Prognostic significance of the expression of vascular endothelial growth factor (VEGF) and VEGF-C in gastric carcinoma

Expression of vascular endothelial growth factor receptor in thymic epithelial tumors

Thymic epithelial tumors (TETs) are rare and the major symptoms are not obvious until the tumor progresses to a relatively large size and compresses the surrounding organs. As its growth is aggressive and it metastasizes to distant organs, it is important to find novel effective therapies. Lenvatinib, a vascular endothelial growth factor receptor (VEGFR) inhibitor, is approved as a drug therapy for thymic carcinoma (TC); however, although it is a molecular targeted therapy, there are no obvious predictors of therapeutic efficacy. The present study aimed to assess the association between clinicopathological factors and the protein expression of VEGFR, which is associated with tumor aggressiveness and the efficacy of VEGFR inhibitors. The VEGFR-2 protein expression was evaluated in 144 patients with TETs who underwent surgical resection. The present study assessed whether the expression of VEGFR-2 protein was associated with TET classification and pathological stage, progression-free survival and overall survival (OS). A total of 94 cases (65.2%) were positive for VEGFR-2 protein. The expression of VEGFR-2 was higher in the more aggressive type B3 thymoma and TC (88.5%) than in types A, AB, B1 and B2 thymoma (60.2%). The 5-year OS rate for the overall population was 53.1%. The 5-year OS rates of patients with negative VEGFR-2 staining score values (66.5%) were significantly longer than in patients with positive VEGFR-2 staining score values (42.5%; P=0.000078). Furthermore, the pathological stage was the only factor significantly associated with OS in multivariate analysis. The results of the present study suggest the possibility that the indications for VEGF inhibitor therapy could be extended to type B3 thymoma.

Exploratory Analysis of Patients With Gastric/Gastroesophageal Junction Adenocarcinoma With or Without Liver Metastasis From the Phase 3 RAINBOW Study

PURPOSE

Liver metastasis (LM) is reported in approximately 40% of patients with advanced/metastatic gastric/gastroesophageal junction adenocarcinoma (metastatic esophagogastric adenocarcinoma; mGEA) and is associated with a worse prognosis. This post-hoc analysis from the RAINBOW trial reported the efficacy, safety, and biomarker outcomes of ramucirumab and paclitaxel combination treatment (RAM+PAC) in patients with (LM+) and without (LM-) LM at baseline.

MATERIALS AND METHODS

Patients (n=665) were randomly assigned on a 1:1 basis to receive either RAM+PAC (LM+: 150, LM-: 180) or placebo and paclitaxel (PL+PAC) (LM+: 138, LM-: 197). The overall survival (OS) and progression-free survival (PFS) were evaluated using stratified Kaplan-Meier and Cox regression models. The correlation of dichotomized biomarkers (VEGF-C, D; VEGFR-1,2) with efficacy in the LM+ versus LM- subgroups was analyzed using the Cox regression model with reported interaction P-values.

RESULTS

The presence of LM was associated with earlier progression than those without LM, particularly in patients receiving PL+PAC (hazard ratio [HR], 1.68). RAM+PAC treatment improved OS and PFS irrespective of LM status but showed greater improvement in LM+ than that in LM- (OS HR, 0.71 [LM+] vs. 0.88 [LM-]; PFS HR, 0.47 [LM+] vs. 0.76 [LM-]). Treatment-emergent adverse events were similar between patients with and without LM. No predictive relationship was observed between biomarker levels (VEGF-C, D; VEGFR-1,2) and efficacy outcome (OS, PFS) (all interaction P-values >0.05).

CONCLUSIONS

RAM provided a significant benefit, irrespective of LM status; however, its effect was numerically stronger in patients with LM. Therefore, RAM+PAC is a clinically meaningful therapeutic option for patients with mGEA and LM.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01170663.

An origami paper-based nanoformulated immunosensor detects picograms of VEGF-C per milliliter of blood

Detecting vascular endothelial growth factor C (VEGF-C), a kind of tumor biomarker, is of significant clinical importance in evaluating the prognosis of patients with cancer. However, laboratory analyses are usually not suitable for point-of-care testing because they are expensive and time consuming. In response to these challenges, we fabricated an origami paper-based microfluidic electrochemical device. To improve the specificity of VEGF-C detection, nanocomposites, synthesized by new methylene blue (NMB), amino-functional single-walled carbon nanotubes (NH₂-SWCNTs), and gold nanoparticles (AuNPs), were used to modify the surface of working electrodes. Results of electrochemical detection showed that the immunosensor had excellent linearity, ranging from 0.01 to 100 ng mL⁻¹ (R² = 0.988), and the limit of detection was 10 pg mL⁻¹. To confirm the high specificity of the device under real-world conditions, we evaluated the device using clinical serum samples from our hospital. The results demonstrated that the device had an excellent performance and could provide a platform for real-time detection of cancers.

Sun, Wang et al. report an origami paper-based immunosensor for the electrochemical detection of the VEGF-C biomarker in blood serum. The immunosensor is made by modifying the surface of working electrodes with new methylene blue, amino-functional single-walled carbon nanotubes, and gold nanoparticles and demonstrates excellent performance with a limit of detection in the range of picograms per milliliter.

Significant response to ramucirumab monotherapy in chemotherapy-resistant recurrent alpha-fetoprotein-producing gastric cancer: A case report

Alpha-fetoprotein (AFP)-producing gastric cancer (AFPGC) is a relatively rare type of gastric cancer characterized by a high incidence of liver and lymph node metastases, and a poor prognosis. Few advanced AFPGC cases treated successfully with conventional chemotherapy have been reported thus far. Although the development of molecular-targeted therapy has improved the prognosis of various types of cancer, there are currently no tailored therapies for AFPGC. In the present report, the case of a chemotherapy-resistant recurrent AFPGC patient who exhibited a significant response to ramucirumab monotherapy is presented. Following six doses of ramucirumab, a metastatic lymph node displayed central necrosis, and the patient's serum AFP levels decreased from 12,800 to 225 ng/ml. AFPGC is known to have increased vascular endothelial growth factor (VEGF) expression and rich neovascularization. Furthermore, in the present case, tumor cells were positive for VEGF. Ramucirumab is a monoclonal antibody for VEGF receptor-2 and the first anti-angiogenic drug approved for the treatment of advanced gastric cancer. However, the clinical efficacy of ramucirumab in patients with AFPGC has not been reported previously. The present report suggests that AFP production in gastric cancer can be a predictor for the response to anti-angiogenic drugs such as ramucirumab.

VEGF is a target molecule for peritoneal metastasis and malignant ascites in gastric cancer: prognostic significance of VEGF in ascites and efficacy of anti-VEGF monoclonal antibody

Background

In gastric cancer, poor prognosis is associated with peritoneal dissemination, which often accompanies malignant ascites. We searched for a target molecule in peritoneal metastasis and investigated its clinical utility as a biomarker.

Methods

Biopsy specimens from both primary lesions and peritoneal metastasis, and if possible, malignant ascites, were obtained from 40 patients with gastric cancer. Vascular endothelial growth factor (VEGF) expression was analyzed by immunohistochemical staining and enzyme-linked immunosorbent assay.

Results

VEGF expression was seen in 70% of peritoneal samples. Of the 40 patients, 35 had malignant ascites. These 35 patients were divided into two groups: 15 with ascites found beyond the pelvic cavity (large group) and 20 whose ascites were within the pelvic cavity (small group). The two groups did not significantly differ by serum VEGF levels, but ascites VEGF levels in the large group were significantly higher than in the small group (P < 0.0001). Serum VEGF and ascites VEGF levels were highly correlated in the large group (r = 0.686). A high ascites VEGF level was found to be a risk factor for survival (P = 0.045). We include a report of a patient with chemoresistant refractory gastric cancer and symptomatic ascites who obtained 8 months of palliation from systemic bevacizumab.

Conclusion

Anti-VEGF therapies are promising, and the ascites VEGF level is an important marker in managing patients with gastric cancer and peritoneal metastasis.

Extent of arterial tumor enhancement measured with preoperative MDCT gastrography is a prognostic factor in advanced gastric cancer after curative resection

OBJECTIVE

The objective of this study was to investigate the correlation between pathologic findings and arterial tumor enhancement at MDCT gastrography of patients with a prognosis of advanced gastric cancer after curative resection.

MATERIALS AND METHODS

The cases of 41 patients with advanced gastric cancer (23 men, 18 women; age range, 35-92 years; median, 60 years) who underwent MDCT gastrography and optical endoscopy before surgery were retrospectively evaluated. Two radiologists reviewed virtual endoscopic and multiplanar reconstruction images to measure arterial phase CT values of the inner tumor margin and healthy gastric wall. They used consensus regions of interest on a cross-sectional image of the largest tumor diameter and then calculated tumor-to-normal wall enhancement ratio (TNR). Advanced gastric cancers were divided into high- and low-TNR groups with mean TNR as the cutoff. The correlations between groups and pathologic factors, patient survival, and mode of recurrence were studied.

RESULTS

Multivariate logistic regression analysis showed that the arterial tumor enhancement ratio correlated with both microvessel density and lymphatic vessel invasion. The survival rate after curative resection was worse for the high-TNR group than for the low-TNR group. The rate of lymphatic and hematogenous recurrences was also higher in the high-TNR group. Multivariate survival analysis revealed that TNR was an independent prognostic factor.

CONCLUSION

The extent of arterial tumor enhancement correlated with tumor angiogenesis and lymphatic vessel invasion and was a useful prognostic indicator after curative resection in patients with advanced gastric cancer.

Double-positive expression of high-mobility group box 1 and vascular endothelial growth factor C indicates a poorer prognosis in gastric cancer patients

Background

Although many studies have indicated that high-mobility group box 1 protein (HMGB1) is associated with oncogenesis and a worse prognosis, the prognostic value of HMGB1 in gastric cancer (GC) remains unclear. In the present work, we aimed to evaluate the role of HMGB1 in GC and examined whether aberrant expression of both HMGB1 and vascular endothelial growth factor C (VEGF-C) increased the malignant potential of GC.

Methods

A total of 166 GC patients and 32 normal subjects were enrolled. HMGB1 and VEGF-C expression was detected by tissue microarrays (TMAs) and immunohistochemical staining. The correlation between HMGB1 and VEGF-C expression and their relationships with clinicopathological GC variables were examined. Univariate and multivariate analyses were performed using the Cox proportional hazard model to predict the factors related to the patients‘ overall survival rates.

Results

HMGB1 and VEGF-C expression were observed in 81 (48.80%) and 88 (53.01%) tumors, respectively, significantly higher than the rates among the corresponding controls. In addition, HMGB1 and VEGF-C expression were positively correlated (R² = 0.972). HMGB1 expression was also closely associated with tumor size, pT stage, nodal status, metastasis status, TNM stage, and poor prognosis. Multivariate survival analysis indicated that patients with HMGB1 and VEGF-C coexpression had the worst prognoses and survival rates (hazard ratio, 2.78; log rank P<0.001).

Conclusions

HMGB1 is commonly expressed in GC. Combined evaluation of HMGB1 and VEGF-C may serve as a valuable independent prognostic factor for GC patients.

Prognostic value of vascular endothelial growth factor expression in resected gastric cancer

BACKGROUND AND AIMS

Vascular endothelial growth factor (VEGF) is a potential prognostic biomarker for patients with resected gastric cancer. However, its role remains controversial. The objective of this study was to conduct a systematic review and meta-analysis of published literature.

METHODS

Relevant literature was identified using Medline and survival data from published studies were collected following a methodological assessment. Quality assessment of eligible studies and meta-analysis of hazard ratio (HR) were performed to review the correlation of VEGF overexpression with survival and recurrence in patients with gastric cancer.

RESULTS

Our meta-analysis included 44 published studies with 4,794 resected patients. VEGF subtype for the prediction of overall survival (OS) included tissue VEGF (HR=2.13, 95% CI 1.71-2.65), circulating VEGF (HR=4.22, 95% CI 2.47-7.18), tissue VEGF-C (HR=2.21, 95% CI 1.58-3.09), tissue VEGF-D (HR=1.73, 95% CI 1.25-2.40). Subgroup analysis showed that HRs of tissue VEGF for OS were, 1.78 (95% CI 0.90-3.51) and 2.31 (95% CI 1.82-2.93) in non-Asians and Asians, respectively. The meta-analysis was also conducted for disease free survival (DFS) and disease specific survival (DSS).

CONCLUSION

Positive expression of tissue VEGF, circulating VEGF, VEGF-C and VEGF-D were all associated with poor prognosis in resected gastric cancer. However, VEGF demonstrated no significant prognostic value for non-Asian populations. Circulating VEGF may be better than tissue VEGF in predicting prognosis.

High density of peritumoral lymphatic vessels measured by D2-40/podoplanin and LYVE-1 expression in gastric cancer patients: an excellent prognostic indicator or a false friend?

BACKGROUND

One of the most important prognostic indicators in gastric cancer is the presence of metastases in lymph nodes. Even now, little is known about lymphangiogenesis in neoplastic tissue, and little is also known about the transmission of a neoplastic cell from the tumor mass into a lymphatic vessel.

METHODS

This study examined the relationships between the density of lymphatic vessels (LVD) stained immunohistochemically with lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and D2-40 (podoplanin) antibodies, the expression of vascular endothelial growth factor (VEGF)-C/D, selected clinical and pathomorphological factors, and the 5-year overall survival of gastric cancer patients.

RESULTS

Statistical analysis showed no impact of increased intratumoral or peritumoral LVD on gastric cancer patient survival, irrespective of the protein used to stain lymphatic vessels. Analysis showed that the probability of overall survival was decreased in the cases with enhanced VEGF-D immunoreactivity (P = 0.0045).

CONCLUSION

The study showed that the studied markers cannot be used to determine the required extent of the surgical procedure, as they have no statistically significant correlation with the degree of progression of the cancer, the stage of the disease assessed according to the TNM 5th classification of malignant tumors, clinicopathological features, and patient survival. VEGF-D is the only marker that can be regarded as an unfavorable prognostic indicator for patients with advanced gastric cancer.

Serum vascular endothelial growth factor-C and lymphoangiogenesis are associated with the lymph node metastasis and prognosis of patients with colorectal cancer

BACKGROUND

The study aims to investigate the relationship among serum vascular endothelial growth factor (SVEGF-C), VEGF-C expression and lymph vessel density (LVD) in tumour tissue, and their influence to colorectal carcinoma (CRC).

METHODS

The SVEGF-C concentration of 110 patients with CRC and 40 healthy donors was examined by ELISA. The 110 tumour tissues and 40 normal colorectal specimens were examined by immunohistochemical staining (SP method) with VEGF-C and podoplanin (lymphatic vessel specific antibody). Kaplan–Meier survival analysis determined the influence on CRC prognosis.

RESULTS

CRC SVEGF-C level (889.0 ± 264.0 pg/mL) significantly exceeded (P = 0.000) the control level (373.2 ± 97.3 ng/L), and was significantly higher in T3, lymph node metastasis (LNM), distant metastasis, and pTNM groups III and IV. LNM prediction sensitivity, specificity, and accuracy of SVEGF-C were 85.7, 80.0 and 83.6%, respectively (875 pg/mL cut-off). VEGF-C expression was elevated in CRC versus control patients (P = 0.000), and was significantly related to LNM and pTNM stages III and IV. Mean LVD in CRC (6.3 ± 0.7/200 HP) significantly exceeded control mean (3.0 ± 0.7/200 HP) (P = 0.000). LVD was significantly higher in LNM and pTNM stages III and IV. SVEGF-C level was significantly higher in VEGF-C positive versus negative patients (P = 0.000), and was related to LVD (P = 0.009). Kaplan–Meier ranking of prognostic factors was SVEGF-C level (P = 0.000), VEGF-C expression (P = 0.001) and LVD (P = 0.012).

CONCLUSION

SVEGF-C level, VEGF-C and LVD are related to LNM and poor prognosis in patients with CRC. SVEGF-C may be a biomarker for LNM in CRC.

Prognostic significance of vascular endothelial growth factor expression in gastric carcinoma: a meta-analysis

PURPOSE

The purpose of this study was to comprehensively and quantitatively summarize available evidences for the use of VEGF protein to evaluate the clinicopathological and prognostic role of VEGF expression in Asian patients with gastric cancer.

METHOD

Searches were applied to MEDLINE, EMBASE, and the Cochrane Library databases until June 2010, without language restrictions. A meta-analysis was performed to clarify the impact of VEGF expression on clinicopathological parameters or over survival (OS) in gastric cancer.

RESULTS

Our combined results showed that VEGF expression in Asian patients with gastric cancer was significantly higher in the case-control studies (1,194 patients and 1,618 controls) (odds ratio [OR] = 112.41, 95% confidence interval [CI] = 64.12-197.06). All the analyses estimated favored a stronger link between the high VEGF expression and the poor 5-year overall survival (1,236 patients) (risk ratio [RR] = 2.45, 95% CI = 2.11-2.83, P = 0.000). When stratifying the studies by the pathological variables, the depth of invasion (3,094 patients) (OR = 1.95, 95% CI = 1.40-2.71, P = 0.000), lymph node metastasis (3,240 patients) (OR = 1.82, 95% CI = 1.29-2.57, P = 0.001), distant metastasis (1,980 patients) (OR = 2.76, 95% CI = 1.22-6.25, P = 0.015), vascular invasion (1,803 patients) (OR = 2.61, 95% CI = 2.09-3.27, P = 0.000), and TNM stage (1,819 patients) (OR = 1.92, 95% CI = 1.57-2.36, P = 0.000) provided significant prognostic information.

CONCLUSION

Our results indicate that VEGF can potently predict the overall survival in Asian patients with gastric cancer. Importantly, VEGF may be converted from candidate to the routine clinical setting for clinicians to predict the outcome of single patient with gastric carcinoma.

Vascular endothelial growth factor +936C/T polymorphism and gastric cancer risk: A meta-analysis

The aim of this study was to determine whether the vascular endothelial growth factor (VEGF) +936C/T polymorphism confers susceptibility to gastric cancer (GC) by conducting a meta-analysis. Publications addressing the association between the VEGF +936C/T polymorphism and GC risk were selected from the Pubmed, Embase and CBM databases. Data were extracted from the studies by two independent reviewers. The meta-analysis was performed using RevMan 5.0.25 and STATA 9.2 software. From these data, the odds ratio (OR) with 95% confidence interval (CI) was calculated. Finally, 8 case-control studies were retrieved reporting a total of 2,131 gastrointestinal cancer patients and 2,670 controls. Meta-analysis results showed that there was no significant association between the VEGF +936C/T polymorphism and GC risk in all comparisons of the T allele vs. C allele (OR=1.08, 95% CI 0.90-1.30, P=0.42), CT+TT vs. CC (OR=1.08, 95% CI 0.87-1.34, P=0.49), TT vs. CC+CT (OR=1.14, 95% CI 0.85-1.53, P=0.37), TT vs. CC (OR=1.18, 95% CI 0.87-1.59, P=0.28) and TT vs. CT (OR=1.11, 95% CI 0.79-1.56, P=0.56). This meta-analysis confirms that there is a lack of association between the VEGF +936C/T polymorphism and GC risk.

Expression of VEGF, EGFR, and IL-6 in gastric adenomas and adenocarcinomas by endoscopic submucosal dissection

BACKGROUND

The degree of intratumoral microvascular density is thought to affect tumor metastasis and prognosis in various human cancers, including gastric cancer. Despite recent medical advancements, gastric adenoma or adenocarcinoma remains a considerable therapeutic challenge. Endoscopic submucosal dissection (ESD) is a more recent approach that is now commonly used for radical resection of gastric adenoma and adenocarcinoma.

AIM AND METHODS

The expression of vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), and interleukin-6 (IL-6) are related to the prognosis of gastric adenocarcinoma. However, the expression of these factors in gastric adenoma/adenocarcinoma following ESD has not been clearly evaluated. Here, we report on our study of the expression of VEGF, EGFR, and IL-6 by immunohistochemical staining in extracted tissue from adenoma or adenocarcinoma of the stomach by ESD and subsequent evaluation of the correlation of VEGF, EGFR, and IL-6 with other clinicopathological parameters. The patient cohort consisted of 102 patients with adenoma or adenocarcinoma of the stomach.

RESULTS

Immunohistochemical staining for VEGF and IL-6 was significantly higher in both high grade dysplasia and adenocarcinoma than in low grade dysplasia (P < 0.05). There was significant correlation between histological grade and intensity of immunohistochemical staining of VEGF (P = 0.039). Histological differentiation of adenocarcinoma was related to IL-6 expression (P = 0.028). The immunoreactivity of VEGF and IL-6 increased significantly in lesions >2 cm compared to lesions <2 cm (P < 0.05).

CONCLUSION

The immunohistochemical expression of IL-6 and VEGF can be considered to be useful for clinical diagnosis and follow-up of adenoma or adenocarcinoma of the stomach.

No association of vascular endothelial growth factor-A (VEGF-A) and VEGF-C expression with survival in patients with gastric cancer

PURPOSE

Although the vascular endothelial growth factor (VEGF) superfamily has been identified to critically influence tumor-related angiogenesis, the prognostic significance of a VEGF expression in gastric cancer is still controversial. Accordingly, the present study analyzed the VEGF-A and VEGF-C expressions and their impact on the prognosis of patients with gastric cancer.

MATERIALS AND METHODS

Three hundred seventy-five consecutive patients who underwent surgical resection for gastric adenocarcinoma with a curative intent were enrolled in the present study. Immunohistochemical staining for VEGF-A and VEGF-C was performed using the formalin fixed, paraffin embedded tumor tissues.

RESULTS

Positive VEGF-A and VEGF-C expressions were observed in 337 (90.1%) and 278 (74.9%) cases, respectively. The survival analysis showed that the expression of VEGF-A and VEGF-C had no effect on the OS and DFS. On the multivariate analysis that included age, gender and the TNM stage, no significant association between the grade of the VEGF-A or VEGF-C expression and survival was observed.

CONCLUSION

The current study suggests that the tissue expression of VEGF-A or VEGF-C alone is not an independent prognostic marker for patients with surgically resected gastric adenocarcinoma.

High preoperative serum vascular endothelial growth factor levels predict poor clinical outcome after curative resection of gastric cancer

BACKGROUND

Tumour vascular endothelial growth factor (VEGF) and tumour urokinase-type plasminogen activator (uPA) are prognostic factors in gastric cancer but surgical specimens are required for testing. The prognostic value of preoperative serum VEGF (s-VEGF) and serum uPA (s-uPA) levels was evaluated in patients undergoing potentially curative (R0) gastric cancer resection.

METHODS

Concentrations of s-VEGF and s-uPA were measured 97 patients with gastric cancer and 20 controls. Angiogenesis was measured in vitro based on human endothelial cell tube formation.

RESULTS

Levels of s-VEGF were higher in patients with gastric cancer than controls (median 288 versus 189 pg/ml respectively; P = 0.002). They were associated with pathological tumour node metastasis (pTNM) stage, pT, pN, lymph node ratio and perineural invasion, and correlated with platelet counts. In multivariable analysis, s-VEGF over 320 pg/ml was the only preoperative predictor of both recurrence and disease-specific survival. Serum from patients with raised s-VEGF levels enhanced angiogenesis in vitro significantly more than serum from those with a s-VEGF level of 320 pg/ml or less.

CONCLUSION

High preoperative s-VEGF level is an independent prognostic factor for recurrence and survival after R0 resection of gastric cancer. This may provide a useful guide to decision making regarding neoadjuvant and adjuvant therapies.

Molecular aspects in the diagnosis of gastric cancer

BACKGROUND

Gastric cancer (GC) represents the second most common cause of cancer-related death worldwide. The prognosis remains poor, with limited treatment options. A better understanding of the initiation and progression of GC would enable the development of general screening strategies and individualized treatment modalities.

OBJECTIVE

The assessment of tools and molecular markers for the early detection and diagnosis of GC.

METHODS

Human clinical studies published within the past 5 years are reviewed. Also, significant previous data on markers in clinical use or on relevant animal or cell culture experiments are considered.

RESULTS/CONCLUSION

Serum-based screening strategies are not ready for routine application but represent an opportunity for the identification of individuals at high risk with the need for primary gastroscopy and further surveillance, which would ultimately improve survival and prognosis of GC. Infection with Helicobacter pylori represents the principal risk factor for gastric carcinogenesis. Bacterial virulence and host genetic factors contribute to individual susceptibility. Key molecular alterations in gastric carcinogenesis are related to intra- and extracellular cascades that regulate cell proliferation, tumor invasion and metastastic spread. For the development of effective prevention and treatment modalities, it is essential to unravel the basic mechanisms of gastric carcinogenesis.

Expression of trefoil factor 1 in gastric cancer and its correlation with neovascularization

AIM: To investigate the expression of trefoil factor 1 (TFF1) and vascular endothelial growth factor (VEGF) in normal gastric mucosa, adjacent carcinoma and gastric carcinoma and to explore its role in neovas-cularization.

METHODS: The expressions of TFF1, VEGF and MVD (CD34 monoclonal antibody labeling) were determined by immunohistochemical method in 174 gastric specimens including 42 normal gastric mucosa, 66 adjacent carcinoma and 66 gastric carcinomas.

RESULTS: In normal control group, adjacent carcinoma and gastric carcinoma group, the expression of TFF1 had a decreasing tendency (209.40 ± 16.00, 199.12 ± 16.68, 189.17 ± 16.20, P < 0.01), but the expression of VEGF and the MVD had a increasing tendency (69.7%, 40.9%, 35.7%; 38.90 ± 6.74, 28.68 ± 5.08, 25.13 ± 4.46). MVD was positively correlated with grey levels of TFF1 (r = 0.811, P < 0.01), in other words, there was a negative correlation between the MVD values and the expression of TFF1.

CONCLUSION: TFF1, a specific anti-oncogene for gastric carcinoma, doesn't have a close correlation with tumor vessel neogenesis.

Impact of vascular endothelial growth factor receptor 1, 2, and 3 expression on the outcome of patients with gastric cancer

Tumor angiogenesis is a multistep interactive process in which vascular endothelial growth factor (VEGF) and its receptors have a major role. However, the clinical significance of these molecules in gastric cancer (GC) remains unclear. Our study group comprised 86 patients who underwent gastrectomy and subsequently received chemotherapy for recurrent or residual tumor. Using immunohistochemical techniques, we analyzed the expression of VEGF receptors (VEGF-R) 1, 2, and 3. VEGF-R1 expression (defined as >5% staining) was found in the tumor cells of 65 tumors (76%) and in the stromal vessels of 36 tumors (42%). VEGF-R2 expression was found in tumor cells and stromal vessels of 0 and 46 tumors (0 and 53%), respectively, and VEGF-R3 expression was found in tumor cells and stromal vessels of 0 and 75 tumors (0 and 87%), respectively. Univariate analysis revealed that VEGF-R expression correlated with shorter survival (VEGF-R1 in stromal vessels, P = 0.001; VEGF-R2 in stromal vessels, P = 0.009; VEGF-R3 in stromal vessels, P = 0.005) and lower response to S-1 (VEGF-R1 in stromal vessels, P = 0.039). Multivariate analysis of potential prognostic factors showed that VEGF-R1 and VEGF-R2 in stromal vessels were independent predictors of poor outcome. Our data suggest that VEGF-R expression can be a predictor of unfavorable clinical outcome in GC. VEGF-R are promising candidates as therapeutic targets.

Positive VEGF immunostaining independently predicts poor prognosis in curatively resected gastric cancer patients: results of a study assessing a panel of angiogenic markers

Angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF) contribute to gastric cancer aggressiveness by up-regulating the expression of proteases. We evaluated the expression and the prognostic significance of angiogenic factors and proteases in 148 patients with R0-resected gastric cancer. Expression of VEGF, Ang-2, cyclooxygenase-2 (COX-2), urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1, matrix metalloproteinases (MMP)-1 and -9 were assayed by immunohistochemistry. After a mean of 63 +/- 4 months, 81 out of 148 patients had died due to disease. The probability of being free of recurrence was 62, 48, and 42% at 2, 5, and 10 years, respectively. Single bivariate analysis identified VEGF, Ang-2, COX-2, PAI-1, and MMP-9 expression, along with several clinicopathological parameters (grade of curability, lymph node ratio, pTNM, pT, pN), as variables associated with both decreased disease-specific survival and recurrence. On multivariate analysis, after adjusting for significant clinical covariables, positive VEGF immunostaining was the primary prognostic factor, and no other tumor marker variable could add any significant improvement for the prediction, for both disease-specific survival (p = 0.001; HR, 3.27; 95% CI, 1.76 to 6.10) and tumor recurrence (p = 0.002; HR, 2.81; 95% CI, 1.48 to 5.35). Our study suggests that VEGF alone may be clinically useful for establishing therapeutic decisions in gastric cancer patients.

Relationship between vascular invasion and microvessel density and micrometastasis

AIM

To evaluate the relationship between vascular invasion and microvessel density (MVD) of tissue and micrometastasis in blood.

METHODS

Vascular invasion was detected by both hematoxylin and eosin staining and immunohistochemiscal staining. Blood samples were collected from 17 patients with vascular invasion and 29 patients without vascular invasion and examined for cytokeratin20 (CK20) expression by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Microvessel density of tissue samples was also determined by immunohistochemistry using antibodies to CD105.

RESULTS

CK20 was detected in 12 of the 17 patients with vascular invasion and in 9 of the 29 patients without vascular invasion. Positive RT-PCR was significantly correlated with vascular invasion (70.6% vs 30.0%, P < 0.05). The average MVD was significantly higher in patients with positive vascular invasion than in patients with negative vascular invasion (29.2 +/- 3.3 vs 25.4 +/- 4.7, P < 0.05). The vascular invasion detected with hematoxylin-eosin staining was less than that with immunohistochemical staining. There was a significant difference between the two staining methods (19.6% vs 36.9%, P < 0.05).

CONCLUSION

Positive CK20 RT-PCR, depth of tumor invasion, lymph node status, metastasis and MVD are significantly correlated with vascular invasion. Immunohistochemical staining is more sensitive than hematoxylin-eosin staining for detecting vascular invasion.

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) expression in colorectal cancer

BACKGROUND AND OBJECTIVES

Vascular endothelial growth factor (VEGF) is known as an important factor in the growth and metastasis of cancer cells. In 2001, a novel angiogenesis factor, endocrine gland-derived vascular endothelial growth factor (EG-VEGF), was cloned. In this study, we investigated the expression of EG-VEGF in colorectal cancer, the relationship between its expression and clinicopathological factors, and the in vitro activity of EG-VEGF transfectants.

METHODS

We determined expression levels of EG-VEGF in 113 advanced colorectal cancers resected in our hospital by quantitative PCR, and compared the expression levels and clinicopathological findings by multivariate analyses.

RESULTS

The expression of EG-VEGF mRNA was positive in 31 cancers and negative in 82 cancers. We found that compared with the negative expression of the EG-VEGF gene, its positive expression was more frequently associated with hematogenous metastasis, and was associated with a poorer survival rate. In addition, EG-VEGF transfectants showed a higher degree of in vitro tubular formation than control cells.

CONCLUSIONS

We speculate that, in colorectal cancers, the EG-VEGF gene functions as an important factor in angiogenesis in primary and metastatic lesions, and consider that it is useful as a novel prognostic factor. EG-VEGF molecule-targeted therapy has the potential for improving survival rates.

Relationship between vascular invasion and microvessel density and micrometastasis

AIM: To evaluate the relationship between vascular invasion and microvessel density (MVD) of tissue and micrometastasis in blood.

METHODS: Vascular invasion was detected by both hematoxylin and eosin staining and immunohistochemiscal staining. Blood samples were collected from 17 patients with vascular invasion and 29 patients without vascular invasion and examined for cytokeratin20 (CK20) expression by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Microvessel density of tissue samples was also determined by immunohistochemistry using antibodies to CD105.

RESULTS: CK20 was detected in 12 of the 17 patients with vascular invasion and in 9 of the 29 patients without vascular invasion. Positive RT-PCR was significantly correlated with vascular invasion (70.6% vs 30.0%, P < 0.05). The average MVD was significantly higher in patients with positive vascular invasion than in patients with negative vascular invasion (29.2 ± 3.3 vs 25.4 ± 4.7, P < 0.05). The vascular invasion detected with hematoxylin-eosin staining was less than that with immunohistochemical staining. There was a significant difference between the two staining methods (19.6% vs 36.9%, P < 0.05).

CONCLUSION: Positive CK20 RT-PCR, depth of tumor invasion, lymph node status, metastasis and MVD are significantly correlated with vascular invasion. Immunohistochemical staining is more sensitive than hematoxylin-eosin staining for detecting vascular invasion.

Markers of tumour angiogenesis and tumour cells in bone marrow in gastric cancer patients

AIMS

Vascular endothelial growth factors VEGF-A, VEGF-C and VEGF-D are considered to be potentially angiogenetic and lymphangiogenetic. "Minimal residual disease" is responsible for cancer progression and recurrence. In this study, we investigated the relation between expressions of VEGF-A, VEGF-C and VEGF-D in gastric cancer tissue and the presence of tumour cells in bone marrow.

METHODS

A total of 50 resected primary gastric adenocarcinomas, 44 non-cancerous gastric mucosa and 36 lymph node metastases were analyzed by immunohistochemistry for VEGF-A, VEGF-C and VEGF-D. The specimens used were drawn from a previous study cohort, where the presence of ITC in bone marrow was confirmed with immunohistochemical assay with cytokeratin (CK)-18.

RESULTS

The levels of expression of VEGF-A, VEGF-C and VEGF-D were highest in tumour (p < 0.001), and the level in lymph node metastases was significantly higher (p < 0.01) than in mucosa. The expression of VEGF-A was correlated significantly with venous tumour invasion (p < 0.05) and the presence of tumour cells in bone marrow (p < 0.05). Tumours expressing high levels of VEGF-D showed significantly advanced stages of tumour infiltration (p < 0.05) and lymph node metastasis (p < 0.01).

CONCLUSIONS

VEGF-A is a significant marker for the presence of tumour cells in the bone marrow of gastric cancer patients. Our results confirm VEGF-D as a predictor for the lymphatic spread of tumour cells. Therefore, the route of metastatic spread of gastric cancer could be determined, at least in part, by the profile of VEGF family members expressed in the primary tumour of gastric cancer patients.

VEGF-C and VEGF-A synergistically enhance lymph node metastasis of gastric cancer

PURPOSE

Vascular endothelial growth factor C (VEGF-C) is the most important molecule in lymphangiogenesis and its relationship with lymph node metastasis has attracted considerable interest. We investigated the relationship of VEGF-C or VEGF-A with clinicopathological factors in gastric cancer patients.

METHODS

Eighty gastric cancer patients who underwent gastric resection were analyzed immunohistochemically for expression of VEGF-C and VEGF-A protein.

RESULTS

Positive immunoreactivity of VEGF-C and VEGF-A was observed in 75 (93.8%) and 41 (51.3%) patients, respectively. VEGF-A expression was significantly correlated with tumor differentiation (p=0.0017) and vascular invasion (p=0.0004). And positive relationship of VEGF-C expression was only demonstrated with tumor differentiation (p=0.0168). Interestingly, however, the frequency of lymph node metastasis was significantly higher in the patients with expression of both VEGF-C and VEGF-A (strong positive expression, p=0.036). Furthermore, the expression of both was also significantly correlated with depth of tumor invasion, tumor differentiation, lymphatic invasion, and vascular invasion.

CONCLUSION

The present results suggest that strong expression of VEGF-A in addition to VEGF-C expression is essential in lymph node metastasis, presumably because enhanced metastatic potential including lymphangiogenesis induced by both VEGF-A and VEGF-C is vital in lymph node metastasis of gastric cancer.

DNA demethylation of vascular endothelial growth factor-C is associated with gene expression and its possible involvement of lymphangiogenesis in gastric cancer

Previous studies have indicated that lymphangiogenesis in solid tumors is associated with lymphatic metastasis. Overexpression of Vascular endothelial growth factor (VEGF)-C plays a major role in lymphangiogenesis in cancers. In the present study, DNA methylation and expression of the VEGF-C gene was investigated in gastric cancer (GC). Four GC cell lines (MKN-45, MKN-74, HSC-39 and HSC-43) showed no expression of VEGF-C, and the VEGF-C gene was found to be methylated in these cells. In contrast, 7 GC cell lines (MKN-1, MKN-7, MKN-28, TMK-1, KATO-III, SH101-P4 and HSC-44PE) expressed VEGF-C, and the VEGF-C gene was found to be unmethylated in these cell lines. In addition, expression of VEGF-C mRNA was retrieved by treatment with a demethylating agent, Aza-2'-deoxycytidine. In GC tissue samples, bisulfite DNA sequencing analysis revealed that VEGF-C was not methylated in 9 (29.0%) of 31 GC samples, whereas demethylation was not observed in corresponding non-neoplastic mucosa samples. Overexpression of VEGF-C mRNA was observed in 16 (51.6%) of 31 GC samples by quantitative reverse transcription-polymerase chain reaction. Of the 9 GC cases with VEGF-C demethylation, 8 (88.9%) overexpressed VEGF-C. In contrast, of the 22 GC cases without VEGF-C demethylation, 8 (36.4%) overexpressed VEGF-C (p = 0.0155). Furthermore, lymphatic vessel density determined by immunostaining of podoplanin in GC tissues was associated with overexpression of VEGF-C (p < 0.0001). These results suggest that demethylation and activation of the VEGF-C gene is likely involved in lymphangiogenesis in GC.

Vascular endothelial growth factor gene polymorphisms associated with prognosis for patients with gastric cancer

BACKGROUND

The present study analyzed vascular endothelial growth factor (VEGF) gene polymorphisms and their impact on the prognosis for patients with gastric cancer.

PATIENTS AND METHODS

Five hundred and three consecutive patients with surgically resected gastric adenocarcinoma were enrolled in the present study. The genomic DNA was extracted from paraffin-embedded tissue and four VEGF (-460T > C, -116G > A, +405G > C, and +936C > T) gene polymorphisms were determined using a polymerase chain reaction-restriction fragment length polymorphism assay.

RESULTS

The survival analysis showed no association of three VEGF gene polymorphisms with the prognosis. For the +936C > T polymorphism, the T/T genotype, however, had a worse overall survival (OS) compared with the C/C genotype (P = 0.037). The -460 T/C or C/C genotype was a poor prognostic factor in patients with stage 0 or I gastric cancer (OS: hazard ratio (HR) = 3.96, disease-free survival (DFS): HR = 4.87). In the haplotype analysis, the CACC haplotype was associated with a significantly worse survival when compared with the TGGC haplotype (OS: HR = 1.72, DFS: HR = 1.73).

CONCLUSIONS

VEGF gene polymorphisms were found to be an independent prognostic marker for patients with gastric cancer. Consequently, the analysis of VEGF gene polymorphisms can help identify patient subgroups at high risk of a poor disease outcome.

Association of serum vascular endothelial growth factor-C and lymphatic vessel density with lymph node metastasis and prognosis of patients with gastric cancer

AIM: To investigate whether serum vascular endothelial growth factor-C (SVEGF-C), VEGF-C, and lymphatic vessel density (LVD) in tumor tissues are related to lymph node metastasis (LNM) and prognosis in gastric cancer.

METHODS: SVEGF-C levels of 80 gastric cancer patients and 20 healthy donors were examined using ELISA. VEGF-C expression and LVD were examined using immunohistochemical staining. Kaplan-Meier survival analysis was performed to determine their influence on the prognosis of the patients.

RESULTS: The SVEGF-C level in gastric cancer patients (595.9 ± 201.0 ng/L) was significantly higher (P = 0.000) than controls (360.0 ± 97.4 ng/L). Both SVEGF-C and LVD were significantly higher in poorly differentiated adenocarcinomas, T3 and T4, LNM, distant metastasis, and pTNM groups III and IV (P = 0.000). The sensitivity and specificity of SVEGF-C for predicting LNM were 82.8% and 81.8%, respectively (cut-off = 542.5 ng/L). The positive expression rate of VEGF-C was significantly higher in cancerous than in normal tissues (65% vs 20%; P = 0.001). VEGF-C expression up-regulation was significantly related to differentiation, depth of invasion, LNM, distant metastasis, and pTNM stage (P = 0.000). LVD was 10.7 ± 3.1/200 HP in the experimental group vs 4.9 ± 1.3/200 HP in controls (P = 0.000); LVD in cancerous tissues with and without LNM was 12.0 ± 2.7/200 HP vs 7.6 ± 0.5/200 HP, respectively (P = 0.000). SVEGF-C and LVD were significantly higher in VEGF-C positive than in negative patients (P = 0.000); SVEGF-C level was related to LVD (P = 0.000). Kaplan-Meier survival analysis factors predicating poor prognosis were: SVEGF-C level (P = 0.001), VEGF-C expression and LVD (both P = 0.000).

CONCLUSION: SVEGF-C level, VEGF-C and LVD are related to LNM and poor prognosis of patients with gastric cancer. SVEGF-C may be a biomarker for LNM in gastric cancer.

Clinicopathological and prognostic significance of vascular endothelial growth factors (VEGF)-C and -D and VEGF receptor 3 in invasive breast carcinoma

AIMS

Vascular endothelial growth factors C and D (VEGF-C and VEGF-D) play a major role in lymphangiogenesis and activate VEGF receptor 3 (VEGFR-3). Our purpose was to study the clinicopathologic and clinical value of VEGF-C, VEGF-D and VEGFR-3 in invasive breast carcinoma.

MATERIAL AND METHODS

Immunohistochemistry was performed in paraffin-embedded tissue specimens from 177 invasive breast carcinomas to detect the proteins VEGF-C, VEGF-D, VEGFR-3, p53, Ki67, c-erbB-2, topoII alpha and ER/PR. The results were statistically processed.

RESULTS

VEGF-C, VEGF-D and VEGFR-3 were found to be predominantly expressed in the cytoplasm of the malignant cells. VEGF-C occasionally showed a submembranous intensification. VEGF-D and VEGFR-3 were also immunodetected in the nuclei of the malignant cells. Nuclear VEGF-D was positively correlated to p53, Ki67 and topoII alpha proteins' expression (p=0.003, p=0.009 and p=0.017 respectively) and nuclear VEGFR-3 to topoII alpha (p=0.034). Cytoplasmic expression of VEGF-C and its submembranous intensification were found to be independent indicators of patients' overall and disease-free survival, respectively (p=0.003 and p=0.044 respectively). The group with high expression of both cytoplasmic VEGF-C and stromal VEGFR-3 showed poor overall survival (p=0.024) and the group with both submembranous VEGF-C and stromal VEGFR-3 immunostaining showed poor both disease-free and overall survival (p=0.012 and p=0.038 respectively).

CONCLUSION

VEGF-D and VEGFR-3 seem to exert proliferative activity in invasive breast carcinomas. VEGF-C was found to be an independent indicator of patient's poor prognosis and the simultaneous expression of tumor VEGF-C and stromal VEGFR-3 yielded additional prognostic information.

The stem cell factor/c-kit receptor pathway enhances proliferation and invasion of pancreatic cancer cells

BACKGROUND

The transmembrane protein c-kit is a receptor tyrosine kinase (KIT) and KIT is expressed in solid tumors and hematological malignancies such as gastrointestinal stromal tumor (GIST), small-cell lung cancer and chronic myelogenous leukemia (CML). KIT plays a critical role in cell proliferation and differentiation and represents a logical therapeutic target in GIST and CML. In pancreatic cancer, c-kit expression has been observed by immunohistochemical techniques. In this study, we examined the influence of c-kit expression on proliferation and invasion using five pancreatic cancer cell lines. In addition, the inhibitory effect of imatinib mesylate on stem cell factor (SCF)-induced proliferation and invasion was evaluated. Finally, we also analyzed KIT and SCF expression in pancreatic cancer tissues using immunohistochemistry and correlated the results with clinical features.

RESULTS

RT-PCR revealed that two pancreatic cancer cell lines, PANC-1 and SW1990, expressed c-kit mRNA. By Western blot analysis, c-kit protein was also present in those lines. In KIT-positive pancreatic cancer cell lines, proliferation and invasion were significantly enhanced by addition of SCF. In contrast, SCF did not enhance proliferation and invasion in the three KIT-negative lines (BxPC-3, Capan-2 and MIA PaCa-2). 5 muM imatinib mesylate significantly inhibited SCF-enhanced proliferation to the same extent compared with the control. Similarly, SCF-enhanced invasive ability was significantly inhibited by 5 muM imatinib mesylate. KIT was expressed in 16 of 42 clinical specimens by immunohistochemistry, and KIT expression was significantly related to venous system invasion. Furthermore, patients expressing both KIT and SCF had a somewhat lower survival.

CONCLUSION

Our results demonstrated that the SCF-KIT pathway enhanced the proliferation and invasiveness in KIT-positive pancreatic cancer cell lines and that the enhanced proliferation and invasion were inhibited by imatinib mesylate. We propose that inhibitors of c-kit tyrosine kinase receptor have the potential to slow the progression of KIT-positive pancreatic cancers.

Increased expression of vascular endothelial growth factor C in papillary thyroid carcinoma correlates with cervical lymph node metastases

PURPOSE

Despite recent studies showing that vascular endothelial growth factor C (VEGF-C) mRNA is up-regulated in papillary thyroid carcinoma (PTC), the role of VEGF-C in lymph node metastasis is still unclear. The aim of this study is to investigate the expression pattern of VEGF-C immunoreactive protein in PTC and its relationship with cervical lymph node metastasis.

EXPERIMENTAL DESIGN

Tissue samples were obtained from 39 specimens of PTC (20 with and 19 without lymph node metastasis) as well as 20 benign thyroid nodules. Overexpression of the VEGF-C protein was evaluated by immunoblotting with specific anti-VEGF-C antibody in paired tumor and nontumor tissues from PTC. The data were compared with patients' clinicopathologic features and lymph node metastasis. Immunohistochemical staining was done on selected paraffin sections to determine cellular localization of VEGF-C and to assess flt-4 (or VEGFR-3)-positive vessel density in PTC lesions.

RESULTS

Overexpression of VEGF-C was detected in 69% of the PTC and in 5% of the benign thyroid specimens. When comparing between the metastatic and nonmetastatic groups of PTC, a higher expression level of VEGF-C was detected in both the tumor (P = 0.004) and adjacent nontumor tissues (P = 0.011). Positive immunostaining for VEGF-C was confirmed in PTC tumor tissues and metastatic lymph nodes, which correlated with flt-4-positive vessel density in tumor and peritumor tissues. The increased expression of VEGF-C protein in PTC is associated with lymph node metastasis (P = 0.004) and lymphovascular permeation (P = 0.001) but is independent of other clinicopatholgic variables.

CONCLUSIONS

The VEGF-C immunoreactive protein is overexpressed in PTC lesions, which correlates with lymph node metastases. VEGF-C expression may play a role in lymphangiogenesis of PTC and further study is necessary to evaluate the clinical application of VEGF-C as a molecular marker for tumor metastases to cervical lymph nodes.

Anti-angiogenic treatment of gastrointestinal malignancies

The scientific rationale to block angiogenesis as a treatment strategy for human cancer has been developed over the last 30 years, but is only now entering the clinical arena. Preclinical studies have demonstrated the importance of the vascular endothelial growth factor (VEGF) pathways in both physiologic and pathologic angiogenesis, and have led to the development of approaches to block its role in tumor angiogenesis. Bevacizumab is an antibody to VEGF and has been shown to prolong survival when given with chemotherapy in the treatment of metastatic colorectal cancer (CRC). Although this is the first anti-angiogenic treatment to be approved for the treatment of human epithelial malignancy, a number of other approaches currently are in development. Soluble chimeric receptors to sequester serum VEGF and monoclonal antibodies against VEGF receptors have both shown considerable promise in the laboratory and are being brought into clinical investigation. A number of small-molecule tyrosine kinase inhibitors that have activity against VEGF receptors also are in clinical trials. Although these novel treatments are being pioneered in CRC, anti-angiogenic approaches also are being tested in the treatment of other gastrointestinal malignancies. Anti-VEGF therapy has shown promise in such traditionally resistant tumors as pancreatic cancer and hepatocellular carcinoma. This review will examine the preclinical foundation and then focus on the clinical studies of anti-VEGF therapy in gastrointestinal cancers.

Vascular Endothelial Growth Factor-D and Its Receptor VEGFR-3: Two Novel Independent Prognostic Markers in Gastric Adenocarcinoma

Purpose

Vascular endothelial growth factor (VEGF)-D and its homolog VEGF-C influence lymphangiogenesis through activation of VEGF receptor 3 (VEGFR-3), and have been implicated in lymphatic tumor spread. Nodal dissemination of gastric adenocarcinomas critically determines clinical outcome and therapeutic options of affected patients. Therefore, we analyzed expression and prognostic significance of VEGF-D along with VEGF-C, and VEGFR-3 in gastric adenocarcinomas.

Materials and Methods

VEGF-C, VEGF-D, and VEGFR-3 were analyzed in 91 R0-resected primary gastric adenocarcinomas, corresponding noncancerous gastric mucosa, and lymph node metastases employing immunohistochemistry and/or in situ hybridization. Blood and lymph vessel densities were assessed after staining with CD31 and LYVE-1–specific antibodies.

Results

VEGF-D and VEGF-C were detected in 67.0% and 50.5% of gastric cancers, respectively. Healthy gastric mucosa was negative for VEGF-C and in 12.5% positive for VEGF-D. Presence of VEGF-D (P = .005) or VEGF-C (P = .006) was correlated with lymphatic metastases and decreased survival (VEGF-D, P < .05; VEGF-C, P < .05). VEGFR-3 was correlated with reduced carcinoma-specific survival (P < .05), and Cox multivariate regression analysis qualified VEGF-D and VEGFR-3, but not VEGF-C, as independent prognostic parameters. In lymph node–positive gastric cancers, presence of VEGF-D/VEGFR-3 was associated with poor survival, whereas absence of VEGF-D/VEGFR-3 defined a subgroup of patients with clearly favorable prognosis.

Conclusion

VEGF-D and VEGFR-3 are novel independent prognostic marker molecules aiding to identify patients with poor prognosis after curative resection of gastric adenocarcinomas. Combined analysis of the VEGF-C/VEGF-D/VEGFR-3 system can be useful to identify patients with unfavorable clinical outcome and thereby may help to refine therapeutic decisions in gastric cancer.

Is the hypoxia-inducible factor pathway important in gastric cancer?

Tumour hypoxia is well recognised in oncology to be a key factor resulting in treatment resistance and poor prognosis. Hypoxia leads to the expression of a number of gene products that are involved in tumour progression, invasion and metastasis formation. The most important of these proteins is thought to be hypoxia-inducible factor-1alpha (HIF-1alpha), which appears to be a master regulator of the cellular response to hypoxia. HIF-1alpha expression is associated with a poor prognosis and treatment response in a number of tumour sites. There is some evidence that the HIF-1alpha pathway might be involved in gastric carcinogenesis. Studies have shown reactive oxygen species from Helicobacter pylori, associated with the development of gastric cancer, stabilise HIF-1alpha. Non-steroidal anti-inflammatory drugs, shown to reduce the risk of gastric cancer, can decrease HIF-1alpha expression. Although a large study correlating HIF-1alpha expression with prognosis is lacking in gastric cancer, the immunohistochemical expression of HIF-1alpha target genes (Glut-1, VEGF, CA9, iNOS) is associated with a poor prognosis. In addition, the targeted inhibition of HIF-1alpha has been shown to inhibit the growth of gastric tumours in animals. Increased understanding of the importance of hypoxia and the HIF-1alpha pathways may therefore hold the key to prevention strategies, improved selection of patients for adjuvant therapy and new treatments for the disease.

VEGF-C expression in breast cancer: clinical importance

It is well known that angiogenesis and lymphangiogenesis play important roles in tumor occurrence and progression. The vascular endothelial growth factor (VEGF) family is the most important family of proteins involved in angiogenesis, and VEGF-C is the most important molecule in lymphangiogenesis. Lymphangiogenesis plays an important role in lymphovascular invasion, metastasis to regional lymph nodes, and distant organ metastasis. In this study, the rate of VEGF-C was investigated in 217 patients with breast cancer. VEGF-C was evaluated by immunohistochemistry and its expression was compared with that of well-known prognostic indicators, such as tumor stage and grade, axillary lymph node involvement, estrogen and progesterone receptor status, c-erb-B2 expression, and extent of lymphovascular invasion. The patient population included 8 men, in addition to women before (n=108), during (n=9), and after (n=92) menopause. Patients had been diagnosed with invasive ductal (n=181) or invasive lobular (n=22) carcinoma, mixed (n=8) or medullary (n=1) carcinoma, or ductal carcinoma in situ (n=5). Tumors ranged from stage 0 to IV and grade I to III and the distribution of estrogen-positive (n=100) and estrogen-negative (n=110) receptor tumors was almost equal. The number of patients with c-erbB2 tumors ranged from 21 to 49 for each tumor stage, and the number of patients with VEGF-C-negative tumors ranged from 28 to 59 for each tumor stage. No important association between VEGF-C expression and other prognostic indicators was found. However, this may be a result of the lack of standardization among the methods used to determine VEGF-C expression. Also, the lymphangiogenic effect may not be overt because of the variety of VEGFR-3 variants, which included nonfunctional variants. To determine the relationship among angiogenesis, lymphangiogenesis, and prognosis, more standardized methods to demonstrate the angiogenesis, and prospective studies to cover a larger, more homogenous patient population are needed.

Blockade of vascular endothelial growth factor receptor signal pathway and antitumor activity of ON-III (2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone), a component from Chinese herbal medicine

Antiangiogenesis is a promising strategy of cancer treatment. Vascular endothelial growth factor receptor [fetal liver kinase/kinase-inserting domain-containing receptor (KDR)] is a tyrosine kinase receptor and has been strongly implicated in tumor angiogenesis. In this study, we report that 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (ON-III), extracted from the dried flower Cleistocalyx operculatus, used in traditional Chinese medicine, reversibly inhibited KDR tyrosine kinase phosphorylation, but epidermal growth factor receptor tyrosine kinase phosphorylation was unaffected under the same concentrations of ON-III. ON-III also inhibited mitogen-activated protein kinase (MAPK) and AKT activation of KDR signal transduction in downstream molecules without reduced total MAPK and AKT. The results in vitro showed that ON-III inhibited growth of human vascular endothelial HDMEC cells in the presence of VEGF preferentially, compared with epidermal growth factor. Systemic administration of ON-III at nontoxic doses in nude mice resulted in inhibition of subcutaneous tumor growth of human hepatocarcinoma Bel7402 and lung cancer GLC-82 xenografts. The tumor vessel density decreased, as determined by immunohistochemical staining, for CD31 after ON-III treatment. These results indicated that ON-III inhibited KDR tyrosine kinase, shut down KDR-mediated signal transduction, and inhibited tumor growth of human xenografts in vivo.

Effect of Weikangning on gastric cancer cell growth and expression of vascular endothelial growth factor and its receptors KDR and Flt-1

AIM: To observe the effect of Chinese traditional herbal decoction Weikang-ning (WKN) on cell growth and expression of VEGF and its receptors KDR and Flt-1 in gastric cancer cell line MGC-803.

METHODS: A total of 120 male Wistar rats were divided into control group, high dose, medium dose and low dose groups fed with natural saline, 20, 10, and 5 g/kg of WKN, respectively. The experimental animals were finally killed for the preparation of drug-containing serum. The gastric cancer cell MGC-803 was cultured with the drug-containing serum drawn from the rats in different groups. We observed the growth condition of the cancer cells with light microscope and flow cytometer. The expression of mRNA of VEGF and its receptors KDR and Flt-1 was detected with RT-PCR.

RESULTS: The proportion of cells in G₀-G₁ phase was (65.40±0.41)%, (56.92±0.62)%, (55.89±0.69)% in high, medium and low dose groups respectively vs (41.35±0.55)% in control group (P<0.01), while the cells in G₂-S and S phases were (11.62±0.62)% and (22.99±0.69)%, (17.08±0.80)% and (26.00±0.71)%, (19.37±0.57)% and (24.74±0.64)% in high, medium and low dose groups, respectively, vs (23.65±0.56)% and (35.00±0.60)% in control group (P<0.01). The expression of mRNA of VEGF and its receptors was significantly decreased, the area of electrophoresis bands (AREA), the absorptivity of mean optical density (A) and the product of AREA and A were significantly lower in WKN-administered groups than that in control group (P<0.01).

CONCLUSION: The decoction of WKN suppresses the growth of gastric cancer cell MGC-803 and decreases the expression of mRNA of both VEGF and its receptors KDR and Flt-1.

Lymphangiogenic growth factors as markers of tumor metastasis

Understanding the complex process of tumor metastasis is a problem which has challenged both clinician and scientist for well over 100 years. Defining molecular markers which reflect the metastatic potential of a tumor has also proved elusive. Recently, members of the vascular endothelial growth factor (VEGF) family of glycoproteins have been demonstrated to be potent mediators of both blood vessel and lymphatic vessel formation in the context of tumor biology. Experimental studies in animal models combined with extensive clinicopathological data provide a compelling case indicating that members of the VEGF family play a key role in the formation of metastases in a broad range of solid tumors. The question of whether VEGF signaling pathways can now serve as therapeutic targets alone, or in combination with other forms of anti-cancer agents, needs to be addressed.

Expression of vascular endothelial growth factor (VEGF)-C in preoperative biopsy specimens and metastatic foci of regional lymph nodes in submucosal gastric carcinoma

BACKGROUND: Vascular endothelial growth factor (VEGF)-C is implicated in lymphangiogenesis, however the exact role of VEGF-C in promoting lymphatic spread of cancer cells remains largely unknown. METHODS: The expression of VEGF-C was immunohistochemically determined in 97 endoscopic biopsy specimens from 46 patients with submucosal gastric carcinoma (SGC). Nodal metastases including micrometastasis and isolated tumor cells (ITC) were evaluated by immunohistochemical staining for cytokeratin in 1650 lymph nodes, and tumor cells in these metastatic nodes were also examined for VEGF-C expression. RESULTS: In biopsy samples, VEGF-C was positively detected in 21 (47%) patients. Metastases were identified in 46 (2.8%) nodes from 15 (33%) patients. Metastases were detected in 39 nodes by hematoxylin-eosin (H&E) staining and in additional 7 nodes as ITC by immunohistochemical staining. The rate of lymph node metastases was significantly correlated with VEGF-C expression in biopsy samples (p < 0.05). The positive and negative predictive values of VEGF-C in biopsy specimens for nodal metastasis were 44 %(10/21) and 80% (20/25), respectively. Among the 46 metastatic nodes, tumor cells in 29 (63%) nodes positive patients expressed VEGF-C, whereas those in 17 (37%) nodes did not. VEGF-C expression was high in macronodular foci in medullary areas, whereas more than half of ITC or micrometastasis located in peripheral sinus lacked the expression of VEGF-C. CONCLUSIONS: Despite the significant correlation, immunodetcetion of VEGF-C in endoscopic biopsy specimens could not accurately predict the nodal status, and thus cannot be applied for the decision of the treatment for SGC. VEGF-C may not be essential for lymphatic transport, but rather important to develop the macronodular lesion in metastatic nodes.

Association between expression of transcription factor Sp1 and increased vascular endothelial growth factor expression, advanced stage, and poor survival in patients with resected gastric cancer

The biological and clinical behaviors of cancer are affected by multiple molecular pathways that are under the control of transcription factors. Improved understanding of how transcription factors affect cancer biology may lead to improved ability to predict clinical outcome and discovery of novel therapeutic strategies. We evaluated the relationship between Sp1 and vascular endothelial growth factor (VEGF) expression, as well as their effect on survival in 86 cases of resected human gastric cancer. The degree of VEGF expression correlated highly with Sp1 expression (P < 0.01). Patients with high Sp1 expression were 98 times more likely to have high VEGF expression compared with those with negative Sp1 expression. Clinically, negative or weak Sp1 expression was associated with early stage (IA) in gastric cancer. Strong Sp1 expression was more frequently observed among patients with stage IB-IV disease (P = 0.035). Similarly, whereas strong Sp1 expression was uncommonly observed among patients with N0 or N1 disease (19 and 16%), N2/N3 gastric cancer was associated with strong Sp1 expression (48%; P = 0.034). Strong Sp1 expression was also associated with inferior survival. The median survival duration in patients who had a tumor with a negative, weak, and strong Sp1 expression was 44, 38, and 8 months (P = 0.0075), respectively, whereas patients with strong VEGF expression had a shorter survival duration; the difference was not statistically significant. When Sp1 and VEGF expression, stage, completeness of resection, histology, and patient age were entered in a Cox proportional hazards model, strong Sp1 expression (P = 0.021) and an advanced disease stage (P < 0.001) were independently prognostic of poor survival. Given the importance of Sp1 in the expression of VEGF, our data suggest that dysregulated Sp1 expression and activation play important roles in VEGF overexpression and, thus, gastric cancer development and progression.

Expression of vascular endothelial growth factor-C and the relationship between lymphangiogenesis and lymphatic metastasis in colorectal cancer

AIM: To investigate the expression of vascular endothelial growth factor-C (VEGF-C) and the relationship between VEGF-C and lymphangiogenesis, lymph node metastasis in colorectal cancer.

METHODS: Fifty six cases of colorectal cancer were selected randomly. Expression of VEGF-C was detected by immuno- histochemistry, and lymphatic vessels were stained by enzyme histochemical method.

RESULTS: VEGF-C expression was found in 66.7% (37/56) patients. In VEGF-C positive and negative patients, the lymphatic vessel density was 25.16 ± 7.52 and 17.14 ± 7.22, respectively (P < 0.05). The rate of lymph node metastasis in VEGF-C positive patients (81.1%) was significantly higher than that in the negative group (42.1%).

CONCLUSION: VEGF-C expression may induce lymphangiogenesis in colorectal cancer, as a result, tumor cells can entry the lymphatic vessels easily. VEGF-C may serve as a useful prognotic factor in colorectal carcinoma.

Clinical significance of VEGF-C status in tumour cells and stromal macrophages in non-small cell lung cancer patients

Recent experimental studies have revealed that tumour-associated stromal macrophages as well as tumour cells express vascular endothelial growth factor C (VEGF-C), which plays important roles in lymphangiogenesis, which is a critical factor in the progression of many malignant tumours including non-small-cell lung cancer (NSCLC). However, no clinical study on VEGF-C expression in both stromal macrophages and tumour cells has been reported, and we conducted the present study to address the issue in resected NSCLC. A total of 206 patients with completely resected pathologic stage I-IIIA NSCLC were retrospectively reviewed. Expression of VEGF-C in primary lung tumour was assessed immunohistochemically. Expression of VEGF-C in tumour cells was high in 125 patients (60.7%), and that in stromal macrophages was positive in 136 patients (71.2%). The status of VEGF-C in tumour cells or in stromal macrophages was not correlated with nodal status or angiogenesis. The 5-year survival rate of high tumoral VEGF-C patients (60.7%) was significantly lower than that of low tumoral VEGF-C patients (39.3%) (P=0.046), and a multivariate analysis confirmed that tumoral VEGF-C status was a significant and independent prognostic factor. Moreover, tumour showing high VEGF-A and VEGF-C expression in tumour cells showed the poorest prognosis (5-year survival rate, 45.1%). The status of VEGF-C in stromal macrophages was not correlated with the prognosis. In conclusion, tumoral VEGF-C status, not stromal VEGF-C status, was a significant prognostic factor in resected NSCLC.

Caspase-3 expression in human gastric carcinoma and its clinical significance

OBJECTIVES

Caspase-3 is one of the most important molecules in the apoptosis cascade, and the relationship between caspase-3 expression and prognosis has been reported in many types of malignancies. However, the involvement of caspase-3 in human gastric carcinoma is not fully understood. We evaluated caspase-3 expression in human gastric carcinoma to clarify the clinicopathological importance and investigated the apoptosis avoidance mechanism by an immunohistological method.

METHODS

Specimens from 151 patients who underwent gastrectomy at the Department of Surgery and Surgical Basic Science of Kyoto University Hospital were investigated. Caspase-3 expression in cancer cells was evaluated by comparing its expression in the germinal center of the lymphoid follicle, and was quantified as the caspase-3 expression index (C3EI). C3EI was compared with the expression of Bcl-2 and the TdT-mediated dUTP biotin nick-end labeling (TUNEL) in 80 randomly selected cases. Actual activation of caspase-3 was determined by immunohistochemistry using monoclonal antibody that recognizes only activated caspase-3.

RESULTS

C3EI correlated significantly with lymph node metastasis (negative 105.5-78.7, positive 153.8 +/- 66.1 p = 0.001) and the lower C3EI group had a better prognosis than the higher group (log-rank test, p = 0.0001). Cox multivariate analysis showed that age, operation curability, tumor invasion and C3EI were significant independent determinants of overall survival. Bcl-2 and TUNEL staining had no significant correlations with C3EI. Immunohistochemistry of activated caspase-3 revealed that most caspase-3 in gastric cancer cells was not activated, in accordance with TUNEL assay.

CONCLUSIONS

Our results show that C3EI is a novel, independent prognostic factor in gastric cancer patients and cancer cells may avoid apoptosis by inhibiting caspase-3 activation.

Role of lymphangiogenic factors in tumor metastasis

Nearly four centuries after the discovery of lymphatic vessels, the molecular mechanisms underlying their development are beginning to be elucidated. Vascular endothelial growth factor C (VEGF-C) and VEGF-D, via signaling through VEGFR-3, appear to be essential for lymphatic vessel growth. Observations from clinicopathological studies have suggested that lymphatic vessels serve as the primary route for the metastatic spread of tumor cells to regional lymph nodes. Recent studies in animal models have provided convincing evidence that tumor lymphangiogenesis facilitates lymphatic metastasis. However, it is not clear how tumor-associated lymphangiogenesis is regulated, and little is known about how tumor cells escape from the primary tumor and gain entry into the lymphatics. This review examines some of these issues and provides a brief summary of the recent developments in this field of research.

Clinicopathological significance of vascular endothelial growth factor-C and cyclooxygenase-2 in esophageal squamous cell carcinoma

BACKGROUND

Vascular endothelial growth factor-C (VEGF-C) is a specific growth factor of lymphatics, which is known to play some role in tumor growth and metastasis to lymph nodes and distant organs in various malignancies. The purpose of the present study was to investigate the expression of VEGF-C in human esophageal squamous cell carcinomas (ESCC) to elucidate its role in tumor progression and lymph node metastasis. Another aim of the study was to investigate the relation between VEGF-C and cyclooxygenase-2 (COX-2) in ESCC.

METHODS

The expression of VEGF-C and COX-2 in ESCC was evaluated in 13 endoscopic mucosal resection specimens and in 21 surgical specimens by immunohistochemical staining. Clinical data were obtained from medical records.

RESULTS

The degree of VEGF-C expression increased as the depth of primary tumor progressed (r = 0.521, P = 0.002), the stage progressed (r = 0.572, P < 0.001), and the degree of COX-2 expression increased (r = 0.387, P = 0.024). The VEGF-C positive rate was different between early cancers in which regional lymph node metastasis was thought to be absent and advanced cancers in which regional lymph node metastases were confirmed after surgery (20.0% vs 100.0%; P < 0.001).

CONCLUSIONS

The VEGF-C expression in ESCC is related to COX-2 expression, and VEGF-C is also associated with the depth of primary tumor, the stage, and probably lymph node metastasis. Thus the investigation of VEGF-C expression in ESCC may assist in management planning.