Measurement of plasminogen activator system components in plasma and tumor tissue extracts obtained from patients with breast cancer: an EORTC Receptor and Biomarker Group collaboration

The plasminogen activator (PA) system comprises the 2 serine proteases, urokinase PA (uPA) and tissue PA (tPA), the 2 serpin inhibitors, PAI-1 and PAI-2 and the uPA receptor (uPAR; CD87). High levels of uPA, PAI-1, uPA-PAI-1 complex and uPAR in breast cancer tissue are associated with poor prognosis, while high levels of tPA or PAI-2 correlate with good prognosis. In this study, pre-operative plasma levels of uPA, PAI-1, uPAR, tPA, uPA-PAI-1 complex, and tPA-PAI-1 complex were measured in patients with benign (n=103) and malignant breast disease (n=113) by immunoenzymatic assays (ELISA). While plasma antigen levels of uPA, PAI-1, uPA-PAI-1 complex and uPAR were not significantly different in the 2 groups, antigen levels of tPA and tPA-PAI-1 complex were significantly higher in patients with breast carcinoma compared to the control group. In plasma from the breast cancer patients, uPA levels correlated weakly but significantly with those of tPA (r=0.20, p=0.035) and uPAR (r=0.208, p=0.028). tPA levels correlated strongly with tPA-PAI-1 complex (r=0.972, p=0.0001) while uPA-PAI-1 levels were significantly associated with PAI-1 levels (r=0.534, p<0.0001), tPA levels (r=0.348, p=0.0003) and tPA-PAI-1 levels (r=0.356, p=0.002). However, no significant correlation was found between plasma and tumor tissue levels of uPA, PAI-1, uPA-PAI-1 complex, tPA or tPA-PAI-1. Our findings indicate that determination of these factors in plasma do not reflect their concentration in tumor tissue. Therefore, measurement of PA components in blood cannot be recommended for assessing prognosis in breast cancer.     

Larger and more invasive colorectal carcinoma contains larger amounts of plasminogen activator inhibitor type 1 and its relative ratio over urokinase receptor correlates well with tumor size

BACKGROUND: Considering recent findings that both urokinase plasminogen activator receptor (uPAR) and plasminogen activator inhibitors (PAIs) are involved in tumor growth through an urokinase-type plasminogen activator (uPA) activity-independent mechanism, the relation between the presence of these factors in tumor tissue and the clinicopathologic variables in colorectal carcinoma was reevaluated. METHODS: In 100 colorectal carcinoma patients, antigen levels of u-PA, uPAR, and PAI-1 and PAI-2 were assayed in both tumor tissues and their normal counterparts. Plasma levels of soluble uPAR also were determined. RESULTS: All uPAR, uPA, PAI-1, and PAI-2 antigen levels in tumor tissue were significantly higher than those in normal tissue. Levels of both uPAR and PAI-1 were significantly higher (3.09 +/- 1.37 and 6.63 +/- 7.49, respectively) in large tumors (>/=50 mm in greatest dimension) than those in smaller tumors (< 50 mm) (2.50 +/- 1.07 and 2.72 +/- 2.70, respectively) (P < 0.05). Significant positive correlation coefficients (r) were obtained between tumor size and the calculated ratios of PAI-1/uPAR (r = 0.490; P < 0.0001) and PAI-1/uPA (r = 0. 469; P < 0.0001). In addition to liver metastases (P = 0.004) and lymph node involvement (P = 0.04), high levels of uPAR (P = 0.05) also were found to be of independent prognostic value by multivariate analysis. CONCLUSIONS: Higher expression of uPAR was related to poor prognosis of patients with colorectal carcinoma and excess amounts of PAI-1 over uPAR or uPAR-bound uPA appeared to play an important role in tumor progression.     

Correlation of tissue and blood plasminogen activation system in breast cancer

The plasminogen activation system plays a crucial role during cancer invasion and metastasis. In the solid tumor, urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor type-1 (PAI-1) and uPA receptor (uPAR) are considered as prognostic factors. In this study, we have investigated whether secretion of the uPA, PAI-1 and uPAR from the primary breast cancer tissue can be detected in the blood of the patients using the ELISA assay. We have found that the plasminogen activation system (uPA, PAI-1, uPAR) of tumor tissue is activated from the early stage of breast cancer. However, only a number of metastatic lymph nodes was a prognostic factor in multivariate analysis for relapse. The blood level of the plasminogen activation system correlated with that of tissue in an order of uPAR (r²=0.61; P=0.001), uPA (r²=0.35; P=0.001) and PAI-1 (r²=0.11; P=0.001). We conclude that the total uPAR level of cancer tissue can be substituted by that which is detected in the blood for further clinical applications.     

Urokinase plasminogen activator system gene expression is increased in human breast carcinoma and its bone metastases — A comparison of normal breast tissue, non-invasive and invasive carcinoma and osseous metastases

The urokinase plasminogen activator (uPA) system has been widely associated with the development of breast carcinoma. However, the role of the urokinase pathway in the development of osseous breast cancer metastases has been largely overlooked. We studied the expression of uPA, urokinase plasminogen activator receptor (uPAR) and plasminogen activator inhibitor type-1 (PAI-1) in human breast carcinomas and their bone metastases, using in situ hybridisation. Studies were performed using paraffin-embedded tissue from 13 ductal carcinomas, 23 invasive ductal carcinomas, five normal breasts and 25 bone metastases. The majority of the tumours examined expressed low to moderate levels of uPA mRNA and low to high levels of uPAR and PAI-1 mRNA, which was predominantly localised to the epithelial tumour cells. There was slight over-expression of uPA and PAI-1 mRNA and a marked increase in uPAR mRNA expression in the malignant tumours compared with benign tissue. Overall, uPAR and PAI-1 mRNA expression was found to be more variable than uPA mRNA, suggesting a possible role of the receptor and inhibitor in the regulation of uPA activity. Increased 1(I) procollagen (COL) and osteopontin (OPN) mRNA expression was detected, primarily in the stromal cells, in malignant tumours compared with the benign tissue. The increased expression of the components of the uPA system on the epithelial tumour cells may account for the activation of the proteolytic cascade that occurs during breast cancer metastasis to bone. Furthermore, the over-expression of COL and OPN suggests a possible interaction between these matrix proteins and the uPA system.     

Prognostic value of the urokinase-type plasminogen activator,and its inhibitors and receptor in breast cancer patients

Urokinase-type plasminogen activator (uPA), its inhibitors (PAI-1 and PAI-2), and its receptor (uPAR) play a key role in tumor invasion and metastasis. This study was designed to evaluate the prognostic impact of uPA, PAI-1, PAI-2, and uPAR and the combination of these factors in a group of 460 primary breast cancer patients. Concentrations of all 4 components of the uPA system were measured in tumor extracts using enzyme-linked immunosorbent assays (American Diagnostica, Inc, Greenwich, CT). After a median follow-up of 33 months, 18.5% of the patients had relapsed. The Cox proportional hazards model was applied for both univariate and multivariate analyses of disease-free survival (DFS). PAI-1 and PAI-2 were shown to provide independent prognostic information in breast cancer. Patients with either low levels of PAI-1 or high levels of PAI-2 were found to have better DFS (relative risk was 2.08 and 1.78, respectively). The prognostic value could be even further improved by a combination of both inhibitors. Aside from the uPA inhibitors, only nodal status and hormonal receptor status retained independent prognostic value. The other 2 invasion markers, uPA and uPAR, showed no statistically significant impact on DFS. In our patients, who were mostly treated with adjuvant therapy, uPA was not found to be an independent prognostic marker for DFS; this could be a consequence of the predictive value of uPA for response to adjuvant therapy and should be further investigated.     

非霍奇金淋巴瘤外周血尿激酶型纤溶酶原激活物及其受体测定的临床意义

 目的 研究非霍奇金淋巴瘤（NHL）患者血中尿激酶型纤溶酶原激活物（uPA）、尿激酶型纤溶酶原激活物受体（uPAR）、纤溶酶原激活剂抑制物-1（PAI-1）水平与NHL发生、发展及预后的关系。方法 采用ELISA方法检测38例初治NHL患者血中uPA,uPAR 及PAI-1水平,分析与不同临床分期、治疗效果、乳酸脱氢酶（LDH）的相关性。结果 NHL患者血uPA,uPAR及PAI-1水平均高于正常对照组（P＜0.05）, NHL患者LDH值增高组与LDH正常组比较uPAR增高（P＜0.05）,uPA,uPAR与LDH三者之间呈正相关（P＜0.01）。结论 uPA及可溶性uPA 受体（suPAR）在NHL的发生、发展中起作用,suPAR可以作为判断NHL肿瘤负荷和预后的指标。     

Physiological and pathological changes of plasma urokinase-type plasminogen activator, plasminogen activator inhibitor-1, and urokinase-type plasminogen activator receptor levels in healthy females and breast cancer patients

The plasma urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and urokinase-type plasminogen activator receptor (uPAR) levels were measured in healthy volunteers and breast cancer patients. In pre-menopause healthy females, blood was sampled weekly during one menstruation cycle and menstruation phases (follicular, ovulatory, luteal) were determined by FSH/LH levels. uPA, PAI-1, and uPAR levels were at the nadir during ovulatory phase. uPA level was highest at follicular phase while PAI-1 level was highest at luteal phase. In comparison between pre- and post-menopause states, uPA and uPAR levels were higher in post-menopause state while PAI-1 level was higher in pre-menopause state. In breast cancer patients, uPA, PAI-1, and uPAR positive rates were low when we use the menopause-state-unmatched cut-off points. As we adjusted the cut-off points by menopause states, the PAI-1 positivity increased mainly in post-menopause cancer patients. These findings suggest that there is a minor but possible sequential change of these molecules during menstruation cycle which might blur the pathological positivity in pre-menopause cancer patients. The pathological elevation of PAI-1 was well detected in post-menopause cancer patients, but this elevation did not correlate with tumor burden such as number of metastatic sites or metastatic location. In conclusion, adjustment of physiological changes of uPA, PAI-1, and uPAR is required in determining pathological elevation of the plasma levels in cancer patients, especially in females.This revised version was published online in October 2005 with corrections to the Cover Date.     

Enhanced benefit from adjuvant chemotherapy in breast cancer patients classified high-risk according to urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (n = 3424)

Risk assessment and prediction of response to treatment are prerequisites for individualized adjuvant therapy decisions in breast cancer. The strong prognostic impact of the two invasion factors urokinase-type plasminogen activator (uPA) and its inhibitor, plasminogen activator inhibitor type 1 (PAI-1), in breast cancer has recently been validated at level-I evidence. This article considers the predictive impact of uPA/PAI-1 on response to adjuvant chemo- and endocrine therapy in 3424 primary breast cancer patients from two different data sets. uPA and PAI-1 antigen levels were measured by ELISA in primary tumor tissue extracts. After a median follow-up of 83 months, uPA/PAI-1 has a significant impact on disease-free survival in Cox multivariate analysis (P < 0.001; hazard ratio, 2.0; 95% confidence interval, 1.8-2.3). Patients with high uPA/PAI-1 levels benefit more strongly from adjuvant chemotherapy than those with low levels. This effect is seen as a significant interaction between chemotherapy and uPA/PAI-1 for the entire collective (P < 0.003; hazard ratio, 0.68; 95% confidence interval, 0.53-0.88) and separately within nodal subgroups. This enhanced benefit in the high uPA/PAI-1 patients occurs over and above the significant impact of both therapies in all patients. We find no corresponding significant interaction between endocrine therapy and uPA/PAI-1; i.e., no significant difference in benefit between patients with high and low uPA/PAI-1. In conclusion, uPA and PAI-1 levels in primary tumor tissue provide clinically relevant information on relapse risk and treatment response that will help to tailor adjuvant therapy concepts in breast cancer, accounting for individual biological tumor characteristics.     

Urokinase receptor and vascular endothelial growth factor are synergistically associated with the liver metastasis of colorectal cancer.

Considering recent findings that the urokinase plasminogen activation (PA) system is involved in invasion and vascular endothelial growth factor (VEGF) is involved in angiogenesis of colorectal cancer, we evaluated these factors in the liver metastasis of primary colorectal cancer. Cancer tissues from 71 colorectal cancer patients were assayed quantitatively for antigen levels of urokinase type plasminogen activator (uPA), uPA receptor (uPAR), and plasminogen activator inhibitor-1 and -2 (PAI-1, PAI-2), and were also assayed immunohistochemically for expression of VEGF protein. Among the PA system factors, both the levels of uPAR and PAI-1 were significantly higher in larger tumors than in smaller ones, and were also significantly higher in tumors that invaded subserosa, serosa or adjacent organs than in mucosal, submucosal tumors or in tumors that invaded the muscle layer. The uPAR levels were significantly higher in tumors with liver metastasis than in those without. VEGF overexpression was significantly more frequent in tumors with lymph node involvement or liver metastasis than in those without. Among the PA system factors, the uPAR levels were significantly higher in tumors with VEGF overexpression and a multivariate analysis revealed that high uPA level and VEGF overexpression were independent risk factors for liver metastasis. The combination of high uPAR level and overexpression of VEGF was associated with the worst prognosis in patients with colorectal cancer. These results suggest that uPAR and VEGF might contribute synergistically to the liver metastasis of colorectal cancer.     

Plasminogen activator inhibitor type 2 in breast cancer.

The serine protease urokinase plasminogen activator (uPA) is causally involved in cancer invasion and metastasis. Activity of this protease in vivo is controlled principally by two inhibitors, one of which is plasminogen activator inhibitor type 2 (PAI-2). In this study, we show that PAI-2 levels were significantly higher in primary breast carcinomas (n = 152) than benign breast tumours (n = 18). In the primary cancers, PAI-2 levels correlated weakly but significantly with those of uPA and PAI-1, but not with tissue type plasminogen activator (tPA) or uPA receptor (uPAR) levels. Using Northern blotting, mRNA for PAI-2 was found in 28.6% of 49 primary breast cancers. In contrast to findings at the protein level, PAI-2 mRNA levels failed to correlate with those for uPA or PAI-1. After immunocytochemistry with primary cancers, PAI-2 was detected predominantly in the malignant cells of primary carcinomas but was also present in stromal cells. Using the median value as a cut-off point, PAI-2 showed no significant relationship with either disease-free interval or overall survival. However, using an optimum cut-off value, patients with low levels of PAI-2 had a worse outcome than those with a high level. We conclude that, unlike PAI-1, high levels of PAI-2 may be a favourable prognostic marker in breast cancer.     

High tumor tissue concentration of plasminogen activator inhibitor 2 (PAI-2) is an independent marker for shorter progression-free survival in patients with early stage endometrial cancer.

Previous studies including various tumor types have shown different associations between tumor tissue levels of plasminogen activator inhibitor 2 (PAI-2) and patient survival. High tumor tissue concentrations of PAI-2 have been associated with good prognosis in patients with breast cancer, small cell lung cancer and ovarian cancer, but with poor histologic differentiation and poor prognosis in patients with colorectal cancer. On the other hand, high tumor tissue concentrations of urokinase plasminogen activator (uPA), uPA receptor (R) and PAI-1 have more consistently been associated with poor histologic differentiation and poor prognosis. Our study quantified PAI-2 and uPAR using specific enzyme-linked immunosorbent assays in homogenates of 274 samples of endometrial cancer tissue. The prognostic power of each factor was analyzed in the subgroup of patients with early stage disease, i.e., International Federation of Gynecology and Oncology (FIGO) surgical stage I-II (n = 188). This group had a median follow-up time of 6.8 years (range 0.7-9.9), and 23 progressions were observed. The 80(th) percentile for PAI-2 and uPAR was used to dichotomize the material, and the results were analyzed for associations with clinical data including progression-free survival. The results were also compared with DNA ploidy status, S-phase fraction, uPA and PAI-1, which we reported in a previous study (Fredstorp Lidebring et al., Eur J Cancer 2001; in press). A high PAI-2 level was associated with shorter progression-free survival in univariate analysis and was an independent prognostic factor in bivariate analyses, which included PAI-1, uPA and DNA ploidy status. In contrast, a high level of uPAR had no association with prognosis in early stage endometrial cancer. The combination of high PAI-2 and PAI-1 levels in tumors revealed a small group of stage I-II patients with an accumulative progression rate of 50%.     

Urokinase Receptor and Vascular Endothelial Growth Factor Are Synergistically Associated with the Liver Metastasis of Colorectal Cancer

Considering recent findings that the urokinase plasniinogen activation (PA) system is involved in invasion and vascular endothelial growth factor (VEGF) is involved in angiogenesis of colorectal cancer, we evaluated these factors in the liver metastasis of primary colorectal cancer. Cancer tissues from 71 colorectal cancer patients were assayed quantitatively for antigen levels of urokinase type plasminogen activator (uPA), uPA receptor (uPAR), and plasminogen activator inhibitor-1 and -2 (PAI-1, PAI-2), and were also assayed immunohistochemically for expression of VEGF protein. Among the PA system factors, both the levels of uPAR and PAI-1 were significantly higher in larger tumors than in smaller ones, and were also significantly higher in tumors that invaded subserosa, serosa or adjacent organs than in mucosal, submucosal tumors or in tumors that invaded the muscle layer. The uPAR levels were significantly higher in tumors with liver metastasis than in those without. VEGF overexpression was significantly more frequent in tumors with lymph node involvement or liver metastasis than in those without. Among the PA system factors, the uPAR levels were significantly higher in tumors with VEGF overexpression and a multivariate analysis revealed that high uPA level and VEGF overexpression were independent risk factors for liver metastasis. The combination of high uPAR level and overexpression of VEGF was associated with the worst prognosis in patients with colorectal cancer. These results suggest that uPAR and VEGF might contribute Synergistically to the liver metastasis of colorectal cancer.     

Predictive impact of urokinase-type plasminogen activator: plasminogen activator inhibitor type-1 complex on the efficacy of adjuvant systemic therapy in primary breast cancer

One of the most thoroughly studied systems in relation to its prognostic relevance in patients with breast cancer, is the plasminogen activation system. This system comprises of, among others, the urokinase-type plasminogen activator (uPA) and its main inhibitor (PAI-1). In this study we investigated whether the uPA:PAI-1 complex is associated with the responsiveness of patients with primary breast cancer to adjuvant systemic therapy. Quantitative enzyme-linked immunosorbent assays were used to assess the levels of uPA, PAI-1, and uPA:PAI-1 complex in 1119 tumors of patients with primary invasive breast cancer. These patients were followed for a median follow-up time of 59 months (range, 2-267 months) after the primary diagnosis. Correlations with well-known clinicopathological factors, and univariate and multivariate survival analyses were performed. High uPA:PAI-1 complex levels were correlated with an adverse histological grade, and inversely associated with negative estrogen and progesterone receptor status. High tumor levels of uPA:PAI-1 complex predicted an early relapse in the univariate relapse-free survival analysis (P < 0.001). The multivariate analysis showed that high uPA:PAI-1 complex levels were associated with a decreased relapse-free survival time (P = 0.033), independently of age, tumor size, number of lymph nodes affected, progesterone receptor status, uPA, adjuvant endocrine, and chemotherapy. More important, it was demonstrated that there is a larger benefit from adjuvant chemotherapy for patients with higher versus lower tumor levels of uPA:PAI-1 complex. The results of this study imply that the expression of uPA:PAI-1 complex independently predicts the efficacy of adjuvant chemotherapy in patients with primary breast cancer.     

Clinical relevance of biologic factors in male breast cancer

There is ample information on the clinical role of biologic factors in female breast cancer: urokinase-type plasminogen activator (uPA), its receptor uPAR, its inhibitors PAI-1 and PAI-2, cathepsin D and pS2-protein. However such reports are missing or very rare for male breast cancer. We determined the cytosolic levels of oestrogen receptor (ER), progesterone receptor (PgR), cathepsin D, pS2-protein, uPA, uPAR, PAI-1 and PAI-2 of the primary tumour tissues from 40 male breast cancer patients. The tumour levels were compared with those of 180 matched females and 4114 historic females with breast cancer. In male breast tumours the level of PgR was higher, those of uPA, PAI-1, PAI-2 and cathepsin D lower. The tumour level of ER in men was similar to those in the matched and postmenopausal women, but much higher than those in the historic women. Male breast cancer seems to be biologically different from female breast cancer. Correlation of the eight cell biologic factors with disease outcome showed that PAI-1 (p=0.03) was the only independent predictive factor for poor prognosis in male breast cancer.     

Dissemination risk index based on plasminogen activator system components in primary breast cancer.

PURPOSE: To study interactions between disease-free survival (DFS) and four components of the plasminogen activator system: urokinase-type plasminogen activator (uPA), its two inhibitors (PAI-1 and PAI-2), and its membrane receptor uPAR. PATIENTS AND METHODS: We conducted a retrospective study of 499 primary breast cancer patients (median follow-up, 6 years). uPA, PAI-1, and PAI-2 were determined on cytosols and uPAR on solubilized pellets, using enzyme-linked immunoadsorbent assay kits (American Diagnostica, Greenwich, CT). Classical univariate and multivariate statistical methods were used together with multiple correspondence analysis to graphically examine interactions between the variables and outcome. RESULTS: By univariate analysis, higher uPA and PAI-1 values were significantly related to shorter DFS (P =.002; P <.00002). PAI-2 was not significantly related to DFS, although patients with high and very low PAI-2 values had a longer DFS. Multiple correspondence analysis showed the parallel impact of uPA and PAI-1 on outcome, and the clearly different behavior of PAI-2 compared with PAI-1. The prognostic contribution of uPAR seemed weak by both methods. A dissemination risk index [uPA x PAI-1/(PAI-2 + 1)], taking into account the modulation of uPA proteolytic activity by the ratio of its two inhibitors, was then tested. Dissemination risk index was selected as an independent variable in the Cox model in the overall population (P <.000001) and in node-positive patients (P <.00001). It was the only variable selected in node-negative patients (P =. 003). CONCLUSION: A dissemination risk index determined on primary tumor and taking into account the different effects of PAI-1 and PAI-2 on uPA can be of major help in clinical management of breast cancer, particularly in node-negative patients.     

Urokinase-type plasminogen activator system and breast cancer (Review)

Malignant tumors have a capacity to degrade the extracellular matrix (ECM) by controlled proteolysis. One proteolytic system involved in these processes is the urokinase-type plasminogen activator (uPA) system, which consists of uPA, uPA receptor (uPAR) and uPA inhibitors 1 and 2 (PAI-1 and PAI-2). In the past two decades, study of the uPA system in human breast cancer has yielded valuable insights. Increased levels of uPA, PAI-1 and uPAR have been reported to be associated with poor prognosis in patients with breast cancer. Furthermore, uPA and PAI-1 may be new prognostic markers for axillary node-negative patients. To date, a growing body of evidence has suggested that uPA system promotes tumor metastasis by several different mechanisms, not just by breaking down the ECM. This article is focused on reviewing the current understanding of uPA system members as prognostic markers in breast cancer, and their cellular localization and tissue distribution. Correlations of the uPA system with other informative markers of breast cancer are also discussed.     

Prognostic significance of PAI-1 and uPA in cytosolic extracts obtained from node-positive breast cancer patients

Cancer cell invasion is accomplished by the concertedaction of several extracellular proteolytic enzyme systems, oneof which is the urokinase plasminogen activation system.The different components of this system, e.g. urokinaseplasminogen activator (uPA), its receptor uPAR, as wellas its main inhibitor plasminogen activator inhibitor type1 (PAI-1) have all been shown to haveprognostic value in breast cancer, i.e. high tumorlevels are associated with a poor prognosis.In orderto further substantiate the prognostic value of uPAand PAI-1, we have tested the cutpoints (medianvalues and optimized cutpoints) from our first study(Cancer Res 53: 2513–2521, 1993) in an independentgroup of breast cancer patients. Breast cancer cytosolsfrom 100 premenopausal and 150 post-menopausal node positivepatients were included. The median observation time was80 months (range 49–145). Univariate analysis showed thathigh PAI-1 levels (above the median PAI-1 value)were significantly associated with short recurrence-free survival (RR:1.65; 95% CI: 1.04–2.63; P=0.03) andshort overall survival (RR: 2.46; 95% CI: 1.52–3.96;P=0.0001) in postmenopausal patients. Postmenopausal patientswith high uPA levels (above the median uPAvalue) had a significantly shorter recurrence-free survival (RR:2.04; 95% CI: 1.17–3.56; P=0.01) andoverall survival (RR: 2.07; 95% CI: 1.16–3.70; P= 0.01) than patients with low uPA values.Nearly identical results were obtained when using theoptimized PAI-1 or uPA value.In a Cox multivariateanalysis which included other established prognostic factors, highPAI-1 was found to be an independent prognosticvariable predicting short overall survival with a relativerisk of 2.27 in postmenopausal women, and highuPA was found to be an independent prognosticvariable predicting short recurrence-free survival with a relativerisk of 1.86 in postmenopausal women. The presentstudy indicates that uPA and PAI-1 are independentand significant prognostic variables in subsets of breastcancer patients.     

Urokinase-type plasminogen activator and its inhibitor type 1 predict disease outcome and therapy response in primary breast cancer

Combined determination of urokinase-type plasminogen activator (uPA) and its inhibitor, activator inhibitor type 1 (PAI-1), supports risk-adapted individualized therapy concepts, particularly in node-negative breast cancer. The prognostic impact of both factors in primary breast cancer was substantiated by a pooled analysis of > 8000 patients with breast cancer and a multicenter prospective randomized therapy trial in node-negative breast cancer; findings achieved the highest level of evidence for tumor biomarkers. Patients with node-negative breast cancer with low antigen levels of uPA and PAI-1 in their primary tumor tissue have a very good prognosis and therefore may be spared the burden of adjuvant chemotherapy, whereas those with elevated uPA/PAI-1 antigen levels carry an increased risk of disease recurrence. Recent retrospective analysis of > 3000 patients indicated that patients with breast cancer with high uPA/PAI-1 values derive a significantly greater benefit from adjuvant chemotherapy than patients with low uPA/PAI-1 levels. Similarly, in the multicenter prospective Chemo N0 trial, administration of cyclophosphamide/methotrexate/5-fluorouracil-based chemotherapy led to a substantial reduction in risk of disease recurrence in patients with high uPA/PAI-1. However, benefit from adjuvant endocrine therapy appears to be independent of a patient's uPA/PAI-1 status. In metastatic breast cancer, retrospective studies showed that elevated uPA or PAI-1 present in the primary tumor tissue are associated with a poor response to later palliative endocrine therapy. These findings suggest that high levels of uPA and/or PAI-1 do reflect an aggressive phenotype that may be overcome or suppressed by early systemic therapy in the adjuvant setting but may be too advanced for response to palliative therapy at a later stage.     

High tumor tissue concentration of urokinase plasminogen activator receptor is associated with good prognosis in patients with ovarian cancer

The urokinase plasminogen activator (uPA) system is involved in tumor growth and metastasis. We assayed the components of the uPA system in homogenates of 64 primary epithelial ovarian tumors and 5 metastases and evaluated the association of these parameters to prognosis in the 51 malignant cases. The levels of uPA, PAI-2 and the uPA:PAI-1 complex increased with progressive loss of histological differentiation (p(trend) <0.001, <0.05 and <0.001). The level of PAI-1 was higher in poorly than in well/moderately differentiated tumors (p = 0.03). The content of uPAR was lower in benign tumors as compared to borderline malignancies (p = 0.002), invasive primary tumors (p < 0.001), and metastases (p = 0.002). Surprisingly, the level of uPAR was lower in poorly differentiated as compared to both borderline (p = 0.01) and well differentiated malignant tumors (p = 0.005). Also, the level of uPAR was lower in advanced as compared to early stages of the disease (p(trend) = 0.002). The median follow-up time for patients was 5.8 years. High tumor tissue levels of uPAR were associated with longer postoperative survival (HR = 0.4, 95% CI = 0.2-0.8, p = 0.01). In contrast, shorter survival was evident in patients with high tumor levels of uPA from 2 years on after operation (HR = 4.6, 95% CI = 1.2-17, p = 0.02). High tPA levels tended to be associated with shorter overall survival after 2 years (HR = 2.9, 95% 95% CI = 0.9-9.8, p = 0.08). Although high tumor tissue content of uPAR was associated with a less aggressive phenotype characterized by well differentiated histology and longer survival, low content of uPAR in the poorly differentiated tumors and metastases presumably results from increased elimination of uPAR.     

Prognostic significance of uPA and uPAR expression in patients with cervical cancer undergoing radiotherapy

Cervical cancer remains a major health threat. Urokinase serves as a marker of metastatic tumors. The present study aimed to determine whether the expression levels of urokinase plasminogen activator (uPA) and urokinase plasminogen activator receptor (uPAR), before and during the course of radiotherapy, serve as prognostic markers for patients with cervical cancer. Cervical tumor tissue biopsies were collected from 72 patients before radiotherapy and after the completion of external beam radiotherapy (EBRT) before intracavitary brachytherapy. The levels of uPA and uPAR were determined using ELISA assays. The significance of the associations between the protein expression levels and the clinical outcomes of patients was determined. Although irradiation enhanced uPA and uPAR expression in cervical cancer cell lines, average uPA levels significantly decreased in tumors, and uPAR levels significantly increased after EBRT. The levels of uPA increased in 12 patients and decreased in 26 patients; and those of uPAR increased in 13 patients and decreased in two patients. Cox regression analysis revealed that increased expression of uPAR was significantly associated with 5-year overall survival rate [hazard ratio (HR), 3.65; 95% confidence interval (CI), 1.18–11.30]. However, the levels of both proteins before radiotherapy failed to predict clinical outcomes. Other significant predictive factors were partial response (HR 7.22; 95% CI 1.17–44.73) and disease progression (HR, 13.41; 95% CI, 1.17–153.07). These findings indicated that increased expression of uPAR in cervical tumor tissue during radiotherapy may serve as a prognostic marker for patients with cervical cancer.