http://repub.eur.nl/res/aut/4731/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/15959/ 2008-01-01T00:00:00Z Mutations in the breast cancer susceptibility genes BRCA1, BRCA2, and CHEK2 are known risk factors for female breast cancer. Mutations in BRCA1 and BRCA2 also are associated with male breast cancer (MBC). Similarly, it had been suggested in the original CHEK2 identification report that the CHEK2 1100delC mutation confers an increased risk for MBC. Here, we have evaluated the risk of CHEK2 1100delC for MBC by genotyping CHEK2 1100delC in 23 familial and 71 unselected Dutch MBC cases. None of the 23 familial MBC cases carried the CHEK2 1100delC mutation. In contrast, CHEK2 1100delC was present in 3 of the 71 (4.2%) unselected MBC cases, which was significantly more prevalent than the 1.1% Dutch population frequency assessed in 1,692 individuals (P = 0.05, OR = 4.1, 95% CI 1.2-14.3). Our data suggest that, in the Netherlands, CHEK2 1100delC is associated with an increased risk for MBC. http://repub.eur.nl/res/pub/13955/ 2005-10-15T00:00:00Z PURPOSE: To evaluate the predictive value of the disintegrin and metalloproteinases, ADAM-9, ADAM-10, ADAM-11, and ADAM-12, and of the matrix metalloproteinases, MMP-2 and MMP-9, in patients with recurrent breast cancer treated with tamoxifen. EXPERIMENTAL DESIGN: A retrospective study was done on 259 frozen specimens of estrogen receptor-positive primary breast carcinomas from patients who developed recurrent disease and were treated with tamoxifen as the first line of therapy. The expression levels of the biological factors were assessed by real-time quantitative reverse transcriptase PCR. RESULTS: Using log-transformed continuous variables, increasing levels of ADAM-9 [odds ratio (OR) = 1.41; P = 0.015] and decreasing levels of MMP-9 (OR, 0.81; P = 0.035) predicted favorable disease control independent from the traditional predictive factors. Furthermore, when tumors were dichotomized at the median level of 70% tumor cell nuclei, our univariate analysis showed particularly strong results for the group of 153 patients with primary tumors containing 30% or more stromal cells. Although estrogen receptor levels lost their predictive power for this group of patients, high levels of ADAM-9 (OR, 1.59; P = 0.007) and ADAM-11 (OR, 1.65; P = 0.001) were significantly associated with a higher efficacy of tamoxifen therapy. CONCLUSIONS: Our results show that especially for primary tumors containing stromal elements, the assessment of mRNA expression levels of ADAM-9 and ADAM-11 could be useful to identify patients with recurrent breast cancer who are likely to benefit or fail from tamoxifen therapy. http://repub.eur.nl/res/pub/13806/ 2005-05-15T00:00:00Z To understand the biological basis of resistance to endocrine therapy is of utmost importance in patients with steroid hormone receptor-positive breast cancer. Not only will this allow us prediction of therapy success, it may also lead to novel therapies for patients resistant to current endocrine therapy. DNA methylation in the promoter regions of genes is a prominent epigenetic gene silencing mechanism that contributes to breast cancer biology. In the current study, we investigated whether promoter DNA methylation could be associated with resistance to endocrine therapy in patients with recurrent breast cancer. Using a microarray-based technology, the promoter DNA methylation status of 117 candidate genes was studied in a cohort of 200 steroid hormone receptor-positive tumors of patients who received the antiestrogen tamoxifen as first-line treatment for recurrent breast cancer. Of the genes analyzed, the promoter DNA methylation status of 10 genes was significantly associated with clinical outcome of tamoxifen therapy. The association of the promoter hypermethylation of the strongest marker, phosphoserine aminotransferase (PSAT1) with favorable clinical outcome was confirmed by an independent quantitative DNA methylation detection method. Furthermore, the extent of DNA methylation of PSAT1 was inversely associated with its expression at the mRNA level. Finally, also at the mRNA level, PSAT1 was a predictor of tamoxifen therapy response. Concluding, our work indicates that promoter hypermethylation and mRNA expression of PSAT1 are indicators of response to tamoxifen-based endocrine therapy in steroid hormone receptor-positive patients with recurrent breast cancer. http://repub.eur.nl/res/pub/13506/ 2004-09-15T00:00:00Z PURPOSE: BCAR1, the human homologue of the rat p130Cas protein, was identified in a functional screen for human breast cancer cell proliferation resistant to antiestrogen drugs. Here, we study the prognostic value of quantitative BCAR1 levels in a large series of breast cancer specimens. EXPERIMENTAL DESIGN: A specific ELISA was developed to measure BCAR1 protein levels in 2593 primary breast tumor cytosols. Tumor levels of BCAR1 were correlated with relapse-free survival (RFS) and overall survival (OS) and compared with collected data on urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor 1 (PAI-1). RESULTS: In tumor cytosols, BCAR1 protein levels varied between 0.02 and 23 ng/mg protein. BCAR1 levels exhibited a positive correlation with steroid hormone receptor levels, age and menopausal status, and uPA and PAI-1 levels. The level of BCAR1 (continuous or categorized as low, intermediate, or high) was inversely related with RFS and OS time. Multivariate analysis showed that BCAR1 levels contributed independently to a base model containing the traditional prognostic factors for both RFS and OS (both P < 0.0001). When added together with uPA and PAI-1 in the multivariate model, BCAR1 contributed independently of PAI-1 and was favored over uPA. Interaction tests allowed for additional analyses of BCAR1 protein levels in clinically relevant subgroups stratified by nodal and menopausal status. CONCLUSIONS: The quantitative BCAR1 protein level represents a prognostic factor for RFS and OS in primary breast cancer, independent of the traditional prognostic factors and the other novel marker PAI-1. http://repub.eur.nl/res/pub/10121/ 2003-01-01T00:00:00Z PURPOSE: In recent studies, we showed that TP53 gene mutation or high levels of cytosolic vascular endothelial growth factor (VEGF) in estrogen receptor (ER)-alpha-positive primary breast tumors predict a poor disease outcome for patients treated with first-line tamoxifen for advanced disease. Mutant TP53 may up-regulate VEGF, whereas, on the other hand, wild-type TP53 may decrease VEGF production. EXPERIMENTAL DESIGN: In the present study, we aimed to assess the combined predictive value of TP53 gene mutation and VEGF status of 160 advanced breast cancer patients with ER-positive tumors who were treated with tamoxifen (median follow-up from start of tamoxifen treatment, 64 months). To assess TP53 gene mutation status, the entire open reading frame was sequenced; for VEGF status, an ELISA was used. RESULTS: In univariate analysis, both TP53 gene mutation (28% of the tumors) and a VEGF level above the median value were significantly associated with a short progression-free survival, post-relapse overall survival, and a poor rate of response to tamoxifen. In Cox multivariate regression analysis including the traditional predictive factors, the addition of TP53 gene mutation and VEGF status, alone or in combination, significantly predicted a poor efficacy of tamoxifen treatment. When the two factors were combined, a significantly decreased odds ratio was seen for the rate of response (odds ratio, 0.27). Similarly, an increased hazard ratio (HR) was seen for progression-free survival (HR, 2.32) and post-relapse overall survival (HR, 1.68) in the group with mutant TP53 and high VEGF compared with the group with both risk factors absent. CONCLUSIONS: Combined TP53 gene mutation status and high VEGF levels of ER-positive primary breast tumors independently predict a poor course of the disease of patients with advanced breast cancer treated with tamoxifen. These patients, having unfavorable tumor characteristics, might benefit more from other types of (individualized) treatment protocols. http://repub.eur.nl/res/pub/9256/ 2000-01-01T00:00:00Z The antigen levels of components of the urokinase-type plasminogen activator (uPA) system of plasminogen activation are correlated with prognosis in several types of cancers, including breast cancer. In the present study involving 2780 patients with primary invasive breast cancer, we have evaluated the prognostic importance of the four major components of the uPA system [uPA, the receptor uPAR (CD87), and the inhibitors PAI-1 and PAI-2]. The antigen levels were determined by ELISA in cytosols prepared from primary breast tumors. The levels of the four factors significantly correlated with each other; the Spearman rank correlation coefficients (r(s)) ranged from 0.32 (between PAI-2 and PAI-1 or uPAR) to 0.59 (between uPA and PAI-1). The median duration of follow-up of patients still alive was 88 months. In the multivariate analyses for relapse-free survival (RFS) and overall survival (OS), we defined a basic model including age, menopausal status, tumor size and grade, lymph node status, adjuvant therapy, and steroid hormone receptor status. uPA, uPAR, PAI-1, and PAI-2 were considered as categorical variables, each with two cut points that were established by isotonic regression analysis. Compared with tumors with low levels, those with intermediate and high levels showed a relative hazard rate (RHR) and 95% confidence interval (95% CI) of 1.22 (1.02-1.45) and 1.69 (1.39-2.05) for uPA, and 1.32 (1.14-1.54) and 2.17 (1.74-2.70) for PAI-1, respectively, in multivariate analysis for RFS in all patients. Compared with tumors with high PAI-2 levels, those with intermediate and low levels showed a poor RFS with a RHR (95% CI) of 1.30 (1.14-1.48) and 1.76 (1.38-2.24), respectively. Similar results were obtained in the multivariate analysis for OS in all patients. Furthermore, uPA and PAI-1 were independent predictive factors of a poor RFS and OS in node-negative and node-positive patients. PAI-2 also added to the multivariate models for RFS in node-negative and node-positive patients, and in the analysis for OS in node-negative patients. uPAR did not further contribute to any of the multivariate models. A prognostic score was calculated based on the estimates from the final multivariate model for RFS. Using this score, the difference between the highest and lowest 10% risk groups was 66% in the analysis for RFS at 10 years and 61% in the analysis for OS. Moreover, separate prognostic scores were calculated for node-negative and node-positive patients. In the 10% highest risk groups, the proportion of disease-free patients was only 27 +/- 6% and 9 +/- 3% at 10 years for node-negative and node-positive patients, respectively. These proportions were 86 +/- 4% and 61 +/- 6% for the corresponding 10% lowest risk groups of relapse. We conclude that several components of the uPA system are potential predictors of RFS and OS in patients with primary invasive breast cancer. Knowledge of these factors could be helpful to assess the individual risk of patients, to select various types of adjuvant treatment and to identify patients who may benefit from targeted therapies that are currently being developed. http://repub.eur.nl/res/pub/9358/ 2000-01-01T00:00:00Z TP53 has been implicated in regulation of the cell cycle, DNA repair, and apoptosis. We studied, in primary breast tumors through direct cDNA sequencing of exons 2-11, whether TP53 gene mutations can predict response in patients with advanced disease to either first-line tamoxifen therapy (202 patients, of whom 55% responded) or up-front (poly)chemotherapy (41 patients, of whom 46% responded). TP53 mutations were detected in 90 of 243 (37%) tumors, and one-fourth of these mutations resulted in a premature termination of the protein. The mutations were observed in 32% (65 of 202) of the primary tumors of tamoxifen-treated patients and in 61% (25 of 41) of the primary tumors of the chemotherapy patients. TP53 mutation was significantly associated with a poor response to tamoxifen [31% versus 66%; odds ratio (OR), 0.22; 95% confidence interval (CI), 0.12-0.42; P < 0.0001]. Patients with TP53 gene mutations in codons that directly contact DNA or with mutations in the zinc-binding domain loop L3 showed the lowest response to tamoxifen (18% and 15% response rates, respectively). TP53 mutations were related, although not significantly, to a poor response to up-front chemotherapy (36% versus 63%; OR, 0.34; 95% CI, 0.09-1.24). In multivariate analysis for response including the classical parameters age and menopausal status, disease-free interval, dominant site of relapse, and levels of estrogen receptor and progesterone receptor, TP53 mutation was a significant predictor of poor response in the tamoxifen-treated group (OR, 0.29; 95% CI, 0.13-0.63; P = 0.0014). TP53-mutated and estrogen receptor-negative (<10 fmol/mg protein) tumors appeared to be the most resistant phenotype. Interestingly, the response of patients with TP53 mutations to chemotherapy after tamoxifen was not worse than that of patients without these mutations (50% versus 42%; OR, 1.35, nonsignificant). The median progression-free survival after systemic treatment was shorter for patients with a TP53 mutation than for patients with wild-type TP53 (6.6 and 0.6 months less for tamoxifen and up-front chemotherapy, respectively). In conclusion, TP53 gene mutation of the primary tumor is helpful in predicting the response of patients with metastatic breast disease to tamoxifen therapy. The type of mutation and its biological function should be considered in the analyses of the predictive value of TP53.