Co-expression of vascular endothelial growth factor C (VEGF-C) and c-erbB2 in human breast carcinoma

Breast Cancer Metastasis: Are Cytokines Important Players During Its Development and Progression?

In breast cancer, an uncontrolled cell proliferation leads to tumor formation and development of a multifactorial disease. Metastasis is a complex process that involves tumor spread to distant parts of the body from its original site. Metastatic dissemination represents the main physiopathology of cancer. Inter- and intracellular communication in all systems in vertebrates is mediated by cytokines, which are highly inducible, secretory proteins, produced not only by immune system cells, but also by endocrine and nervous system cells. It has become clear in recent years that cytokines, as well as their receptors are produced in the organisms under physiological and pathological conditions; recently, they have been closely related to breast cancer metastasis. The exact initiation process of breast cancer metastasis is unknown, although several hypotheses have emerged. In this study, we thoroughly reviewed the role of several cytokines in breast cancer metastasis. Data reviewed suggest that cytokines and growth factors are key players in the breast cancer metastasis induction. This knowledge must be considered with the aim to development of new therapeutic approaches to counter breast cancer metastasis.

Associations of angiogenesis-related proteins with specific prognostic factors, breast cancer subtypes and survival outcome in early-stage breast cancer patients. A Hellenic Cooperative Oncology Group (HeCOG) trial

Several studies support an important role of angiogenesis in breast cancer growth and metastasis. The main objectives of the study were to investigate the immunohistochemical expression of vascular endothelial growth factor (VEGF) family ligands (VEGF-A and VEGF-C) and receptors (VEGFR1, VEGFR2 and VEGFR3) in breast cancer and their associations with clinicopathological parameters, cancer subtypes/subgroups and patient outcome. Formalin-fixed paraffin-embedded tumor tissue samples were collected from early-stage breast cancer patients treated with anthracycline-based chemotherapy within a randomized trial. Immunohistochemistry was performed on serial 2.5 μm thick tissue sections from tissue microarray blocks. High VEGF-A, VEGF-C, VEGFR1, VEGFR2 and VEGFR3 protein expression was observed in 11.8% (N = 87), 80.8% (N = 585), 28.1% (N = 202), 64.6% (N = 359) and 71.8% (N = 517) of the cases, respectively. Significant associations were observed among all proteins (all p-values <0.05), with the exception of the one between VEGF-C and VEGFR1 (chi-square test, p = 0.15). Tumors with high VEGF-A protein expression, as compared to tumors with low expression were more frequently ER/PgR-negative (33.3% vs. 20.8%, chi-square test, p = 0.009) and HER2-positive (44.8% vs. 20.6%, p<0.001). In addition, tumors with high VEGFR1 expression, were more frequently HER2-positive (32.8% vs. 19.6%, p<0.001), while tumors with high VEGFR3 expression were more frequently ER/PgR-negative (24.9% vs. 17.0%, p = 0.024) and HER2-positive (26.9% vs. 14.8%, p = 0.001). High VEGF-A and VEGF-C protein expression was associated with increased DFS in the entire cohort (HR = 0.57, 95% CI 0.36–0.92, Wald’s p = 0.020 and HR = 0.71, 95% CI 0.52–0.96, p = 0.025, respectively), as well as in specific subtypes/subgroups, such as HER2-positive (VEGF-A, HR = 0.32, 95% CI 0.14–0.74, p = 0.008) and triple-negative (VEGF-C, HR = 0.44, 95% CI 0.21–0.91, p = 0.027) patients. High vs. low VEGFR1 expression was an unfavorable factor for DFS in triple-negative patients (HR = 2.74, 95% CI 1.26–5.98, p = 0.011), whereas the opposite was observed among the ER/PgR-positive patients (HR = 0.69, 95% CI 0.48–0.98, p = 0.041). Regarding OS, high VEGF-C protein expression was associated with increased OS in the entire cohort (HR = 0.64, 95% CI 0.46–0.89, Wald’s p = 0.008), as well as in in specific subtypes/subgroups, such as ER/PgR-negative (HR = 0.37, 95% CI 0.20–0.71, p = 0.003) and triple-negative (HR = 0.42, 95% CI 0.19–0.90, p = 0.026) patients. In conclusion, high expression of angiogenesis-related proteins is associated with adverse clinicopathological parameters in early-stage breast cancer patients and may be surrogate markers of biologically distinct subgroups of ER/PgR-negative or triple-negative tumors with superior outcome. Further validation of our findings in independent cohorts is needed.

Hallmarks of Bone Metastasis

Breast cancer bone metastasis develops as the result of a series of complex interactions between tumor cells, bone marrow cells, and resident bone cells. The net effect of these interactions are the disruption of normal bone homeostasis, often with significantly increased osteoclast and osteoblast activity, which has provided a rational target for controlling tumor progression, with little or no emphasis on tumor eradication. Indeed, the clinical course of metastatic breast cancer is relatively long, with patients likely to experience sequential skeletal-related events (SREs), often over lengthy periods of time, even up to decades. These SREs include bone pain, fractures, and spinal cord compression, all of which may profoundly impair a patient's quality-of-life. Our understanding of the contributions of the host bone and bone marrow cells to the control of tumor progression has grown over the years, yet the focus of virtually all available treatments remains on the control of resident bone cells, primarily osteoclasts. In this perspective, our focus is to move away from the current emphasis on the control of bone cells and focus our attention on the hallmarks of bone metastatic tumor cells and how these differ from primary tumor cells and normal host cells. In our opinion, there remains a largely unmet medical need to develop and utilize therapies that impede metastatic tumor cells while sparing normal host bone and bone marrow cells. This perspective examines the impact of metastatic tumor cells on the bone microenvironment and proposes potential new directions for uncovering the important mechanisms driving metastatic progression in bone based on the hallmarks of bone metastasis.

Disrupting Tumor Angiogenesis and "the Hunger Games" for Breast Cancer

Angiogenesis, one of the hallmarks of cancers, has become an attractive target for cancer therapy since decades ago. It is broadly thought that upregulation of angiogenesis is involved in tumor progression and metastasis. Though tumor vessels are tortuous, disorganized, and leaky, they deliver oxygen and nutrients for tumor development. Based on this knowledge, many kinds of drugs targeting angiogenesis pathways have been developed, such as bevacizumab. However, the clinical outcomes of anti-angiogenesis therapies are moderate in metastatic breast cancer as well as in metastatic colorectal cancer and non-small cell lung cancer, even combined with traditional chemotherapy. In this chapter, the morphologic angiogenesis patterns and the key molecular pathways regulating angiogenesis are elaborated. The FDA-approved anti-angiogenesis drugs and current challenges of anti-angiogenesis therapy are described. The strategies to overcome the barriers will also be elucidated.

Angiogenesis and Antiangiogenesis in Triple-Negative Breast cancer

Several data support a central role for angiogenesis in breast cancer growth and metastasis. Observational studies have demonstrated that microvascular density (MVD) is a prognostic factor in invasive breast cancer, whereas others reached the opposite conclusion. Vascular endothelial growth factor is the most important angiogenic factor with proven significance in breast cancer, as it has been assessed in both experimental and clinical studies. Triple-negative breast cancer (TNBC) is a type of breast cancer which lacks estrogen, progesterone, and HER-2/neu receptors. MVD in both basal-like and TNBC is significantly higher than in non–basal-like and non-TNBC. In breast cancer and other malignancies, the development of agents that inhibit tumor angiogenesis has been an active area of investigation. In TNBC, clinical trials combining targeted agents and chemotherapy have failed to show substantial survival improvement. There is evidence that patients with TNBC may have a greater probability of obtaining some kind of clinical efficacy benefit from bevacizumab-based therapy.

Association between VEGF-A, C and D expression and lymph node involvement in breast cancer: a meta-analysis

BACKGROUND

Metastasis is the primary cause of death in patients with breast cancer. Although VEGF-A, C and D are considered to be prime factors in lymph node metastasis in breast cancer, the published studies have conflicting conclusions.

METHODS

To resolve this conflict, we conducted a meta-analysis of 37 studies (n = 5,001 patients) evaluating the correlation between VEGF-A, C and D immunohistochemical expression and lymph node metastasis (LNM). The meta-analysis included 22 studies of VEGF-A, 17 of VEGF-C, and 6 of VEGF-D. The relationships between VEGF-A, C and D and clinicopathological parameters were also examined.

RESULTS

The results showed a significant association between VEGF-A or VEGF-C overexpression and LNM (risk ratio [RR] = 1.28 [95% CI 1.04-1.58], p = 0.02; and RR = 1.36 [95% CI 1.07-1.72], p = 0.01, respectively). Subgroup evaluation showed a significant association between VEGF-A, C and D overexpression and LNM when analyses were limited to Asian patients (RR = 1.78 [95% CI 1.28-2.46], p = 0.0005; RR = 1.38 [95% CI 1.04-1.84], p = 0.03, and RR = 2.62 [95% CI 1.35-5.09], p = 0.004, respectively). VEGF-A overexpression was significantly associated with lymph vessel invasion (RR = 1.86 [95% CI 1.33-2.60], p = 0.0003). Overexpression of VEGF-C or VEGF-D was significantly associated with HER-2 positivity (RR = 1.30 [95% CI 1.06-1.59], p = 0.01; and RR = 1.75 [95% CI 1.01-3.03], p = 0.05, respectively).

CONCLUSIONS

With some limitations, our meta-analysis indicated that VEGF-A and C could predict LNM in patients with breast cancer, particularly Asian patients.

The prognostic and predictive value of mRNA expression of vascular endothelial growth factor family members in breast cancer: a study in primary tumors of high-risk early breast cancer patients participating in a randomized Hellenic Cooperative Oncology Group trial

INTRODUCTION

The main prognostic variables in early breast cancer are tumor size, histological grade, estrogen receptor/progesterone receptor (ER/PgR) status, number of positive nodes and human epidermal growth factor receptor 2 (HER2) status. The present study evaluated the prognostic and/or predictive value of vascular endothelial growth factor (VEGF) family members in high-risk early breast cancer patients treated with adjuvant chemo-hormonotherapy.

METHODS

RNA was isolated from 308 formalin-fixed paraffin-embedded primary tumor samples from breast cancer patients enrolled in the HE10/97 trial, evaluating adjuvant dose-dense sequential chemotherapy with epirubicin followed by cyclophosphamide, methotrexate, fluorouracil (CMF) with or without paclitaxel (E-T-CMF versus E-CMF). A fully automated method based on magnetic beads was applied for RNA extraction, followed by one-step quantitative RT-PCR for mRNA analysis of VEGF-A, -B, -C and vascular endothelial growth factor receptor (VEGFR) 1, 2, 3.

RESULTS

With a median follow-up of 8 years, 109 patients (35%) developed a relapse and 80 patients (26%) died. In high VEGF-C and VEGFR1 mRNA expressing tumors, ER/PgR-negative tumors (Fisher's exact test, P = 0.001 and P = 0.021, respectively) and HER2-positive tumors (P <0.001 and P = 0.028, respectively) were more frequent than in low VEGF-C and VEGFR1 expressing tumors, respectively. From the VEGF family members evaluated, high VEGFR1 mRNA expression (above the 75th percentile) emerged as a significant negative prognostic factor for overall survival (OS; hazard ratio (HR) = 1.60, 95% confidence interval (CI): 1.01 to 2.55, Wald's P = 0.047) and disease-free survival (DFS; HR = 1.67, 95% CI: 1.13 to 2.48, P = 0.010), when adjusting for treatment group. High VEGF-C mRNA expression was predictive for benefit from adjuvant treatment with paclitaxel (E-T-CMF arm) for OS (test for interaction, Wald's P = 0.038), while in multivariate analysis the interaction of VEGF-C with taxane treatment was significant for both OS (Wald's P = 0.019) and DFS (P = 0.041) and continuous VEGF-B mRNA expression values for OS (P = 0.019).

CONCLUSIONS

The present study reports, for the first time, that VEGF-C mRNA overexpression, as assessed by qRT-PCR, has a strong predictive value in high-risk early breast cancer patients undergoing adjuvant paclitaxel-containing treatment. Further studies are warranted to validate the prognostic and/or predictive value of VEGF-B, VEGF-C and VEGFR1 in patients treated with adjuvant therapies and to reveal which members of the VEGF family could possibly be useful markers in identifying patients who will benefit most from anti-VEGF strategies.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12611000506998.

Contactin-1 (CNTN-1) overexpression is correlated with advanced clinical stage and lymph node metastasis in oesophageal squamous cell carcinomas

OBJECTIVE

Oesophageal squamous cell carcinoma is one of the deadliest malignancies worldwide. Contactin-1, a neural adhesion molecule, is implicated in tumour invasion and metastasis. The purpose of this study was to investigate the expression of CNTN-1 in normal and cancerous oesophageal tissue, and the potential relevance to clinicopathological features.

METHODS

Thirty normal oesophageal tissue samples and 82 primary oesophageal squamous cell carcinoma tissue samples were included in this study. The expression levels of CNTN-1, VEGF-C and HIF-1α messenger RNA were determined using reverse transcriptase-polymerase chain reaction and quantitative real-time polymerase chain reaction. The expression of the CNTN-1 protein was measured using immunohistochemistry.

RESULTS

The expression of CNTN-1 messenger RNA was significantly increased in the tumour tissue compared with the normal oesophageal tissue (P=0.001). The oesophageal squamous cell carcinoma tissue consistently showed higher CNTN-1 protein levels. The CNTN-1 expression correlated with the oesophageal squamous cell carcinoma stage (P=0.006), lymph node metastasis (P=0.018) and lymphatic invasion (P=0.035). The messenger RNA level of CNTN-1 correlated significantly with those of VEGF-C and HIF-1α.

CONCLUSIONS

The expression of CNTN-1 is upregulated in the oesophageal squamous cell carcinoma tissue and related to stage, lymph node metastasis and lymphatic invasion. Thus, CNTN-1 may be involved in the progression and pathogenesis of oesophageal squamous cell carcinoma.

Tumor-derived VEGF-C, but not VEGF-D, promotes sentinel lymph node lymphangiogenesis prior to metastasis in breast cancer patients

Breast cancer usually initially metastases to the sentinel lymph nodes (SLNs). Recent studies have demonstrated that tumor cells induce SLN lymphangiogenesis before metastasis in several malignancies. In addition, tumor-derived VEGF-C or VEGF-D may induce lymphangiogenesis and promote lymph node metastasis. To explore the mechanisms of lymph node metastasis in breast cancer, we investigated whether primary tumors induce SLN lymphangiogenesis before metastasis and determined the function of tumor-derived VEGF-C and VEGF-D in SLN lymphangiogenesis. Expression of VEGF-C and VEGF-D was examined using immunohistochemistry in 63 primary breast tumors. No significant relationships between VEGF-C and VEGF-D (P=0.420), and VEGF-C or VEGF-D expression and clinical parameters (age, tumor size, grade, hormonal receptor status, her-2 status) were observed (P>0.05). Expression of the lymphatic-specific markers VEGFR-3, Prox-1 and LYVE-1 was measured using quantitative real-time RT-PCR in uninvolved SLNs from 63 patients and compared to control lymph nodes from patients with benign breast disease. Expression of Prox-1 and LYVE-1 mRNA was significantly higher in uninvolved SLNs from breast cancer patients than that in control lymph nodes (P<0.01). Interestingly, expression of VEGFR-3, Prox-1 and LYVE-1 was significantly higher in SLNs from patients with high VEGF-C-expressing tumors than low VEGF-C-expressing tumors (P<0.05), but not VEGF-D-high-expressing tumors (P>0.05). This study demonstrates that primary breast tumors induce SLN lymphangiogenesis before metastasis occurs and that tumor-derived VEGF-C, but not VEGF-D, plays an important role in SLN lymphangiogenesis in breast cancer.

Role of Src in breast cancer cell migration and invasion in a breast cell/bone-derived cell microenvironment

The preferential metastasis of breast cancer cells to bone comprises a complex set of events including homing and preferential growth, which may require unique factors produced by bone or other cells in the immediate microenvironment. In this study, an in vitro co-culture system composed of bone mesenchymal stem cells and breast cancer cell lines is used to examine the role of Src kinase on breast cancer cell migration and invasion in the presence of bone-derived cells. This research shows that Src kinase activity in breast cancer cell lines with either high or low levels of endogenous Src activity is increased by bone-derived cell-conditioned medium but not HS68 fibroblast-conditioned medium. Breast cancer cells exhibit enhanced migration in co-culture with bone-derived cells but not HS68 fibroblasts or no co-cultured cells. Inhibition of Src kinase activity using the inhibitors PP2 or saracatinib or using siRNA abrogates the preferential migration of the breast cancer cell lines in response to bone-derived cells. Inhibition of Src activity with saracatinib does not have any significant effect on breast cancer cell invasion in the presence of bone-derived cells. Factors are identified that are produced preferentially by bone-derived cells over HS68 cells that may impact breast cancer cell behavior. This research implicates Src kinase as an important effector of bone-derived cell signals on breast cancer cell migration.

Lymphangiogenesis and lymphatic metastasis in breast cancer

Lymphatic metastasis is the main prognostic factor for survival of patients with breast cancer and other epithelial malignancies. Mounting clinical and experimental data suggest that migration of tumor cells into the lymph nodes is greatly facilitated by lymphangiogenesis, a process that generates new lymphatic vessels from pre-existing lymphatics with the aid of circulating lymphatic endothelial progenitor cells. The key protein that induces lymphangiogenesis is vascular endothelial growth factor receptor-3 (VEGFR-3), which is activated by vascular endothelial growth factor-C and -D (VEGF-C and VEGF-D). These lymphangiogenic factors are commonly expressed in malignant, tumor-infiltrating and stromal cells, creating a favorable environment for generation of new lymphatic vessels. Clinical evidence demonstrates that increased lymphatic vessel density in and around tumors is associated with lymphatic metastasis and reduced patient survival. Recent evidence shows that breast cancers induce remodeling of the local lymphatic vessels and the regional lymphatic network in the sentinel and distal lymph nodes. These changes include an increase in number and diameter of tumor-draining lymphatic vessels. Consequently, lymph flow away from the tumor is increased, which significantly increases tumor cell metastasis to draining lymph nodes and may contribute to systemic spread. Collectively, recent advances in the biology of tumor-induced lymphangiogenesis suggest that chemical inhibitors of this process may be an attractive target for inhibiting tumor metastasis and cancer-related death. Nevertheless, this is a relatively new field of study and much remains to be established before the concept of tumor-induced lymphangiogenesis is accepted as a viable anti-metastatic target. This review summarizes the current concepts related to breast cancer lymphangiogenesis and lymphatic metastasis while highlighting controversies and unanswered questions.

The prognostic significance of VEGF-C and VEGF-A in non-Hodgkin lymphomas

Angiogenesis and lymphangiogensis are important in the proliferation and survival of the malignant hemeopoietic neoplasms. The aim of this study is to determine the prognostic role of angiogenesis and lymphangiogenesis in the development of lymphoma. For this aim, VEGF-A and VEGF-C were explored by immunohistochemistry in 177 cases. VEGF-C and VEGF-A were found to be positive in 34 and 61% of the samples. There was a good correlation between VEGF-C and VEGF-A expression (p = 0.0001). The clinical prognostic indicators were not significantly different between VEGF-C (+) and (-) and/or VEGF-A (+) and (-) cases. Overall survival (OS) rate was shorter in cases with VEGF-A (+) and VEGF-C (+) cases than with negative cases (p = 0.03 and p = 0.0005, respectively). The OS was significantly shorter in aggressive lymphomas expressing VEGF-A and VEGF-C but not in indolent lymphomas. The results of Cox regression analyses showed that VEGF-A and VEGF-C expressions are independent prognostic parameters (OR: 2.6, 95% CI: 1.3-5.0 for both (+) cases). In conclusion, VEGF-C and VEGF-A were positive in 34 and 61%, respectively, of the cases with NHL. The significant correlation between VEGF-C and VEGF-A suggests that lymphangiogenesis is important in the pathogenesis of lymphomas as shown in angiogenesis. The significantly shorter survival rates of VEGF-C and/or VEGF-A expressions indicate that angiogenesis and lymphangiogenesis are important in clinical outcome. Autocrine VEGF-A and VEGF-C crosstalks in lymphoma cells are important in lymphoma biology and inhibition of these signals with anti-angiogenic/anti-lymphangiogenic drugs and combination with chemo-immunotherapy regimens will be more useful in these cases.

Lymphatic metastasis in breast cancer: importance and new insights into cellular and molecular mechanisms

Lymph node metastasis is the main prognosis factor in a number of malignancies, including breast carcinomas. The means by which lymph node metastases arise is not fully understood, and many questions remain about their importance in the further spread of breast cancer. Nevertheless, a number of key cellular and molecular mechanisms of lymphatic metastasis have been identified. These include induction of intra- or peri-tumoral lymphangiogenesis or co-option of existing lymphatic vessels to allow tumour cells to enter the lymphatics, although it remains to be established whether this is primarily an active or passive process. Gene expression microarrays and functional studies in vitro and in vivo, together with detailed clinical observations have identified a number of molecules that can play a role in the genesis of lymph node metastases. These include the well-recognised lymphangiogenic cytokines VEGF-C and VEGF-D as well as chemokine-receptor interactions, integrins and downstream signalling pathways. This paper briefly reviews current clinical and experimental evidence for the underlying mechanisms and significance of lymphatic metastasis in breast cancer and highlights questions that still need to be addressed.

Vascular Endothelial Growth Factor–C (VEGF-C) Expression in Normal Human Tissues

OBJECTIVE

To characterize vascular endothelial growth factor-C (VEGF-C) protein expression in normal human tissues by immunohistochemistry (IHC). VEGF-C is a growth factor for lymphatic endothelial cells. VEGF-C mRNA and protein are expressed in a variety of cancerous tissues, but the localization of VEGF-C protein in many normal human tissues has not been clearly demonstrated to date. We therefore performed an immunohistochemical survey of the distribution of intracellular VEGF-C protein in a range of normal human tissue types.

METHODS

Five microm sections were cut from archived human tissues. Sections were dewaxed, rehydrated, and subjected to microwave pretreatment. They were incubated with VEGF-C antibody before detection with biotinylated secondary antibody using 'Elite' avidin-biotin enzyme complex and diaminobenzidine substrate. The primary antibody recognized the C-terminus of the VEGF-C propeptide that is cleaved before secretion and hence only cellular protein was detected. Negative controls used the same concentration of normal goat IgG.

RESULTS

Staining manifested as small punctate cytoplasmic granules. Strong expression was observed in large intestine epithelium, and mammary duct epithelium, skeletal and cardiac muscle, thyroid, ovary, and the prostate. Weaker expression was also detected in the hepatocytes close to the terminal hepatic venules of the liver, vascular smooth muscle, and placenta. No expression was consistently detected in spleen or thymus.

CONCLUSIONS

Intracellular VEGF-C protein is widely expressed in many normal human adult tissues. Its expression in cancer is not therefore per se indicative of a prolymphangiogenic change. To demonstrate the latter, a quantitative change in expression level is required.

Tumor-induced lymphangiogenesis: a target for cancer therapy?

Recent advances in understanding the biology of lymphangiogenesis, the new growth of lymphatic vessels, have cast new light on the molecular basis of metastasis to regional lymph nodes. The receptor tyrosine kinase VEGFR-3 is virtually exclusively expressed on lymphatic but not blood endothelium in the adult, and activation of VEGFR-3 by its ligands VEGF-C and VEGF-D is sufficient to induce lymphangiogenesis. Correlative studies with human tumors and functional studies using animal tumor models show that increased levels of VEGF-C or VEGF-D in tumors lead to enhanced numbers of lymphatic vessels in the vicinity of tumors, which in turn promotes metastasis to regional lymph nodes by providing a greater number of entry sites into the lymphatic system for invading tumor cells. These findings have prompted studies to investigate whether inhibitors of VEGFR-3 activation might represent novel therapeutic agents for the suppression of metastasis. However, a number of points regarding the therapeutic potential of anti-lymphangiogenic treatments in the context of cancer remain to be addressed. The spectrum and relative importance of molecules that induce lymphangiogenesis and the regulation of their expression during tumor progression, the reversibility of tumor-induced lymphangiogenesis, and possible side-effects of anti-lymphangiogenesis-based therapies all need to be investigated. Most importantly, the extent to which lymph node metastases contribute to the formation of metastases in other organs remains to be elucidated. These aspects are the focus of this review, and their investigation should serve as a roadmap to possible translational application.

Serum vascular endothelial growth factor C (VEGF-C) as a specific biomarker for advanced cervical cancer: Relationship to insulin-like growth factor II (IGF-II), IGF binding protein 3 (IGF-BP3) and VEGF-A [corrected]

OBJECTIVES

An early non-invasive diagnosis of cervical cancer and its metastasis can save lives. We have shown that serum IGF-II levels can be effectively used for a specific early diagnosis of cervical cancer. Here, we shall determine if serum levels of vascular endothelial growth factors B and C (VEGF-A [corrected] VEGF-C) associated with vasculogenic and lymphogenic metastasis may be used for an early diagnosis of advanced metastatic cervical cancer and compare these levels with those of the serum IGF-II and IGF-binding protein 3 (IGF-BP3).

MATERIAL AND METHODS

(a) Serum levels of IGF-II, IGF-BP3, VEGF-A [corrected] (VEGF(165)) and VEGF-C (ELISA kits) were determined in: 82 controls with normal Pap smears; 29 women with atypical squamous cells of undetermined significance (ASCUS) and normal cervical biopsy; 46 ASCUS and cervical intraepithelial neoplasia (CIN) on biopsy; 8 pre-therapy CIN-I; 23 successfully treated CIN-I; 75 persistent CIN-I; 14 CIN-II/III pre-therapy; 14 successfully treated CIN-II/III; 70 persistent CIN-II/III; 86 pre-therapy cervical cancer; 26 in early grades of cervical cancer; 21 in late grades of cervical cancer; 22 cervical cancer patients in remission; 50 persistent cervical cancer; 18 with ovarian cancer; and 57 with endometrial cancer. (b) Serial serum samples collected over 5 years in 5 women with progressing cervical cancer were also tested. (c) Serum and tissue VEGF-C were enumerated in 20 matched serum (ELISA) and tissue (semi-quantitative immunofluorescent antibody assay) samples from controls, early cervical cancer, late cervical cancer, ovarian cancer and endometrial cancer patients. Student's t test, chi-square analysis and linear regression analysis were used.

RESULTS

(a) As anticipated, serum IGF-II levels were elevated as early as ASCUS with CIN on biopsy and continued to be elevated in CIN (all grades; pre-therapy and persistent) and cervical cancer (pre-therapy, early, late and persistent). Serum IGF-II levels were normal in ASCUS with normal biopsy, successfully treated CIN-I, II/III, cervical cancer as well as pre-therapy ovarian and endometrial cancers (therapy efficacy: P < 0.0001 by chi-square analysis). Serum IGF-BP3 showed a significant decrease with advancing disease. Serum VEGF-A [corrected] levels were the highest in pre-therapy, early, advanced and persistent cervical cancer, as well as in ovarian and endometrial cancers. Serum VEGF-C levels, on the other hand, were the highest in late and persistent cervical cancers, but not in ovarian or endometrial cancers. (b) In the 5 women with serial samples, the serum levels of the growth factors showed similar trends. (c) VEGF-C levels in serum and tissue were elevated in cervical cancers especially in advanced grades, while they were normal in serum and tissue from the controls and women with ovarian and endometrial cancers. There was a highly significant positive correlation between VEGF-C and IGF-II and a negative correlation between IGF-BP3 and VEGF-C (P < 0.0001).

CONCLUSION

Serum IGF-II up-regulation is specific to cervical cancer and helps in the early diagnosis of malignant proliferation, while serum VEGF-C up-regulation appears to be a unique marker for an early diagnosis of cervical cancer metastasis. VEGF-C and IGF-II systems appear to be interrelated in cervical cancer, contributing to the early malignant cell proliferation and lympho-vascular metastasis. Serum IGF-BP3 and VEGF-A [corrected] appear to be common markers for all gynecological cancers.

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.