The Prognostic Value of Vascular Endothelial Growth Factor, Urokinase Plasminogen Activator and Plasminogen Activator Inhibitor-1 in Node-Negative Breast Cancer

Epidemiology of breast cancer, a paradigm of the "common soil" hypothesis

Breast cancer is the leading cause of death in women aged 20-50 years, with some geographical difference. The yearly incidence of the disease is increasing while the related mortality is steadily decreasing. Breast cancer is associated not only with specific hormones or factors related with reproduction, but mostly to more general environmental factors, linked to socioeconomic conditions and lifestyles (smoking, stress, physical exercise and particularly dietary habits). The latter, indeed, are risk factors or conditions common to hormone-dependent tumors and other chronic degenerative disorders, such as ischemic cardio cerebro-vascular and neuro-degenerative disease. Breast cancer can indeed be considered as a paradigm of the so-called "common soil" concept, according to which the above mentioned conditions, although having different clinical manifestations, share some pathogenetic mechanisms and risk factors and intermediate predisposing phenotypes (see Type2 diabetes, metabolic syndrome or obesity). In an epidemiological perspective, evidence has been accumulated on the common response of breast cancer and cardiovascular disorders to healthy lifestyles and in particular to the beneficial effects of a close adhesion to the Mediterranean dietary model. The latter would mainly be effective thanks to its anti-inflammatory properties, thus controlling the subclinical condition of low-grade inflammation, a common risk factor of all the "common soil" disorders. Results from the prospective cohort of the Moli-sani Study (nearly 25,000 adults from the general population of the Southern Italy region of Molise) are highly suggestive in this context. In a public health perspective, the "common soil" hypothesis may thus promote the application of preventive strategies, particularly targeting lifestyles, for a broad spectrum of widely prevalent disorders, ranging from breast cancer to myocardial infarction or cognitive impairment conditions.

Levels of uPA and PAI-1 in breast cancer and its correlation to Ki67-index and results of a 21-multigene-array

Background

Conventional parameters including Ki67, hormone receptor and Her2/neu status are used for risk stratification for breast cancer. The serine protease urokinase plasminogen activator (uPA) and the plasminogen activator inhibitor type-1 (PAI-1) play an important role in tumour invasion and metastasis. Increased concentrations in tumour tissue are associated with more aggressive potential of the disease. Multigene tests provide detailed insights into tumour biology by simultaneously testing several prognostically relevant genes. With OncotypeDX®, a panel of 21 genes is tested by means of quantitative real-time polymerase chain reaction.

The purpose of this pilot study was to analyse whether a combination of Ki67 and uPA/PAI-1 supplies indications of the result of the multigene test.

Methods

The results of Ki67, uPA/PAI-1 and OncotypeDX® were analysed in 25 breast carcinomas (luminal type, pT1/2, max pN1a, G2). A statistical and descriptive analysis was performed.

Results

With a proliferation index Ki67 of < 14%, the recurrence score (RS) from the multigene test was on average in the low risk range, with an intermediate RS usually resulting if Ki67 was > 14%. Not elevated values of uPA and PAI-1 showed a lower rate of proliferation (average 8.5%) than carcinomas with an increase of uPA and/or PAI-1 (average 13.9%); p = 0.054, Student’s t-test. When Ki67 was > 14% and uPA and/or PAI-1 was raised, an intermediate RS resulted. These differences were significant when compared to cases with Ki67 < 14% with non-raised uPA/PAI-1 (p < 0.03, Student’s t-test). Without taking into account the proliferative activity, an intermediate RS was also verifiable if both uPA and PAI-1 showed raised values.

Conclusion

A combination of the values Ki67 and uPA/PAI-1 tended to depict the RS to be expected. From this it can be deduced that an appropriate analysis of this parameter combination may be undertaken before the multigene test in routine clinical practice. The increasing cost pressure makes it necessary to base the implementation of a multigene test on ancillary variables and to potentially leave it out if not required in the event of a certain constellation of results (Ki67 raised, uPA and PAI-1 raised).

Is the Urokinase-type Plasminogen Activator System a Reliable Prognostic Factor in Gastric Cancer?

Aim

The aim of this prospective study was to evaluate the clinical and prognostic impact of immunohisto-chemically assessed uPA and PAI-1 in patients with gastric cancer.

Methods

This prospective study analyzed specimens obtained from 105 gastric cancer patients who underwent gastrectomy with extended lymphadenectomy. The immunohistochemical expression of uPA and PAI-1 was studied semiquantitatively in the tumor epithelium and was correlated with the clinicopathological features of each patient.

Results

Univariate analysis revealed no statistically significant association of uPA levels with pT and pN category (p=0.655 and 0.053, respectively), grading (p=0.374), depth of tumor invasion (p=0.665), UICC classification (p=0.21) and the Laurén classification (p=0.578). PAI-1 expression showed no statistically significant correlation with pT, pN and M category (p=0.589, 0.414, and 0.167, respectively), grading (p=0.273), and the Laurén classification (p=0.368). Only the UICC classification was significantly correlated with PAI-1 (p=0.016). Kaplan-Meier analysis revealed no significant association of uPA and PAI-1 with overall survival (p=0.0929 and 0.0870, respectively).

Conclusions

Our results could not verify any prognostic value of uPA and PAI-1 levels in patients with gastric carcinoma. Therefore, the uPA-system as a biologically defined prognostic marker to identify high-risk gastric cancers should be applied with caution. However, considering the number of patients involved and the borderline level of significance observed in this study, a larger number of events may have resulted in significant differences.

Prognostic significance of uPA/PAI-1 level, HER2 status, and traditional histologic factors for survival in node-negative breast cancer patients

BACKGROUND

The association of HER2 status with urokinase plasminogen activator (uPA) and plasminogen activator inhibitor 1 (PAI-1) levels raises the question whether uPA/PAI-1 level carries additional clinically relevant prognostic information independently from HER2 status. The aim of our study was to compare the prognostic value of uPA/PAI-1 level, HER2 status, and traditional prognostic factors for survival in node-negative breast cancer patients.

PATIENTS AND METHODS

A retrospective analysis of 858 node-negative breast cancer patients treated in Maribor University Clinical Center, Slovenia, in the years 2000-2009 was performed. Data were obtained from patient medical records. The median follow-up time was 100 months. Univariate and multivariate analyses of disease-free (DFS) and overall survival (OS) were performed using the Cox regression and the Cox proportional hazards model.

RESULTS

In univariate analysis, age, tumor size, grade, lymphovascular invasion, HER2 status and UPA/PAI-1 level were associated with DFS, and age, tumor size, grade, and uPA/PAI-1 level were associated with OS. In the multivariate model, the most important determinants of DFS were age, estrogen receptor status and uPA/PAI-1 level, and the most important factors for OS were patient age and tumor grade. The HR for death from any cause in the multivariate model was 1.98 (95% CI 0.83-4.76) for patients with high uPA and/or PAI-1 compared to patients with both values low.

CONCLUSIONS

uPA/PAI-1 level clearly carries an independent prognostic value regardless of HER2 status in node-negative breast cancer and could be used in addition to HER2 and other markers to guide clinical decisions in this setting.

The long journey of cancer biomarkers from the bench to the clinic

BACKGROUND

Protein cancer biomarkers serve multiple clinical purposes, both early and late, during disease progression. The search for new and better biomarkers has become an integral component of contemporary cancer research. However, the number of new biomarkers cleared by the US Food and Drug Administration has declined substantially over the last 10 years, raising concerns regarding the efficiency of the biomarker-development pipeline.

CONTENT

We describe different clinical uses of cancer biomarkers and their performance requirements. We also present examples of protein cancer biomarkers currently in clinical use and their limitations. The major barriers that candidate biomarkers need to overcome to reach the clinic are addressed. Finally, the long and arduous journey of a protein cancer biomarker from the bench to the clinic is outlined with an example.

SUMMARY

The journey of a protein biomarker from the bench to the clinic is long and challenging. Every step needs to be meticulously planned and executed to succeed. The history of clinically useful biomarkers suggests that at least a decade is required for the transition of a marker from the bench to the bedside. Therefore, it may be too early to expect that the new technological advances will catalyze the anticipated biomarker revolution any time soon.

SERPINE1 intron polymorphisms affecting gene expression are associated with diffuse-type gastric cancer susceptibility

BACKGROUND

A primary inhibitor of plasminogen activators, SERPINE1 (serpin peptidase inhibitor 1, clade E, member 1, also known as plasminogen activator inhibitor type 1), is an important regulator in tumorigenesis and is highly expressed in many cancers.

METHODS

Five tag single nucleotide polymorphisms (SNPs) and 1 insertion polymorphism within SERPINE1 were genotyped in 1101 unrelated Korean individuals (a case group of 612 patients with gastric cancer and a control group of 489 healthy individuals). Associations with susceptibility to diffuse-type gastric cancer (DGC) and intestinal-type gastric cancer were assessed using multivariate logistic regression analyses adjusted for age and sex. Allelic differences in the contribution to gene expression were measured using luciferase assays.

RESULTS

SNP c.1162+162C>T (rs2227692) in intron 7 was associated with susceptibility to DGC but not with susceptibility to intestinal-type gastric cancer. The minor allele-carrying genotypes C/T and T/T had 1.6-fold greater odds of DGC than the C/C genotype (P = .00084). This SNP was linked to a repeat-number variation c.1162+604AAAG(11_17), a deletion (del) variation c.1162+664_1162+673del, and another SNP c.1162+859T>A (rs2070683) in intron 7 based on the sequencing of 5 patients and 5 controls. The risk haplotype of the 4 variations exhibited a 30% greater gene expression level than the nonrisk haplotype in luciferase reporter assays (P = .025). In contrast, DGC susceptibility was not associated with the c.-1969_-1968insG polymorphism (rs1799768) in the promoter, commonly known as 4G/5G, in which the minor 5G allele is less active in transcription than the major 4G allele.

CONCLUSIONS

An association between SERPINE1 and DGC susceptibility was observed with 4 correlated polymorphisms in intron 7 rather than the 4G/5G polymorphism in the promoter, although all polymorphisms affected gene expression.

uPA and PAI-1 in breast cancer: review of their clinical utility and current validation in the prospective NNBC-3 trial

The plasminogen activator system is a complex system with multiple interactions and members participating in fibrinolysis, cell migration, angiogenesis, wound healing, embryogenesis, tumor cell dissemination, and metastasis in a variety of solid tumors. Increased levels of uPA and/or PAI-1 in primary tumor tissues of breast cancer patients correlate with tumor aggressiveness and poor clinical outcome. Patients with high tumor tissue antigen content of uPA and/or PAI-1 have a worse probability of disease-free and overall survival than patients with low levels of both of the biomarkers, serving as prognostic markers. The clinical utility of uPA and PAI-1 has been proven on the highest level of evidence (LOE-I). Next to being clinically useful prognostic factors allowing estimates of the course of disease in early breast cancer, uPA and PAI-1 may also serve as predictive factors predicting response to systemic therapy. Node-negative primary breast cancer patients with high uPA/PAI-1 levels benefit significantly from adjuvant chemotherapy. The aim of the ongoing NNBC-3 trial is to determine the benefits of a sequential anthracycline-docetaxel regimen in high-risk node-negative breast cancer patients compared to the current standard of anthracycline-based chemotherapy. At present, uPA and PAI-1 provide the unique opportunity to allow validated and clinically relevant risk assessment of breast cancer patients, over and above that provided by established risk factors. Therefore, in the evidence-based, annually updated AGO guidelines for breast cancer management, the German Working Group for Gynecological Oncology (AGO) has recommended both biomarkers as risk-group-classification markers for routine clinical decision making in node-negative breast cancer, next to established clinical and histomorphological factors.

The plasminogen activator inhibitor "paradox" in cancer

Proteolysis in general and specifically the plasminogen activating system regulated by urokinase (uPA) its specific receptor, the GPI membrane anchored urokinase receptor (uPAR) and the specific plasminogen activator inhibitor 1 (PAI-1) plays a major role in tumorigenesis, tumor progression, tumor invasion and metastasis formation. This is exemplified by a body of published work showing a positive correlation between the expression of uPA or uPAR in several tumors and their malignancy. It is generally assumed that such a "pro-malignant" effect of the uPA-uPAR system is mediated by increased local proteolysis thus favoring tumor invasion, by a pro-angiogenic effect of this system and also by uPA-uPAR signaling towards the tumor thereby shifting the tumor phenotype to a more "malignant" one. However, when tumor patients are analyzed for long term survival, those with high levels of the inhibitor of the system, PAI-1 have a much worse prognosis than those with lower PAI-1 levels. This indicates that increased overall proteolysis alone cannot be made responsible for the adverse effects of the plasminogen activating system in tumors. Moreover, it becomes increasingly evident that components of the fibrinolytic system secreted by the tumor cells themselves are not solely responsible for a correlation between the plasminogen activating system and tumor malignancy; components of the plasminogen activating system secreted by stroma cells or cells of the immune system such as macrophages contribute also to the impact of fibrinolysis on malignancy. This review summarizes the evidence for the role of plasminogen activator inhibitor-1 in mediating the malignant phenotype and possible mechanism thereby trying to explain the "PAI-1 paradox in cancer" on a molecular level.

Tumor-associated proteolytic factors uPA and PAI-1: critical appraisal of their clinical relevance in breast cancer and their integration into decision-support algorithms

This review considers the past, present, and projected future clinical relevance of the serine protease urokinase-type plasminogen activator (uPA), and its inhibitor, plasminogen activator inhibitor-type 1 (PAI-1), in breast cancer. These factors play a key role in tumor invasion and metastasis in many cancers. In primary breast cancer, their prognostic and predictive impact has been validated at the highest level of evidence by a multicenter therapy trial (Chemo N0) and a large European Organisation for Research and Treatment Cancer-Receptor and Biomarker Group EORTC RBG pooled analysis (n = 8377). The greatest clinical use is in node-negative breast cancer, where the test can avoid over-treatment by adjuvant chemotherapy in patients with non-aggressive disease. In intermediate-risk patients as defined by the international St. Gallen consensus, it can be used to identify patients who should receive chemotherapy because their tumor is more aggressive than classical pathological factors would suggest. Gene expression signatures are already being used in clinical trials to define the population of patients with breast cancer who should receive chemotherapy. The decision for treatment ignores the highly validated information that could be provided by uPA/PAI-1. A current and future challenge is to integrate the information provided by tumor biological factors, particularly uPA/PAI-1, into refined risk assessment and decision support algorithms incorporating gene expression signatures. This article describes a paradigm ("marker fusion") for doing so and a bioinformatics approach based on this paradigm. This concept could be useful in assessing and maximizing the performance of risk assessment and the quality of therapeutic indications.