Fritz Jänicke

Detection of Circulating Tumor Cells in Peripheral Blood of Patients with Metastatic Breast Cancer: A Validation Study of the CellSearch System

Purpose: The CellSearch system (Veridex, Warren, NJ) is designed to enrich and enumerate circulating tumor cells (CTCs) from peripheral blood. Here, we validated the analytic performance of this system for clinical use in patients with metastatic breast cancer. Experimental Design: This prospective multicenter study conducted at three independent laboratories involved samples from 92 patients with metastatic breast cancer. Intra- and inter-assay variability using controls containing defined numbers of cells (average, 50 and 1,000, respectively), cell stability based on varying storage and shipment conditions, recovery precision from samples spiked with 4 to 12 tumor cells, inter-instrument variability, and positivity of samples from metastatic breast cancer patients were tested. Results: Intra- and inter-assay precision for two sites were high: All eight positive controls analyzed in the same run and >95% of the run to run control values (n = 299) were within the specified ranges. Recovery rate of spiked samples averaged between 80% and 82%. CTCs were detected in ∼70% of metastatic breast cancer patients. CTC values of identical samples processed either immediately after blood drawing or after storage for 24, 48, or 72 h at room temperature or at 4°C did not differ significantly. Shipment of samples had no influence on CTC values. When analyzing identical samples in different centers, inter-instrument accordance was high. Conclusions: The CellSearch system enables the reliable detection of CTCs in blood and is suitable for the routine assessment of metastatic breast cancer patients in the clinical laboratory. Blood samples should be shipped at room temperature and CTC counts are stable for at least 72 h.

Urokinase (uPA) and its inhibitor PAI-1 are strong and independent prognostic factors in node-negative breast cancer

SummaryEvidence has accumulated that invasion and metastasis in solid tumors require the action of tumor-associated proteases, which promote the dissolution of the surrounding tumor matrix and the basement membranes. The serine protease urokinase-type plasminogen activator (uPA), which is elevated in solid tumors, appears to play a key role in these processes.We used enzyme-linked immunoassays (ELISA) to test for uPA antigen and its inhibitor PAI-1 in tumor tissue extracts of 247 breast cancer patients who were enrolled in a prospective study. The relation of these data to known prognostic factors and to other variables such as DNA analysis and cathepsin D was studied. Disease-free and overall survival were analyzed according to Coxs proportional hazard model.The major new finding is that breast cancer patients with either high uPA (>2.97 ng/mg protein) or high content of the uPA inhibitor PAI-1 (>2.18 ng/mg protein) in their primary tumors have an increased risk of relapse and death. Multivariate analyses revealed uPA to be an independent and strong prognostic factor. The impact of uPA is as high as that of the lymph node status. In node-negative patients the impact of uPA is closely followed by that of PAI-1. Since uPA and PAI-1 are independent prognostic factors, the node-negative patients could be subdivided further by combining these two variables. In this refined analysis, patients whose primary tumors have lower levels of both antigens evidently have a very low risk of relapse (93% disease-free survival at three years) in contrast to patients with high uPA and high PAI-1 (55% disease-free survival at three years).The combination of uPA and PAI-1 in our group of patients with axillary node-negative breast cancer allows us to identify the 45 percent of patients having an increased risk of relapse. Consequently, more than half of the patients had less than a 10% probability of relapse and thus would possibly be candidates for being spared the necessity of adjuvant therapy.

Circulating Tumor Cells in Breast Cancer: Correlation to Bone Marrow Micrometastases, Heterogeneous Response to Systemic Therapy and Low Proliferative Activity

Purpose: The incidence and biological characteristics of circulating tumor cells in the blood of patients with breast cancer were examined and subgroups were evaluated in the context of systemic treatment and the presence of disseminated tumor cells in bone marrow. Experimental Design: Circulating tumor cells were isolated from the peripheral blood of patients with breast cancer using a gradient system designed for the enrichment of circulating tumor cells (OncoQuick). Circulating tumor cells were identified with the anti-cytokeratin antibody, A45-B/B3. In subsets of patients, expression of the proliferation-associated Ki-67 antigen in circulating tumor cells and the concomitant presence of micrometastases in bone marrow were examined. Results: In patients with primary breast cancer (stage M0), circulating tumor cells were detected in 5 of 60 patients (8.3%) after surgery and before initiation of adjuvant chemotherapy; a positive correlation to the presence of disseminated tumor cells in bone marrow was observed (P = 0.030, n = 53). During the course of adjuvant chemotherapy, repeated analysis of 20 M0 patients revealed the occurrence of circulating tumor cells in 7 of 16 patients that were initially negative. Patients with metastatic disease (stage M1) showed circulating tumor cells in 25 of 63 cases (39.7%, P < 0.0001 as compared with M0 patients), and a positive finding was correlated with elevated concentrations of the serum tumor marker CA15.3 (P = 0.0093). Performing repeated analysis in a subgroup of 25 M1 patients, circulating tumor cells were found more frequently in patients with progressive disease than in patients with stable disease or remission (87.5% versus 43.8% of patients with circulating tumor cells, respectively; P = 0.047). Independent of the disease-stage, none of the 47 patients examined for the proliferative status of their circulating tumor cells showed coexpression of Ki-67. Conclusions: Circulating tumor cells seem to be nonproliferating cells that persist during chemotherapy. Circulating tumor cell detection is linked to disease progression and elevated tumor marker concentrations in patients with metastatic breast cancer.

Cathepsin B efficiently activates the soluble and the tumor cell receptor-bound form of the proenzyme urokinase-type plasminogen activator (Pro-uPA).

Action of purified human cathepsin B on recombinant single-chain urokinase-type plasminogen activator (pro-uPA) generated enzymatically active two-chain uPA (HMW-uPA), which was indistinguishable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot from plasmin-generated HMW-uPA and from elastase- or thrombin-generated inactive two-chain urokinase-type plasminogen activator. Preincubation of cathepsin B with E-64 (transepoxysuccinyl-L-leucylamino- (4-guanidino)butane, a potent inhibitor for cathepsin B) prior to the addition of pro-uPA prevented the activation of pro-uPA. The cleavage site within the cathepsin B-treated urokinase-type plasminogen activator (uPA) molecule, determined by N-terminal amino acid sequence analysis, is located between Lys158 and Ile159. Pro-uPA is cleaved by cathepsin B at the same peptide bond that is cleaved by plasmin or kallikrein. Binding of cathepsin B-activated pro-uPA to the uPA receptor on U937 cells did not differ from that of enzymatically inactive pro-uPA, indicating an intact receptor-binding region within the growth factor-like domain of the cathepsin B-treated uPA molecule. Not only soluble but also tumor cell receptor-bound pro-uPA could be efficiently cleaved by cathepsin B to generate enzymatically active two-chain uPA. Thus, cathepsin B can substitute for plasmin in the proteolytic activation of pro-uPA to enzymatically active HMW-uPA. In contrast, no significant activation of pro-uPA by cathepsin D was observed. As tumor cells may produce both pro-uPA and cathepsin B, implications for the activation of tumor cell-derived pro-uPA by cellular proteases may be considered.

Estrogen receptor alpha (ESR1) gene amplification is frequent in breast cancer

Using an Affymetrix 10K SNP array to screen for gene copy number changes in breast cancer, we detected a single-gene amplification of the ESR1 gene, which encodes estrogen receptor alpha, at 6q25. A subsequent tissue microarray analysis of more than 2,000 clinical breast cancer samples showed ESR1 amplification in 20.6% of breast cancers. Ninety-nine percent of tumors with ESR1 amplification showed estrogen receptor protein overexpression, compared with 66.6% cancers without ESR1 amplification (P < 0.0001). In 175 women who had received adjuvant tamoxifen monotherapy, survival was significantly longer for women with cancer with ESR1 amplification than for women with estrogen receptor–expressing cancers without ESR1 amplification (P = 0.023). Notably, we also found ESR1 amplification in benign and precancerous breast diseases, suggesting that ESR1 amplification may be a common mechanism in proliferative breast disease and a very early genetic alteration in a large subset of breast cancers.

Effective activation of the proenzyme form of the urokinase‐type plasminogen activator (pro‐uPA) by the cysteine protease cathepsin L

Increased levels of both the cysteine protease, cathepsin L, and the serine protease, uPA (urokinase‐type plasminogen activator), are present in solid tumors and are correlated with malignancy. uPA is released by tumor cells as an inactive single‐chain proenzyme (pro‐uPA) which has to be activated by proteolytic cleavage. We analyzed in detail the action of the cysteine protease, cathepsin L, on recombinant human pro‐uPA. Enzymatic assays, SDS‐PAGE and Western blot analysis revealed that cathepsin L is a potent activator of pro‐uPA. As determined by N‐terminal amino acid sequence analysis, activation of pro‐uPA by cathepsin L is achieved by cleavage or the Lys158‐lle159 peptide bond, a common activation site of serine proteases such as plasmin and kallikrein. Similar to cathepsin B (Kobayashi et al., J. Biol. Chem. (1991) 266, 5147‐5152) cleavage of pro‐uPA by cathepsin L was most effective at acidic pH (molar ratio of cathepsin L to pro‐uPA of 1:2,000). Nevertheless, even at pH 7.0, pro‐uPA was activated by cathepsin L, although a 10‐fold higher concentration of cathepsin L was required. As tumor cells may produce both pro‐uPA and cathepsin L, implications for the activation of tumor cell‐derived pro‐uPA by cathepsin L may be considered. Different pathways activation of pro‐uPA in tumor tissues may coexist: (i) autocatalytic intrinsic activation of pro‐uPA; (ii) activation by serine proteases (plasmin, kallikrein. Factor XIIa); and (iii) activation by cysteine proteases (cathepsin B and L).

Expression of Extracellular Matrix Metalloproteases Inducer on Micrometastatic and Primary Mammary Carcinoma Cells

Purpose: EMMPRIN (extracellular matrix metalloprotease inducer) is a glycosylated member of the immunoglobulin superfamily known to stimulate the production of matrix metalloproteases (MMPs) 1, 2, and 3 and MT1-MMP in peritumoral fibroblasts. We here evaluated whether EMMPRIN expression is related to tumor progression in human breast cancer. Experimental Design: An immunohistochemical study using high-density tissue microarrays (n = 2222 breast cancer samples) and EMMPRIN-specific antibodies HIM6 and MEM-M6/1 was performed, and staining results were statistically correlated with various clinicopathological parameters. To analyze the putative association between EMMPRIN expression and bone marrow (BM) micrometastasis, an additional set of 55 breast tumors from patients with or without micrometastatic cells as determined with anti-cytokeratin antibody A45-B/B3 were included in our study. Cytokeratin-positive cells in BM were costained with EMMPRIN-specific antibody 1G6.2. Results: Positive EMMPRIN staining correlated significantly with various histopathological risk factors (higher tumor grade, increased tumor size, negative estrogen receptor status and progesterone receptor status, and higher mitotic index) as well as decreased tumor-specific survival (log-rank, P = 0.0027). In particular, in patients > 50 years (i.e., postmenopausal women), EMMPRIN expression was an independent prognosticator as shown by Cox regression analysis (relative risk = 1.7, 95% confidence interval 1.4–4.3, P = 0.036). An involvement of EMMPRIN in tumor progression was also supported by the fact that it was expressed on ∼90% of micrometastatic cells in BM. Conclusions: EMMPRIN expression in primary tumor predicts an unfavorable prognosis in breast cancer, suggesting a crucial role of EMMPRIN in progression of human mammary carcinomas.

Prognostic significance of urokinase (uPA) and its inhibitor PAI-1 for survival in advanced ovarian carcinoma stage FIGO IIIc

SummaryStrong evidence has accumulated on the prognostic value of tumour-associated proteolytic factors in patients afflicted with solid malignant tumours, including advanced ovarian cancer. We evaluated the prognostic impact of the protease urokinase plasminogen activator (uPA) and its inhibitor PAI-1 on overall survival in patients with advanced ovarian cancer stage FIGO IIIc in order to select patients at risk. uPA and PAI-1 antigen were determined by ELISA in primary tumour tissue extracts of 86 ovarian cancer patients FIGO stage IIIc enrolled in a prospective study. Univariate and multivariate analyses were performed using the Cox proportional hazard model. The time-varying coefficient model of Gray was used to assess the time-dependent strength of prognostic factors tumour mass, uPA and PAI-1 on overall survival. In all patients, uPA and PAI-1 (optimized cut-offs of 2.0 and 27.5 ng mg-1 protein respectively), in addition to the traditional prognostic parameters of residual tumour mass, nodal status, grading and ascites volume, were of prognostic significance in univariate analysis for overall survival. Even in patients with residual tumour mass (n = 43), the statistically independent prognostic impact of PAI-1 persisted, allowing further discrimination between low- and high-risk patients. In multivariate analysis, residual tumour mass (P < 0.001, relative risk (RR) 4.5), PAI-1 (P < 0.001; RR 3.1) and nodal status (P = 0.022, RR 2.6) turned out to be strong, statistically independent prognostic parameters. Evaluation of the time-dependent prognostic impact of residual tumour mass and PAI-1 on overall survival (n = 86, 50 months) revealed that the prognostic power of these factors increased with time. In patients with advanced ovarian cancer, both residual tumour mass and PAI-1 are statistically independent strong prognostic factors. Even within patient subgroups with or without residual tumour mass, PAI-1 allowed selection of patients at risk who might benefit from individualized therapy protocols.

Intensive Dose-Dense Compared With Conventionally Scheduled Preoperative Chemotherapy for High-Risk Primary Breast Cancer

PURPOSE To compare preoperative intense dose-dense (IDD) chemotherapy with conventionally scheduled preoperative chemotherapy in high-risk primary breast cancer (BC). PATIENTS AND METHODS In this randomized phase III trial a total of 668 eligible primary BC patients stratified for tumors > or = 3 cm (n = 567) or inflammatory BC (n = 101) were randomly assigned to receive concurrent preoperative epirubicin/paclitaxel every 3 weeks or dose-dense and dose-escalated sequential epirubicin followed by paclitaxel every 2 weeks. All patients received three cycles of cyclophosphamide, methotrexate, and fluorouracil chemotherapy after surgery. RESULTS IDD treatment significantly improved pathologic complete response rate (18% v 10%; odds ratio [OR] 1.89; P = .008), disease-free survival (DFS; hazard ratio [HR], 0.71; P = .011), and overall survival (OS; HR, 0.83; P = .041) compared to epirubicin/paclitaxel. Patients with inflammatory BC had a particularly poor prognosis and did not appear to benefit from IDD therapy in this trial (DFS HR, 1.10; P = .739; OS HR, 1.25; P = .544). In contrast, patients with noninflammatory BC significantly benefited from IDD treatment (DFS HR, 0.65, P = .005; OS HR, 0.77, P = .013). Treatment effects in multivariate analysis were significant for noninflammatory BC (DFS HR, 0.65, P = .015; OS HR, 0.79, P = .034), but not for all patients (DFS HR, 0.76; P = .088; OS HR, 0.82; P = .059). IDD therapy was associated with significantly more nonhematologic toxicities, anemia, and thrombocytopenia, but with similar neutropenia and infection rates. CONCLUSION Our results support the efficacy and short-term safety of IDD as preoperative chemotherapy. IDD was less well tolerated compared to standard treatment, but improved clinical outcomes in patients with noninflammatory high-risk primary BC.

Ten-year analysis of the prospective multicentre Chemo-N0 trial validates American Society of Clinical Oncology (ASCO)-recommended biomarkers uPA and PAI-1 for therapy decision making in node-negative breast cancer patients

AIM Final 10-year analysis of the prospective randomised Chemo-N0 trial is presented. Based on the Chemo-N0 interim results and an European Organisation for Research and Treatment of Cancer (EORTC) pooled analysis (n=8377), American Society of Clinical Oncology (ASCO) and Arbeitsgemeinschaft Gynäkologische Onkologie (AGO) guidelines recommend invasion and metastasis markers urokinase-type plasminogen activator (uPA)/plasminogen activator inhibitor-1 (PAI-1) for risk assessment and treatment decision in node-negative (N0) breast cancer (BC). METHODS The final Chemo-N0 trial analysis (recruitment 1993-1998; n=647; 12 centres) comprises 113 (5-167) months of median follow-up. Patients with low-uPA and PAI-1 tumour tissue levels (n=283) were observed. External quality assurance guaranteed uPA/PAI-1 enzyme-linked immunosorbent assay (ELISA) standardisation. Of 364 high uPA and/or PAI-1 patients, 242 agreed to randomisation for CMF chemotherapy (n=117) versus observation (n=125). RESULTS Actuarial 10-year recurrence rate (without any adjuvant systemic therapy) for high-uPA/PAI-1 observation group patients (randomised and non-randomised) was 23.0%, in contrast to only 12.9% for low-uPA/PAI-1 patients (plog-rank=0.011). High-risk patients randomised to cyclophosphamide-methotrexate-5-fluorouracil (CMF) therapy had a 26.0% lower estimated probability of disease recurrence than those randomised for observation (intention-to-treat (ITT)-analysis: hazard ratio (HR) 0.74 (0.44-1.27); plog-rank=0.28). Per-protocol analysis demonstrated significant treatment benefit: HR 0.48 (0.26-0.88), p=0.019, disease-free survival (DFS) Cox regression, adjusted for tumour stage and grade. CONCLUSIONS Chemo-N0 is the first prospective biomarker-based therapy trial in early BC defining patients reaching good long-term DFS without adjuvant systemic therapy. Using a standardised uPA/PAI-1 ELISA, almost half of N0-patients could be spared chemotherapy, while high-risk patients benefit from adjuvant chemotherapy. These 10-year results validate the long-term prognostic impact of uPA/PAI-1 and the benefit from adjuvant chemotherapy in the high-uPA/PAI-1 group at highest level of evidence. They thus support the guideline-based routine use of uPA/PAI-1 for risk-adapted individualised therapy decisions in N0 breast cancer.