Clinical usefulness of serum and plasma vascular endothelial growth factor in cancer patients: which is the optimal specimen?

Vascular endothelial growth factor (VEGF) is secreted by various human cancer cells and plays a key role in cancer angiogenesis and metastasis. Recently, evidence of VEGF storage in blood cells including platelets has been reported. The serum VEGF levels were reported to increase during clotting as a result of its release from platelets, and plasma sample instead of serum was recommended for measuring the circulating VEGF more accurately. However, platelets have been implicated in tumor metastasis since circulating tumor cells forming aggregates with platelets were observed. The purpose of this study was to clarify which is an optimal specimen to measure VEGF in cancer patients, serum or plasma. We measured serum and plasma VEGF levels and platelet counts in 173 cancer patients and 42 healthy people, and found that serum VEGF levels were significantly higher than matched plasma VEGF and the VEGF difference (serum VEGF - plasma VEGF) correlated with platelet counts (r=0.624, p<0.05) in both cancer patients and healthy controls. We selected cancer patients with normal platelet counts (130-400x103/microl, Plt-normal cancer group). Interestingly, serum VEGF levels were higher in Plt-normal cancer group than in healthy controls. The theoretical platelet-derived VEGF in serum, calculated based on actual blood platelet counts (pg per 106 platelets), was also significantly higher in Plt-normal cancer group than in normal controls. It is, therefore, suggested that, although the serum VEGF levels are affected by blood platelets, platelet-derived VEGF also reflect biology of cancer cells, and that serum would be the more useful specimen for measurement of circulating VEGF in cancer patients for prognosis.     

Are basic fibroblast growth factor and vascular endothelial growth factor prognostic indicators in pediatric patients with malignant solid tumors?

Angiogenesis plays an important role in the growth, progression, and metastasis of solid tumors. Among angiogenic factors, basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) appear to be useful markers in adults with cancer. The aim of this pilot study was to determine the levels of VEGF in serum and bFGF in serum and urine of children with solid tumor at diagnosis (as measured by ELISA), and to investigate whether these parameters provide prognostic information. Forty consecutive patients with different types of cancer were prospectively included in this study. Median values of all studied angiogenic factors were higher in patients than in controls (n = 40), and the differences were statistically significant for bFGF in serum and urine: 10 versus 3 pg/ml (P = 0.0004) and 6406 versus 0 pg/g of creatinine (P < 0.0001), respectively. Among patients, median serum values of bFGF and VEGF were higher in children with metastatic disease (n = 14) than in those with localized disease (n = 26). The difference was statistically significant for serum bFGF: 17.5 versus 6 pg/ml (P = 0.02). Serum angiogenic factor levels correlated with outcome. The estimated event-free survival at 3 years was 79% for patients with normal bFGF values (n = 13) versus 42% (n = 26; P = 0.02) for those with high levels, and 71% in case of normal VEGF values (n = 20) versus 38% (n = 19; P = 0.04) for those with high levels. No benefit of normal urinary bFGF values was observed. Our results provide a rationale for exploring the clinical interest of bFGF and VEGF measurements in body fluids of a larger group of children with cancer.     

Hypoxia-inducible factor-1α and vascular endothelial growth factor expression in circulating tumor cells of breast cancer patients

Introduction  

The detection of peripheral blood circulating tumor cells (CTCs) and bone marrow disseminated tumor cells (DTCs) in breast cancer patients is associated with a high incidence of disease relapse and disease-related death. Since hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) play an important role in angiogenesis and tumor progression, the purpose of the current study was to investigate their expression in CTCs.     

Correlation of plasma and serum vascular endothelial growth factor levels with platelet count in colorectal cancer: clinical evidence of platelet scavenging?

Most studies measuring circulating vascular endothelial growth factor (VEGF) have sampled serum rather than plasma. There has been much debate whether the collection of sera (which causes the activation of platelets and VEGF release) is a true reflection of tumor angiogenic activity or whether platelets act as scavengers of VEGF. Addressing this issue, we measured serum and plasma VEGF, before and after colorectal resection, with reference to platelet counts. Serum and plasma samples were collected from 116 colorectal cancer (CRC) and 116 control patients. Ninety CRC and 32 benign resections were performed. Both plasma and serum VEGF were significantly higher in CRC patients (18.5 and 327 pg/ml, respectively) compared with controls (9.0 and 151.5 pg/ml, respectively; P < 0.0001). Paired serum and plasma VEGF measurements correlated in both CRC (r = 0.56) and control patients (r = 0.73; P < 0.0001). Serum and plasma VEGF levels correlated with platelet count in CRC patients (r = 0.58 and 0.44, respectively) but not in controls. Plasma and serum VEGF levels, and VEGF concentration per platelet, increased with advancing disease stage. The correlation of serum and plasma VEGF with platelet counts in CRC but not in benign disease may be attributable to the scavenging of VEGF from the tumor source by platelets, with plasma levels reflecting free circulating VEGF in equilibrium with platelet levels. VEGF levels in citrated plasma are low and lie close to the limits of ELISA sensitivity. We recommend that a standardized measurement of serum VEGF--normalized by the patient's platelet count to give a value of serum VEGF per platelet--be adopted.     

Does vascular endothelial growth factor (VEGF) predict local relapse and survival in radiotherapy-treated node-negative breast cancer?

The aim of this study was to determine the association of vascular endothelial growth factor (VEGF) content in 302 consecutive node-negative breast cancer (NNBC) patients treated with only locoregional radiotherapy to relapse free- (RFS) and overall survival (OS). VEGF content in tumour cytosols was measured by an enzymatic immunoassay for the major isoform VEGF165. The median age was 56 years, the median follow-up time 56 months. A wide range (0.01-144.79 pg microg(-1) DNA) of VEGF content was found (median 1.92). Significant associations were found between VEGF and oestrogen receptor (ER) content, progesterone receptor (PR) and tumour size (P = 0.005). Univariate analysis displayed significant reduced RFS and OS for patients with higher VEGF content (P = 0.0113 and P = 0.0075 respectively). A total of 43 recurrences have been found (ten local relapses within the breast, five in the axillary or supraclavicular lymph nodes and 28 distant metastasis). There was no significant correlation between the localization of the relapse and the VEGF content. Multivariate analysis suggested VEGF as the only predictor of OS (relative risk (RR) = 3.6, 95% confidence interval (CI) = 0.97-13.37), and in patients with T1 tumours (n = 236) the multivariate analysis clearly displayed VEGF as the only independent predictor of both RFS and OS (RR = 5.1, CI = 1.07-24.59). In the subgroup with ER-positive tumours (n = 229), multivariate analysis showed VEGF as the only significant predictor of RFS and OS (RR = 10.44, CI = 1.26-86.38). The results suggest VEGF165 as a predictor of RFS and OS in NNBC patients treated with locoregional radiotherapy, comprising especially patients with favourable prognosis of T1 tumours, or ER-positive tumours. The high VEGF expression might define a radioresistant phenotype, or indicate an early distant spread which might require adjuvant systemic treatment.     

Clinical significance of vascular endothelial growth factor‐C (VEGF‐C) in breast cancer

Vascular endothelial growth factorC (VEGFC) is a specific ligand which induces lymphangiogenesis. We examined the expression of VEGFC protein to determine its role in the progression of breast cancer. Immunohistochemical analysis revealed that VEGFC was overexpressed in 39 of 98 breast cancer specimens (39.8%) but not in adjacent normal mammary glands. The expression of VEGFC showed a significant correlation with lymphatic vessel invasion (p=0.0004). It is noteworthy that the 5year disease free survival rate of the VEGFC positive group was significantly poorer than that of negative group (p=0.0356). We suggest that as expression of VEGFC is not implicated in lymphatic spread, it may prove to be a promising marker to predict the recurrence of breast cancer.     

Interleukin 8 and vascular endothelial growth factor -- prognostic factors in human gastric carcinomas?

Gastric carcinoma cells express potent angiogenic factors including vascular endothelial growth factor (VEGF). We previously reported that interleukin-8 (IL-8) acts as an angiogenic factor for human gastric carcinomas. More recently, we found that IL-8 upregulates matrix metalloproteinase-9 (MMP-9) expression and increases invasive activity of gastric carcinoma cells. The purpose of this study was to determine whether the expression of IL-8 and VEGF correlates with clinicopathological parameters in human gastric carcinomas. IL-8 and VEGF expression levels were measured by an enzyme-linked immunosorbent assay (ELISA) in 56 gastric carcinomas and the surrounding normal mucosa. Macroscopic and histopathological tumour findings, presence of metastasis and prognosis were obtained from the patient records and endoscopic, surgical and pathological reports. IL-8 protein levels were higher in most neoplasms than in the corresponding normal mucosal tissue. In contrast, VEGF expression in the tumours was similar to that in normal mucosa. The IL-8 level in the neoplasms correlated significantly with the depth of invasion, venous invasion and lymphatic invasion. VEGF expression in the tumours correlated well with the depth of invasion and lymph node metastasis. No correlation between IL-8 and VEGF expression in the tumours was observed. The survival rates of patients with tumours displaying high IL-8 and VEGF expression levels were significantly lower (P<0.05) than those of patients with tumours displaying low IL-8 and VEGF expression. The results suggest that IL-8 and VEGF may be independent and important prognostic factors in human gastric carcinomas.     

Is CT scan monitoring useful in patients with epithelial ovarian cancer and follow-up negative CA 125 serum levels?

We retrospectively reviewed our series of ovarian cancers to assess the benefit of routine follow-up abdominal computer tomography (CT) scans in asymptomatic patients with CA 125 levels <35 U/ml. A chart review was undertaken of all patients with a diagnosis of ovarian cancers treated and followed at the Institute of Obstetrics and Gynecology, University of Ancona, from January 1986 to January 1994. In asymptomatic patients, the routine follow-up consisted of physical examination and CA 125 serum level determination every three to four months for the first two years, and every six months thereafter for a minimum of 5 years. At each visit, a history and a bimanual vaginal examination were completed. The pelvic and abdomen CT scans were performed every six months for the first year and then annually. Inclusion criteria were CA 125 levels >35 U/ml prior to surgery or initial chemotherapy, and complete routine follow-up. Fifty-two patients (75%) satisfied the inclusion criteria. After surgery, 32 of the 52 CA 125 positive patients (61%) showed a decrease in CA 125 levels; 10 other patients showed a negativity of CA 125 after cisplatinum polychemotherapy. After a median time of 49 months (range 16-117 months), 9 of the 42 patients (21%) developed a relapse. The overall CA 125 sensitivity at the time of relapse was 78%, with a specificity of 94%; the sensitivity for early detection of relapses was 70%. Two-hundred and seventy-six abdominal and pelvic CT scans were performed and 8 were positive for tumor relapse, with an overall sensitivity of 89%. The sensitivity of CT scans was 33% for early detection of relapses. The routine performance of follow-up CT scans did not significantly improve the overall detection of early relapses in ovarian carcinoma. A longitudinal monitoring of serum CA 125 is a reliable method of follow-up. Abdominal and pelvic CT scans should be performed in patients who, after a period in which they have been classified as not having evidence of disease with normal CA 125 serum levels, show elevated and rising CA 125, with the aim of finding and characterizing relapses.     

Targeting the fibroblast growth factor receptor 2 in gastric cancer: promise or pitfall?

Gastric cancer is the third leading cause of death from cancer worldwide. Systemic chemotherapy remains the mainstay therapeutic option for this poor prognosis cancer. Trastuzumab, the epidermal growth factor receptor 2 (ERBB2 or HER2)-antibody, is the only biological agent approved for the molecularly selected population of HER2-positive gastric cancer patients. Over the last decade, several groups have been working for deepening into the molecular characterization of gastric cancer, shedding some light into the heterogeneity of this tumour. The published data have broadened the landscape towards a future molecular classification into several subtypes of gastric cancer, enabling a better selection of the optimal therapeutic strategy. The fibroblast growth factor receptor (FGFR) pathway plays a key role in gastric cancer pathogenesis, with 1.2%–9% of gastric cancer patients harbouring FGFR2 amplifications. Several selective FGFR inhibitors have been developed in the last years, with promising efficacy signals. However, there is still scarce evidence of the most reliant molecular determinants of response to these targeted agents. Homogeneous high-level clonal FGFR2-amplification, high FGFR2 mRNA or protein levels, specific FGFR2 C3 isoform expression, FGF ligand co-overexpression or detection of FGFR2 copy number in plasma circulating tumour DNA, are considered some of the potential predictive biomarkers to the FGFR inhibition. The successful development of highly specific FGFR inhibitors will rely on our capacity of establishing new personalized strategies, based on a deeper knowledge of the key alterations that drive oncogenesis in gastric cancer. Further efforts seem mandatory in order to implement accurate predictive biomarkers in the next stages of the FGFR inhibitors development.     

In-utero exposures and breast cancer risk: joint effect of estrogens and insulin-like growth factor?

Initial evidence from observational studies led to the suggestion that high maternal estrogens in-utero are central factors in the development of adult breast cancer. Subsequently, several studies attempted to illuminate this hypothesis, but few of the more detailed observational studies show a clear and strong association between prenatal estrogen exposure and breast cancer risk in adulthood. To date, the potential underlying biological mechanisms remain unclear and controversial. However, recent observations of a relation between insulin-like growth factor-1 (IGF-1) and breast cancer risk may shed new light on the role of in-utero exposure, early growth, and risk of breast cancer. More research is needed to elucidate this potential mechanism.     

Genetic polymorphisms in the vascular endothelial growth factor gene and breast cancer risk. The Austrian “tumor of breast tissue: incidence, genetics, and environmental risk factors” study

PURPOSE: Vascular endothelial growth factor (VEGF) is a key regulator of tumor-induced angiogenesis and is required for growth of tumors. We tested the hypothesis that VEGF gene polymorphisms may be associated with breast cancer. EXPERIMENTAL DESIGN: We performed a case-control study including 804 female incident breast cancer patients and 804 female age-matched healthy control subjects. We selected seven VEGF candidate polymorphisms and determined genotypes by 5'-nuclease (TaqMan) assays. Furthermore, VEGF plasma levels and genotypes were analyzed in a group of 81 healthy volunteers (64 men and 17 women). RESULTS: Haplotype analysis showed two separate blocks of high-linkage disequilibrium, formed by five polymorphisms upstream of the coding sequence (promoter and 5' untranslated region) and two polymorphisms downstream of the coding sequence. None of the single polymorphisms or haplotypes was significantly associated with the presence of breast cancer. After Bonferroni correction for multiple testing, only one statistical signifcant association between VEGF genotypes and haplotypes and tumor characteristics was observed (-634C allele and small tumor size; p < 0.001). In a multivariate regression analysis including sex, age, VEGF genotypes, and haplotypes as covariates and VEGF plasma level as dependent variable, none of the VEGF polymorphism or haplotypes was a significant predictor of VEGF plasma levels. CONCLUSIONS: Our findings do not support the hypothesis that VEGF polymorphisms are associated with breast cancer risk. The association of the VEGF -634C allele with small tumor size is in clear contrast to a previous publication and should be interpreted with caution until replicated by additional studies.     

Vascular endothelial growth factor -634G/C and vascular endothelial growth factor -2578C/A polymorphisms and lung cancer risk: a case–control study and meta-analysis

Vascular endothelial growth factor (VEGF) is a major regulator of angiogenesis in the process of tumor growth and metastasis. In present study, we conducted a case–control study and meta-analysis to evaluate the genetic effects of VEGF -634G/C and VEGF -2578C/A polymorphisms and risk of lung cancer. A total of 175 subjects were recruited for case–control study and seven studies were included in the meta-analysis. Our case–control study showed that VEGF -634G/C polymorphism had no association with lung cancer risk (CC vs. GG: OR?=?0.88, 95 % CI?=?0.37–2.11), whereas there was an association between VEGF -2578CC genotype and decrease in lung cancer risk (CC vs. CA/AA: OR?=?0.52, 95 % CI?=?0.28–0.96). A meta-analysis was further performed and statistically similar results were obtained (CC vs. GG: OR?=?0.91, 95 % CI?=?0.60–1.39 for VEGF ?634; CC vs. AA: OR?=?0.53, 95 % CI?=?0.32–0.89 for VEGF ?2578). Our study showed that the variant genotypes of the VEGF -2578C/A polymorphism, but not the VEGF -634G/C polymorphism, was associated with lung cancer risk. More studies are needed to detect VEGF -634G/C and VEGF ?2578 polymorphisms and their association with lung cancer in different ethnic populations incorporated with environmental exposures.     

Folate and breast cancer: what about high-risk women?

Folate is a water-soluble B-vitamin and is an important cofactor in one-carbon metabolism. This vitamin plays an important role in the pathogenesis of several chronic diseases. In recent years, there has been much interest in the relationship between folate status and breast cancer risk, particularly given the dramatic increase in dietary intake and blood serum folate levels in North America as a result of mandatory folic acid fortification and the widespread use of folic acid supplementation. The well-described dual effects of folate on carcinogenesis underscore the need to clarify the role of folate in the development and progression of breast cancer. This is of particular importance among those at high risk of developing breast cancer because of benign breast disease, a strong family history of breast cancer or an inherited mutation in BRCA1 or BRCA2. BRCA mutation carriers face a high lifetime risk of developing breast cancer, estimated at 80?% compared with 11?% in the general population. Predictive genetic testing permits the identification of these high-risk women prior to diagnosis; however, prevention is limited to surgery and chemoprevention, and the importance of modifiable risk factors such as diet and lifestyle has not been elucidated. Our goal is to develop practical and safe interventions for high-risk women leading to a decrease in the number of breast cases and deaths attributed to breast cancer.