Markers associated with genomic instability, immunogenicity and immune therapy responsiveness in Metaplastic carcinoma of the breast: Expression of γH2AX, pRPA2, P53, PD-L1 and tumor infiltrating lymphocytes in 76 cases.

BACKGROUND: Metaplastic breast cancer (MpBC) is an aggressive subtype of breast carcinoma that is often resistant to conventional chemotherapy. Therefore, novel treatment strategies are urgently needed. Immune check point inhibitors have shown activity in programmed death-ligand 1 (PD-L1) - positive metastatic triple negative breast carcinoma (TNBC), which raises the possibility that immunotherapy may also be effective in MpBC as most of the MpBCs are triple negative. The aim of the present study was to assess genomic instability and immunogenicity in tumor specimens of patients with MpBC. METHODS: A total of 76 patients diagnosed with MpBC over a 15-year period were included in the study. We performed immunohistochemical analyses for tumor cell PD-L1, immune cell PD-L1 and p53 on tissue microarrays (TMAs), analyzed stromal and intratumoral tumor infiltrating lymphocytes (TILs) from hematoxylin and eosin-stained (H&E) slides and scored gamma-H2AX (γH2AX) and phosphorylated-RPA2 (pRPA2) from whole tissue sections. We correlated marker expression with clinicopathologic features and clinical outcome. RESULTS: All tumors expressed γH2AX and pRPA2 with median expressions of 43% and 44%. P53- (68%), tumor cell PD-L1- (59%) and immune cell PD-L1-positivity (62%) were common in MpBCs. Median stromal TIL and intratumoral TIL counts were 5% and 0. The spindle and squamous cell carcinomas expressed the highest levels of PD-L1 and TILs, and carcinoma with mesenchymal differentiation the lowest. CONCLUSIONS: MpBC appears to be an immunogenic cancer with high genomic instability and frequent PD-L1-positivity, implying that check point inhibitors might be effective in MpBC. Expression levels of PD-L1 and TILs varied across different histologic subtypes, suggesting that immunotherapy might be less effective in carcinoma with mesenchymal differentiation.

Axillary nodal metastatic burden in patients with breast cancer with clinically positive axillary nodes.

BACKGROUND: The aim of this study was to determine preoperative factors and tumour characteristics related to a high nodal tumour burden in patients with clinically node-positive breast cancer. These findings were used to construct a predictive tool to evaluate the patient-specific risk of having more than two axillary lymph node metastases. METHODS: Altogether, 507 consecutive patients with breast cancer and axillary lymph node metastasis diagnosed by preoperative ultrasound-guided needle biopsy were reviewed. These patients underwent breast surgery and axillary lymph node dissection at Helsinki University Hospital between 2010 and 2014. Patients were grouped into those with one or two, and those with more than two lymph node metastases. RESULTS: There were 153 patients (30·2 per cent) with one or two lymph node metastases and 354 (69·8 per cent) with more than two metastases. Five-year disease-free survival was poorer for the latter group (P = 0·032). Five-year overall survival estimates for patients with one or two and those with more than two lymph node metastases were 87·0 and 81·4 per cent respectively (P = 0·215). In multivariable analysis, factors significantly associated with more than two lymph node metastases were: age, tumour size, lymphovascular invasion in the primary tumour, extracapsular extension of metastasis in lymph nodes, and morphology of lymph nodes. These factors were included in a multivariable predictive model, which had an area under the curve of 0·828 (95 per cent c.i. 0·787 to 0·869). CONCLUSION: The present study provides a patient-specific prediction model for evaluating nodal tumour burden in patients with clinically node-positive breast cancer.

A predictive tool to estimate the risk of axillary metastases in breast cancer patients with negative axillary ultrasound.

BACKGROUND: Sentinel node biopsy (SNB) is the "gold standard" in axillary staging in clinically node-negative breast cancer patients. However, axillary treatment is undergoing a paradigm shift and studies are being conducted on whether SNB may be omitted in low-risk patients. The purpose of this study was to evaluate the risk factors for axillary metastases in breast cancer patients with negative preoperative axillary ultrasound. METHODS: A total of 1,395 consecutive patients with invasive breast cancer and SNB formed the original patient series. A univariate analysis was conducted to assess risk factors for axillary metastases. Binary logistic regression analysis was conducted to form a predictive model based on the risk factors. The predictive model was first validated internally in a patient series of 566 further patients and then externally in a patient series of 2,463 patients from four other centers. All statistical tests were two-sided. RESULTS: A total of 426 of the 1,395 (30.5 %) patients in the original patient series had axillary lymph node metastases. Histological size (P < 0.001), multifocality (P < 0.001), lymphovascular invasion (P < 0.001), and palpability of the primary tumor (P < 0.001) were included in the predictive model. Internal validation of the model produced an area under the receiver operating characteristics curve (AUC) of 0.731 and external validation an AUC of 0.79. CONCLUSIONS: We present a predictive model to assess the patient-specific probability of axillary lymph node metastases in patients with clinically node-negative breast cancer. The model performs well in internal and external validation. The model needs to be validated in each center before application to clinical use.

Overabundant FANCD2, alone and combined with NQO1, is a sensitive marker of adverse prognosis in breast cancer.

BACKGROUND: Defective DNA repair is central to the progression and treatment of breast cancer. Immunohistochemically detected DNA repair markers may be good candidates for novel prognostic and predictive factors that could guide the selection of individualized treatment strategies. PATIENTS AND METHODS: We have analyzed nuclear immunohistochemical staining of BRCA1, FANCD2, RAD51, XPF, and PAR in relation to clinicopathological and survival data among 1240 paraffin-embedded breast tumors, and additional gene expression microarray data from 76 tumors. The antioxidant enzyme NQO1 was analyzed as a potential modifier of prognostic DNA repair markers. RESULTS: RAD51 [hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.70-0.94, P = 0.0050] and FANCD2 expression (HR 1.50, 95% CI 1.28-1.76, P = 1.50 × 10(-7)) were associated with breast cancer survival. High FANCD2 expression correlated with markers of adverse prognosis but remained independently prognostic in multivariate analysis (HR 1.27, 95% CI 1.08-1.49, P = 0.0043). The FANCD2-associated survival effect was most pronounced in hormone receptor positive, HER2-negative tumors, and in tumors with above-median NQO1 expression. In the NQO1-high subset, patients belonging to the highest quartile of FANCD2 immunohistochemical scores had a threefold increased risk of metastasis or death (HR 3.10, 95% CI 1.96-4.92). Global gene expression analysis indicated that FANCD protein overabundance is associated with the upregulation of proliferation-related genes and a downregulated nucleotide excision repair pathway. CONCLUSION: FANCD2 immunohistochemistry is a sensitive, independent prognostic factor in breast cancer, particularly when standard markers indicate relatively favorable prognosis. Taken together, our results suggest that the prognostic effect is linked to proliferation, DNA damage, and oxidative stress; simultaneous detection of FANCD2 and NQO1 provides additional prognostic value.

International multicenter tool to predict the risk of four or more tumor-positive axillary lymph nodes in breast cancer patients with sentinel node macrometastases.

Recently, many centers have omitted routine axillary lymph node dissection (ALND) after metastatic sentinel node biopsy in breast cancer due to a growing body of literature. However, existing guidelines of adjuvant treatment planning are strongly based on axillary nodal stage. In this study, we aim to develop a novel international multicenter predictive tool to estimate a patient-specific risk of having four or more tumor-positive axillary lymph nodes (ALN) in patients with macrometastatic sentinel node(s) (SN). A series of 675 patients with macrometastatic SN and completion ALND from five European centers were analyzed by logistic regression analysis. A multivariate predictive model was created and validated internally by 367 additional patients and then externally by 760 additional patients from eight different centers. All statistical tests were two-sided. Prevalence of four or more tumor-positive ALN in each center's series (P = 0.010), number of metastatic SNs (P < 0.0001), number of negative SNs (P = 0.003), histological size of the primary tumor (P = 0.020), and extra-capsular extension of SN metastasis (P < 0.0001) were included in the predictive model. The model's area under the receiver operating characteristics curve was 0.766 in the internal validation and 0.774 in external validation. Our novel international multicenter-based predictive tool reliably estimates the risk of four or more axillary metastases after identifying macrometastatic SN(s) in breast cancer. Our tool performs well in internal and external validation, but needs to be further validated in each center before application to clinical use.

Outcome of patients with ductal carcinoma in situ and sentinel node biopsy.

BACKGROUND: In sentinel node biopsy (SNB), tumor-positive findings, mainly micrometastases and isolated tumor cells (ITC) have been found in up to 8%-16% of patients with pure ductal carcinoma in situ (DCIS) or microinvasive DCIS (DCISM). The prognostic significance of such findings is largely unknown. The aim of this study is to examine the outcome of DCIS and DCISM patients with SNB. METHODS: A total of 280 breast cancer patients with pure or microinvasive DCIS underwent SNB between April 2001 and December 2010 at the Breast Surgery Unit of Helsinki University Central Hospital. Patient, tumor, SNB procedure, and follow-up data were gathered. The median follow-up was 50 months (range 7-123 months). RESULTS: Altogether, 21 patients had tumor-positive sentinel node findings. Of these, 14 were in pure DCIS patients (1 macrometastasis, 1 micrometastasis, 12 ITC) and 7 in DCISM patients (1 macrometastasis, 2 micrometastases, 4 ITC). Also, 16 patients, 10 with pure DCIS and 6 with DCISM, underwent completion axillary lymph node dissection (ALND). Only 1 of them, a patient with DCISM, had additional tumor positive finding in the ALND. During a median follow-up of 50 months (range 7-123 months) there were 5 local recurrences. One patient with pure DCIS and tumor-negative SNB developed overt axillary metastases and later also distant metastases. CONCLUSIONS: DCIS and DCISM patients do have tumor positive findings, but a majority of these are ITC or micrometastases. In light of this study, these findings do not affect the outcome of DCIS or DCISM patients.

A simple nomogram to evaluate the risk of nonsentinel node metastases in breast cancer patients with minimal sentinel node involvement.

BACKGROUND: Tumor-positive sentinel node biopsy (SNB) suggests a risk of nonsentinel node metastases in breast cancer. This risk is lower after micrometastasis or isolated tumor cells (ITC) in the sentinel node (SN), and recent studies suggest that completion axillary lymph node dissection (ALND) might not improve outcome in these patients. We aim to validate existing predictive models and to develop a new model for micrometastatic and ITC patients. METHODS: A series of 484 patients with micrometastases or ITC in SN followed by ALND was used to evaluate factors affecting nonsentinel node involvement. Logistic regression analysis was performed to construct a predictive model, which was validated by a separate series of 51 patients. RESULTS: Only 7.2% of patients had additional metastases on completion ALND. Tumor diameter and multifocality associated with nonsentinel status on multivariate analysis. A predictive model was constructed showing good [area under the curve (AUC) 0.791] discrimination in the validation series. Previously published models performed poorly in our patient population. CONCLUSIONS: Nonsentinel node metastases are rare with micrometastasis or ITC in SN. Most published predictive models for nonsentinel node involvement perform poorly in the present patient population. We developed a new predictive model which seems to perform well in discriminating patients with more than 10% risk of additional metastases. However, the presented nomogram needs to be validated with an independent patient series to evaluate its accuracy, especially for high-risk patients.

Potential CYP2C9-mediated drug-drug interactions in hospitalized type 2 diabetes mellitus patients treated with the sulphonylureas glibenclamide, glimepiride or glipizide.

OBJECTIVES: Sulphonylureas are widely used in the treatment of type 2 diabetes mellitus (T2DM). Based on laboratory findings, we determined the clinical significance of potential CYP2C9-mediated drug-drug interactions in hospitalized patients receiving glibenclamide, glimepiride or glipizide, all of which are metabolized by CYP2C9, together with a CYP2C9 inhibitor. DESIGN, SETTING AND SUBJECTS: An observational pharmaco-epidemiological database study was performed in a university hospital setting with 3884 patients with T2DM. MAIN OUTCOME MEASURES: Efficacy and safety of sulphonylurea therapy during the potential interaction (sulphonylurea treatment with a CYP2C9 inhibitor) vs. control periods (sulphonylurea treatment without a CYP2C9 inhibitor) were estimated using laboratory parameters. RESULTS: Almost 20% of patients were exposed to a potential drug-drug interaction with a CYP2C9 inhibitor during sulphonylurea treatment. More than 75% of the potential interactions occurred with trimethoprim, metronidazole and fluconazole. When all sulphonylureas were pooled and adjusted for age, gender, ward and sulphonylurea dose, mean and maximum fasting plasma glucose concentrations as well as maximum values of glycosylated haemoglobin were significantly lower during the interaction periods compared with control periods, whereas mean and minimum activities of alanine amino transferase and gamma-glutamyl transferase were higher. The minimum fasting plasma glucose values were more often below the target range in patients with potential interactions. The sulphonylurea dose did not differ significantly between patients who were or were not concomitantly treated with a potentially interacting drug. CONCLUSIONS: Concomitant use of a CYP2C9 inhibitor results in exaggerated pharmacodynamic effects of sulphonylureas and increases the risk of hypoglycaemia in T2DM patients receiving glibenclamide, glimepiride or glipizide.

High cyclin B1 expression is associated with poor survival in breast cancer.

Cyclin B1 regulates the G(2)-M transition of the cell cycle. Cyclin B1 expression is higher in premalignant and malignant than normal breast lesions. Correlation of cyclin B1 expression with other histopathological variables and prognostic role in breast cancer are not fully understood. Traditionally used prognostic criteria identify large subset of patients to receive adjuvant chemotherapy and to be exposed to adverse effects. A reliable and simple method helping prognostic evaluation in breast cancer is needed. We analysed cyclin B1 expression on 1348 invasive breast cancers and studied correlations with other histopathological variables and survival. High cyclin B1 correlated with high tumour grade, large tumour size and positive nodal status, oestrogen and progesterone receptor negativity, positive HER2 and p53 status, young age at diagnosis, and high cyclin E, cyclin A and Ki67 expression. Among patients not given adjuvant chemotherapy high cyclin B1 was a strong predictor of shorter overall and metastasis-free survival (RR 3.74, P<0.0005 and RR 3.51, P<0.0005, respectively), and remained as an independent prognostic factor also in multivariate analysis (RR 1.80, P=0.04 and RR 2.31, P=0.02, respectively). This study suggests high cyclin B1 associates with aggressive phenotype and is an independent prognostic factor in breast cancer.

The prevalence of and risk factors for four or more metastatic axillary lymph nodes in breast cancer patients undergoing sentinel node biopsy.

BACKGROUND: Our aim was to investigate the prevalence of and risk factors for having four or more positive axillary lymph nodes among breast cancer patients undergoing sentinel node (SN) biopsy. PATIENTS AND METHODS: Between February 2005 and July 2007, 1,062 breast cancer patients with the clinical tumour size not larger than 3 cm underwent SN biopsy and axillary clearance (AC), when SN was positive. These patients were identified in a prospectively collected database. RESULTS: Four or more positive axillary nodes were detected in 68 patients representing 6% of the entire study population and 16% of the 436 node positive cases. Features regarded as predictive for a very low risk included (1) T1a or T1b tumours, (2) grade I tumours, (3) tumours with a favourable subtype, that is mucinous, tubular or medullary breast cancer, (4) no nodal macrometastases and (5) SN ratio lower than 0.5. CONCLUSIONS: Only few patients with T1a-b tumours or grade 1 tumours, as well as those with minimal involvement of the sentinel nodes have four or more positive axillary lymph nodes. However, these risk factors can be definitely assessed only after surgery, decreasing their value in the clinical decision making.

Tumor targeting with a selective gelatinase inhibitor.

Several lines of evidence suggest that tumor growth, angiogenesis, and metastasis are dependent on matrix metalloproteinase (MMP) activity. However, the lack of inhibitors specific for the type IV collagenase/gelatinase family of MMPs has thus far prevented the selective targeting of MMP-2 (gelatinase A) and MMP-9 (gelatinase B) for therapeutic intervention in cancer. Here, we describe the isolation of specific gelatinase inhibitors from phage display peptide libraries. We show that cyclic peptides containing the sequence HWGF are potent and selective inhibitors of MMP-2 and MMP-9 but not of several other MMP family members. Our prototype synthetic peptide, CTTHWGFTLC, inhibits the migration of human endothelial cells and tumor cells. Moreover, it prevents tumor growth and invasion in animal models and improves survival of mice bearing human tumors. Finally, we show that CTTHWGFTLC-displaying phage specifically target angiogenic blood vessels in vivo. Selective gelatinase inhibitors may prove useful in tumor targeting and anticancer therapies.

Effect of treatment of larynx and hypopharynx carcinomas on serum syndecan-1 concentrations.

PURPOSE: Syndecan-1 is a multifunctional transmembrane heparan sulfate proteoglycan present on a variety of cell types that mediates basic fibroblast growth factor (bFGF) and other growth factor binding. High serum syndecan-1 (S-syndecan-1) ectodomain levels have been found to be associated with poor outcome in lung cancer and myeloma, but little is known about the effect of cancer treatment on S-syndecan-1 levels. We studied S-syndecan-1 levels longitudinally in a series of patients diagnosed with locoregional squamous cell larynx or hypopharynx carcinoma (n=44) and who we treated with surgery and/or radiation therapy. METHODS: S-syndecan-1 and S-bFGF levels were measured with ELISA prior to, during, and following primary treatment of patients. Syndecan-1 expression was assessed from formalin-fixed and paraffin-embedded tumour samples using immunohistochemistry. RESULTS: S-syndecan-1 levels tended to correlate positively with S-bFGF levels, and the pretreatment levels decreased from a median value of 75 to 58 ng/ml 3 months following treatment (P<0.0001). Patients treated with radiation therapy had a transient increase in S-syndecan-1 during the course of radiation therapy. Patients whose S-syndecan-1 decreased >or=10% from the pretreatment level had more favourable survival than those whose levels remained stable or increased (P=0.0069). Recurred cancer was associated with elevated S-syndecan-1 as compared to the levels measured 3 months following completion of primary therapy. CONCLUSIONS: These findings suggest that a part of S-syndecan-1 originates from the cancerous tissue, and that S-syndecan-1 levels generally decrease following successful cancer treatment.

The prevalence of axillary lymph-node metastases in patients with pure tubular carcinoma of the breast and sentinel node biopsy.

AIMS: We aimed to evaluate the prevalence of and the risk factors for axillary lymph-node metastases in pure tubular carcinoma (PTC) of the breast. The role of axillary staging and treatment in PTC was also evaluated. METHODS: Between March 2001 and August 2004, 33 PTC patients underwent sentinel node (SN) biopsy as a part of their surgical treatment. Level I/II axillary clearance was carried out in case of tumour positive SN findings. To confirm the correct histological diagnosis (PTC, >90% tubular component), the breast tumours were reviewed by an expert breast pathologist. RESULTS: The SN were successfully harvested in all patients. The median number of SN harvested in the axilla was 3 (range 1-10). Nine (27%) of the 33 patients had axillary nodal metastases. The median number of metastatic nodes was 1 (range 1-3). The median size of the SN metastases was 0.5 mm (mean 1.7 mm, range 0.4-5 mm). In six patients, micrometastases were the only tumour positive SN findings. The median histological tumour size was similar, 9 vs 10mm, in patients with or without axillary metastases. The median patient age was 54 (range 44-71) and 57 (range 39-80) years, respectively. After the histopathological review, six of the 27 patients with true PTC had axillary metastases. The review did not significantly change the risk factors for axillary metastases. CONCLUSIONS: Every fourth PTC patient has axillary lymph-node metastases, most often micrometastases. SN biopsy appears as a feasible method for axillary staging in PTC patients.

Damage to multicellular human H-2 glioma spheroids incubated with LAK cells: an ultrastructural study.

Local brain tumor therapy using lymphokine-activated killer (LAK) cells and recombinant interleukin-2 (rIL-2) has not proved to be effective in preliminary clinical trials. One obstacle to effective use of this therapy is ignorance about the events that follow contact of the LAK cells with glioma tissue. We used multicellular spheroids grown from human glioma cell lines as targets to study, in vitro, the effect of LAK cells against three-dimensional glioma tissue. Here we describe the ultrastructural changes in spheroids of H-2 glioma cells incubated in pellets of LAK cells for up to 24 hours. In H-2 spheroids, cellular damage was not restricted to the effector cell-target cell (effector-target) contact; it extended farther, at least partly because of nonspecific changes in the spheroid micromilieu. Formation of cytoplasmic blebs, a characteristic effect of T cells, natural killer cells, and LAK cells on single target cells, also occurs in H-2 spheroids, and it is not limited to the effector-target contact area either. These findings suggest that LAK cells release membrane-damaging agents that remain active outside the effector-target area, in the micromilieu of H-2 spheroid tissue.

Chromosomal aberrations in lymphocytes predict human cancer independently of exposure to carcinogens. European Study Group on Cytogenetic Biomarkers and Health.

An increased risk of cancer in healthy individuals with high levels of chromosomal aberrations (CAs) in peripheral blood lymphocytes has been described in recent epidemiological studies. This association did not appear to be modified by sex, age, country, or time since CA test, whereas the role played by exposure to carcinogens is still uncertain because of the requisite information concerning occupation and lifestyle was lacking. We evaluated in the present study whether CAs predicted cancer because they were the result of past exposure to carcinogens or because they were an intermediate end point in the pathway leading to disease. A nested case-control study was performed on 93 incident cancer cases and 62 deceased cancer cases coming from two prospective cohort studies performed in Nordic countries (Denmark, Finland, Norway, and Sweden) and Italy. For each case, four controls matched by country, sex, year of birth, and year of CA test were randomly selected. Occupational exposure and smoking habit were assessed by a collaborative group of occupational hygienists. Logistic regression models indicated a statistically significant increase in risk for subjects with a high level of CAs compared to those with a low level in the Nordic cohort (odds ratio, 2.35; 95% confidence interval, 1.31-4.23) and in the Italian cohort (odds ratio, 2.66; 95% confidence interval, 1.26-5.62). These estimates were not affected by the inclusion of occupational exposure level and smoking habit in the regression model. The risk for high versus low levels of CAs was similar in subjects heavily exposed to carcinogens and in those who had never, to their knowledge, been exposed to any major carcinogenic agent during their lifetime, supporting the idea that chromosome damage itself is involved in the pathway to cancer. The results have important ramifications for the understanding of the role played by sporadic chromosome damage for the origin of neoplasia-associated CAs.

Lymphatic endothelium and Kaposi's sarcoma spindle cells detected by antibodies against the vascular endothelial growth factor receptor-3.

Lymphatic vessels have been difficult to study in detail in normal and tumor tissues because of the lack of molecular markers. Here, monoclonal antibodies against the extracellular domain of the vascular endothelial growth factor-C receptor that we have named VEGFR-3 were found to specifically stain endothelial cells of lymphatic vessels and vessels around tumors such as lymphoma and in situ breast carcinoma. Interestingly, the spindle cells of several cutaneous nodular AIDS-associated Kaposi's sarcomas and the endothelium around the nodules were also VEGFR-3 positive. The first specific molecular marker for the lymphatic endothelium should provide a useful tool for the analysis of lymphatic vessels in malignant tumors and their metastases and the cellular origin and differentiation of Kaposi's sarcomas.

Breast cancer prognosis and isolated tumor cell findings in axillary lymph nodes after core needle biopsy and fine needle aspiration cytology: Biopsy method and breast cancer outcome.

BACKGROUND: It is unknown whether performing a core needle biopsy (CNB) to diagnose breast cancer increases the incidence of isolated tumor cells (ITC) in the axillary sentinel lymph nodes. METHODS: Patients diagnosed with unilateral invasive pT1 breast cancer (≤2 cm in diameter, n = 1525) at a single center between February 2001 and August 2005 were included in this prospective observational cohort study. The patients were categorized into two groups according to the type of the preoperative breast needle biopsy performed, the CNB and the fine needle aspiration cytology (FNAC) groups, and followed up for a median of 9.5 years after breast surgery. RESULTS: 868 (56.9%) patients had FNAC and 657 (43.2%) CNB. In the subset of patients with no axillary metastases (pN0, n = 1005) 70 patients had ITC, 37 (4.3%) out of the 546 patients in FNAC group and 33 (5.0%) out of the 459 patients in the CNB group (p = 0.798). The type of tumor biopsy did not influence breast cancer-specific survival (p = 0.461) or local recurrence-free survival (p = 0.814) in univariable survival analyses. Overall, survival favored the CNB group in a univariable analysis, but no difference in survival emerged in a multivariable analysis (p = 0.718). CONCLUSIONS: CNB was not associated with a greater incidence of ITC in axillary lymph nodes as compared with FNAC, and did not have an adverse effect on survival outcomes in a patient population treated with modern adjuvant therapies.

Deregulated hepsin protease activity confers oncogenicity by concomitantly augmenting HGF/MET signalling and disrupting epithelial cohesion.

Hepsin belongs to a family of cell-surface serine proteases, which have sparked interest as therapeutic targets because of the accessibility of extracellular protease domain for inhibitors. Hepsin is frequently amplified and/or overexpressed in epithelial cancers, but it is not clear how enhanced hepsin expression confers a potential for oncogenicity. We show that hepsin is consistently overexpressed in more than 40% of examined breast cancers, including all major biological subtypes. The effects of doxycycline-induced hepsin overexpression were examined in mammary epithelial organoids, and we found that induced hepsin acutely downmodulates its cognate inhibitor, hepatocyte growth factor (HGF) activator inhibitor type 1 (HAI-1). Hepsin-induced depletion of cellular HAI-1 led to a sharp increase in pericellular serine protease activity. The derepressed hepsin proteolytically activated downstream serine proteases, augmented HGF/MET signalling and caused deterioration of desmosomes and hemidesmosomes; structures important for cell cohesion and cell-basement membrane interaction. Moreover, chronic induction of hepsin considerably shortened the latency of Myc-dependent tumourigenesis in the mouse mammary gland. The serine protease and uPA system inhibitor WX-UK1, identified as a micromolar range hepsin inhibitor, prevented hepsin from augmenting HGF/MET signalling and disrupting desmosomes and hemidesmosomes. The findings suggest that the oncogenic activity of hepsin arises not only from elevated expression level but also from depletion of HAI-1, events which together trigger gain-of-function activity impacting HGF/MET signalling and epithelial cohesion. Thus, hepsin overexpression is a major oncogenic conferrer to a serine protease activity involved in breast cancer dissemination.

Arrhythmic disorder mapped to chromosome 1q42-q43 causes malignant polymorphic ventricular tachycardia in structurally normal hearts.

OBJECTIVES: The purpose of this study was to provide clinical and anatomical characteristics as well as genetic background of a malignant arrhythmogenic disorder. BACKGROUND: An inherited autosomally dominant cardiac syndrome causing stress-induced polymorphic ventricular tachycardia and syncope in the absence of structural myocardial changes was detected in two families. METHODS: Two unrelated families with six victims of sudden death and 51 living members were evaluated. Resting and exercise electrocardiograms (ECG), echocardiography, magnetic resonance imaging (MRI), cineangiography, microscopic examination of endomyocardial biopsies and a drug testing with a class IC antiarrhythmic agent flecainide were performed. A genetic linkage analysis was carried out to map the gene locus. RESULTS: Of the 24 affected individuals, 10 had succumbed with six cases of sudden death, and 14 survivors showed evidence of disease. Exercise stress test induced ventricular bigeminy or polymorphic ventricular tachycardia in affected individuals. Three children initially examined before 10 years of age developed arrhythmias during a four-year follow-up. Resting ECGs were normal in affected subjects except a slight prolongation of the QT intervals adjusted for heart rate (QTc) (430 +/- 18 vs. 409 +/- 19 ms, affected vs. nonaffected, p < 0.01). Administration of flecainide did not induce ECG abnormalities encountered in familial idiopathic ventricular fibrillation. Ventricular volumes, contractility and wall measurements were normal by echocardiography, right ventricular cineangiography and MRI. Histopathological examination showed no fibrosis or fatty infiltration. The cumulative cardiac mortality by the age of 30 years was 31%. The disease locus was assigned to chromosome 1q42-q43, with a maximal pairwise lod score of 4.74 in the two families combined. Only one heterozygous carrier was clinically unaffected suggesting high disease penetrance in adulthood. CONCLUSIONS: A distinct cardiac disorder linked to chromosome 1q42-q43 causes exercise-induced polymorphic ventricular tachycardia in structurally normal hearts and is highly malignant. Delayed clinical manifestation necessitates repeated exercise electrocardiography to assure diagnosis in young individuals of the families.

The prevalence of non-sentinel node metastases in breast cancer patients with sentinel node micrometastases.

AIMS: The aim of the study was to estimate the prevalence of and risk factors for non-sentinel node (NSN) involvement in breast cancer patients with sentinel node (SN) micrometastases. METHODS: Eighty-four patients with SN micrometastases were included. Both the SN and NSN were examined using serial sectioning and immunohistohemistry. Various indices were evaluated as possible risk factors for NSN involvement. RESULTS: NSN involvement was found in 22/84 patients. The median size of the NSN metastases was 1.25 mm (0.01-12 mm). The NSN metastases were larger than 2 mm in 8 patients and smaller than 0.2 mm in 6 patients. NSN involvement was observed in 14/35 patients with metastatic findings in all removed SN. Three of the 23 patients with 2 or 3 tumour negative SN had NSN metastases. None of the 12 patients with 4 or more uninvolved SN had NSN metastases. NSN involvement could not excluded by other patient, tumour or sentinel node related factors. CONCLUSIONS: Every fourth patient will have residual disease in the axilla, 10% even large metastases, if axillary clearance is omitted in patients with SN micrometastases. The risk of NSN involvement seems negligible in patients with a single SN micrometastasis and four or more healthy SN harvested.