Vascular endothelial growth factor in premenopausal women--indicator of the best time for breast cancer surgery?

Effect of vitamin D supplementation on inflammatory markers and total antioxidant capacity in breast cancer women using a machine learning technique

Aim

This study aimed to establish a learning system using an artificial neural network (ANN) to predict the effects of vitamin D supplementation on the serum levels of vitamin D, inflammatory factors, and total antioxidant capacity (TAC) in women with breast cancer.

Methods

The data set of the current project was created from women with breast cancer who were referred to the Shafa State Hospital of Patients with Cancers in Ahvaz city, Iran. Modeling was implemented using the data set at the serum levels of vitamin D, tumor necrosis factor-α (TNF-α), transforming growth factor β (TGF-β), and TAC, before and after vitamin D3 supplement therapy. A prediction ANN model was designed to detect the effects of vitamin D3 supplementation on the serum level changes of vitamin D, inflammatory factors and TAC.

Results

The results showed that the ANN model could predict the effect of vitamin D3 supplementation on the serum level changes of vitamin D, TNF-α, TGF-β1, and TAC with an accuracy average of 85%, 40%, 89.5%, and 88.1%, respectively.

Conclusions

According to the findings of the study, the ANN method could accurately predict the effect of vitamin D3 supplementation on the serum levels of vitamin D, TNF-α, TGF-β1, and TAC. The results showed that the proposed ANN method can help specialists to improve the treatment process more confidently in terms of time and accuracy of predicting the influence of vitamin D supplementation on the factors affecting the progression of breast cancer (https://www.irct.ir/ identifier: IRCT2015090623924N1).

Circulating Vascular Endothelial Growth Factor and Soluble fms-Like Tyrosine Kinase-1 as Biomarkers for Endometrial Remodeling Across the Menstrual Cycle

OBJECTIVE

To characterize variation in circulating vascular endothelial growth factor (VEGF) and its receptor, soluble fms-like tyrosine kinase-1 (sFLT-1), across the menstrual cycle in normal ovulating women in relation to reproductive hormones to identify the utility of VEGF and sFLT-1 as peripheral biomarkers of endometrial remodeling.

METHODS

Ninety-six healthy, regularly menstruating ovulatory women, aged 18-44 years, enrolled in the BioCycle Study, a prospective cohort study at a U.S. academic research center. Vascular endothelial growth factor and sFLT-1 were measured in concurrently collected plasma, serum, and urine up to eight times across a single cycle. Reproductive hormones were measured in serum. Mean concentrations of VEGF and sFLT-1 were compared across phases of the cycle, and correlations between specimen types were calculated. Harmonic models estimated associations between VEGF and sFLT-1 and characteristics of hormonal patterns.

RESULTS

No variation in VEGF or sFLT-1 levels were detected over the menstrual cycle. Median (25th percentile, 75th percentile) concentrations of VEGF during the menstrual cycle were 31.2 pg/mL (24.1, 56.9) in plasma, 194.1 pg/mL (125.4, 350.2) in serum, and 101.7 pg/mL (64.2, 165.8) in urine. Plasma and serum measures were consistently correlated, whereas urinary measures were not. Vascular endothelial growth factor was not consistently associated with reproductive hormone concentrations, although sFLT-1 was associated with higher mean and amplitude of estradiol.

CONCLUSION

Circulating VEGF and sFLT-1 did not vary across the menstrual cycle and therefore are unlikely to be useful peripheral biomarkers of endometrial changes across the menstrual cycle. For studies measuring circulating VEGF for other reasons, plasma may be the preferred medium and timing to menstrual cycle phase need not be considered for reproductive-age women.

Discordance in 21-gene recurrence scores between paired breast cancer samples is inversely associated with patient age

Background

The Oncotype DX 21-gene Recurrence Score is a genomic-based algorithm that guides adjuvant chemotherapy treatment decisions for women with early-stage, oestrogen receptor (ER)-positive breast cancer. However, there are age-related differences in chemotherapy benefit for women with intermediate Oncotype DX Recurrence Scores that are not well understood. Menstrual cycling in younger women is associated with hormonal fluctuations that might affect the expression of genomic predictive biomarkers and alter Recurrence Scores. Here, we use paired human breast cancer samples to demonstrate that the clinically employed Oncotype DX algorithm is critically affected by patient age.

Methods

RNA was extracted from 25 pairs of formalin-fixed paraffin-embedded, invasive ER-positive breast cancer samples that had been collected approximately 2 weeks apart. A 21-gene signature analogous to the Oncotype DX platform was assessed through quantitative real-time PCR, and experimental recurrence scores were calculated using the Oncotype DX algorithm.

Results

There was a significant inverse association between patient age and discordance in the recurrence score. For every 1-year decrease in age, discordance in recurrence scores between paired samples increased by 0.08 units (95% CI − 0.14, − 0.01; p = 0.017). Discordance in recurrence scores for women under the age of 50 was driven primarily by proliferation- and HER2-associated genes.

Conclusion

The Oncotype DX 21-gene Recurrence Score algorithm is critically affected by patient age. These findings emphasise the need for the consideration of patient age, particularly for women younger than 50, in the development and application of genomic-based algorithms for breast cancer care.

Timing of breast cancer surgery during the menstrual cycle-is there an optimal time of the month?

An intriguing relationship between menstrual cycle phase at the time of breast cancer surgery and clinical outcomes was first proposed in the late 1980s. Despite a number of clinical studies conducted to address this, as well as meta-analyses and systematic reviews, there remains significant controversy surrounding the effect of menstrual cycle phase at time of surgery on the prognosis of premenopausal breast cancer. While some studies have suggested that surgery performed during the luteal phase results in the most favourable outcome, other studies report the follicular phase is more favourable, and others show no association. Given the conflicting results, there remains insufficient evidence to determine whether there is an optimal time of the month to perform surgery. This issue has dogged breast cancer surgery for decades; knowledge of an optimal time of the month to conduct surgery would be a simple approach to improving patient outcomes. This review explores the potential biological mechanisms through which the hormonal milieu might contribute to differences in prognosis, and why clinical findings are so variable. It is concluded that a significant problem with current clinical research is the lack of insight from mechanistic studies. While there are a number of plausible biological mechanisms that could lead to altered survival, supporting evidence is limited. There are also variable approaches to defining the menstrual cycle phase and hormone receptor status of the tumour and few studies controlled for prognostic factors such as tumour size and stage, or addressed the impact of adjuvant treatments. Elucidation of the specific confounding factors, as well as biological mechanistic pathways that could explain the potential relationship between timing of surgery and survival, will greatly assist in designing robust well-controlled prospective clinical studies to evaluate this paradigm.

Circulating Angiogenesis Regulators in Cancer Patients

Background/Aims

To date, numerous studies have demonstrated that several angiogenesis regulators circulate in the blood and may function as endocrine factors in cancer patients. This review aims to give a comprehensive insight into the possible clinical value of circulating angiogenesis regulators, mainly basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF), angiogenin, pleiotrophin, thrombospondin (TSP) and endostatin (ES) in cancer patients.

Methods

A computerized (MEDLINE) and a manual search based on the reference lists of the publications were performed to identify articles published on this topic.

Results

In a detailed literature search, approximately 100 publications were found up to the end of 1999. Circulating angiogenic factors such as bFGF, VEGF, HGF and angiogenin have been evaluated not only as diagnostic and/or prognostic factors but also as predictive factors in cancer patients. On the other hand, little is known about the clinical significance of negative regulators. Neither the source nor the mechanism of protein externalization has been clarified in detail.

Conclusions

Although there are no known factors with established clinical utility, circulating angiogenesis regulators may be useful in several situations. They could be used to determine the risk of developing cancer, to screen for early detection, to distinguish benign from malignant disease, and to distinguish between different types of malignancies. In patients with established malignancies such factors might be used to determine prognosis, to predict the response to therapy, and to monitor the clinical course. Further investigations are warranted to assess the specific utility of each factor.

Surrogate Markers of Tumoral Angiogenesis

Background

Angiogenesis is a prerequisite for tumor growth and metastasis. Vascular cell adhesion molecule-1 (VCAM-1) is expressed on endothelial cells as a result of vascular endothelial growth factor (VEGF) stimulation.

Purpose

To determine if measurement in serum of VEGF or VCAM-1 provides an accurate measure of tumor angiogenesis.

Methods

VCAM-1 and VEGF were measured in the serum of women with early and advanced breast cancer by ELISA. Levels were compared to levels of VCAM-1 and VEGF in women with normal breasts and levels of the endothelial glycoprotein von Willebrand factor. Levels of VEGF and VCAM-1 in women with early breast cancer were correlated with established clinicopathological prognostic markers and intratumoral microvessel density (IMD).

Results

In early breast cancer serum VCAM-1 correlated closely with the microvessel density in tumors (r=0.61, p<0.001). Women with lymph node-positive and high-grade tumors had higher levels of serum VCAM-1 than women with lymph node-negative and low-grade tumors. Serum VEGF demonstrated no correlation with established prognostic features or IMD. Levels of VCAM-1 and VEGF were raised in women with advanced breast cancer.

Conclusion

Serum VCAM-1 is a surrogate marker of angiogenesis in breast cancer and its measurement may help in the assessment of antiangiogenic drugs currently in phase II trials.

Validation of Blood Collection Procedures for the Determination of Circulating Vascular Endothelial Growth Factor (VEGF) in Different Blood Compartments

Aims of the study.

Studies on circulating VEGF have reported mixed results, possibly due to a lack of standardization of the pre-analytical phase. The aim of our investigation was to standardize the sampling procedure for the determination of VEGF in different blood fractions.

Basic procedures.

We evaluated various clotting times for obtaining serum in 30 subjects, as well as different procedures for the preparation of plasma Edinburgh anticoagulant mixture (EDTA, PGE1, theophylline) and CTAD. VEGF was also assayed in lysed whole blood. In vitro platelet activation was monitored by measuring the levels of PF4. VEGF and PF4 were measured using commercially available enzyme-linked immunoassays.

Main findings.

Clotting time increased the release of VEGF, which reached a plateau between 2 and 4 hours. The percent increase of VEGF at 2 hours ranged from 118% to 4515% (median 327%) compared to samples centrifuged within 10 min from withdrawal. VEGF was not different and PF4 was very low or undetectable in Edinburgh plasma and CTAD plasma, while it was significantly higher in sodium citrate plasma. VEGF in CTAD plasma was not correlated with platelet count or leukocytes. Serum VEGF did not correlate with the leukocyte number, but it correlated significantly with the platelet count.

Principal conclusions.

The procedures for sample collection described above are highly standardized and easy to perform in a routine setting. We therefore suggest systematic evaluation of VEGF in CTAD plasma, in serum (clotting for 2 hours at room temperature) and in whole blood, until prospective controlled clinical studies will have clarified in which blood compartment(s) VEGF provides clinically relevant information.

Differential effect of age on survival in advanced NSCLC in women versus men: analysis of recent Eastern Cooperative Oncology Group (ECOG) studies, with and without bevacizumab

BACKGROUND

The impact of age on prognosis in advanced stage non-small cell lung cancer (NSCLC) may differ by sex.

PATIENTS AND METHODS

Eligible patients (N=1590) from E1594, a 4-arm platinum-based chemotherapy trial, and E4599 (carboplatin/paclitaxel ± bevacizumab) chemotherapy arm were divided into male and female cohorts and separated into age groups of <60 or ≥60 years old. Eligible E4599 patients (N=850) were similarly separated by age and sex and by treatment (± bevacizumab). Survival was calculated separately for each cohort.

RESULTS

The median survival time (MST) for women ≥60 years old treated with chemotherapy alone on E1594 and E4599 was 11.6 months versus 9.0 months for women <60 (p=0.03). MST was 7.4 and 8.3 months for men ≥60 and <60 years old respectively (NS). In E4599 the age <60 by bevacizumab treatment interaction was statistically significant (p=0.03) for women (younger had greater benefit), with no age effect in men.

CONCLUSIONS

In this unplanned, exploratory subgroup analysis of advanced stage NSCLC ECOG trials, women ≥60 years old treated with chemotherapy live longer than men and younger women. In contrast, bevacizumab survival benefit was more pronounced in men of any age and in younger women on E4599.

Relationship between CCL5 and transforming growth factor-β1 (TGFβ1) in breast cancer

PURPOSE

Investigate circulating CCL5 in breast cancer patients and healthy controls, along with gene expression levels in corresponding tumour tissue and isolated primary stromal cells. Hormonal control of CCL5, and a potential relationship with TGFβ1, was also investigated.

METHODS

Circulating levels of CCL5 and TGFβ1 were measured in 102 breast cancer patients and 66 controls using ELISA. Gene expression levels (CCL5, CCR5, TGFβ1, TGFβRII) were quantified in corresponding tumour tissue (n = 43), normal tissue (n = 16), and isolated tumour (n = 22) and normal (n = 3) stromal cells using RQ-PCR. CCL5 and circulating menstrual hormones (LH, FSH, Oestradiol, Progesterone) were analysed in serum samples from healthy, premenopausal volunteers (n = 60).

RESULTS

TGFβ1 was significantly higher in breast cancer patients (Mean(SEM) 27.4(0.9)ng/ml) compared to controls (14.9(0.9)ng/ml). CCL5 levels decreased in the transition from node negative (59.6(3.7)ng/ml) to node positive disease (40.5(6.3)ng/ml) and increased again as the number of positive lymph nodes increased (⩾3 positive 50.95(9.8)ng/ml). A significant positive correlation between circulating CCL5 and TGFβ1 (r = 0.423, p<0.0001) was observed, and mirrored at the gene expression level in tumour tissue from the same patients (r = 0.44, p<0.001). CCL5, CCR5 and TGFβ1 expression was significantly higher in tumour compared to normal breast tissue (p < 0.001). A significant negative correlation was observed between circulating CCL5, Oestradiol and Progesterone (r = -0.50, r = -0.39, respectively, p < 0.05).

CONCLUSION

CCL5 expression is elevated in the tumour microenvironment. The data support a role for hormonal control of circulating CCL5 and also highlight a potentially important relationship between CCL5 and TGFβ1 in breast cancer.

Vascular endothelial growth factor and its relationship to the prognosis and treatment of breast, ovarian, and cervical cancer

Tumor neovascularization is a complex process that plays a crucial role in the development of many different types of cancer. Vascular endothelial growth factor (VEGF) is a potent mitogen that is involved with mitogenesis, angiogenesis, endothelial survival, and the induction of hematopoiesis. By increasing vascular permeability in endothelial cells, it helps tumors recruit wound-healing proteins fibrin and fibrinogen from the plasma, suggesting that tumor formation is a process of abnormal wound healing dependent on the ability to generate a blood supply. The human female reproductive tract is highly dependent on VEGF for normal functions such as endometrial proliferation and development of the corpus luteum. The unique influence of female sex steroid hormones on the expression and activity of VEGF deems angiogenesis an important facet of the development of breast and ovarian cancer. Additionally, the up-regulation of VEGF by the E6 oncoprotein of the human papillomavirus suggests that VEGF plays an important role in the development of cervical cancer. Clinical trials have investigated the humanized monoclonal antibody bevacizumab as potential treatment for all three forms of cancer; the data show that in breast cancer, the use of bevacizumab may lengthen the disease-free survival for women with advanced breast cancer, but does not appear to change their overall survival. It may have a role as salvage chemotherapy for ovarian and cervical cancer, though further research is needed to establish it as a definitive form of treatment.

The effect of menopause and hysterectomy on systemic vascular endothelial growth factor in women undergoing surgery for breast cancer

Background

Vascular endothelial growth factor (VEGF) is a potent angiogenic cytokine produced physiologically by the uterus. Pathological secretion by tumours promotes growth and metastasis. High circulating VEGF levels potentially have a deleterious effect on breast cancer by promoting disease progression.

The aims of this study were to investigate circulating VEGF levels in breast cancer patients and assess the effect of menopause or hysterectomy on systemic VEGF.

Methods

Patients undergoing primary surgery for breast cancer and controls matched for age, menopausal and hysterectomy status were prospectively recruited. Serum VEGF, FSH, LH, estrogen, progesterone and platelet levels were measured. Serum VEGF was corrected for platelet load (sVEGFp) to provide a biologically relevant measurement of circulating VEGF. SVEGFp levels were analyzed with respect to tumor characteristics, menopausal status and hysterectomy status.

Results

Two hundred women were included in the study; 89 breast cancer patients and 111 controls. SVEGFp levels were significantly higher in breast cancer patients compared to controls (p = 0.0001), but were not associated with clinico-pathological tumor characteristics. Systemic VEGF levels reduced significantly in the breast cancer patients following tumor excision (p = 0.018). The highest systemic VEGF levels were observed in postmenopausal breast cancer patients. Postmenopausal women who had had a previous hysterectomy had significantly higher VEGF levels than those with an intact postmenopausal uterus (p = 0.001).

Conclusion

This study identifies an intact postmenopausal uterus as a potential means of reducing circulating levels of VEGF which could confer a protective effect against breast cancer metastatic potential.

Systemic chemokine levels in breast cancer patients and their relationship with circulating menstrual hormones

INTRODUCTION

The chemokines Stromal Cell-Derived Factor-1alpha (SDF-1alpha/CXCL12) and Monocyte Chemotactic Protein-1 (MCP-1/CCL2) have been implicated in breast cancer progression. We recently reported elevated systemic MCP-1 in breast cancer patients. This study investigated circulating levels of SDF-1alpha in breast cancer patients, and addressed potential hormonal regulation of these two potent chemokines.

METHODS

SDF-1alpha levels were determined by ELISA in 114 breast cancer patients and 85 controls, and correlated with clinical data. Blood samples were collected from 36 healthy premenopausal volunteers weekly for four weeks to measure Luteinising Hormone (LH), Follicular Stimulating Hormone (FSH), Oestradiol and Progesterone using a Bayer ADVIA Centaur Immunoassay system, in parallel with SDF-1alpha and MCP-1. CXCL12 expression was determined using RQ-PCR in primary tumour stromal cells (n = 16) harvested at surgery.

RESULTS

Plasma SDF-1alpha was significantly higher in breast cancer patients than age-matched controls and had a significant correlation with tumour grade and epithelial subtype. Investigation of menstrual variations of these chemokines revealed lower SDF-1alpha levels in the mid-luteal phase of the menstrual cycle and a significant positive correlation with circulating Oestradiol. MCP-1 levels showed no correlation with menstrual hormones. There was a trend towards increased CXCL12 expression in tumour compared to normal stromal cells.

CONCLUSIONS

The elevated level of SDF-1alpha detected in breast cancer patients, and it's correlation with prognostic indicators, highlights the importance of this chemokine in disease progression. Elucidation of factors influencing chemokine secretion supports clarification of their role in tumourigenesis.

Monocyte chemotactic protein-1 secreted by primary breast tumors stimulates migration of mesenchymal stem cells

PURPOSE

Major barriers to effective adenovirus-based gene therapy include induction of an immune response and tumor-specific targeting of vectors. The use of mesenchymal stem cells (MSC) as systemic delivery vehicles for therapeutic genes has been proposed as a result of their combined ability to home in on the tumor site and evade the host immune response. This study is aimed at investigating factors mediating homing of human MSCs to breast cancer primary cultures and cell lines in vitro and in vivo.

EXPERIMENTAL DESIGN

Fluorescently labeled MSCs were given to mice bearing breast cancer xenografts, and tumor tissue was harvested to detect MSC engraftment. MSC migration in response to primary breast tumors in vitro was quantified, and chemokines secreted by tumor cells were identified. The role of monocyte chemotactic protein-1 (MCP-1) in cell migration was investigated using antibodies and standards of the chemokine. Serum MCP-1 was measured in 125 breast cancer patients and 86 healthy controls.

RESULTS

Engrafted MSCs were detected in metastatic breast tumors in mice after systemic administration. There was a significant increase in MSC migration in response to primary breast tumor cells in vitro (6-fold to 11-fold increase). Tumor explants secreted a variety of chemokines including GROalpha, MCP-1, and stromal cell-derived factor-1alpha. An MCP-1 antibody caused a significant decrease (37-42%) in MSC migration to tumors. Serum MCP-1 levels were significantly higher in postmenopausal breast cancer patients than age-matched controls (P < 0.05).

CONCLUSIONS

These results highlight a role for tumor-secreted MCP-1 in stimulating MSC migration and support the potential of these cells as tumor-targeted delivery vehicles for therapeutic agents.

Perioperative endocrine status and prognosis in early breast cancer

Although the relationship between breast cancer and hormones has been known for almost two centuries, it is only during the last 16 years that evidence suggesting the hormonal profile of the patient at the time of surgery can affect the outcome, came to light. A series of studies investigated the hypothesis that unopposed estrogen (observed during the follicular phase of the cycle) may adversely affect the overall and/or disease-free survival of women operated on at that time. The findings have been, at times, contradictory. The retrospective nature of the studies, poor recording of last menstrual period, small study size, and the possible effect of the timing of the diagnostic procedures (cytology or core biopsy) on the outcome may be responsible for the conflicting results. Despite this, more sophisticated studies based on pathological or hormonal observations/measurements, confirmed the relation of luteal phase surgery to better outcome. Estrogen-induced increased protease activity activates a cascade of proteolysis and allows the more discohesive tumor cells to gain access to the circulation. Moreover, disseminated cells might be able to proliferate easier because of several estrogen-dependent growth factors. Diminished immune function during the follicular phase, because of natural killer cell activity and mononuclear cell phagocytic activity down-regulation may also be implicated in the dissemination of viable tumor cells. Taken together these findings provide a framework for explaining the observation that luteal phase surgery can lead to an improved outcome. By altering the perioperative hormonal milieu it may be possible to reduce deaths from breast cancer in a simple and nontoxic manner.

Does the timing of breast cancer surgery in pre-menopausal women affect clinical outcome? An update

There is some evidence that breast cancer surgery during the luteal phase in pre-menopausal women is associated with a better clinical outcome, however the evidence for this is still equivocal.

In this paper, after summarizing the normal physiology of the menstrual cycle, we examine how such an association may occur and provide a comprehensive review of the literature in the area.

Does surgery induce angiogenesis in breast cancer? Indirect evidence from relapse pattern and mammography paradox

A significant bimodal relapse hazard pattern has been observed in two independent databases for patients untreated with adjuvant chemotherapy. This implies there is more than one mode of relapse. The earliest and most closely grouped relapses occur 8-10 months after surgery for young women with node-positive disease. Analysis of these data using computer simulation suggested that surgery probably instigated angiogenesis in dormant distant disease in approximately 20% of cases for premenopausal node-positive patients. We explore if this could explain the mammography paradox for women aged 40-49: an unexplained temporary excess in mortality for the screened population compared to controls. Calculations based on our data predict surgery-induced angiogenesis would accelerate disease by a median of two years and produce 0.11 early deaths per 1000 screened young women in the third year of screening. The predicted timing as well as the magnitude of excess mortality agree with trial data. Surgery-induced angiogenesis could account for the mammography paradox for women aged 40-49 and the bimodal relapse hazard pattern. According to the proposed biology, removing tumors could remove the source of inhibitors of angiogenesis or growth factors could appear in response to surgical wounding. While this needs confirmation, this could be considered when designing treatment protocols particularly for young women with positive nodes. It reinforces the need for close coordination between surgical resection and ensuing medical intervention. Women need to be advised of risk of accelerated tumor growth and early relapse before giving informed consent for mammography.

Cancer growth and spread are saltatory and phase-locked to the reproductive cycle through mediators of angiogenesis

The frequency of breast cancer metastatic spread is affected by the menstrual cycle phase of its resection. Breast cancer growth, post-resection spread, and cure frequency are each modulated by the estrous cycle in C(3)HeB/FeJ mice. Tumor metastases are 2- to 3-fold more frequent when the resection is done during diestrus as compared with estrus. Tumor angiogenesis is essential for both cancer growth and lethal metastatic cancer spread. The balance between vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) modulates new blood vessel formation and blood vessel permeability. Sex hormones modulate the expression of these key angiogenesis regulators in the endometrium and uterus. We, therefore, asked whether the estrous cycle modulates the density of CD31-positive vessels within the tumor, the permeability of tumor blood vessels, levels of VEGF and bFGF immunoreactive protein in normal breast and breast cancer, and whether expression of these genes are modulated by the estrous cycle stage in C(3)HeB/FeJ mice. We find that tumor blood vessel density and blood volume do not vary throughout the cycle; however, tumor capillary permeability is regulated by the estrous cycle being highest in diestrus, the cycle stage associated with the highest cancer growth rate and the highest frequency of post-resection cancer metastasis. VEGF protein levels in breast cancer are >100-fold higher than in normal breast. VEGF protein in this mammary tumor varies with the estrus cycle with highest levels in proestrus. In a non-breast tumor, methylcholantrenene A sarcoma, from CD(2)F(1) mice, tumor VEGF protein also varies with the estrus cycle with highest levels in proestrus and diestrus. VEGF gene expression in the mammary tumor does not change significantly across the cycle, but is modulated by the cycle in normal breast tissue. bFGF protein concentration is 6-fold higher in normal breast than in breast cancer. bFGF protein pattern in both tumor and breast are similar, opposite to VEGF, and affected by oophorectomy. bFGF message is modulated by the cycle in both breast cancer and normal breast. The changes in breast cancer capillary permeability, VEGF, and bFGF that occur during each fertility cycle, in breast tissue and breast cancer, putatively in response to cyclical changes in sex hormones, might contribute, at least in part, to both the modulation of cancer growth and post-resection breast cancer spread by the fertility cycle. These fertility cycle-induced effects on tumor biology also seem to extend to non-breast cancer biology.

Inhibition of the stress response to breast cancer surgery by regional anesthesia and analgesia does not affect vascular endothelial growth factor and prostaglandin E2

Angiogenesis is essential for breast cancer metastases formation and is mediated by vascular endothelial growth factor (VEGF) and prostaglandin E2 (PGE2). We hypothesized that serum levels of VEGF and PGE2 are increased by the stress response to breast cancer surgery and attenuated by paravertebral anesthesia and analgesia (PVAA). Thirty women undergoing mastectomy were enrolled in this prospective, randomized study, to receive general anesthesia (GA) and postoperative opioid analgesia (morphine 0.1 mg/kg bolus and patient-controlled infusion) or GA and PVAA (72-h infusion). All patients received rectal diclofenac. Venous blood samples were taken preoperatively and at 4 and 24 h postoperatively for serum glucose, cortisol, C-reactive protein, VEGF, and PGE2. PVAA inhibited the surgical stress response, as indicated by significantly less plasma glucose, cortisol, and C-reactive protein. VEGF and PGE2 values did not differ significantly between the groups. Mean (SD) percentage change in VEGF at 4 and 24 h respectively were 3% +/- 44% versus 9% +/- 80%, P=0.29 and 5% +/- 43% versus -10% +/- 63%, P=0.41 for patients with combined general and PVAA and GA alone, respectively. Mean percentage change in postoperative PGE2 at 4 and 24 h respectively was 10% +/- 17% versus 11% +/- 69%, P=0.29 and 34% +/- 19% versus 47% +/- 18%, P=0.15. We conclude that despite inhibiting the surgical stress response, PVAA had no effect on serum levels of putative breast cancer angiogenic factors, VEGF and PGE2.

Incidence of chemotherapy-induced amenorrhea depending on the timing of treatment by menstrual cycle phase in women with early breast cancer

BACKGROUND

The aim of this study was to characterize the factors associated with chemotherapy-induced amenorrhea (CIA) and to examine whether the phase of the menstrual cycle at chemotherapy start could affect the rate of CIA in premenopausal women with early breast cancer.

METHODS

CIA was defined as the cessation of menses for at least 3 months during or after chemotherapy. Menstrual phase was defined as days 1-6, follicular phase as days 7-14, luteal phase as days 15-20 and premenstrual phase as days 21-28. Univariate and multivariate predictors of CIA were examined.

RESULTS

Among 111 premenopausal women, univariate analysis showed a higher incidence of CIA in patients treated in the follicular phase rather than in other menstrual cycle phases (67.6% compared with 45.5%; P=0.03). The rate of CIA increased with age: 65.2% and 45.8% in patients aged >42 and </=42 years, respectively (P=0.05). Upon multivariate analysis these differences remained statistically significant and duration of chemotherapy of more than six cycles correlated significantly with the incidence of CIA (P=0.03).

CONCLUSIONS

The major implication of this analysis is that the timing of treatment within the menstrual cycle may potentially modulate the onset of CIA. This work and its future confirmation using prospective randomized trials would be useful in predicting the likelihood of CIA and in counseling breast cancer patients, especially those with a good prognosis who benefit less from chemical castration.

Prognostic significance of serum vascular endothelial growth factor and endostatin in patients with hepatocellular carcinoma

BACKGROUND

Vascular endothelial growth factor (VEGF) and endostatin stimulate and inhibit tumour angiogenesis respectively. Recent studies have demonstrated the prognostic value of serum levels of both VEGF and endostatin in patients with various types of cancer. Their significance in patients with hepatocellular carcinoma (HCC) remains unclear.

METHODS

Serum VEGF and endostatin levels were measured by enzyme immunoassay in 108 patients with HCC before surgical resection and in 20 healthy controls. Preoperative serum VEGF and endostatin levels were correlated with clinicopathological features and long-term survival.

RESULTS

Serum VEGF levels in patients with HCC were significantly higher than those in controls, but serum levels of endostatin were similar in the two groups. High serum levels of VEGF, but not endostatin, were significantly associated with venous invasion and advanced tumour stage. Patients with a serum VEGF level higher than median (over 245.0 pg/ml) had significantly worse overall and disease-free survival than those with a lower level (P = 0.012 and P = 0.022 respectively). On multivariate analysis, serum VEGF level was an independent prognostic factor (hazard ratio 1.86 (95 per cent confidence interval 1.10 to 3.92); P = 0.032). Serum endostatin levels did not have significant prognostic influence on overall or disease-free survival.

CONCLUSION

A high serum level of VEGF is a predictor of poor outcome after resection of HCC. Serum VEGF, but not endostatin, may be a useful prognostic marker in patients with HCC.

Models of Breast Cancer Growth and Investigations of Adjuvant Surgical Oophorectomy

Clinical observations of the natural history of breast cancer and its response to a variety of therapeutic interventions have contributed to changing concepts about the growth and metastatic spread of this disease. Increased attention has been given to tumor cell dormancy and the occurrence of greatly delayed metastatic disease development, which has been important to rethinking therapy. Although gene profiling of breast tumors recently has highlighted the importance of individual tumor characteristics in patients' prognosis, considerable data also support the concept of breast cancer as a problem of macro- and microenvironmental regulatory imbalance and dynamic chaos. Observations of unexpectedly large survival benefits from adjuvant surgical oophorectomy done in the luteal phase of the menstrual cycle in premenopausal women are consistent with an interpretation that extratumoral interactions in the host environment are important in prognosis. These observations also suggest that a treatment paradigm shift from an exclusive focus on cell kill and specific tumor cell molecular targets to one focused also on broad host regulatory control may be useful. Clinical trials and laboratory mechanistic investigations based on these data and observations can determine the potential impact of therapeutic interventions targeting host system macro and micro tumor cell environments.

No association between serum levels of insulin-like growth factor-I, vascular endothelial growth factor, prolactin and clinicopathological characteristics of breast carcinoma after surgery

BACKGROUND

Angiogenesis is essential for tumour growth and metastasis. Vascular endothelial growth factor (VEGF) has been suggested as the major angio-genic factor in breast carcinoma. Both insulin-like growth factor-I (IGF-I) and prolactin are involved in the progression of breast cancer at least partly by stimulating angiogenesis.

AIM

The aim of the present study was to investigate the association between serum IGF-I, VEGF and prolactin levels and clinicopathological characteristics of breast carcinoma.

METHODS

Serum IGF-I, VEGF and prolactin levels were measured in breast cancer patients and controls and these levels were compared with well-known clinicopathological characteristics of breast carcinoma, including tumour size, axillary lymph node and oestrogen/progesterone receptor status, tumour grade and disease stage.

RESULTS

Serum prolactin, VEGF and IGF-I levels were found to be similar in breast cancer patients and control subjects (P > 0.05). When the patients were divided into groups according to their tumour size, axillary lymph node status, tumour grade, oestrogen/progesterone receptor status and disease stage, no significant differences in serum prolactin, VEGF and IGF-I levels were found among the groups (P > 0.05).

CONCLUSIONS

The present study failed to demonstrate an association between serum levels of VEGF, IGF-I and prolactin and well-known clinicopathological characteristics of breast carcinoma.

Monitoring of circulating angiogenic factors in dendritic cell-based cancer immunotherapy

BACKGROUND

A promising treatment approach for patients with malignant disease that recently has found its way into clinical trials is based on vaccination with autologous dendritic cells loaded with tumor antigens. However, adequate assays for monitoring clinical and immunologic responses still are under debate. In recent years, the determination of angiogenic markers has shown considerable potential in the diagnosis and prognosis of patients with malignant disease, because tumor growth and spread are promoted by angiogenesis, the formation of new blood vessels.

METHODS

The authors established a method for measuring the plasma levels of three modulators of angiogenesis: vascular endothelial growth factor, platelet-derived endothelial cell growth factor, and thrombospondin-1. The angiogenic blood profile of a healthy control group was characterized and compared with a group of patients with malignant disease. Ultimately, levels of circulating angiogenic factors were monitored in the course of dendritic cell-based cancer immunotherapy.

RESULTS

Baseline levels of angiogenic mediators varied substantially among healthy individuals but showed consistent values for each individual. Blood levels of circulating angiogenic factors were elevated significantly in patients with advanced disease and were highly sensitive to dendritic cell-based immunotherapy.

CONCLUSIONS

To our knowledge, the current report was the first to analyze circulating levels of angiogenic factors during dendritic cell-based immunotherapy. The authors observed a noteworthy change in the angiogenic blood profile with treatment, and this change was correlated with the induction of an immunologic response.

A critical review of vascular endothelial growth factor (VEGF) analysis in peripheral blood: is the current literature meaningful?

Vascular endothelial growth factor (VEGF) is a potent angiogenic growth factor with a key role in many physiological and pathological processes. Investigation into the implications of circulating levels of this cytokine is progressing at an exponential rate. However, there are important inconsistencies between reports ranging from method of sample collection, processing, software manipulation and data interpretation and controversy as to whether plasma, serum or whole blood will provide the best prognostic information. Different techniques of centrifugation and temperature on sample handling and the impact of in vitro collection of blood on subsequent VEGF results have not been fully appreciated. We provide a critical review of the literature, report the results of our further investigations, suggest a uniform protocol for handling blood samples and highlight previously unsuspected problems in data interpretation.

Breast cancer screening: controversies and future directions

PURPOSE OF REVIEW

Recent criticisms of the mature breast cancer screening trials claimed that there is no evidence that screening saves lives. This has developed into a major public controversy, causing physicians, women, and policy analysts to rethink and debate mammography-screening guidelines. We have studied this subject from a different perspective -- using computer simulation to fit a simple growth model to clinical data. We can thus provide another viewpoint of the screening controversy that may help elucidate the underlying biology and aid policy makers in devising sound screening guidelines.

RECENT FINDINGS

We agree with some reviewers that there is partial validity to the criticism. Based on our studies, we have arrived at a new explanation of why screening has not lived up to expectations.

SUMMARY

Our fundamental hypothesis is that breast cancers often undergo periods during which they are temporarily dormant. In addition, surgical intervention to remove primary tumors can interrupt this dormancy. Therefore screening finds smaller tumors with fewer positive lymph nodes, which is beneficial. But then the resulting extirpation accelerates the growth of dormant distant micrometastases, and results in earlier relapses than in women who have not been screened. This partly offsets the early detection advantage. One hypothetical mechanism proposed to explain this biology is that surgical wounding, particularly for premenopausal node-positive patients, can trigger the angiogenesis of dormant avascular micrometastases.

A comparison of serum and plasma levels of vascular endothelial growth factor during the menstrual cycle in healthy female volunteers

Angiogenesis is the formation of new blood vessels from the existing vasculature, and is essential for the growth and metastasis of most solid tumours. One of the most important growth factors involved in the angiogenesis process is vascular endothelial growth factor. Vascular endothelial growth factor expression has been shown to be regulated by female hormones in breast cancer cell lines, and two previous authors have reported on cyclical variations in serum vascular endothelial growth factor concentrations with conflicting results. No work has been performed on variations in plasma levels of vascular endothelial growth factor during the menstrual cycle. We therefore conducted the first prospective trial to compare serum and plasma levels of vascular endothelial growth factor in healthy pre-menopausal volunteers. Twenty healthy pre-menopausal women were recruited and had blood samples taken over one menstrual cycle with an average of eight samples taken per patient. Plasma and serum samples were then analysed for sex hormones and vascular endothelial growth factor 165. Serum vascular endothelial growth factor levels were found to be significantly higher than plasma vascular endothelial growth factor levels (P<0.005). We found no significant difference between serum and plasma vascular endothelial growth factor in the luteal and follicular phases of the cycle. The majority of the measurements for plasma levels of vascular endothelial growth factor at all phases of the cycle were under the limit of detection of the vascular endothelial growth factor ELISA kit. We found no significant correlation between plasma or serum levels of vascular endothelial growth factor and either FSH, LH, Oestradiol or Progesterone levels. This study has demonstrated no difference in serum concentrations of vascular endothelial growth factor during the different phases of the menstrual cycle in a group of healthy volunteers. We also demonstrated no obvious difference in plasma concentrations of vascular endothelial growth factor between the phases of the cycle, but most of the measurements were below the level of accuracy reported by the ELISA kit manufacturer. With the sensitivity of this ELISA test, therefore, we must still regard the question of whether there is a variation in plasma concentrations of vascular endothelial growth factor throughout the menstrual cycle as unanswered.

Stabilization of breast cancer xenograft tumour neovasculature by angiopoietin-1

Angiopoietin-1 is a promoter of physiological vasculogenesis and angiogenesis because it induces vascular branching and smooth muscle recruitment to newly formed blood vessels. However, angiopoietin-1 expression in tumours appears to be uncommon, and angiopoietin-1 overexpression in cancer cells has been reported to lead to inhibition of xenograft tumour growth. We report here that angiopoietin-1 overexpression resulted in stabilization of tumour edge-associated blood vessels, as it prevented vessel dilation and dissociation of smooth muscle cells from existing vessels. In addition, angiopoietin-1 stimulated an infiltration of mesenchymal cells into the tumours, such that the coverage of microvessels by pericytes increased markedly, and the cancer cells were separated into small masses by the host stroma. The rates of both cancer cell proliferation and apoptosis decreased significantly in the presence of angiopoietin-1. Tie2, the receptor for angiopoietin-1, was found to be present in vascular smooth muscle cells in culture in addition to endothelial cells. These findings suggest that a vascular stabilization effect of angiopoietin-1 accounts for the inhibition of tumour growth.

Low-dose oral methotrexate and cyclophosphamide in metastatic breast cancer: antitumor activity and correlation with vascular endothelial growth factor levels

BACKGROUND

Anticancer chemotherapy is thought to be effective by means of direct cytotoxicity on tumor cells. Alternative mechanisms of efficacy have been ascribed to several common anticancer agents, including cyclophosphamide (CTX), methotrexate (MTX), anthracyclines and taxanes, postulating an antiangiogenic activity.

PATIENTS AND METHODS

We evaluated the clinical efficacy and impact on serum vascular endothelial growth factor (VEGF) levels of low-dose oral MTX and CTX in patients with metastatic breast cancer. MTX was administered 2.5 mg bd on days 1 and 2 each week and CTX 50 mg/day administered continuously.

RESULTS

Sixty-four patients were enrolled, 63 were evaluable: Eastern Cooperative Oncology Group (ECOG) performance status 0-1, > or =2 sites of metastatic disease (n = 50 patients), progressive disease at study entry (n = 51), 1 regimen for metastatic disease (n = 32) and > or =2 regimens (n = 20). Among the 63 evaluable patients, there were two complete remissions (CR), 10 partial remissions (PR) for an overall response rate of 19.0% (95% CI 10.2% to 30.9%) and an overall clinical benefit (CR+ PR+ stable disease >24 weeks) of 31.7% (95% CI 20.6% to 44.7%). Grade > or =2 leucopenia was registered in only 13 patients. The median serum VEGF level for the subgroup of patients on treatment for at least 2 months decreased with treatment from 315 pg/ml (95% CI 245 to 435) at baseline to 248 pg/ml (95% CI 205 to 311) at 2 months (P <0.001). Both responders and non-responders showed similar reductions in serum VEGF (P = 0.78). After 6 months patients still on treatment had a median VEGF level of 195 pg/ml (95% CI 96 to 355), which was significantly lower than the median baseline values (P = 0.001).

CONCLUSIONS

Continuously low-dose CTX and MTX is minimally toxic and effective in heavily pretreated breast cancer patients. A drop in VEGF was associated with the treatment and so alternative hypotheses, other than that of direct toxicity on tumor cells, must be favored when trying to explain the anticancer effect.

Tumour dormancy: findings and hypotheses from clinical research on breast cancer

Breast cancer metastatic development is commonly considered as resulting from continuous tumour growth from tumour seeding until clinical recurrence is documented. Continuous growth model inferences, however, fail to explain clinical findings concerning local recurrences, as well as the time-distribution of first treatment failure and mortality for patients undergoing mastectomy. The tumour dormancy hypothesis is considered to provide a more reasonable description of the natural history of breast cancer, while primary tumour removal is believed to be a potential perturbing factor for metastasis development. A new model of the natural history of operable breast cancer, incorporating tumour dormancy and starting signals from surgery for micrometastatic growth is proposed.

Low pO2 and beta-estradiol induce VEGF in MCF-7 and MCF-7-5C cells: relationship to in vivo hypoxia

Previous work from this laboratory demonstrated that MCF-7 breast carcinoma cells grown in nude mice contained minimal hypoxia but that tamoxifen treatment of these tumors resulted in increased hypoxia (Evans S. et al., Cancer Research, 1997). These findings led to studies exploring the link between estrogen signaling and tumor oxygenation and determining the role of VEGF in this process. The stimulation of estrogen-dependent MCF-7 breast carcinoma cells in vitro with beta-estradiol resulted in a two-fold induction of VEGF mRNA and 1.3-2-fold increase in protein, similar to what was observed when these cells were exposed to 0. 1% oxygen. Furthermore, the two stimuli given together had an additive effect on (increasing) VEGF expression, suggesting that the combination of hypoxia and estrogen may be important in upregulating VEGF in some breast cancers. Estrogen-independent MCF-7-5C cells, developed by growing MCF-7 cells in long-term culture in estrogen-free media, were also studied. Using EF5, a fluorinated 2-nitroimidazole which localizes to hypoxic cells, MCF-7-5C tumors grown in nude mice were found to contain lower pO2 levels and more hypoxic regions than similarly grown MCF-7 tumors. We tested the hypothesis that this might be the result of defective expression of VEGF in MCF-7-5C cells in response to beta-estradiol and/or hypoxia. However, MCF-7-5C and MCF-7 cells showed a similar induction of VEGF in vitro in response to either beta-estradiol or hypoxia. Therefore, although these two cell lines grown as tumors have substantial differences in the presence and patterns of hypoxia, this could not be explained by a difference in VEGF induction.

Premenopausal status accelerates relapse in node positive breast cancer: hypothesis links angiogenesis, screening controversy

Much attention has been given to determining the benefit of mammographic screening to reduce breast cancer mortality. Eight randomized clinical trials have been conducted in four countries: the US, Canada, Scotland and Sweden. Trials report an early and stable 30% reduction in breast cancer mortality for women aged 50-59. For women under 50, unexpectedly, the early years of screening produce a disadvantage to the screened population. Only in later years does an advantage appear. To help understand this, we studied relapse patterns using a breast cancer database of 1,173 pre- and postmenopausal, node negative and positive patients treated with surgery only and having 16-20 years of follow-up. This approach is relevant since at least five of the eight screening trials began before the widespread use of adjuvant chemotherapy in the 1980s. Surgical cure rates were independent of menopausal status. However, a major difference in early relapse rate was found. In premenopausal and node positive patients, 27% of all distant relapses occurred within the first 10 months following resection. This is twice the early relapse frequency of any other clinical group. Using computer simulation, we interpret that these early relapses probably result from a disadvantage induced at surgery. A disinhibition or surgery/wounding induced angiogenic surge might be responsible. Disinhibition is known to occur in animal models such as Lewis lung where lung metastases are avascular and dormant until the primary is removed. Sudden outgrowth of tumor after wounding has been observed for a century. According to the simulation, in breast cancer this induction apparently accelerates inevitable relapses by a median of two years. This is offset in later years with a balancing reduction in relapses. These data suggest that the angiogenic switch may be upregulated more frequently among premenopausal women, perhaps depending upon the sex hormones. The acceleration would cause 0.11 deaths per 1,000 screened aged 40-49 subjects in years 2-3, a value comparable to the early year excess mortality in trials of a significant 0.15 deaths per 1,000 subjects. Equal screening advantage is predicted for node negative (but not node positive) pre- and postmenopausal patients. The acceleration of relapse after surgery may explain the paradoxical effect of mammographic screening for women under 50.

Vascular endothelial growth factor as prognostic factor in renal cell carcinoma

PURPOSE

Vascular endothelial growth factor (VEGF) has been recognized as an important constituent of vascularization and growth of solid tumors. Serum VEGF levels were evaluated and correlated to clinicopathologic findings and clinical outcome in patients with renal cell carcinoma (RCC).

MATERIALS AND METHODS

Serum samples were collected before surgery in 164 patients with RCC. Levels of VEGF165 protein in sera were measured using a quantitative ELISA. Univariate and multivariate analyses were performed.

RESULTS

The VEGF165 level in serum was significantly increased (p = 0.0001) in patients with RCC (median 343.4 pg./ml.) compared with the control patients (median 103.8 pg./ml.). The level of VEGF165 in serum correlated to clinical stage and histopathological grade. Patients with VEGF165 levels below median value had significantly longer survival time than patients with higher levels (p = 0.0001). This was also shown when VEGF165 was analyzed in univariate Cox regression (p = 0.0001). The impact of VEGF165 on survival was especially shown in patients having tumors with vein invasion (pT3b-c N0 M0) and in patients with clinical stages I - III (p = 0.0240 and p = 0.0023, respectively). When using multivariate analysis, only tumor stage and grade remained as independent prognostic variables.

CONCLUSIONS

In RCC, serum VEGF165 level was significantly correlated to tumor stage and grade. Increased levels were correlated to adverse survival. Although, VEGF did not remain as an independent prognostic factor in multivariate analysis the levels of VEGF165 in serum was found useful for the identification of patients with potentially progressive disease especially for those with vein invasion.

Survival of premenopausal breast carcinoma patients in relation to menstrual cycle timing of surgery and estrogen receptor/progesterone receptor status of the primary tumor

BACKGROUND

Premenopausal breast carcinoma patients who undergo tumor excision during the follicular phase of their menstrual cycle may have a significantly worse prognosis than those whose tumors are excised in other phases of the menstrual cycle.

METHODS

Outcome was determined in a series of 112 premenopausal women with operable breast carcinoma in relation to the timing of surgery within the menstrual cycle and the estrogen receptor (ER) and progesterone receptor (PR) status of their primary tumors as determined by immunohistochemistry.

RESULTS

Those patients with ER positive tumors who underwent surgery in the early and luteal phase of the cycle had a significantly better survival than women with ER negative tumors (chi-square test = 15.56; P < 0.001). This also was true for PR status (chi-square test = 18.21; P < 0.001). After follicular phase surgery, tumor receptor status had no effect on overall survival. Patients with the best prognosis had ER/PR positive tumors excised on Days 0-2 and 13-32 but even those women with ER or PR negative tumors removed during the luteal phase of their menstrual cycle fared better than patients whose tumors were removed during the follicular phase.

CONCLUSIONS

There was a better survival rate for patients with both ER/PR positive and negative tumors treated during the luteal phase of the menstrual cycle. This could be the result of progesterone acting on the surrounding peritumoral normal tissue, thereby exerting a straitjacket effect and improving cohesion of the primary carcinoma. Unopposed estrogen in the follicular phase of the cycle may enable more tumor emboli to escape and successfully establish micrometastases.

Serum vascular endothelial growth factor in patients with head and neck squamous cell carcinoma

Vascular endothelial growth factor (VEGF) is a key pro-angiogenic cytokine expressed by most human tumours. Two isoforms, VEGF121 and VEGF165, are soluble and can be assayed in serum. Serum VEGF has been shown to be significantly raised in patients with solid tumours and shows some promise as a potentially useful tumour marker. Serum levels of VEGF were assayed in 52 patients with untreated head and neck squamous cell carcinoma (HNSCC) and 104 healthy controls. Serum VEGF is significantly raised in patients with HNSCC (P < 0.001), but there was no association with either tumour stage or specifically the presence of nodal metastases. Sixteen patients (31%) had a higher serum VEGF than 95th centile of controls, suggesting that serum VEGF measurement is of little practical use as an initial diagnostic tool. The finding that patients with HNSCC have significantly raised serum VEGF probably relates to enhanced platelet aggregation in these patients.

Vascular endothelial growth factor A (VEGF-A) mRNA expression levels decrease after menopause in normal breast tissue but not in breast cancer lesions

We hypothesized that the regulation of microvascular functions and angiogenesis in breast tissue, a well known target of ovarian steroid action, is dependent on the hormonal exposure of the breast. Relative expression levels of VEGF-A (vascular endothelial growth factor A), a putative key regulator of angiogenesis in breast cancer, were analysed in the tumour and the adjacent non-neoplastic breast tissue of 19 breast cancer patients by quantitative reverse transcriptase polymerase chain reaction. In non-neoplastic breast specimens the expression levels of all detected VEGF-A-isoforms (189, 165, 121) were significantly higher in premenopausal compared to post-menopausal women (P = 0.02) and were inversely correlated with the patient's age (P = 0.006). In contrast, in cancerous tissues menopausal status had no influence on VEGF-A-expression levels. Benign and malignant tissues exhibited a similar expression pattern of VEGF-A-isoforms relative to each other. Thus, the regulation of the vasculature in normal breast tissue, as opposed to breast cancer tissue, appears to be hormonally dependent. Endogenous and therapeutically used hormonal steroids might, therefore, cause clinically relevant changes of the angiogenic phenotype of the human breast.