated with increased progression-free survival (p = 0.012 and p = 0.035, respectively), and with improved overall survival (p = 0.019) with respect to CC allele. Patients with VEGF-A rs3025039 harboring allele TT had also reduced mortality risk (p = 0.049) compared with the CC allele. The VEGF-A rs833061 variant was found to be related with response to treatment, with 61.1% of patients harboring the CC allele achieving partial treatment response. High pre-treatment circulating levels of VEGF-A were associated with shorter progression-free survival (p = 0.036). In conclusion, in this prospective study, genetic variants in VEGFR-1 and VEGF-A and plasma levels of VEGF-A were associated with clinical benefit, progression-free survival, or overall survival in a cohort of advanced non-squamous non-small-cell lung cancer patients receiving chemotherapy plus antiangiogenic therapy.

Hypoxia in Lung Cancer Management: A Translational Approach

Simple Summary

Hypoxia is a common feature of lung cancers. Nonetheless, no guidelines have been established to integrate hypoxia-associated biomarkers in patient management. Here, we discuss the current knowledge and provide translational novel considerations regarding its clinical detection and targeting to improve the outcome of patients with non-small-cell lung carcinoma of all stages.

Abstract

Lung cancer represents the first cause of death by cancer worldwide and remains a challenging public health issue. Hypoxia, as a relevant biomarker, has raised high expectations for clinical practice. Here, we review clinical and pathological features related to hypoxic lung tumours. Secondly, we expound on the main current techniques to evaluate hypoxic status in NSCLC focusing on positive emission tomography. We present existing alternative experimental approaches such as the examination of circulating markers and highlight the interest in non-invasive markers. Finally, we evaluate the relevance of investigating hypoxia in lung cancer management as a companion biomarker at various lung cancer stages. Hypoxia could support the identification of patients with higher risks of NSCLC. Moreover, the presence of hypoxia in treated tumours could help clinicians predict a worse prognosis for patients with resected NSCLC and may help identify patients who would benefit potentially from adjuvant therapies. Globally, the large quantity of translational data incites experimental and clinical studies to implement the characterisation of hypoxia in clinical NSCLC management.

Potentially functional variants of HBEGF and ITPR3 in GnRH signaling pathway genes predict survival of non-small cell lung cancer patients

The gonadotropin-releasing hormone (GnRH) signaling pathway controls reproductive functions and cancer growth and progression. However, few studies investigated roles of genetic variants of GnRH pathway genes in survival of patients with non-small cell lung cancer (NSCLC). Therefore, we first evaluated associations between 22,528 single-nucleotide polymorphisms (SNPs) in 101 GnRH pathway genes and survival of 1185 NSCLC patients using a dataset from Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. We found 572 SNPs to be significantly associated with overall survival (OS) of NSCLC (P ≤ 0.05, Bayesian false discovery probability ≤0.80). We then validated these SNPs in another dataset with 984 NSCLC patients from the Harvard Lung Cancer Susceptibility Study. Finally, two independent SNPs (HBEGF rs4150236G>A and ITPR3 rs116454384C>T) remained significantly associated with NSCLC OS in the combined analysis with hazards ratios of 0.84 (95% confidence interval = 0.76-0.92, P = 0.0003) and 0.85 (0.78-0.94, 0.0012), respectively; their genetic score (the number of protective genotypes) was associated with a better OS and disease-specific survival (P_trend = 0.0002 and 0.0001, respectively). Further expression quantitative trail loci analysis showed a significant correlation between ITPR3 rs116454384 T allele and an increased mRNA expression level in both whole blood and normal lung tissue, and high ITPR3 mRNA expression levels in tumors were associated with a better survival of NSCLC patients. Because ITPR3 mutations were rare in tumors, ITPR3 rs116454384C>T likely had an effect on cancer progression by regulating the gene expression. Therefore, genetic variants of HBEGF rs4150236G>A and ITPR3 rs116454384C>T may be predictors for NSCLC survival, but HBEGF rs4150236G>A functional relevance remains to be determined.

Prognostic effect of VEGF gene variants in metastatic non-small-cell lung cancer patients

INTRODUCTION

Clinical and pathological characteristics are still considered prognostic markers in metastatic non-small-cell lung cancer (NSCLC) patients but they cannot explain all interindividual variability. Tumoral angiogenesis mediated by the vascular endothelial growth factor (VEGF) is critical for the progression and metastasis of the disease. We aimed to investigate the prognostic role of genetic variants within the VEGF pathway in patients with metastatic NSCLC.

MATERIALS AND METHODS

We prospectively included 170 patients with metastatic NSCLC treated with first-line platinum-based chemotherapy. A comprehensive panel of single-nucleotide polymorphisms (SNPs) in genes belonging to the VEGF pathway (VEGFA, VEGFR1/FLT1, VEGFR2/KDR, GRB2, ITGAV, KISS1, KRAS, PRKCE, HIF1α, MAP2K4, MAP2K6, and MAPK11) were genotyped in blood DNA samples. SNPs were evaluated for association with overall survival (OS) and progression-free survival (PFS).

RESULTS

In multivariate analyses adjusted for patient characteristics, we found that VEGFA rs2010963 and VEGFR2 rs2071559 were significantly associated with OS [Hazard Ratio (HR) 0.7 (0.5-0.9); p = 0.026 and HR 1.5 (1.1-2.3); p = 0.025, respectively]. Additionally, ITGAV rs35251833 and MAPK11 rs2076139 were significantly associated with PFS [HR 2.5 (1.4-4.3; p = 0.002 and HR 0.6 (0.5-0.9); p = 0.013, respectively].

CONCLUSION

Our findings reinforce the potential clinical value of germline variants in VEGFA and VEGFR2 and show for the first time variants in ITGAV and MAPK11 as promising prognostic markers in metastatic NSCLC patients receiving platinum-based chemotherapy.

A microRNA‑125a variant, which affects its mature processing, increases the risk of radiation‑induced pneumonitis in patients with non‑small‑cell lung cancer

The present study aimed to investigate the role of microRNA (miR)‑125a in the development of pneumonitis inpatients with non‑small‑cell lung cancer that received radiotherapy. In addition, the study aimed to determine how the miR‑125a affects its target, transforming growth factor β (TGFβ). Bioinformatics tools were used to identify a potential miR‑125a binding site in the 3'untranslated region of TGFβ, which was subsequently confirmed using a dual‑luciferase reporter system. In addition, tissue samples were collected from patients with lung cancer and genotyped as CC (n=36), CT (n=28) or TT (n=6). The expression levels of miR‑125a and TGFβ in these samples were determined, and CC genotype samples demonstrated upregulated miR‑125a expression, and downregulated TGFβ protein and mRNA expression compared with samples carrying the minor allele, T. To further investigate the association between the rs12976445 polymorphism and the risk of pneumonitis in patients with lung cancer that received radiotherapy, 534 lung cancer patients diagnosed with pneumonitis and 489lung cancer patients without pneumonitis were recruited. rs12976445 was shown to be significantly associated with the risk of pneumonitis. In conclusion, the rs12976445 polymorphism increased expression levels of TGFβ by decreasing the expression of miR‑125a, and therefore may be associated with the development of pneumonitis in patients with lung cancer that receive radiotherapy.

Potentially Functional Variants of ATG16L2 Predict Radiation Pneumonitis and Outcomes in Patients with Non-Small Cell Lung Cancer after Definitive Radiotherapy

INTRODUCTION

Autophagy not only plays an important role in the progression of cancer but is also involved in tissue inflammatory response. However, few published studies have investigated associations between functional genetic variants of autophagy-related genes and radiation pneumonitis (RP) as well as clinical outcomes in patients with NSCLC after definitive radiotherapy.

METHODS

We genotyped nine potentially functional single-nucleotide polymorphisms (SNPs) in four autophagy-related genes (autophagy related 2B gene [ATG2B], autophagy related 10 gene [ATG10], autophagy related 12 gene [ATG12], and autophagy related 16 like 2 gene [ATG16L2]) in 393 North American patients with NSCLC treated by definitive radiotherapy and assessed their associations with RP, local recurrence-free survival (LRFS), progression-free survival (PFS), and overall survival (OS) in multivariable Cox proportional hazard regression analyses.

RESULTS

We found that patients with the ATG16L2 rs10898880 CC variant genotype had a better LRFS, PFS, and OS (adjusted hazard ratio = 0.59, 0.64, and 0.64; 95% confidence interval: 0.45-0.79, 0.48-0.84, and 0.48-0.86; p = 0.0004, 0.002, and 0.003, respectively), but a greater risk for development of severe RP (adjusted hazard ratio = 1.80, 95% confidence interval: 1.04-3.12, p = 0.037) than did patients with AA/AC genotypes. Further functional analyses suggested that the ATG16L2 rs10898880 C variant allele modulated expression of the ATG16L2 gene.

CONCLUSION

This is the first report that one potentially functional SNP rs10898880 in ATG16L2 may be a predictor of RP, LRFS, PFS, and OS in patients with NSCLC after definitive radiotherapy. Additional larger, prospective studies are needed to confirm these findings.

Blood-based biomarkers for precision medicine in lung cancer: precision radiation therapy

Both tumors and patients are complex and models that determine survival and toxicity of radiotherapy or any other treatment ideally must take into account this variability as well as its dynamic state. The genetic features of the tumor and the host, and increasingly also the epi-genetic and proteomic characteristics, are being unraveled. Multiple techniques, including histological examination, blood sampling, measurement of circulating tumor cells (CTCs), and functional and molecular imaging, can be used for this purpose. However, the effects of radiation on the tumor and on organs at risk (OARs) are also influenced by the applied dose and volume of irradiated tissues. Combining all these biological, clinical, imaging, and dosimetric parameters in a validated prognostic or predictive model poses a major challenge. Here we aimed to provide an objective review of the potential of blood markers to guide high precision radiation therapy. A combined biological-mathematical approach opens new doors beyond prognostication of patients, as it allows truly precise oncological treatment. Indeed, the core for individualized and precision medicine is not only selection of patients, but even more the optimization of the therapeutic window on an individual basis. A holistic model will allow for determination of an individual dose-response relationship for each organ at risk for each tumor in each individual patient for the complete oncological treatment package. This includes, but is not limited to, radiotherapy alone. Individualized dose-response curves will allow for consideration of different doses of radiation and combinations with other drugs to plan for both optimal toxicity and complete response. Insights into the interactions between a multitude of parameters will lead to the discovery of new pathways and networks that will fuel new biological research on target discovery.

Association between VEGF-460T/C gene polymorphism and clinical outcomes of nasopharyngeal carcinoma treated with intensity-modulated radiation therapy

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that plays a critical role in the development, metastasis, and recurrence of tumors. This study aims to determine the correlation of single-nucleotide polymorphisms in the VEGF gene with the prognosis of nasopharyngeal carcinoma (NPC). The VEGF -460T/C gene polymorphisms in the genomic DNA of the blood samples of 338 patients with NPC were investigated through polymerase chain reaction and direct DNA sequencing. Results showed a significant association between the -460C-allele carriers and the aggressive forms of NPC as defined by stages N2-3 (odds ratio =1.820, 95% confidence interval [CI]: 1.118-2.962, P=0.015). Furthermore, the VEGF -460T/C polymorphism was significantly associated with 3-year overall survival (OS), distant metastasis-free survival (DMFS), and progression-free survival (PFS) (T/C + C/C vs T/T: 3-year OS 78.8% vs 95.1%, P=0.003; 3-year DMFS 80.2% vs 90.6%, P=0.036; 3-year PFS 73.9% vs 86.7%, P=0.042) but was not associated with the local recurrence-free survival (LRFS) of the patients. The multivariate analysis indicated that the VEGF -460C-allele carrier was an independent significant prognostic factor for OS (hazard ratio [HR] 4.096, 95% CI: 1.333-12.591, P=0.014). N classification was an independent significant prognostic factor for DMFS in patients with locoregionally advanced NPC (HR 3.674, 95% CI: 1.144-11.792, P=0.029). However, neoadjuvant chemotherapy (NACT) followed by concurrent chemoradiotherapy (CCRT) was not superior to CCRT alone in terms of the 3-year OS, LRFS, DMFS, and PFS of patients with VEGF -460T/C polymorphism. In conclusion, the VEGF -460T/C gene polymorphism may negatively affect the clinical outcomes of patients with NPC and may be considered a potential prognostic factor for this disease.

The Different Effect of VEGF Polymorphisms on the Prognosis of Non-Small Cell Lung Cancer according to Tumor Histology

Vascular endothelial growth factor (VEGF) contributes to tumor angiogenesis. The role of VEGF single nucleotide polymorphisms (SNPs) in lung cancer susceptibility and its prognosis remains inconclusive and controversial. This study was performed to investigate whether VEGF polymorphisms affect survival outcomes of patients with early stage non-small cell lung cancer (NSCLC) after surgery. Three potentially functional VEGF SNPs (rs833061T>C, rs2010963G>C, and rs3025039C>T) were genotyped. A total of 782 NSCLC patients who were treated with surgical resection were enrolled. The association of the SNPs with overall survival (OS) and disease free survival (DFS) was analyzed. In overall population, none of the three polymorphisms were significantly associated with OS or DFS. However, when the patients were stratified by tumor histology, squamous cell carcinoma (SCC) and adenocarcinoma (AC) had significantly different OS (Adjusted hazard ratio [aHR] = 0.76, 95% CI = 0.56-1.03 in SCC; aHR = 1.33, 95% CI = 0.98-1.82 in AC; P for heterogeneity = 0.01) and DFS (aHR = 0.75, 95% CI = 0.58-0.97 in SCC; aHR = 1.26, 95% CI = 1.00-1.60 in AC; P for heterogeneity = 0.004) according to the rs833061T>C genotypes. Our results suggest that the prognostic role of VEGF rs833061T>C may differ depending on tumor histology.

The role of NOS2A -954G/C and vascular endothelial growth factor +936C/T polymorphisms in type 2 diabetes mellitus and diabetic nonproliferative retinopathy risk management

Type 2 diabetes mellitus (T2DM) remains one of the major health problems in Europe. Retinopathy is one of the major causes of morbidity in T2DM, strongly influencing the evolution and prognosis of these patients. In the last 2 decades, several studies have been conducted to identify the possible genetic susceptibility factors involved in the pathogenesis of the disease. However, there is little data related to the involvement of vascular endothelial growth factor (VEGF) and nitric oxide synthase (NOS) gene polymorphisms in the T2DM Caucasian population. The objective of this study was to identify a possible connection between NOS2A −954G/C (rs2297518) and VEGF +936C/T (rs3025039) polymorphisms and the risk of developing T2DM and nonproliferative diabetic retinopathy in a Caucasian population group. We investigated 200 patients diagnosed with T2DM and 208 controls. Genotypes were determined by multiplex polymerase chain reaction-restriction fragment length polymorphism. Statistical and comparative analyses (Fisher’s exact test) for dominant and recessive models of NOS2A −954G/C and VEGF +936C/T polymorphisms revealed an increased risk of T2DM (χ²=8.14, phi =0.141, P=0.004, odds ratio [OR] =2.795, 95% confidence interval [CI] =1.347–5.801; χ²=18.814, phi =0.215, P<0.001, OR =2.59, 95% CI =1.675–4.006, respectively). Also, comparative analysis for the recessive model (using Pearson’s chi-square test [χ²] and the phi coefficient [phi]) reveals that the variant CC genotype of NOS2A gene is more frequently associated with T2DM without retinopathy (χ²=3.835, phi =−0.138, P=0.05, OR =0.447, 95% CI =0.197–1.015). In conclusion, the results of the study place VEGF +936C/T polymorphisms among the genetic risk factor for T2DM, whereas NOS2A −954G/C polymorphisms act like a protective individual factor for nonproliferative retinopathy.

rs833061 and rs699947 on promoter gene of vascular endothelial growth factor (VEGF) and associated lung cancer susceptibility and survival: a meta-analysis

Background

As 2 important SNPs located in the promoter region of VEGF gene, the roles of rs833061 (−460C>T) and rs699947 (−2578C>A) in lung cancer susceptibility and survival remain inconclusive and controversial.

Material/Methods

For better understanding of these 2 SNPs in lung cancer risk and survival, a meta-analysis was performed to pool findings of previous studies and to generate large-scale evidence.

Results

Based on the 10 eligible studies included, this study observed that the −460C>T polymorphism generally had no significant effect on lung cancer risk. However, subgroup analysis found that −460TT homozygote variant might confer significantly increased cancer risk for Asians (TT vs. CC: OR=1.69, 95% CI 1.08–2.63, p=0.02), but not in Caucasians. Similar results were observed in −2578C>A in Asians (AA vs. CC: OR=3.00, 95% CI 1.51–5.95, p=0.002; AA vs. AC: OR=3.15, 95% CI 1.00–9.91, p=0.05; AA vs. (AC+CC): OR=2.92, 95% CI 1.51–5.65, p=0.001). In lung cancer survival, 4 trials included had conflicting results. One found −460C>T polymorphism had no effect on survival, 1 observed risk increasing, while the remaining 2 observed risk decreasing. This inconsistency was closely related to the different therapeutic practices applied in different studies, the effects of which were significantly affected by VEGF expression.

Conclusions

−460TT and −2578AA homozygote might lead to significantly increased cancer risk for Asians, but the effects on survival remain to be explored. These 2 SNPs might be potential indicators of lung cancer risk for Asians and should be considered when planning chemotherapy and radiotherapy for lung cancer patients.

Estimation of vascular endothelial growth factor gene -460 C/T polymorphism as a biomarker in oral squamous cell carcinoma patients from the Indian subcontinent

AIM

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies in India. Vascular endothelial growth factor (VEGF), a major mediator of angiogenesis, is known to play a key role in the pathophysiology of tumorigenesis. Polymorphisms of the VEGF gene have been shown to influence the risk of OSCC, but it remains to be elucidated in the Indian population. Thus, the present study was designed to detect the VEGF gene -460 C/T polymorphism in OSCC patients from the Indian population, which is genetically distinct from previously-studied populations.

METHODS

Peripheral blood samples of 80 OSCC patients and 80 healthy individuals were collected for a case-control study design. The VEGF gene -460 C/T polymorphism was detected by polymerase chain reaction-based restriction analysis.

RESULTS

The analysis revealed significant differences between normal individuals and patients with OSCC (P < 0.05). The distribution of the TT homozygote and the T allele in the patient group was significantly greater than in the control group.

CONCLUSION

The present study provides novel evidence of the role of the VEGF gene -460 C/T polymorphism as a suitable genetic marker of OSCC in the Indian population.

VEGF pathway polymorphisms as prognostic and pharmacogenetic factors in cancer: a 2013 update

With the recent advances in genomic medicine and the development of targeted antiangiogenic therapy for cancer patients, there has been an increased interest in the role of predictive and prognostic markers for antiangiogenic therapy. Here, we provide a summary of the angiogenesis pathway, the role of predictive and prognostic markers in cancer and a summary of the current literature and studies on predictive and prognostic markers for antiangiogenic therapy. Our aim is to summarize those studies that are currently in the literature with an emphasis on the future directions of the field from 2013 and beyond. We conclude by providing our perspective on the future directions of this growing field, as well as possible challenges and pitfalls along the way.

Relationship between serum VEGF level and radiosensitivity of patients with nonsmall cell lung cancer among asians: a meta-analysis

This meta-analysis aims to evaluate the relationships between serum vascular endothelial growth factor (VEGF) level and radiosensitivity in patients with nonsmall cell lung cancer (NSCLC) among Asians. We searched CISCOM, CINAHL, Web of Science, PubMed, Google Scholar, EBSCO, Cochrane Library, and CBM databases from their inception through October 1, 2013. Meta-analysis was performed using the STATA 12.0 software. Fourteen clinical studies were included in this meta-analysis, including five case-control studies and nine cohort studies. Our meta-analysis results revealed that levels of serum VEGF in NSCLC patients were higher than that of healthy controls. There was a significant difference in serum VEGF levels between before and after radiotherapy in NSCLC patients. Further, we found significant differences in serum VEGF levels between effective and noneffective clinical response groups pre- and postradiotherapy. Serum VEGF levels showed no significant associations with tumor-node-metastasis (TNM) stage and histologic grade in NSCLC patients. NSCLC patients with positive VEGF expression had shorter overall survival than those with negative VEGF expression. Our meta-analysis suggests that serum VEGF level may be a useful biomarker in predicting radiosensitivity and prognosis of NSCLC patients among Asians.

Relationship of serum levels of VEGF and TGF-β1 with radiosensitivity of elderly patients with unresectable non-small cell lung cancer

This study aimed to evaluate the relationship of serum levels of vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1) with radiosensitivity of elderly patients with unresectable non-small cell lung cancer (NSCLC) receiving three-dimensional conformal radiation therapy (3D-CRT). Fifty-eight elderly patients with unresectable NSCLC and 40 healthy controls were enrolled in this study. Serum levels of VEGF and TGF-β1 were detected by the enzyme-linked immunosorbent assay (ELISA) method before and after 3D-CRT. Clinical performances of serum VEGF and TGF-β1 levels in predicting radiosensitivity of NSCLC patients with 3D-CRT were evaluated. Serum VEGF and TGF-β1 levels of NSCLC patients were higher than those of health controls (all p < 0.05). After 3D-CRT treatment, 41 patients achieved effective clinical response (complete response (CR) + partial response (PR)) and 17 patients were ineffective clinical response (stable disease (SD) + progressive disease (PD)). There was no significant difference in the VEGF and TGF-β1 levels between the effective and ineffective groups before 3D-CRT (all p > 0.05). Serum levels of VEGF and TGF-β1 after 3D-CRT in the effective group were lower compared with the levels before 3D-CRT treatment (p < 0.001 and 0.027, respectively). However, no significant differences in serum VEGF and TGF-β1 levels between before and after 3D-CRT in the ineffective group were observed (p = 0.196 and 0.517, respectively). We observed significant differences in serum VEGF and TGF-β1 levels between the effective and ineffective groups after 3D-CRT (p < 0.001 and 0.013, respectively). Sensitivity and specificity of VEGF combined with TGF-β1 in predicting radiosensitivity of NSCLC patients with 3D-CRT were 87.8 and 94.1%, respectively. In conclusion, our results indicate that serum VEGF and TGF-β1 levels may accurately predict radiosensitivity of elderly patients with unresectable NSCLC receiving 3D-CRT.

Monoclonal antibodies in lung cancer

INTRODUCTION

Lung cancer is the leading cause of cancer death worldwide. As clinical benefits to conventional cancer therapies are still formidable, there is an urgent need for novel agents and approaches to improve the overall clinical outcomes for patients with lung cancer.

AREAS COVERED

This article reviews the current understanding of targeted therapy for lung cancer with monoclonal antibodies (mAbs), mainly bevacizumab and cetuximab. The results from several key clinical trials validating the effectiveness and safety of bevacizumab and cetuximab, the relation of cancer biomarkers, the polymorphic correlation of targeted genes with the therapeutic outcome of mAb-based treatment, as well as the impact of Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) trial on personalised treatment of lung cancer are discussed.

EXPERT OPINION

The addition of bevacizumab or cetuximab to chemotherapy has shown promising benefits to the patients with non-small-cell lung cancer. However, the overall benefits of mAb-based targeted therapy to lung cancer patients vary among individuals. It is therefore necessary to define reliable predictive biomarkers in an effort to better identify patients who are most likely to benefit from treatment with these novel agents in lung cancer.

Expression of hPNAS-4 radiosensitizes Lewis lung cancer

PURPOSE

This study aimed to transfer the hPNAS-4 gene, a novel apoptosis-related human gene, into Lewis lung cancer (LL2) and observe its radiosensitive effect on radiation therapy in vitro and in vivo.

METHODS AND MATERIALS

The hPNAS-4 gene was transfected into LL2 cells, and its expression was detected via western blot. Colony formation assay and flow cytometry were used to detect the growth and apoptosis of cells treated with irradiation/PNAS-4 in vitro. The hPNAS-4 gene was transferred into LL2-bearing mice through tail vein injection of the liposome/gene complex. The tumor volumes were recorded after radiation therapy. Proliferating cell nuclear antigen (PCNA) immunohistochemistry staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were performed to detect the tumor cell growth and apoptosis in vivo.

RESULTS

The hPNAS-4 gene was successfully transferred into LL2 cells and tumor tissue, and its overexpressions were confirmed via western blot analysis. Compared with the control, empty plasmid, hPNAS-4, radiation, and empty plasmid plus radiation groups, the hPNAS-4 plus radiation group more significantly inhibited growth and enhanced apoptosis of LL2 cells in vitro and in vivo (P<.05).

CONCLUSIONS

The hPNAS-4 gene was successfully transferred into LL2 cells and tumor tissue and was expressed in both LL2 cell and tumor tissue. The hPNAS-4 gene therapy significantly enhanced growth inhibition and apoptosis of LL2 tumor cells by radiation therapy in vitro and in vivo. Therefore, it may be a potential radiosensitive treatment of radiation therapy for lung cancer.

Vascular endothelial growth factor pathway polymorphisms as prognostic and pharmacogenetic factors in cancer: a systematic review and meta-analysis

Angiogenesis is an important host process that interacts with cancer cells to promote growth, invasion, and metastasis. Numerous therapeutic agents targeting the VEGF pathway have been developed. Host variability in VEGF pathway can influence angiogenesis-dependent signaling, altering sensitivity to antiangiogenic drugs and prognosis. A systematic review and meta-analysis was conducted (May 1990-July 2011). Eligible studies involved cancer patients and compared polymorphisms in the VEGF pathway [VEGF and molecules directly interacting with VEGF: KDR, FLT1, FGF, FGF2, FGFR, NRP1, endostatin (encoded by COL18A1)], and reported one of the following outcomes: overall survival, progression-free survival, time to recurrence, disease-free survival, response rate, or drug toxicity. We identified 48 cancer studies assessing prognosis and 12 cancer studies exploring pharmacogenetics of anti-VEGF therapy across various VEGF pathway polymorphisms. There was marked inter- and intradisease site heterogeneity in the effect of polymorphisms on both outcome and response to therapy. Meta-analyses of 5 VEGF polymorphisms (+936C>T, -460T>C, +405G>C, -1154G>A, and -2578C>A) identified a significant prognostic relationship: VEGF +405G>C variants showed a highly statistically significant improvement in overall survival [HR, 0.74; 95% confidence interval, 0.60-0.91; P = 0.004]. Variants (heterozygotes and/or homozygotes) of VEGF +405G>C were significantly associated with improved survival in a meta-analysis of multiple cancer sites.

Incorporating single-nucleotide polymorphisms into the Lyman model to improve prediction of radiation pneumonitis

PURPOSE

To determine whether single-nucleotide polymorphisms (SNPs) in genes associated with DNA repair, cell cycle, transforming growth factor-β, tumor necrosis factor and receptor, folic acid metabolism, and angiogenesis can significantly improve the fit of the Lyman-Kutcher-Burman (LKB) normal-tissue complication probability (NTCP) model of radiation pneumonitis (RP) risk among patients with non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

Sixteen SNPs from 10 different genes (XRCC1, XRCC3, APEX1, MDM2, TGFβ, TNFα, TNFR, MTHFR, MTRR, and VEGF) were genotyped in 141 NSCLC patients treated with definitive radiation therapy, with or without chemotherapy. The LKB model was used to estimate the risk of severe (grade≥3) RP as a function of mean lung dose (MLD), with SNPs and patient smoking status incorporated into the model as dose-modifying factors. Multivariate analyses were performed by adding significant factors to the MLD model in a forward stepwise procedure, with significance assessed using the likelihood-ratio test. Bootstrap analyses were used to assess the reproducibility of results under variations in the data.

RESULTS

Five SNPs were selected for inclusion in the multivariate NTCP model based on MLD alone. SNPs associated with an increased risk of severe RP were in genes for TGFβ, VEGF, TNFα, XRCC1 and APEX1. With smoking status included in the multivariate model, the SNPs significantly associated with increased risk of RP were in genes for TGFβ, VEGF, and XRCC3. Bootstrap analyses selected a median of 4 SNPs per model fit, with the 6 genes listed above selected most often.

CONCLUSIONS

This study provides evidence that SNPs can significantly improve the predictive ability of the Lyman MLD model. With a small number of SNPs, it was possible to distinguish cohorts with >50% risk vs <10% risk of RP when they were exposed to high MLDs.

Polymorphisms of the vascular endothelial growth factor gene and severe radiation pneumonitis in non-small cell lung cancer patients treated with definitive radiotherapy

Vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis and lung cancer progression. We hypothesized that VEGF polymorphisms may modulate the risk of radiation pneumonitis (RP) in non-small cell lung cancer (NSCLC) patients treated with definitive radiotherapy. We genotyped three potentially functional VEGF single nucleotide polymorphisms (-460 T > C [rs833061], -634 G > C [rs2010963] and +936 C > T [rs3025039]) and estimated the associations of their genotypes and haplotypes with severe radiation pneumonitis (RP ≥grade 3) in 195 NSCLC patients. We found that the VEGF genotypes of rs2010963 and rs3025039 single nucleotide polymorphisms as well as the -460C/-634G/+936C haplotype were predictors of RP development (adjusted hazard ratio [adjHR] = 2.33, 95% confidence interval [CI], 1.01-5.37, P = 0.047 for CC vs GG genotypes; adjHR = 28.13, 95% CI, 5.24-151.02, P < 0.001 for TT vs CC genotypes; and adjHR = 2.51, 95% CI, 1.27-4.98, P = 0.008 for T-C-T vs C-G-C haplotypes). In addition, there was a trend towards reduced RP risk in patients carrying an increased number of protective VEGF genotypes. Our data suggest that VEGF polymorphisms can modulate the risk of radiation pneumonitis in NSCLC patients treated with definitive radiotherapy. Large and independent studies are needed to confirm our findings.