Multiparametric prognostic evaluation of biological factors in primary breast cancer

Association of uPA and PAI-1 tumor levels and 4G/5G variants of PAI-1 gene with disease outcome in luminal HER2-negative node-negative breast cancer patients treated with adjuvant endocrine therapy

BACKGROUND

The aim of this study was to evaluate the prognostic potential of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) tumor tissue levels and examine the association between these biomarkers and classical prognostic factors in early node-negative luminal breast cancer patients. The clinical value of 4G/5G variants of PAI-1 gene was evaluated.

PATIENTS AND METHODS

This study involved 81 node-negative, estrogen receptor-positive and/or progesterone receptor-positive and human epidermal growth factor receptor 2-negative operable breast cancer patients who underwent radical surgical resection and received adjuvant endocrine therapy. Determination of uPA and PAI-1 concentrations in the breast cancer tissue extracts was performed using FEMTELLE® uPA/PAI-1 ELISA. An insertion (5G)/deletion (4G) polymorphism at position - 675 of the PAI-1 gene was detected by PCR-RFLP analysis.

RESULTS

Our research showed that patients with uPA tumor tissue levels higher than 3 ng/mg of protein had significantly reduced disease-free survival (DFS) and overall survival (OS) when compared to patients with uPA tumor tissue levels lower or equal to 3 ng/mg of protein. Patients with PAI-1 tumor tissue levels higher than 14 ng/mg of protein had significantly decreased OS in comparison with patients with PAI-1 tumor tissue levels lower or equal to 14 ng/mg of protein. ROC analysis confirmed the uPA and PAI-1 discriminative potential for the presence/absence of relevant events in these patients and resulted in higher cut-off values (5.65 ng/mg of protein for uPA and 27.10 ng/mg of protein for PAI-1) than standard reference cut-off values for both biomarkers. The prognostic importance of uPA and PAI-1 ROC cut-off values was confirmed by the impact of uPA higher than 5.65 ng/mg of protein and PAI-1 higher than 27.10 ng/mg of protein on poorer DFS, OS and event-free survival (EFS). We observed that patients with dominant allele in PAI-1 genotype (heterozygote and dominant homozygote, - 675 4G/5G and - 675 5G/5G) had significantly increased DFS, OS and EFS when compared with patients with recessive homozygote genotype (- 675 4G/4G).

CONCLUSION

Our study indicates that uPA and PAI-1 tumor tissue levels and 4G/5G variants of PAI-1 gene might be of prognostic significance in early node-negative luminal HER2-negative breast cancer patients treated with adjuvant endocrine therapy.

A Sensitive and Robust Assay for Urokinase and Tissue-Type Plasminogen Activators (Upa and Tpa) and Their Inhibitor Type I (Pai-1) in Breast Tumor Cytosols

uPA and PAI-1 are becoming established as amongst the most effective markers of poor prognosis for patients with node-negative breast cancer; tPA is an index of longer survival. This paper describes a sensitive ELISA for the measurement of uPA, tPA and PAI-1 in breast cancer cytosols. The structure of the assay involves coating Ab (sheep α-Chicken IgY), catching Ab (chicken α-analyte), tagging Ab (rabbit α-analyte) and detecting Ab (goat α-rabbit IgG) labelled with HRP. The assay has a high degree of accuracy and specificity. Comparison with the American Diagnostica kits shows the results’ equivalence for PAI-1 and tPA. For uPA the results of the assay were twice as high. The assay is sensitive and relatively inexpensive. It is the first published assay to yield strictly comparative values for uPA, tPA and PAI-1 in tissue extracts and is readily subject to external quality control.

Mutation Analysis in the Coding Sequence of Thymidine Kinase 1 in Breast and Colorectal Cancer

We report the first mutational study of thymidine kinase 1 (TK1) performed in human solid tumors. We sequenced cDNAs representing the complete coding region of TK1 in human breast (n=22) and colorectal (n=26) cancer. Codon 106 near the ATP binding site constantly differed (ATG → GTG; Met → Val) from the one deposited by Bradshaw and Deininger in the Genbank database (Accession number NM_003258). Silent polymorphisms at codon 11 (CCC → CCT; Pro → Pro) and codon 75 (GCG → GCA; Ala → Ala) were frequently detected in tumors as well as in normal tissues. In breast cancer the two polymorphisms were observed in 63.6% of the samples analyzed. No significant association could be found between polymorphisms and TK activity. In colorectal cancer the incidence of the two changes was 73.1% and 69.2%, respectively. Interestingly, one colon cancer with high cytosolic TK activity displayed two missense mutations located in and near the putative phosphorylation site by tyrosine kinase (s) (TAT → CAT; Tyr → His) and by cAMP-, cGMP-dependent protein kinase (TAC → TGC; Tyr → Cys), respectively; adjacent normal mucosa showed no mutation. This may open new avenues that imply TK1 activity in tumor cell proliferation.

Prognostic Significance of Plasminogen Activator Inhibitor-1 in Breast Cancer, with Special Emphasis on Locoregional Recurrence-Free Survival

The independent prognostic value of protease uPA and its inhibitor PAI-1 for survival in breast cancer patients is firmly established. However, there is very little data on the prognostic value of serine proteases and their inhibitors for locoregional recurrence in breast cancer. The prognostic value of PAI-1 for local control in a group of 766 patients treated at our institute with either breast conserving treatment or modified radical mastectomy was evaluated. The locoregional recurrence-free survival (LRFS) of patients with PAI-1 values above the median value was significantly worse than that of patients with PAI-1 values below the median value (log-rank; p=0.0078). In multivariate analysis PAI-1 levels proved to be of independent statistical significance for LRFS (p=0.0401, relative risk 2.28, 95% confidence interval 1.04–5.02). The independent prognostic value of PAI-1 for metastasis-free survival and overall survival was also confirmed. In addition, our data suggest that PAI-1 antigen levels in tumor tissue might be of prognostic value for survival after locoregional recurrence (log-rank; p=0.0618). According to our findings, PAI-1 levels could be used as a biological marker that could facilitate the identifation of patients with a higher risk of local relapse already at the time of primary treatment. These patients should then be offered more aggressive treatment.

Prognostic Value of Plasminogen Activator Inhibitors in Breast Cancer

The prognosis of cancer is primarily dependent on its potential to invade and metastasize. Data from both pre-clinical and clinical studies strongly suggest that serine proteases, as well as their inhibitors and receptor, play a central role in the processes leading to metastasis. We therefore investigated the prognostic value of plasminogen activator inhibitors type 1 (PAI-1) and type 2 (PAI-2) and the combination of both inhibitors in 332 patients with operable breast cancer. PAI-1 and PAI-2 content was measured in the primary tumor cytosols using an enzyme-linked immunosorbent assay. For PAI-1 the median value (3.9 ng/mg protein) was used as cutoff, while the optimized cutoff for PAI-2 (6.5 ng/mg protein) was obtained using the log-rank statistic. After a median follow-up of 46 months 96 (29%) patients relapsed. In univariate analysis patients with a high PAI-1 or a low PAI-2 content had an increased risk of relapse. The difference was statistically significant for PAI-1 (p<0.0001) and almost statistically significant for PAI-2 (p=0.057). Stage, tumor size, differentiation grade, lymph node status and hormone receptor status also showed significant univariate impact on disease-free survival (DFS). In multivariate analysis (Cox model) PAI-1 (p<0.0001, RR=2.78), PAI-2 (p=0.0075, RR=2.17), UICC stage (p=0.0014, RR=2.2), differentiation grade (p=0.0097, RR=1.91) and nodal status (p<0.0001, RR=2.9) retained their significance. When both inhibitors were combined the worst prognosis was observed in patients with simultaneous high PAI-1 and low PAI-2 levels, whereas low PAI-1 in combination with high PAI-2 values indicated a very favorable prognosis. In conclusion, our study showed that both PAI-1 and PAI-2 had independent prognostic value in breast cancer. Combination of both inhibitors further improved the differentiation of patients with respect to prognosis.

New insights into the metastatic behavior after breast cancer surgery, according to well-established clinicopathological variables and molecular subtypes

Despite advances in treatment, up to 30% of patients with early breast cancer (BC) experience distant disease relapse. However, a comprehensive understanding of tumor spread and site-specific recurrence patterns remains lacking. This retrospective case-control study included 103 consecutive patients with metastatic BC admitted to our institution (2000–2013). Cases were matched according to age, tumor biology, and clinicopathological features to 221 patients with non-metastatic BC (control group). The median follow-up period among the 324 eligible patients was 7.3 years. While relatively low values for sensitivity (71%) and specificity (56%) were found for axillary lymph node (ALN) involvement as an indicator of risk and pattern of distant relapse, nodal status remained the most powerful predictor of metastases (OR: 3.294; CL: 1.9–5.5). Rates of dissemination and metastatic efficiency differed according to molecular subtype. HER2-positive subtypes showed a stronger association with systemic spread (OR: 2.127; CL: 1.2–3.8) than other subgroups. Classification as Luminal or Non-Luminal showed an increased risk of lung and distant nodal recurrence, and a decreased risk in bone metastases in the Non-Luminal group (OR: 2.9, 3.345, and 0.2, respectively). Tumors with HER2 overexpression had a significantly high risk for distant relapse (OR: 2.127) compared with HER2-negative tumors and also showed higher central nervous system (CNS) and lung metastatic potential (OR: 5.6 and 2.65, respectively) and low risk of bone disease progression (OR: 0.294). Furthermore, we found significant associations between biological profiles and sites of recurrence. A new process of clinical/diagnostic staging, including molecular subtypes, could better predict the likelihood of distant relapses and their anatomical location. Recognition and appreciation of clinically distinct molecular subtypes may assist in evaluation of the probability of distant relapses and their sites. Our analysis provides new insights into management of metastatic disease behavior, to lead to an optimal disease-tailored approach and appropriate follow-up.

uPA and PAI-1 as biomarkers in breast cancer: validated for clinical use in level-of-evidence-1 studies

Urokinase plasminogen activator (uPA) is an extracellular matrix-degrading protease involved in cancer invasion and metastasis, interacting with plasminogen activator inhibitor-1 (PAI-1), which was originally identified as a blood-derived endogenous fast-acting inhibitor of uPA. At concentrations found in tumor tissue, however, both PAI-1 and uPA promote tumor progression and metastasis. Consistent with the causative role of uPA and PAI-1 in cancer dissemination, several retrospective and prospective studies have shown that elevated levels of uPA and PAI-1 in breast tumor tissue are statistically independent and potent predictors of poor patient outcome, including adverse outcome in the subset of breast cancer patients with lymph node-negative disease. In addition to being prognostic, high levels of uPA and PAI-1 have been shown to predict benefit from adjuvant chemotherapy in patients with early breast cancer. The unique clinical utility of uPA/PAI-1 as prognostic biomarkers in lymph node-negative breast cancer has been confirmed in two independent level-of-evidence-1 studies (that is, in a randomized prospective clinical trial in which the biomarker evaluation was the primary purpose of the trial and in a pooled analysis of individual data from retrospective and prospective studies). Thus, uPA and PAI-1 are among the best validated prognostic biomarkers currently available for lymph node-negative breast cancer, their main utility being the identification of lymph node-negative patients who have HER-2-negative tumors and who can be safely spared the toxicity and costs of adjuvant chemotherapy. Recently, a phase II clinical trial using the low-molecular-weight uPA inhibitor WX-671 reported activity in metastatic breast cancer.

The role of thymidine kinase in cancer diseases

Thymidine kinase 1 (TK 1-fetal) is a cell cycle-dependent marker that increases dramatically during the S-phase of the cell cycle. In this review, the authors discuss serum levels of thymidine kinase in a variety of neoplasias. Determination of thymidine kinase helps to monitor the follow-up of solid tumours and haematological malignancies as well as indicating the efficacy of adjuvant and palliative chemotherapy. Elevated levels of thymidine kinase must always be interpreted together with a detailed knowledge of the patient's condition because nonspecific elevations of serum levels (inflammatory and autoimmune diseases) must be excluded.

Patients with metastatic breast cancer using bevacizumab as a treatment: is there still a role for it?

OPINION STATEMENT

Over the last few decades, the angiogenesis mechanism has increasingly been studied and implicated in cancer pathophysiology. At present, it is known that angiogenesis plays a relevant role in tumor growth, and more importantly many new molecules exists can potentially interfere with this process. Bevacizumab, a humanized monoclonal antibody targeting the vascular endothelial growth factor A (VEGF-A) now commonly used in the treatment of colorectal, renal cell, and brain cancer, is the first anti-angiogenesis drug delivered in combination with chemotherapy that has consistently shown clinical efficacy in the treatment of breast cancer. Since the ECOG 2100 trial has shown that bevacizumab added to paclitaxel as a first-line treatment for advanced breast cancer nearly doubled the time to progression and tumor response rate, its approval was granted almost worldwide. However, other phase III trials revealed a smaller absolute improvement in progression-free survival (PFS) and response rates, and no trials yet have demonstrated survival enhancement which led to a great controversy and debate over the use of bevacizumab. The discrepancy between PFS and overall survival also raises the question of whether or not bevacizumab has been applied sub-optimally in some of the studies, if a predictive biomarker(s) exists to select the group of patients whom would receive the greatest benefit and what is the appropriate clinical end-point for approval and funding of new targeted agents. In this article we will review the bevacizumab mechanism of action and the clinical trials that assessed its benefit in the treatment of metastatic breast cancer (MBC).

A nomogram predicting the probability of primary breast cancer survival at 2- and 5-years using pathological and biological tumor parameters

PURPOSE

Our objective was to develop a nomogram to predict individual overall survival (OS) for primary breast cancer, based on pathological and biological tumor parameters.

METHODS

A retrospective study in a cohort of 180 patients with primary breast cancer was used to build the nomogram. Pathological factors and tumor proteases measured prospectively in primary tumors were used. A multivariate Cox proportional hazards model was used to explore the relationship with OS, and regression coefficients were used to build the nomogram. The nomogram was internally validated with 200 bootstrap re-samples.

RESULTS

The final variables included in the nomogram comprised tumor size (P = 0.04), nodal pathological status (P = 0.01), estrogen receptor status (P = 0.04), urokinase plasminogen activator inhibitor-1 (PAI-1; P = 0.02), thymidine kinase (P = 0.03), and cathepsin D (P = 0.004). The predictive accuracy of the nomogram at estimating the probability of OS, at both 2 and 5 years, was respectively 0.874 and 0.832 before and after calibration.

CONCLUSION

A nomogram to predict 2- and 5-year OS in BC, using histological and biological parameters was successfully developed. This prognostic tool should prove useful in decision-making and therapeutic research.

Comparative aspects of the proliferation marker thymidine kinase 1 in human and canine tumour diseases

As cell proliferation is one of the hallmarks of cancer, various types of proliferation markers are used as important tools in diagnosis, prognosis, treatment decision-making and follow-up in clinical oncology. The S phase-specific protein thymidine kinase 1 (TK1) can be used in immunohistochemistry for RNA/protein expression in tissue specimens and for activity or protein/peptide levels in serum from patients. TK1 has been used mainly in haematologic malignancies in humans, but also found beneficial in canine malignancies. As the protein sequence homology is high between humans and dogs, findings in canine models will have a high comparative value in further human research as well. In the present review, we will focus on the recent results concerning TK1's S phase-correlated expression, increased serum levels of TK1 in patients with malignancies and the relevance for veterinary and comparative oncology. Finally, the benefit of recently developed specific anti-TK1 antibodies suitable for immunologic assay is discussed.

Emerging biomarkers in breast cancer care

Currently, decision-making for breast cancer treatment in the clinical setting is mainly based on clinical data, histomorphological features of the tumor tissue and a few cancer biomarkers such as steroid hormone receptor status (estrogen and progesterone receptors) and oncoprotein HER2 status. Although various therapeutic options were introduced into the clinic in recent decades, with the objective of improving surgery, radiotherapy, biochemotherapy and chemotherapy, varying response of individual patients to certain types of therapy and therapy resistance is still a challenge in breast cancer care. Therefore, since breast cancer treatment should be based on individual features of the patient and her tumor, tailored therapy should be an option by integrating cancer biomarkers to define patients at risk and to reliably predict their course of the disease and/or response to cancer therapy. Recently, candidate-marker approaches and genome-wide transcriptomic and epigenetic screening of different breast cancer tissues and bodily fluids resulted in new promising biomarker panels, allowing breast cancer prognosis, prediction of therapy response and monitoring of therapy efficacy. These biomarkers are now subject of validation in prospective clinical trials.

Predicting distant dissemination in patients with early breast cancer

BACKGROUND

Prediction of distant metastases is of paramount importance in the knowledge and management of breast cancer patients. The objective of this study was to assess conventional prognostic factors in a large database of patients with early breast cancer, including those with small tumors diagnosed through regional screening, to determine the risk of distant dissemination.

METHODS

The study included 4,797 patients of the Stockholm database who did not receive systemic adjuvant treatments. The main endpoint was metastasis free-interval. Individual risks of distant metastasis were estimated using the regression coefficients of the significant prognostic factors in Cox multivariate analyses. For each level of metastatic risk the pattern of failure was analyzed by a model assuming competing risks.

RESULTS

The three independent significant prognostic factors were histologic tumor size, number of involved axillary lymph nodes and progesterone receptor level. However, the latter factor added limited additional information of borderline clinical significance. Thus, subsequent estimations were done with a prognostic score taking into account only the former two most performant factors in the whole population. The risk of distant metastasis of observed values of tumor size categories fitted with published results of a series containing significantly larger tumors. A large variation of tumor size predicts 10-year distant metastasis risk ranging from below 10% up to 90%. Tumors of 10 mm or less had a 10-year metastatic risk of less than 10%.

CONCLUSIONS

The results of this study are consistent with a linear effect of tumor size, within the range of data, on 10-year distant dissemination probabilities. Further refinement on prognostic value is needed for tumors of 15 mm or less.

Inhibition of human breast cancer cell (MBA-MD-231) invasion by the Ea4-peptide of rainbow trout pro-IGF-I

It was shown previously that Ea4-peptide of trout pro-IGF-I exerted mitogenic activity in non-transformed cells and inhibited colony formation in a soft agar medium of established human cancer cells. Here we report that the same peptide inhibits the invasion of human breast cancer cells (MDA-MB-231) through a matrigel membrane in a dose-dependent manner. The expression of urokinase-type plasminogen activator (uPA), tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor 1 (PAI1) genes in MDA-MB-231 cells were downregulated by treatment with rtEa4-peptide. The inhibition of expression of these genes in response to rtEa4-peptide treatment was reduced to the control level when inhibitors for c-Jun N-terminal kinase 1/2 (JNK1/2), mitogen activated protein kinase kinase 1/2 (Mek1/2), p38 mitogen activated protein kinase (p38 MAPK), phosphatidylinositol 3-kinase (PI3K), and phosphokinase C (PKC) were used. These results suggest that inhibition of invasion of MDA-MB-231 cells by rtEa4-peptide may be mediated via the suppression of uPA, tPA, and PAI1 gene activities through signal transduction pathways.

Twenty-five years of follow-up in patients with operable breast carcinoma: correlation between clinicopathologic factors and the risk of death in each 5-year period

BACKGROUND

Some investigators have suggested a decreased prognostic value for conventional prognostic factors over time in patients with breast carcinoma. The objective of this study was to assess the effect of prognostic factors on the risk of death in patients with breast carcinoma over a long follow-up.

METHODS

The authors assessed clinicopathologic prognostic factors in patients with early-stage breast carcinoma over a follow-up > 25 years and analyzed the variation of their effect on death in consecutive 5-year follow-up intervals. The study included 2410 women who primarily underwent complete surgical resection. Time-dependent variables were analyzed by using different multivariate models.

RESULTS

Four factors were related strongly to the risk of death in the first 5 years: tumor size, histologic grade, the number of involved axillary lymph nodes, and age at diagnosis. After 10-15 years of follow-up, only age at diagnosis was related to the risk of death. The effect of powerful prognostic factors, except age at diagnosis, on the risk of death was time limited, and no effects or very small effects were detectable after 10 years of follow-up.

CONCLUSIONS

Conventional and widely accepted prognostic factors may explain a significant portion of early deaths among patients with early-stage breast carcinoma, but they were of limited value to explain late mortality, that also may be influenced by late events, such as new primary malignancies and treatment complications. Cancer 2006. (c) 2006 American Cancer Society.

Proliferative markers as prognostic and predictive tools in early breast cancer: where are we now?

In the last few decades, proliferative markers have been broadly evaluated as prognostic and predictive factors for early stage breast cancer patients. Several papers evaluating one or more markers have been published, often with contradictory results. As a consequence, there is still uncertainty about the role of these proliferative markers. The present paper critically reviews the current knowledge about the following markers: thymidine labeling index, S phase fraction/flow cytometry, Ki 67, thymidine kinase (TK), cyclins E, cyclin D, the cyclin inhibitors p27 and p21, and topoisomerase IIalpha. For each marker, the prognostic and predictive role was separately analyzed. Only papers published in English in peer-reviewed journals before June 2004 that include at least 100 evaluable patients were selected. In addition, the prognostic and predictive role of the proliferative markers had to be assessed through multivariate analyses. One hundred and thirty-two papers fulfilled these criteria and 159 516 patients were analyzed. Unfortunately, several methodological problems in the research to date prevent us from including any one of these proliferative markers among the standard prognostic and predictive factors. Early incorporation of translational research and new technologies with clinical trials are needed to prospectively validate biological markers and allow their use in clinical practice.

[Combined flow cytometry determination of S-phase fraction and DNA ploidy is an independent prognostic factor in node-negative invasive breast carcinoma: review of a series of 271 patients with stage I and II breast cancer]

PURPOSE

To assess the significance of S-phase fraction (SPF) and DNA ploidy evaluated by DNA flow cytometry as prognostic markers in stage I or II breast cancer.

PATIENTS AND METHODS

A series of 271 patients, treated by surgery, radiotherapy+/-systemic therapy was analysed (median follow up: 64 months). Standardized flow cytometry cell preparation from frozen samples and consensus rules for data interpretation were followed. Three SPF classes were defined on the basis of tertiles after adjustment for ploidy. Four groups were defined based on combinations of DNA ploidy (DIP: diploid; ANEUP: aneuploid) and SPF: DIP and low SPF (DL, N=37), DIP and medium or high SPF (DMH, N=76), ANEUP and low SPF (AL, N=24), ANEUP and medium or high SPF (AMH, N=68). Local control rate (LCR), disease-free survival (DFS), metastasis-free survival (MFS), and overall survival (OS) were correlated with DNA ploidy, SPF, DL to AMH groups, T and N stages, SBR grading, age, and hormonal status on univariate and multivariate analysis (Cox model).

RESULTS

On univariate analysis, DFS and LCR were higher for DIP tumours. High SPF values were associated with shorter DFS. LCR, MFS, DFS, and OS rates were significantly different with an increasingly poorer prognosis from DL to AMH. On multivariate analysis, groups DL to AMH, histological node involvement and T stage were independently associated with MFS, and DFS. In N- patients, DL to AMH remained independent for MFS and DFS. For SBR III tumours, MFS and OS were significantly different in DL to AMH groups. These results strongly support the use of combined evaluation of DNA ploidy and SPF as independent parameters in clinical trials for N- stage I and II breast cancer.

Combined flow cytometry determination of S-phase fraction and DNA ploidy is an independent prognostic factor in node-negative invasive breast carcinoma: analysis of a series of 271 patients with stage I and II breast cancer

PURPOSE

To assess the significance of S-phase fraction (SPF) and DNA ploidy evaluated by DNA flow cytometry as prognostic markers in stage I or II breast cancer.

PATIENTS AND METHODS

A series of 271 patients, treated by surgery, radiotherapy +/- systemic therapy was analyzed (median follow up: 64 months). Standardized flow cytometry cell preparation from frozen samples and consensus rules for data interpretation were followed. Three SPF classes were defined on the basis of tertiles after adjustment for ploidy. Four groups were defined based on combinations of DNA ploidy (DIP: diploid; ANEUP: aneuploid) and SPF: DIP and low SPF (DL, n=37), DIP and medium or high SPF (DMH, n=76), ANEUP and low SPF (AL, n=24), ANEUP and medium or high SPF (AMH, n=68). Local control rate (LCR), disease-free survival (DFS), metastasis-free survival (MFS), and overall survival (OS) were correlated with DNA ploidy, SPF, DL to AMH groups, T and N stages, SBR grading, age, and hormonal status on univariate and multivariate analysis (Cox model).

RESULTS

On univariate analysis, DFS and LCR were higher for DIP tumours. High SPF values were associated with shorter DFS. LCR, MFS, DFS, and OS rates were significantly different with an increasingly poorer prognosis from DL to AMH. On multivariate analysis, groups DL to AMH, histological node involvement and T stage were independently associated with MFS, and DFS. In N- patients, DL to AMH remained independent for MFS and DFS. For SBR III tumours, MFS and OS were significantly different in DL to AMH groups. These results strongly support the use of combined evaluation of DNA ploidy and SPF as independent parameters in clinical trials for N- stage I and II breast cancer.

A comparative study: immunohistochemical detection of cytosolic thymidine kinase and proliferating cell nuclear antigen in breast cancer

To explore the expression of cytosolic thymidine kinase 1 (TK1) as a cell proliferative marker in human breast cancers, immunohistochemistry was used to detect the expression of TK1 in 52 malignant breast lesions, 20 benign breast lesions, and 16 normal breast tissues. The results were compared to the expression of proliferating cell nuclear antigen (PCNA) in the same specimens. The TK1-labelling index (TK1-LI) and PCNA-labeling index (PCNA-LI) were significantly higher in malignant lesions than in nonmalignant lesions (p < 0.0001 and p < 0.0013, respectively). The TK1-LI (78.9%) in malignant lesions was higher compared to PCNA-LI (64.5%). No significant difference was found for TK1-LI and PCNA-LI between benign lesions and normal tissues. Concerning the tumor stages and the tumor grades, TK1-LI showed a significant correlation with the increased tumor stages (p = 0.023) and tumor grades (p = 0.009). However, PCNA-LI was neither significantly different in tumor stages (p = 0.062) nor in tumor grades (p = 0.073). We conclude that TK1 might be a more accurate marker than PCNA for estimation of cell proliferation and malignant potentials in breast carcinomas.

Molecular prognostic indicators in breast cancer

Here we review a panel of oncogene products, proteases and markers of proliferation that have shown potential as prognostic indicators in primary breast cancer. The relative merits of specific genetic mutations as well as alterations at the protein level are discussed. Finally an assessment is made of the transfer of knowledge from the laboratory to the bed-side.

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.

Potential markers predicting distant metastasis in axillary node-negative breast carcinoma

Prognostic parameters for axillary node-negative (ANN) breast cancer are still rare. Our aim was to establish potential markers that predict distant metastasis in ANN breast carcinoma and permit detection of the patients with high metastasis risk. A case control study was designed that comprised 64 ANN patients who developed distant metastasis during a 5-10 year follow-up period, 64 ANN patients with recurrence-free survival and 64 node-positive (ANP) comparitors. Immunohistochemistry and/or in situ hybridization were used to detect nm23, Cathepsin-D (Cath-D), Epidermal Growth Factor Receptor (EGFR) and Laminin Receptor (LR) in 192 cases. A significantly lower expression of both nm23 mRNA and protein was found in the ANN-group with poor prognosis compared with the ANN-group with good prognosis (p < 0.01). The protein levels of Cath-D, EGFR and LR were significantly higher in the ANN-group with poor prognosis and in the ANP-group compared with the ANN-group with good prognosis (p < 0.01 or p < 0.05), but no differences were found between the poor ANN-group and the ANP-group. Multiple regression analysis showed a close correlation of nm23, Cath-D and EGFR expression with occurrence of distant metastasis of ANN breast carcinoma. All markers except nm23 correlated with conventional histopathologic criteria such as tumor grade, margin and vessel invasion. The results suggest the combined detection of nm23, Cath-D and EGFR as predictive markers of distant metastasis in ANN breast cancer patients. Quantitative analysis together with clinicopathologic factors could contribute to estimate the potential risk of metastasis and select individual therapy regimen.

Immunoradiometric assay of cathepsin D: Estrogen regulated vs. non estrogen- regulated cathepsin D expression in relation to clinicopathological features of breast cancer

Background: Cellular biomarkers may predict tumor cell behavior in breast cancer. One of the most paradoxical biomarker in breast cancer is cathepsin D. Patients and methods: The study includes 152 patients with histologically verified breast carcinoma. Clinicopathological findings were classified according to classical breast carcinoma-host features (age and menopausal status) and carcinoma features (lymph node status, tumor size type and grade). Estrogen and progesterone receptors were assayed in accordance with the recommendation of the EORTC. Cathepsin D concentrations were determined using immunoradiometric assay. The results were analyzed using non-parametric statistical methods. Results: All differences in the proportion of breast carcinoma classified as cathepsin D-positive and disagreements on the association of cathepsin D status with clinicopathological features of breast cancer are the result of varying cut-off values used by different authors. Using the cut-off value, which defines estrogen-regulated vs. nonestrogen-regulated cathepsin D expres sion, this study points to the cathepsin D status as a complementary biolog ical information to ER and PR status, and a dependent biomarker in relation to age of patients and lymph node status. Conclusion: The classification of tumors according to the cathepsin D status within ER and PR status could provide more information on the association between cathepsin D status and clinical-pathological features of breast cancer.

May cathepsin D immunoreactivity be used as a prognostic factor in endometrial carcinomas? A comparative immunohistochemical study

OBJECTIVE

To investigate the prognostic value of immunohistochemical detection of cathepsin D and the association between cathepsin D and established prognostic factors in endometrial carcinoma.

METHODS

Cathepsin D immunoreactivity was determined by an immunohistochemical technique in a series of 79 patients with surgical stage I-III primary endometrial carcinoma.

RESULTS

Of 79 tissue specimens, 48 (61%) showed a positive reaction for cathepsin D. A significant correlation between cathepsin D and histological grade was found (P < 0.05). The other established clinicopathological prognostic factors were not associated with cathepsin D. There was not any significant difference in prognosis between the positive cases and negative cases for cathepsin D (P > 0.05). In the univariate analysis cathepsin D immunoreactivity did not show significant prognostic value for overall survival (P > 0.05). The multivariate analysis also showed that cathepsin D was not related to patient outcome (P = 0.24, relative risk = 0.34, 95% confidence interval = 0.05-2.09).

CONCLUSIONS

Our results suggest that cathepsin D immunoreactivity may not be of prognostic value but more studies are needed to evaluate the relationship between its immunoreactivity in tumor cells and in other cells.

Thymidine kinase as a proliferative marker: clinical relevance in 1,692 primary breast cancer patients

PURPOSE

To assess the prognostic value of thymidine kinase (TK), an enzyme involved in the DNA synthesis salvage pathway, relative to other prognostic factors in primary breast cancer.

PATIENTS AND METHODS

This retrospective study involved 1,692 patients with operable breast cancer treated in six institutions (median follow-up, 82 months). Among the 857 node-negative patients, 135 received adjuvant chemotherapy (fluorouracil, doxorubicin, cyclophosphamide [FAC] or fluorouracil, etoposide, and cisplatin [FEC]). TK was assayed in cytosol with a quantitative radioenzymatic technique. Disease-specific survival (DSS), local recurrence-free interval (LRI), and distant-relapse-free interval (DRI) were investigated.

RESULTS

High TK levels were associated with large tumor size, high histologic grade, and steroid hormone receptor negativity. Univariate analysis of the entire data set showed that high TK levels were related to shorter DSS (P < 10(-5)), LRI (P < 10(-3)), and DRI (P < 10(-5)). In time-dependent Cox models, high TK levels remained an independent predictor of the three outcomes, both in the overall population and in node-negative patients, although its prognostic value decreased over time. In node-negative patients, the introduction of an interaction term in multivariate analysis suggested that chemotherapy was more efficacious for patients who had tumors with high TK contents. In node-positive patients, high TK levels were related only to an increased risk of LRI.

CONCLUSION

High TK values are an important risk factor in node-negative patients and seem to be associated with a beneficial effect of adjuvant FAC or FEC in patients who received adjuvant chemotherapy. The rationale of chemotherapy for patients with slowly proliferating tumors has to be discussed from a risk-benefit point of view.

S-phase fraction and urokinase plasminogen activator are better markers for distant recurrences than Nottingham Prognostic Index and histologic grade in a prospective study of premenopausal lymph node-negative breast cancer

PURPOSE

Histologic grade, Nottingham Prognostic Index (NPI), estrogen receptor (ER) and progesterone receptor (PgR) status, and tumor size have previously been shown to be important prognostic indicators for distant recurrence of breast cancer. The purpose of this study was to compare the prognostic value of these factors with flow cytometric S-phase fraction (SPF), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor type 1 (PAI-1) in premenopausal patients with lymph node-negative breast cancer.

PATIENTS AND METHODS

In 237 consecutive premenopausal patients with lymph node-negative breast cancer and freshly frozen tumor material available, SPF, ER and PgR status, uPA and its inhibitor PAI-1, histologic grade, and NPI were evaluated.

RESULTS

SPF was univariately the most powerful prognostic factor for distant recurrence, followed by uPA, histologic grade, PgR, age, ER, NPI, and PAI-1, the latter being nonsignificant. Multivariate analysis revealed that neither NPI nor histologic grade was significant after adjustment for SPF, a fact that may be explained by the strong association between these factors. uPA was, however, an independent prognostic factor in addition to SPF, NPI, or histologic grade.

CONCLUSION

In this prospective study, SPF and uPA were found to be independent prognostic factors in premenopausal women with lymph node-negative breast cancer. We suggest that SPF, if performed under standardized conditions, can replace histologic grade as a selection instrument for adjuvant medical treatment. The value of the combination of SPF and uPA needs to be confirmed in an independent prospective trial.

DNA-synthesizing enzymes in breast cancer (thymidine kinase, thymidylate synthase and thymidylate kinase): association with flow cytometric S-phase fraction and relative prognostic importance in node-negative premenopausal patients

S-phase fraction (SPF) is a reference for cell-kinetic analysis. In this study, the links between SPF and the essential enzymes participating in the pyrimidine synthesis were investigated in breast cancer and their relationships with the natural history of the disease were compared. We measured thymidine kinase (TK) for salvage synthesis, thymidylate synthase (TS) for de novo synthesis and thymidylate kinase (TMK), which is required for both pathways. Our study population consisted of 211 premenopausal women with node-negative tumors. SPF was assessed prospectively by flow cytometry, whereas enzyme activities were measured retrospectively in cytosols using radioenzymatic methods. Among the enzymes analyzed, only TK demonstrated a strong correlation with SPF (r(s) = 0.59). In univariate analysis, high SPF and high levels of TK were associated with increased risk of developing distant recurrences (p < 0.001). Correlations with other prognostic factors (histological grade, steroid receptors, DNA ploidy status, urokinase plasminogen activator and plasminogen activator inhibitor type 1) confirmed a parallel association of SPF and TK with the most aggressive tumors. In contrast, TS and TMK were not associated with prognosis. After adjustment for SPF, the risk of relapse increased significantly with TK values. Subgroup analysis showed that additional information was provided by TK in the tumors with low SPF. When urokinase plasminogen activator (uPA) was a candidate variable in multivariate analysis, TK remained significant. Combined with SPF and uPA, TK could be useful to define premenopausal node-negative patients with rapidly proliferating tumors at a high risk of metastatic disease.

Co-expression of thymidine kinase and cathepsin D in 200 primary breast carcinomas

We assayed thymidine kinase (TK) and cathepsin D (Cath-D) in 200 breast carcinomas and we found that they were significantly correlated. This correlation was present in lymph node positive tumours, in G2 and G3, in T1 and in invasive ductal carcinomas. In addition, TK and Cath-D did not correlate with oestrogen receptor (ER) and progesterone receptor (PgR) status. We conclude that the relationship between Cath-D and TK may indicate a tumour population of high proliferation activity and invasiveness potential, related to a more aggressive phenotype, whose identification may be useful in defining prognosis.

P53 determination alongside classical prognostic factors in node-negative breast cancer: an evaluation at more than 10-year follow-up

BACKGROUND

There is heterogeneity of methods and conflicting results concerning the prognostic value of p53 in node-negative breast cancer. The clinical value of a quantitative method for measuring tumoralp53 content still needs to be evaluated.

PATIENTS AND METHODS

A long-term retrospective study was conducted on 297 node-negative patients with a median follow-up greater than 10 years (11 years, 101-172 months). Classic prognostic factors were considered including age, tumor size, histoprognostic grade and estradiol (ER) and progesterone receptors (PR). In addition, the value of p53 determination (immunoluminometric assay in tumor cytosol) was assessed for this long follow-up period.

RESULTS

p53 concentrations were significantly linked to the histological grade (P = 0.001), to tumor size (P = 0.02) and ER status (P = 0.01). Higher p53 tumoral concentrations were found in tumors with large size, pejorative histological grade and negative ER status. In contrast, p53 tumoral concentrations were not influenced by menopausal or PR status. Multivariate Cox analysis demonstrates that tumor size was the only significant predictor of disease-free survival (P = 0.049) with a risk factor at 1.38. As regards specific survival, univariate Cox analysis indicates that p53 taken as a continuous variable is a significant predictor (P = 0.024) together with histological grade, tumor size and ER status. In a multivariate Cox analysis there were two significant and independent variables for predicting overall survival: tumor size (P = 0.031) and, ER status (P = 0.015) with the highest risk factor (RR = 2.14).

CONCLUSIONS

The present investigation points out that the prognostic power of p53 tumor determination evaluated at more than 10 years median survival is not higher than the well-recognized classic prognostic factors in node-negative breast cancer. The present data highlight the need to assess the prognostic value of potentially new biological factors in node-negative breast cancer on cohorts of patients followed over periods in excess of 10 years.

Plasma D-dimer levels in operable breast cancer patients correlate with clinical stage and axillary lymph node status

PURPOSE

To investigate the relationship between preoperative plasma D-dimer levels and extent of tumor involvement in operable breast cancer patients.

PATIENTS AND METHODS

A total of 140 preoperative plasma specimens were obtained from women scheduled to undergo diagnostic breast biopsies. Ninety-five patients in the initial group went on to undergo axillary lymph node dissection. Of the 140 patients from whom plasma samples were obtained, 102 were subsequently diagnosed with invasive breast carcinoma, nine were subsequently diagnosed with ductal carcinoma-in-situ, and 20 were subsequently diagnosed with benign breast disease. Plasma D-dimer levels were quantitated using a commercially available immunoassay kit (DIMERTEST; American Diagnostica, Greenwich, CT). The relationships between plasma D-dimer and other prognostic variables (tumor size, estrogen receptor, progesterone receptor, nuclear grade, histologic grade, lymphovascular invasion, and clinical stage grouping) were then examined using univariate and multivariate linear and logistic regression analyses.

RESULTS

Median plasma D-dimer levels were significantly higher in patients with invasive carcinoma than those patients with either benign breast disease or carcinoma-in-situ (P =.0001). A significant relationship existed between the presence of elevated D-dimer (> 100 ng/mL) and involved axillary lymph nodes (chi(2) test; P =.001). Elevated D-dimer levels predicted positive lymph node involvement in both univariate regression (P =.0035) and multivariate linear regression (P =.012) models. In addition, elevated D-dimer levels predicted the presence of lymphovascular invasion in univariate logistic regression (P =. 0025) and multivariate logistic regression analysis (P =.0053). Quantitative D-dimer levels were highly correlated with clinical stage grouping (analysis of variance test; P =.002).

CONCLUSION

Plasma D-dimer levels were markers of lymphovascular invasion, clinical stage, and lymph node involvement in operable breast cancer. This correlation suggests that detectable fibrin degradation, as measured by plasma D-dimer, is a clinically important marker for lymphovascular invasion and early tumor metastasis in operable 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 plasminogen activator: a prognostic marker in multiple types of cancer

Urokinase plasminogen activator (uPA) is a serine protease causally involved in cancer invasion and metastasis. Consistent with its role in cancer spread, uPA has been shown to be a prognostic marker in a variety of malignancies, especially breast cancer. Approximately 20 different groups have shown that high levels of uPA in breast tumor tissue predict poor outcome. As a prognostic marker in breast cancer, uPA provides information that is independent of traditionally used factors such as tumor size, tumor grade, axillary node status and estrogen receptor status. Furthermore, uPA is prognostic in node-negative patients, and a clinical trial is currently under way to assess whether uPA and its inhibitor, plasminogen activator inhibitor-1, can differentiate between the majority of node-negative breast cancer patients who are cured by surgery from the minority who might benefit from adjuvant therapy. uPA is also prognostic in other malignancies, such as gastric, colorectal, esophageal, renal, endometrial, and ovarian cancers. uPA may thus be a prognostic indicator for multiple types of adenocarcinoma.

Risk-group discrimination in node-negative breast cancer using invasion and proliferation markers: 6-year median follow-up

Factors reflecting two major aspects of tumour biology, invasion (urokinase-type plasminogen activator (uPA), plasminogen activator inhibiter (PAI-1), cathepsin D) and proliferation (S-phase fraction (SPF), Ki-67, p53, HER-2/neu), were assessed in 125 node-negative breast cancer patients without adjuvant systemic therapy. Median follow-up time was 76 months. Antigen levels of uPA, PAI-1 and cathepsin D were immunoenzymatically determined in tumour tissue extracts. SPF and ploidy were determined flow-cytometrically, Ki"'-67, p53, and HER-2/neu immunohistochemically in adjacent paraffin sections. Their prognostic impact on disease-free (DFS) and overall survival (OS) was compared to that of traditional factors (tumour size, grading, hormone receptor status). Univariate analysis determined PAI-1 (P < 0.001), uPA (P = 0.008), cathepsin D (P = 0.004) and SPF (P = 0.023) as significant for DFS. All other factors failed to be of significant prognostic value. In a Cox model, only PAI-1 was significant for DFS (P < 0.001, relative risk (RR) 6.2). In CART analysis for DFS, the combination of PAI-1 and uPA gave the best risk group discrimination. For OS, PAI-1, cathepsin D, tumour size and ploidy were statistically significant in univariate, but PAI-1 was the only independently significant factor in Cox analysis (P < 0.001, RR 8.9). In particular, this analysis shows that PAI-1 is still a strong and independent prognostic factor in node-negative breast cancer after extended 6-year median follow-up.

Prognostic significance of Ki-67 and topoisomerase IIalpha expression in infiltrating ductal carcinoma of the breast. A multivariate analysis of 863 cases

To evaluate the prognostic relevance of Ki-67 and topoisomerase IIalpha expression in relation to tumor stage, grade, and hormone receptor content, 942 ductal infiltrating carcinomas of the breast were examined by means of the monoclonal antibodies Ki-S11 (Ki-67) and Ki-S4 (topoisomerase IIalpha). pS2, c-erbB2, and p53 were additionally considered as prognostic variables. The median follow-up time was 149 months. Eight-hundred-and-sixty-three tumors reacted with Ki-S11 and Ki-S4; the labeling indices of the two antigens were closely associated (r = 0.93). Both correlated positively with the tumor size, c-erbB2, and p53 expression, and negatively with patient age, hormone receptor content, and pS2 immunostaining. In the univariate analysis, Ki-S11 and Ki-S4 scores, nodal status, tumor size, tumor grade, and progesterone receptor content strongly predicted both overall and metastasis-free survival (p < 0.00001). Estrogen receptor status, p53, and c-erbB2 were of minor significance. Concerning overall survival, multivariate Cox regression analysis selected a Ki-S4 score >25% (p < 0.00001) next to the nodal status, and before tumor size, progesterone receptor content, and patient age. Independent predictors of the occurrence of distant metastases were nodal status, Ki-S4, tumor size, grade 1, and progesterone receptor negativity, in that order. The Ki-S11 score was of independent prognostic significance only if examined as a continuous variable. We conclude that topoisomerase IIalpha expression as assessed by monoclonal antibody Ki-S4 may add valuable information to current prognostic models for breast cancer. Its predictive value appears to be essentially related to the proliferative activity of tumor cells.

Cathepsin-D, urokinase plasminogen activator and type-1 plasminogen activator inhibitor in early breast cancer: an immunohistochemical study of prognostic value and relations to tenascin-C and other factors

Cytosolic determinations of cathepsin-D (cath-D), urokinase plasminogen activator (uPA) and its specific inhibitor PAI-1 have shown an association with adverse prognosis in breast cancer. Our aim was to study the distribution of these markers in small axillary node-negative breast carcinomas using immunohistochemistry and relate the semiquantitative results to known prognostic factors, the expression of tenascin-C (Tn-C) in invasion border of the tumour and prognosis. All the 158 women (159 tumours) were treated with breast conserving surgery and postoperative radiotherapy. Cytoplasmic immunoreactivity for cath-D was seen in carcinoma cells in 47% and in stromal cells in 44%. Nearly all tumours expressed uPA and PAI-1, which were categorized to cytoplasmic expression in carcinoma cells and diffuse stromal expression and quantified -/+/++/ and further dichotomized for purposes of analysis. Expression of uPA and PAI-1 in stromal fibroblasts was recorded as -/+. Cytoplasmic and stromal cell cath-D contents were associated with grade, proliferation, Tn-C expression in the tumour invasion border and the development of distant metastasis. In multivariate analysis stromal cath-D proved to be an independent prognostic factor for metastasis. Stromal expression of uPA was associated with an increased risk of local recurrence; otherwise high levels of uPA did not associate with other prognostic factors nor with prognosis. Fibroblastic expression of PAI-1 showed an association with both local and distant disease recurrence. However, no consistent association between the immunohistochemically quantified uPA and PAI-1 and prognosis was found. In conclusion, immunohistochemical determination of cath-D seems to be a viable method to predict a higher risk of metastasis but not local recurrence in small axillary node-negative breast carcinomas.

The urokinase plasminogen activator system as a target for prognostic studies in breast cancer

The identification of patients at high risk of relapse is currently one of the most important issues in breast cancer research. However, the selection of high-risk patients continues to be difficult due to the unpredictable course of this disease. Axillary lymph node status is currently recognized as the best clinical discriminant between good and poor prognosis, yet almost 30% of node-negative patients and 65% of node-positive patients will experience a relapse. Additional prognostic markers are therefore urgently needed. Since metastatic disease is the main cause of cancer patient morbidity and mortality, the measurement of molecules functionally involved in the regulation of tumor invasion and metastasis is attractive as a means to predict prognosis. Cancer invasion is a complex process in which degradation of the extracellular matrix plays a crucial role. This degradation is accomplished by the concerted action of several proteolytic enzyme systems, including generation of plasmin by the urokinase pathway of plasminogen activation, matrix metalloproteases, and other extracellular proteases. Increased expression and secretion of urokinase plasminogen activator (uPA) strongly correlates with the malignant phenotype of many types of cells, and the central role of uPA in tumor invasion is now well established. This review will focus on the prognostic impact of components of the urokinase plasminogen activation system in breast cancer with emphasize on methodological issues.

The relationship between prognostic and predictive factors in the management of breast cancer

The discovery of new prognostic factors proceeds at a much more rapid pace than our knowledge of how to properly utilize this information in the management of patients with breast cancer, especially those with early breast cancer that has not metastasized to regional lymph nodes. Prognostic factors provide information on how the patient is likely to do regardless of treatment. Predictive factors provide information on whether a patient is likely to benefit from therapy. Most factors identified to date provide prognostic information, but relatively few provide information that is truly helpful in making a therapeutic decision in the management of individual patients. In large part this is because there has been insufficient study of the factor, especially prospective evaluations of the factor. Unfortunately this has resulted in the premature use of this information under the general rubric that patients with a poor prognosis deserve more treatment in spite of the fact that there may be no benefit from that therapy in the poor prognostic group.

Prognostic impact of urokinase-type plasminogen activator (uPA) and its inhibitor (PAI-1) in cytosols and pellet extracts derived from 892 breast cancer patients

To evaluate the clinical relevance of urokinase-type plasminogen activator (uPA) and its type-1 inhibitor (PAI-1) measured by a recently developed enzyme-linked immunosorbent assay (ELISA), we analysed both components in samples derived from 892 patients with primary breast cancer (median follow-up 99 months). The assays were performed in cytosolic extracts as well as in corresponding detergent extracts of pellets obtained after ultracentrifugation, which was carried out when preparing the cytosolic fractions for routine steroid hormone receptor determination. Statistically significant correlations were found between the cytosolic levels and those determined in the pellet extracts (Spearman correlation coefficient r = 0.60, P < 0.0001 for uPA and r = 0.65, P < 0.0001 for PAI-1). Furthermore, strong correlations were found between the levels of both uPA (r = 0.85, P < 0.0001) and PAI-1 (r = 0.90, P< 0.0001) in the cytosols and their levels previously measured with ELISAs based on commercial reagents. In both Cox univariate and multivariate analysis, high cytosolic levels of uPA or PAI-1 were significantly associated with increased rates of relapse and death. The levels of uPA and PAI-1 in the pellet extracts also provided prognostic information, although to a lesser extent compared with the cytosolic extracts. The prediction of prognosis on the basis of uPA and PAI-1 assessed by an alternative ELISA once again emphasizes the established prognostic role and usefulness of these parameters in selection of breast cancer patients at high or low risk of recurrence.

Immunologic proliferation marker Ki-S2 as prognostic indicator for lymph node-negative breast cancer

BACKGROUND

Proper treatment of lymph node-negative breast cancer depends on an accurate prognosis. To improve prognostic models for this disease, we evaluated whether an immunohistochemical marker for proliferating cells, Ki-S2 (a monoclonal antibody that binds to a 100-kd nuclear protein expressed in S, G2, and M phases of the cell cycle), is an accurate indicator of prognosis.

METHODS

We studied 371 Swedish women with lymph node-negative breast cancer; the median follow-up time was 95 months. The fraction of tumor cells in S phase was assessed by flow cytometry, and tumor cell proliferation was measured immunohistochemically with the monoclonal antibodies Ki-S2 and Ki-S5 (directed against the nuclear antigen Ki-67). A combined prognostic index was calculated on the basis of the S-phase fraction, progesterone receptor content, and tumor size.

RESULTS

In multivariate analyses that did or did not (263 and 332 observations, respectively) include the S-phase fraction and the combined prognostic index, the Ki-S2 labeling index (percentage of antibody-stained tumor cell nuclei) emerged as the most statistically significant predictor of overall survival, disease-specific survival, and disease-free survival (all two-sided P<.0001). In the risk group defined by a Ki-S2 labeling index of 10% or less, life expectancy was not statistically significantly different from that of age-matched women without breast cancer, whereas the group with a high Ki-S2 labeling index had an increased risk of mortality of up to 20-fold.

CONCLUSIONS

Cellular proliferation is a major determinant of the biologic behavior of breast cancer. Prognosis is apparently best indicated by the percentage of cells in S through M phases of the cell cycle. Measurement of the Ki-S2 labeling index of a tumor sample may improve a clinician's ability to make an accurate prognosis and to identify patients with a low risk of recurrence who may not need adjuvant therapy.

Clinical relevance of the urokinase plasminogen activator system in breast cancer

Until recently clinical features and the hormone-receptor status were the only factors used to select systemic (adjuvant) treatment for breast cancer patients. Other biological factors are needed as well to predict the probability of relapse and response with more certainty. The uPA-system is such a prognostic and predictive factor in breast cancer. In this review, the results of research groups that have related relapse-free survival to the quantitative levels of uPA-system proteins and/or activities are discussed. Only studies that described the results from assays on cytosols or triton extracts of breast tumours were included. The levels of uPA-system proteins help to predict the probability of relapse and response, and knowledge of the expression levels of the various components of the uPA-system may lead to new treatment modalities targeted on specific properties of the uPA-system.

External quality assessment of trans-European multicentre antigen determinations (enzyme-linked immunosorbent assay) of urokinase-type plasminogen activator (uPA) and its type 1 inhibitor (PAI-1) in human breast cancer tissue extracts

High levels of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) in breast cancer tissue extracts have been associated with rapid disease progression. In these studies, different enzyme-linked immunosorbent assay (ELISA) kits have been applied for the quantification, and consequently the ranges of uPA and PAI-1 levels reported differ considerably. Therefore, the Receptor and Biomarker Study Group (RBSG) of the European Organization for Research and Treatment of Cancer (EORTC) and a consortium of the BIOMED-1 project 'Clinical Relevance of Proteases in Tumor Invasion and Metastasis' initiated three collaborative between-laboratory assessment trials aimed at controlling uPA and PAI-1 antigen analyses. For this purpose, two control preparations were produced from different sources: pooled human breast cancer specimens (QC-240893) and human breast cancer xenografts raised in nude mice (QC-101094). The lyophilized preparations were stable for prolonged times (at least 3 and 27 months respectively) at 4 degrees C. Furthermore, a good parallelism following dilution was found for uPA and PAI-1. The data from QC trial no. 1 clearly indicated that acceptable between-laboratory coefficients of variation (CVs) for uPA (<8.2%) and PAI-1 (<16.6%) in QC-240893 could be achieved when the same type of ELISA kit (American Diagnostica) was used. From the second trial, in which ten EORTC laboratories each received five identical lyophilized QC-101094 samples, it appeared that the within-laboratory variations for uPA and PAI-1 determinations obtained by 'experienced' laboratories were lower (<12.9%) than those from non-experienced laboratories (<36.4%). In a third QC trial, five BIOMED-1 laboratories, all of which employed ELISA procedures for uPA and PAI-1, participated in six subsequent quality assessment rounds receiving five samples of QC-101094. Although for each laboratory the within-run CVs for uPA as well as for PAI-1 were low (<7.8%), the between-run CVs were found to be considerably higher (up to 56.2% for uPA and to 27.6% for PAI-1). Consequently, because of the different ELISA formats used, the absolute analyte values measured in the different laboratories varied substantially. The use of 'common external standards' in the different ELISAs resulted in a significant reduction of the between-laboratory CVs from 61.3% to 15.7% (uPA) and from 42.1% to 19.1% (PAI-1). The present data demonstrate that in multicentre studies the same ELISA kit should be used, and that external quality assurance (QA) is mandatory. Furthermore, it appears from the present study that standardization of the protein assay as a tissular parameter is imperative.

Modulation of the estrogen-regulated proteins cathepsin D and pS2 by opioid agonists in hormone-sensitive breast cancer cell lines (MCF7 and T47D): evidence for an interaction between the two systems

In many cancer cell lines, including breast, prostate, lung, brain, head and neck, retina, and the gastrointestinal tract, opioids decrease cell proliferation in a dose-dependent and reversible manner. Opioid and/or other neuropeptide receptors mediate this decrease. We report that only the steroid-hormone-sensitive cell lines MCF7 and T47D respond to opioid growth inhibition in a dose-dependent manner. Therefore, an interaction of the opioid and steroid receptor system might exist, as is the case with insulin. To investigate this interaction, we have assayed two estrogen-inducible proteins (pS2 and the lysosomal enzyme cathepsin D) in MCF7 and T47D cells. When cells were grown in the presence of FBS (in which case a minimal quantity of estrogens and/or opioids is provided by the serum), we observed either no effect of etorphine or ethylketocyclazocine (EKC) or an increase of secretion and/or production of pS2 and cathepsin D. However, when cells were cultured in charcoal-stripped serum and in the absence of phenol red, the effect of the two opioids is different: EKC decreased the production and/or secretion of pS2 and cathepsin D, whereas etorphine increased their synthesis and/or secretion. The differential effect of the two general opioids was attributed to their different receptor selectivity. Furthermore, the variations of the ratio of secreted/produced protein and the use of cycloheximide indicate that opioids selectively modify the regulatory pathway of each protein discretely. In conclusion, through the interaction with opioid and perhaps other membrane-receptor sites, opioid agonists modify in a dose-dependent manner the production and the secretion of two estrogen-regulated proteins. Opioids may therefore disturb hormonal signals mediated by the estrogen receptors. Hence, these chemicals may have potential endocrine disrupting activities.

Role of epidermal-growth-factor receptor in tumor progression in transformed human mammary epithelial cells

The presence of epidermal-growth-factor receptors (EGFR) and of its ligands (TGFalpha and amphiregulin) in breast-cancer tissues suggests that they play a paracrine/autocrine role in tumor growth or progression. This hypothesis was tested on 3 cell lines, S2T2, NS2T2A and NS2T2A1. These epithelial cells are derived from a normal human breast-epithelial-cell culture transformed by SV40-T Ag, are of the same clonal origin, have respectively increasing levels of EGFR, TGFalpha, amphiregulin and of thymidine-kinase activity associated with increasing tumorigenic potential in nude mice (tumor intake and tumor volume). The monoclonal antibody MAb 425, which blocks ligands interaction with EGFR, reduced by more than 90% anchorage-independent growth of the most tumorigenic cells, NS2T2A1. Another anti-EGFR MAb, 528, reduced to 25% of controls the mean tumor mass after NS2T2A1 grafting in mice. Anti-sense RNA expression of EGFR in these cells confirmed the importance of this receptor in tumor progression, since it reduced significantly the tumor volume and tumor weight of NS2T2A1 cells to 16% of those in mock-transfected control cells.

Oestradiol regulation of the components of the plasminogen-plasmin system in MDA-MB-231 human breast cancer cells stably expressing the oestrogen receptor

To understand the hormonal regulation of the components of the plasminogen-plasmin system in human breast cancer, we examined the oestradiol (E2) regulation of plasminogen activators (PAs), namely urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1) and uPA receptor (uPAR), in our model system. We used stable transfectants of the MDA-MB-231 human breast cancer cells that express either the wild-type (S30 cells) or the mutant 351asp-->tyr oestrogen receptor (ER) (BC-2 cells). Northern blot analysis showed that there was a concentration-dependent down-regulation of uPA, tPA and PAI-1 mRNAs by E2. In contrast, uPAR mRNA was not modulated by E2. The pure anti-oestrogen ICI 182,780 was able to block E2 action, indicating that the regulation of these genes is ER mediated. The E2 also inhibited the expression and secretion of uPA, tPA and PAI-1 proteins as determined by enzyme-linked immunosorbent assay (ELISA) in cell extracts (CEs) and conditioned media (CM). Zymography of the CM confirmed the inhibitory effect of E2 on uPA activity. Thus, we now report the regulation of uPA, PAI-1 and tPA by E2 in both mRNA and protein levels in ER transfectants. The association between down-regulation of the uPA by E2 and known E2-mediated growth inhibition of these cells was also explored. Our findings indicate that down-regulation of uPA by E2 is an upstream event of inhibitory effects of E2 on growth of these cells as the addition of exogenous uPA did not block the growth inhibition by E2.

High-dose therapy with peripheral blood stem cell (PBSC) support using an innovative mobilization regimen in patients with high-risk primary or chemoresponsive metastatic breast cancers

High-dose therapy followed by peripheral blood stem cell (PBSC) support was performed in 29 patients with primary high-risk (Group I) or chemoresponsive metastatic (Group II) breast cancer patients. Group I patients had received PBSC mobilization within 4 weeks of modified radical mastectomy. Group II patients had to achieve minimal residual disease (MRD) by induction chemotherapy before being considered eligible for PBSC mobilization and high-dose therapy. An innovative FE120C regimen (5-FU 600 mg/m2, i.v., day 1; epirubicin 120 mg/m2, i.v., day 1; cyclophosphamide 600 mg/m2, i.v., day 1) plus G-CSF (300 microg/day, subcutaneous injection for 9 days, from day 4 post-FE120C) was used to mobilize PBSCs. After high-dose CTCb (cyclophosphamide 6,000 mg/m2, thiothepa 500 mg/m2, carboplatin 800 mg/m2, in 4 days), patients received PBSC infusion and daily C-CSF 300 microg subcutaneous injection. There were 19 and 16 patients enrolled into Group I and Group II, respectively. Ten of the Group II patients had achieved minimal residual disease (MRD) after induction chemotherapy. The median numbers of mobilized total CD34 + cells for Group I and Group II patients were 27.3 (9.2 to 114.1) x 10(6)/kg and 17.1 (5.9 to 69.1) x 10(6)/kg respectively. The median time to neutrophil recovery (ANC > or = 500/microL) was 8 and 9 days in Group I and II, respectively. The median time to platelet recovery (> or = 50,000/microL) was 10 and 15 days in Group I and II, respectively. No major treatment-related toxicities were noted. In Group I, 13 out of 19 patients (68.4%; 43-87%, 95% C.I.) remained recurrence-free with a median follow-up of 31 months (6 + to 55 + months). In Group II, 3 out of 10 patients (30%; 7-65%, 95% C.I.) remained progression-free at 33 +, 35 +, 39 + months from induction therapy. We suggest that the FE120C plus G-CSF is an effective and innovative regimen for PBSC mobilization in breast cancer patients, and high-dose CTCb therapy with PBSC support is a safe and well-tolerated treatment modality.