Vascular endothelial growth factor expression in invasive papillary thyroid carcinoma

A Five-Gene Prognostic Nomogram Predicting Disease-Free Survival of Differentiated Thyroid Cancer

Background

Differentiated thyroid cancer (DTC) is the most common type of thyroid tumor with a high recurrence rate. Here, we developed a nomogram to effectively predict postoperative disease-free survival (DFS) in DTC patients.

Methods

The mRNA expressions and clinical data of DTC patients were downloaded from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database. Seventy percent of patients were randomly selected as the training dataset, and thirty percent of patients were classified into the testing dataset. Multivariate Cox regression analysis was adopted to establish a nomogram to predict 1-year, 3-year, and 5-year DFS rate of DTC patients.

Results

A five-gene signature comprised of TENM1, FN1, APOD, F12, and BTNL8 genes was established to predict the DFS rate of DTC patients. Results from the concordance index (C-index), area under curve (AUC), and calibration curve showed that both the training dataset and the testing dataset exhibited good prediction ability, and they were superior to other traditional models. The risk score and distant metastasis (M) of the five-gene signature were independent risk factors that affected DTC recurrence. A nomogram that could predict 1-year, 3-year, and 5-year DFS rate of DTC patients was established with a C-index of 0.801 (95% CI: 0.736, 0.866).

Conclusion

Our study developed a prediction model based on the gene expression and clinical characteristics to predict the DFS rate of DTC patients, which may be applied to more accurately assess patient prognosis and individualized treatment.

The correlation between ultrasonographic features, bFGF, and the local invasiveness of thyroid papillary carcinoma

The present study aimed to investigate the correlation between ultrasonographic features, basic fibroblast growth factor (bFGF), and the local invasiveness of papillary thyroid carcinoma (PTC).A total of 350 samples of thyroid nodules were collected. Routine ultrasonography was performed before the operation and routine pathological diagnosis and bFGF detection were performed after the operation.'These 350 samples of thyroid nodules included 90 samples of nodular goiter, 36 samples of focal thyroiditis, and 224 samples of PTC. A total of 326 thyroid nodules were examined for bFGF. The results revealed that the difference in the expression of bFGF between the benign and malignant groups was statistically significant (P < .05) and the difference in the positive expression of bFGF between the invasive and non-invasive PTC groups was statistically significant (P < .05).Whether the shape of PTC is regular or not and whether there is micro-calcification in PTC and other ultrasonographic features, the size and location of the lesions and the age of the patient help make a preliminary prediction of local invasiveness before the operation. Postoperative detection of bFGF is helpful for further risk assessments of PTC.

Mechanisms of the Impact of Hashimoto Thyroiditis on Papillary Thyroid Carcinoma Progression: Relationship with the Tumor Immune Microenvironment

BACKGROUND

The relationship between Hashimoto thyroiditis (HT) and papillary thyroid carcinoma (PTC) remains uncertain. We assessed the impact of HT on the tumor immune microenvironment (TIME) in PTC.

METHODS

Thirty patients with PTC (group 1) and 30 patients with PTC and HT (group 2) were enrolled in this pilot study. The distribution and number of CD8+ lymphocytes, plasma cells (CD138+), regulatory T cells (forkhead box P3 [FOXP3+)], mast cell tryptase (MCT+), and M2 macrophages (CD163+) were evaluated. To test the hypothesis that HT impacts PTC development via signal transducer and activator of transcription 6 (STAT6) activation and M2 macrophage polarization, we investigated STAT6 expression in tumor and stromal cells. We also evaluated vascular endothelial growth factor (VEGF) expression by lymph node metastasis (LNM) status.

RESULTS

TIME showed significant between-group differences. Group 1 patients demonstrated immune desert or immune-excluded immunophenotypes, while an inflamed phenotype with more CD8+ cells (P&lt;0.001) predominated in group 2. Immune-excluded TIME was associated with the highest LNM rate. In PTC, LNM was associated with more numerous CD163+ cells. Moreover, LNM in group 1 was associated with increased numbers of mast cells peritumorally and FOXP3+ cells intratumorally and peritumorally. Group 2 demonstrated higher STAT6 but not higher VEGF expression in tumor cells. High VEGF expression was associated with LNM regardless of HT status.

CONCLUSION

Concomitant HT impacted PTC signaling via STAT6 and TIME by increasing the number of CD8+ cells. LNM is associated with increases in CD163+ cells and VEGF expression in PTC, whereas HT affected LNM through different mechanisms.

MiRNAs Are Involved in Tall Cell Morphology in Papillary Thyroid Carcinoma

Five percent of papillary thyroid carcinomas (PTC) show an adverse clinical outcome (ACO). The tall cell variant of papillary thyroid carcinomas (TCV) is a good predictor of an ACO, however, the identification of tall-cells is subjective. Micro RNAs are short non-coding ribonucleic acids (miRNA). Their expression in PTC could be a powerful, more objective predictor of prognosis.

METHODS

Forty-four PTC underwent miRNA profiling, twenty-four of them were TCV. The miRNA dataset was validated by analysis of expression of known target proteins (vascular endothelial growth factor (VEGF) and phosphatase and tensin homolog (PTEN)) in 125 patients including 48 TCV and 57 with an ACO.

RESULTS

One hundred and forty-nine miRNAs were significantly associated with an ACO, seventy-one of them with TC-morphology. Twenty-two miRNAs were identified as targets for VEGF and thirty-two as targets for PTEN. In univariate and multivariable analysis, reduced expression of PTEN and an increased expression of VEGF were associated with shorter relapse free survival. A classifier, including TC-morphology, pT-stage, VEGF, and PTEN, predicted relapse with an 80% accuracy.

CONCLUSIONS

Some miRNAs predict outcome in PTC and are involved in TC-morphology in PTC. These miRNAs may serve as more objective indicators of an ACO than tall cell morphology. PTEN and VEGF protein expression are prognostically relevant and are at least partially regulated by miRNAs.

Expression of vascular endothelial growth factor receptor 2 and clinical response to lenvatinib in patients with anaplastic thyroid cancer

PURPOSE

Angiogenesis plays a crucial role in the development, growth, and metastasis of carcinomas, and studies have reported conflicting evidence regarding the VEGFR expression in anaplastic thyroid cancer. We investigated the expression of VEGFR2 in patients with anaplastic thyroid cancer (ATC) and analyzed the clinical response to the VEGFR inhibitor lenvatinib.

METHODS

This cross-sectional study included primary tumor samples obtained from 12 patients with ATC, including 5 males and 7 females (age range 63-89 years) who underwent surgery or core needle biopsy for a thyroid tumor in the Department of Breast and Endocrine Surgery at Kanagawa Cancer Center in Kanagawa, Japan. VEGFR2 protein expression in the ATC samples was analyzed by immunohistochemistry in all patients, and the therapeutic effect of lenvatinib was evaluated in seven patients who underwent tissue biopsy and lesion evaluation.

RESULTS

VEGFR expression was not detected in any of the samples from the 12 patients. Four of the 12 patients treated with lenvatinib had partial response, the three patients achieved stable disease, and the five patients were not examined.

CONCLUSIONS

There was no correlation between the expression of VEGFR2 in tumor tissue and the clinical response to lenvatinib among patients with ATC. Further studies are necessary to elucidate the mechanism underlying the response to lenvatinib.

Overwhelming rapid metabolic and structural response to apatinib in radioiodine refractory differentiated thyroid cancer

Currently, patients with radioiodine refractory differentiated thyroid cancer (RAIR-DTC) have limited treatment options. In this study, we aimed to assess the short-term efficacy and safety of apatinib in RAIR-DTC. Ten adult patients were prospectively enrolled to receive oral apatinib (750 mg q.d). The primary endpoints were change in serum thyroglobulin (Tg) concentration, disease control rate (DCR) and objective response rate (ORR) based on RECIST 1.1 criteria. The secondary endpoints included change in glucose metabolism, evaluated by maximum standard uptake value (SUVmax), and safety. As early as 2 weeks after apatinib treatment, the serum Tg concentration decreased by 21.0% in 8 patients available for detection without interference, and a further sharp decline by 81.4% compared with the baseline level occurred at 8 weeks post-treatment. The DCR and ORR were 100% (10/10) and 90% (9/10), respectively. The sum of tumor diameter shrank to 22.8±8.1 mm from 38.8±15.7 mm (P=0.001). Moreover, a significant decrease in SUVmax was observed from 6.53±5.14 to 2.56±1.67 and 2.45±1.48 at 4-week and 8-week time-points after treatment (P=0.032 and 0.020), respectively. The common grade 3 adverse events (AEs) included hand-foot-skin reaction (50%), hypertension (30%), and hypocalcemia (20%). No severe AE related to apatinib was observed during treatment. Hence, apatinib seems to be a promising therapeutic option for RAIR-DTC patients. Apart from RECIST 1.1 criteria, the biochemical marker (Tg) and glucose metabolism index (SUVmax) could be adopted in assessing the early response to TKI in RAIR-DTC.

Pathological processes and therapeutic advances in radioiodide refractory thyroid cancer

While in most patients with non-medullary thyroid cancer (TC), disease remission is achieved by thyroidectomy and ablation of tumor remnants by radioactive iodide (RAI), a substantial subgroup of patients with metastatic disease present tumor lesions that have acquired RAI resistance as a result of dedifferentiation. Although oncogenic mutations in BRAF, TERT promoter and TP53 are associated with an increased propensity for induction of dedifferentiation, the role of genetic and epigenetic aberrations and their effects on important intracellular signaling pathways is not yet fully elucidated. Also immune, metabolic, stemness and microRNA pathways have emerged as important determinants of TC dedifferentiation and RAI resistance. These signaling pathways have major clinical implications since their targeting could inhibit TC progression and could enable redifferentiation to restore RAI sensitivity. In this review, we discuss the current insights into the pathological processes conferring dedifferentiation and RAI resistance in TC and elaborate on novel advances in diagnostics and therapy to improve the clinical outcome of RAI-refractory TC patients.

Thick tumor capsule is a valuable risk factor for distant metastasis in follicular thyroid carcinoma

OBJECTIVE

While the biological behavior of follicular thyroid carcinoma (FTC) has been studied in great detail using clinical experience, few studies have investigated pre- or intraoperative factors related to the risk of distant metastasis (DM) among patients with FTC. The aim of this study was to analyze the characteristics of FTC with DM.

METHODS

This study retrospectively investigated 102 patients with FTC who underwent surgery between 1988 and 2013. We compared clinicopathological characteristics between FTC with and without DM.

RESULTS

Univariate analysis revealed nodal metastasis (p=0.045), serum thyroglobulin (Tg) at initial operation (≥1000ng/ml; p<0.0001), widely invasive appearance according to macroscopic findings (p<0.0001), thick tumor capsule (≥1mm; p<0.0001), vascular invasion (p=0.0003), extrathyroidal invasion (p=0.047), and venous tumor embolism (p=0.045) as significant risk factors for DM. Multivariate analysis conducted using pre- and intraoperative factors identified thick tumor capsule (≥1mm), serum Tg at initial operation (≥1000ng/ml), and macroscopically widely invasive appearance as risk factors independently associated with development of DM.

CONCLUSION

Patients with these risk factors should undergo total thyroidectomy and radioactive iodine ablation.

Radiolabeling of VEGF165 with 99mTc to evaluate VEGFR expression in tumor angiogenesis

Angiogenesis is the main process responsible for tumor growth and metastatization. The principal effector of such mechanism is the vascular endothelial growth factor (VEGF) secreted by cancer cells and other components of tumor microenvironment. Radiolabeled VEGF analogues may provide a useful tool to noninvasively image tumor lesions and evaluate the efficacy of anti-angiogenic drugs that block the VEGFR pathway. Aim of the present study was to radiolabel the human VEGF165 analogue with 99mTechnetium (99mTc) and to evaluate the expression of VEGFR in both cancer and endothelial cells in the tumor microenvironment. 99mTc-VEGF showed in vitro binding to HUVEC cells and in vivo to xenograft tumors in mice (ARO, K1 and HT29). By comparing in vivo data with immunohistochemical analysis of excised tumors we found an inverse correlation between 99mTc-VEGF165 uptake and VEGF histologically detected, but a positive correlation with VEGF receptor expression (VEGFR1). Results of our studies indicate that endogenous VEGF production by cancer cells and other cells of tumor microenvironment should be taken in consideration when performing scintigraphy with radiolabeled VEGF, because of possible false negative results due to saturation of VEGFRs.

Proliferation, angiogenesis and differentiation related markers in compact and follicular-compact thyroid carcinomas in dogs

Immunohistochemical markers (IGF-1, IGF-1R, VEGF, FGF-2, RARα and RXR) were evaluated in healthy canine thyroid glands (n=8) and in follicular-compact (n=8) and compact thyroid carcinomas (n=8). IGF-1, IGF-1R and VEGF expression was higher in fibroblasts and endothelial cells of compact carcinoma than in healthy glands (P < 0.05). Compared to follicular-compact carcinoma, compact carcinoma had higher IGF-1R expression in fibroblasts, and higher FGF-2 expression in endothelial cells (P < 0.05). RARα expression was higher in endothelial cells of compact carcinoma than in those of other groups (P < 0.05). The upregulation of these proliferation- and angiogenesis-related factors in endothelial cells and/or fibroblasts and not in follicular cells of compact carcinoma compared to healthy glands supports the relevance of stromal cells in cancer progression.

The treatment landscape in thyroid cancer: a focus on cabozantinib

Although patients with thyroid cancer generally fare well, there is a subset for which this is not necessarily true. Progress in understanding the molecular aberrations in thyroid cancer has led to a change in the management of these cases. Since 2011, four multikinase inhibitors (MKIs) have been approved by the US Food and Drug Administration for thyroid cancer – cabozantinib and vandetanib for medullary thyroid cancer and sorafenib and lenvatinib for differentiated thyroid cancer. This change in the treatment landscape has raised challenges for practitioners who may not be familiar with the use of MKIs or with the treatment and natural history of advanced thyroid cancer in general. This article reviews the epidemiology, molecular drivers, and initial treatment of patients with thyroid cancer and offers practical guidance to assist with the determination of when to appropriately start an MKI. As an example, cabozantinib and its efficacy are discussed in detail. Close monitoring is required for all patients on targeted agents to assess for adverse effects and response to therapy. An approach to managing drug-related adverse events is detailed. Since these drugs are not curative and have not yet proven to prolong overall survival, it is critical to weigh the risks and benefits of treatment at every visit. The potential value of changing to a different agent following failure of an MKI is also addressed.

VEGF-D and A Preoperative Serum Levels Predict Nodal and Distant Metastases in Differentiated Thyroid Cancer Patients

BACKGROUND

Preoperative tumor aggressiveness biomarkers may help surgeons decide the extent of an operation. However, whether serum angiogenetic factors can be used to predict the prognosis of patients with differentiated thyroid cancer is still unclear.

METHODS

Seventy-six DTC patients were prospectively recruited. Preoperative serum samples were collected and measured for Tie-2, Ang-1, Ang-2, VEGF-A, and VEGF-D levels. The potential correlations between their serum levels and clinicopathologic features as well as their prognoses were analyzed.

RESULTS

Older age (>45 years old) and higher VEGF-A serum levels were independent predictors of extrathyroidal extension. The VEGF-D serum level was an independent factor for lymph node metastases and VEGF-A was an independent factor for distant metastases. None of these serum angiogenetic factors were significantly different between patients who were disease free and those with recurrences. The presence of lymph node metastases was the only independent factor for recurrence over the 2-year follow-up.

CONCLUSION

Preoperative serum VEGF-A and VEGF-D levels were significantly elevated in DTC patients with distant and lymph node metastases. These findings, when combined with other clinicopathological factors, may help in surgical decisions.

Targeting vascular endothelial growth factor (VEGF) pathway in iodine-refractory differentiated thyroid carcinoma (DTC): from bench to bedside

Thyroid cancer is the most common endocrine malignancy, representing 1% of all human malignancies; its incidence has been escalating worldwide during the last decades. In recent years important molecular pathways contributing to tumor progression and worse survival rates have been identified in iodine-refractory differentiated thyroid carcinoma (DTC) with the consequent development of molecular therapeutics to target these specific oncogenic pathways. For example, a positive correlation has been found between expression of vascular endothelial growth factor (VEGF) and a more aggressive phenotype of DTC. This has led to the widespread adoption of VEGF-targeted therapeutics in the preclinical and clinical settings. In this review we will provide an overview of the different aspects of the use of VEGF-pathway-oriented treatments in iodine-refractory DTC with particular focus on future prospects.

(99m)Tc-labeled-rhTSH analogue (TR1401) for imaging poorly differentiated metastatic thyroid cancer

BACKGROUND

Differentiated thyroid carcinomas originating from thyroid follicular cells are frequent tumors of the thyroid with relatively good prognosis due to improved surgical techniques and follow-up procedures. Poorly differentiated thyroid cancers, which lose iodine uptake ability, in most cases still express thyrotropin (TSH) receptors (TSHR). Therefore, the aim of this study was to radiolabel a superagonist recombinant human TSH (rhTSH) analogue for imaging poorly differentiated thyroid cancer.

METHODS

The TSHR superagonist, TR1401, was labeled with (99m)Tc using an indirect method via succinimidyl-6-hydrazinonicotinate hydrochloride conjugation. In vitro quality controls included SDS-PAGE, cysteine challenge, and cell-binding assay on TSHR positive cell lines (JP09 and ML-1). In vivo studies included tumor targeting experiments in athymic nude CD-1 mice xenografted with several different TSHR positive cells (JP09, K1, and ML-1) and TSHR negative cells (JP02) as control.

RESULTS

The superagonist rhTSH analogue TR1401 was labeled with high labeling efficiency (>95%) and high specific activity (9250 MBq/mg). The labeled molecule retained its biologic activity and structural integrity. In tumor targeting experiments, a focal uptake of radiolabeled TR1401 was observed in TSHR positive cells but not in TSHR negative cells. The same observation was made in a dog with spontaneous intraglandular thyroid cancer.

CONCLUSIONS

We were able to radiolabel the rhTSH superagonist analogue TR1401 with (99m)Tc efficiently with retention of in vitro and in vivo binding capacity to TSHR. The relative role of such novel radiopharmaceutical versus (131)I scanning of thyroid cancer will require future histopathologic and clinical studies, but it may open new perspectives for presurgical staging of thyroid cancer, and diagnosis of radioiodine negative local relapses and/or distant metastases.

Expressions of D2-40, CK19, galectin-3, VEGF and EGFR in papillary thyroid carcinoma

OBJECTIVE

To investigate the expressions of D2-40, CK19, galectin-3, VEGF, and EGFR in papillary thyroid carcinoma and their clinical significances.

METHODS

The expressions of D2-40, CK19, galectin-3, VEGF, and EGFR in 38 cases of papillary thyroid carcinoma and 12 cases of thyroid papillary hyperplasia were detected by immunohistochemical staining.

RESULTS

The positive expression rates of D2-40, CK19, Galectin-3, VEGF and EGFR in patients with papillary thyroid carcinoma were all significantly higher than those in patients with thyroid papillary hyperplasia (all P<0.05). The expressions of D2-40, VEGF, and EGFR in papillary thyroid carcinoma with lymph node metastasis were significantly higher than those without lymph node metastasis (P<0.05). The expressions of GK19 and galectin-3 showed no significant differences between the papillary thyroid carcinomas with and without lymph node metastasis (P>0.05).

CONCLUSIONS

The detection of D2-40, CK19, galectin-3, VEGF, and EGFR is helpful for the diagnosis and differential diagnosis of papillary thyroid carcinoma and thyroid papillary hyperplasia.

Relationship between VEGF protein expression and lymph node metastasis in papillary thyroid carcinoma among Asians: a meta-analysis

We carried out the current meta-analysis of relevant cohort studies in an attempt to investigate the relationships between vascular endothelial growth factor (VEGF) protein expression and lymph node (LN) metastasis in papillary thyroid carcinoma (PTC) among Asians. A range of electronic databases were searched, including Web of Science (1945∼2013), the Cochrane Library Database (Issue 12, 2013), MEDLINE (1966∼2013), EMBASE (1980∼2013), CINAHL (1982∼2013), and Chinese Biomedical Database (CBM) (1982~2013) with cross-referencing without language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Crude odds ratio (OR) with their 95 % confidence interval (95 %CI) was calculated. Twelve clinical cohort studies with a total of 1,045 PTC patients were included in our meta-analysis, The results of our meta-analysis revealed that patients with VEGF-positive tumors had a 3.02-fold higher risk of LN metastasis than that of patients with VEGF-negative tumors (OR=3.02, 95 %CI=2.05~4.43, P<0.001). Furthermore, subgroup analysis by country suggested that VEGF-positive expression was associated with an increased risk of LN metastasis in PTC patients among Chinese populations (OR=3.33, 95 %CI=2.30~4.83, P<0.001), but not among Korean, Turkish, and Japanese populations (all P>0.05). Our findings support the view that VEGF protein expression may be correlated with LN metastasis in PTC patients, especially among Chinese populations.

Correlation of immunohistochemical markers and BRAF mutation status with histological variants of papillary thyroid carcinoma in the Korean population

Several pathologic characteristics are associated with an adverse clinical outcome in papillary thyroid carcinoma (PTC), including the histological variant. This study aimed to investigate immunohistochemical expression and BRAF mutation status based on the histological variant and evaluated potential markers of aggressive behavior of PTC in Korean patients. In all, 407 PTC cases were classified to each histological variant, and the 94 representative cases were subjected to immunohistochemistry and BRAF mutation analysis. The classic type, follicular variant (FV) and tall cell variant (TCV) represented 76.9%, 14.2% and 6%, respectively. TCV showed a larger tumor size (P = 0.009), frequent extrathyroidal extension (P = 0.022) and cervical lymph node (LN) metastasis (P = 0.018). TCV and FV showed the reduced expression of galectin-3 (P = 0.003) and HBME1 (P = 0.114). Regardless of histology, PTEN loss and diffuse S100A4 expression were associated with LN metastasis (P = 0.007, P = 0.013). All TCVs harbored BRAF V600E mutation, and FV harbored less BRAF V600E mutation (P = 0.043). Immunohistochemical evaluation showed characteristic patterns in histological variants. PTEN and S100A4 expression are suggested as indicators of regional lymph node metastasis.

Phase I trial of OTS11101, an anti-angiogenic vaccine targeting vascular endothelial growth factor receptor 1 in solid tumor

OTS11101 is a novel peptide vaccine that acts as an angiogenesis inhibitor by inducing cytotoxic T lymphocyte (CTL) cells that specifically target vascular endothelial cells expressing vascular endothelial growth factor (VEGF) receptor 1. We conducted a phase I study to evaluate the safety, tolerability, maximum tolerated dose, and pharmacodynamic biomarker status of this vaccine. Nine patients with advanced solid tumors received 1.0, 2.0, or 3.0 mg of OTS11101 subcutaneously, once a week in a 28-day cycle. Three patients experienced grade 1 injection site reactions, which were the most frequent adverse events. Grade 2 proteinuria and hypertension each occurred in one patient. As other toxicities were generally mild, the maximum tolerated dose was not reached. Furthermore, we explored the induction of specific activated CTLs, and biomarkers related to angiogenesis. A pharmacodynamics study revealed that induction of specific CTLs was observed for a dose of 2.0 and 3.0 mg. The serum concentrations of soluble VEGF receptor 1 and 2 after vaccination increased significantly compared with baseline. A microarray was performed to give a comprehensive analysis of gene expression, suggesting that OTS11101 vaccination resulted in T cell activation in a clinical setting. In conclusion, OTS11101 was well tolerated in patients up to 3.0 mg once weekly and our biomarker analysis suggested that this anti-angiogenesis vaccine is biologically active.

BRAF(V600E) mutation and expression of proangiogenic molecular markers in papillary thyroid carcinomas

OBJECTIVE

Tyrosine kinase inhibitors (TKIs) are evaluated for treatment of radioiodine refractory thyroid cancer. Their effects in this setting are based on blockade of proangiogenic signaling mediated by receptors for vascular endothelial growth factors (VEGFs) and platelet-derived growth factors (PDGF). Most TKIs also block other cancer-relevant kinases, such as B-type Raf kinase (BRAF), which are constitutively activated in approximately half of papillary thyroid carcinomas (PTCs), but the impact of these effects is not clear.

DESIGN

The aim of our study was to investigate the impact of BRAF(V600E) on proangiogenic gene expression and microvascular features of PTCs.

METHODS

mRNA levels for VEGFA, VEGF receptors, and coreceptors (VEGFRs 1, 2, and 3, neuropilin-1), and PDGF receptor β (PDGFRβ or PDGFRB) were measured with real-time PCR in BRAF(V600E) (n=55) and wild-type BRAF (BRAF-wt; n=35) PTCs. VEGF and VEGFR protein expression and microvessel densities (MVD) and lymphatic vessel densities (LVDs) were assessed by immunohistochemistry in 22 of the 90 PTCs (including 11 BRAF(V600E) cases). Angiogenic gene expression was also studied in vitro after induction/silencing of the BRAF(V600E) mutation in thyrocyte lines.

RESULTS

Transcript levels of proangiogenic factors were significantly lower in BRAF(V600E) PTCs versus BRAF-wt PTCs (P<0.0001), but MVD and LVDs were not significantly different. VEGFA mRNA levels in thyroid cell lines decreased when BRAF(V600E) mutation was induced (P=0.01) and increased when it was silenced (P=0.01).

CONCLUSIONS

Compared with BRAF-wt PTCs, those harboring BRAF(V600E) exhibit downregulated VEGFA, VEGFR, and PDGFRβ expression, suggesting that the presence of BRAF mutation does not imply a stronger prediction of response to drugs targeting VEGF and PDGFB signaling pathways.

Serum vascular endothelial growth factor-D levels correlate with cervical lymph node metastases in papillary thyroid carcinoma

The aim of this multicenter study was to evaluate the clinical relevance of serum vascular endothelial growth factor-D (VEGF-D) in papillary thyroid carcinoma (PTC). This prospective study consisted of 74 patients with primary PTC and 15 patients with benign thyroid nodules treated from 2008 to 2009. VEGF-D concentration was compared with patient clinicopathologic features and lymph node metastases. There was no significant difference in mean serum VEGF-D levels between the PTC and benign thyroid nodule groups. Within the PTC group, serum VEGF-D levels were significantly higher in patients with lymph node metastases than in patients without metastases (241.92 vs. 213.89 pg/ml, respectively; P = 0.035). Receiver operating characteristic curve analysis revealed that preoperative serum VEGF-D levels were predictive of lymph node metastases in the patients >45 years. Serum VEGF-D level that was correlated with the presence of cervical lymph node metastases in PTC patients might be a useful prognostic indicator.

Vascular endothelial growth factors and angiopoietins in presentations and prognosis of papillary thyroid carcinoma

AIMS

Angiogenesis from thyroid cancer cell plays the important roles in post-surgical persistent, recurrent, and metastatic papillary thyroid cancer (PTC). This study is to investigate the expression of angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), Tek/Tie-2 receptor, and vascular endothelial growth factors (VEGF) in normal, benign thyroid tissues and different stage of PTC. We expect angiogenetic factors are important in the presentation of local-regional neck or distant metastases in PTC.

MATERIALS AND RESULTS

A total of 101 tissues from the subjects underwent thyroidectomy were enrolled in the study. There were 22 control and 79 thyroid cancer patients in different TNM stagings were collected. Ang-1 illustrated highest mean immunostaining score in metastatic group. Comparing with normal and benign thyroid tissues, thyroid cancer tissues illustrated significantly high expression of three angiogenetic factors and Tie-2 receptor. Of the PTC, significantly high expression of three angiogenetic factors and Tie-2 receptor were illustrated in recurrent cases. VEGF showed statistical difference in disease-free cancer mortality, and recurrent groups.

CONCLUSIONS

Immunochemical staining illustrated VEGF, Ang-1, Ang-2 expression in PTC tissues related to clinical staging; however, we need more information concerning these factors with long-term follow-up results.