C. F. Singer

The incidence of pancreatic cancer in BRCA1 and BRCA2 mutation carriers

Background:Germline mutations in BRCA1 and BRCA2 predispose to pancreatic cancer. We estimated the incidence of pancreatic cancer in a cohort of female carriers of BRCA1 and BRCA2 mutation. We also estimated survival rates in pancreatic cancer cases from families with a BRCA mutation.Methods:We followed 5149 women with a mutation for new cases of pancreatic cancer. The standardised incidence ratios (SIR) for pancreatic cancer were calculated based on age group and country of residence. We also reviewed the pedigrees of 8140 pedigrees with a BRCA1 or a BRCA2 mutation for those with a case of pancreatic cancer. We recorded the year of diagnosis and the year of death for 351 identified cases.Results:Eight incident pancreatic cancer cases were identified among all mutation carriers. The SIR for BRCA1 carriers was 2.55 (95% CI=1.03–5.31, P=0.04) and for BRCA2 carriers was 2.13 (95% CI=0.36–7.03, P=0.3). The 5-year survival rate was 5% for cases from a BRCA1 family and 4% for cases from a BRCA2 family.Conclusion:The risk of pancreatic cancer is approximately doubled in female BRCA carriers. The poor survival in familial pancreatic cancer underscores the need for novel anti-tumoural strategies.

MMP-2 and MMP-9 Expression in Breast Cancer-Derived Human Fibroblasts is Differentially Regulated by Stromal-Epithelial Interactions

Tissue remodeling is a key element in the local invasion and metastasis of malignant breast tumors. The degradation of extracellular matrix that is associated with this process is thought to be mediated by a number of Zn2+-dependent matrix metalloproteinases (MMPs). In most cases these enzymes are not produced by the malignant epithelium itself but by adjacent breast stroma, suggesting an important role for cell-cell interactions. We have analyzed Gelatinase A (MMP-2) and Gelatinase B (MMP-9) gene expression in a panel of six breast cancer cell lines and six primary cultures of stromal cells deriving from breast cancer biopsies. With one exception we did not detect MMP-2 or MMP-9 gene expression in any of the established tumor cell lines. Conversely, tumor stroma-derived fibroblasts expressed MMP-2 mRNA, although no MMP-9 mRNA was seen in RNase protection assays. When fibroblasts were cultured in the presence of media conditioned by MCF-7 tumor cells, MMP-2 enzyme production increased but MMP-9 activity remained undetectable. However, when fibroblasts and MCF-7 tumor cells were co-cultured together, MMP-9 was induced. These observations were confirmed by immunocytochemical analysis of co-cultures of MCF-7 and tumor-derived fibroblasts in which MMP-2 and MMP-9 protein expression was confined to stromal cells adjacent to MCF-7 tumor cells. No MMP-2 or MMP-9 staining was detected in monocultures of the two respective cell types. We conclude that MMP-2 expression is present in the stroma of malignant tumors and is increased by paracrine stimulation mediated by soluble factors. In contrast, MMP-9 expression tumor-derived fibroblasts requires direct contact with malignant tumor epithelium.

Use of high-throughput protein array for profiling of differentially expressed proteins in normal and malignant breast tissue.

AbstractcDNA arrays provide a powerful tool to identify gene expression pattern that are potentially associated with tumor invasion and metastasis. However, genes work at the protein level and, since the transcriptional activity of a gene does not necessarily reflect cellular protein expression, the identification and quantification of proteins is essential for the understanding of molecular events leading to malignant transformation. We have therefore employed a high-throughput protein microarray system which contains 378 well-characterized monoclonal antibodies in order to compare the gene expression pattern of malignant and adjacent normal breast tissue in a patient with primary breast cancer. Using this technique, we have identified a number of proteins that show increased expression levels in malignant breast tissues such as casein kinase Ie, p53, annexin XI, CDC25C, eIF-4E and MAP kinase 7. The expression of other proteins, such as the multifunctional regulator 14-3-3e was found to be decreased in malignant breast tissue, whereas the majority of proteins remained unchanged when compared to the corresponding non-malignant samples. The protein expression pattern was confirmed by immunohistochemistry, in which antibodies against 8 representative proteins known to be involved in carcinogenesis were employed in paraffin-embedded normal and malignant tissue sections deriving from the same patient. In each case, the results obtained by IHC matched the data obtained by antibody microarray system. Taken together, we have described for the first time a tumor cell specificity protein expression pattern by use of a novel commercially available antibody microarray system. We have thus demonstrated the feasibility of high-throughput protein arrays in the proteomic analysis of human breast tissue. We hypothesize that the use of protein arrays will not only increase our understanding of the molecular events, but could prove useful in evaluating prognosis and in determining optimal antineoplastic therapy.

Expression of Sex Steroid Receptors and their Co-Factors in Normal and Malignant Breast Tissue: AIB1 is a Carcinoma-Specific Co-Activator

The differential expression pattern of estrogen receptor alpha (ER-α), estrogen receptor beta (ER-β) and their co-activator/co-repressor proteins is thought to modulate estrogenic action and to be present already during the early stages of tumorigenesis. It has therefore been postulated that certain co-activator and co-repressor proteins contribute to the development of breast cancer. There are some reports providing information on gene amplification and mRNA over-expression of certain co-factors in breast cancer, but to date there is only limited knowledge about their respective protein expressions. The aim of this study was to examine the expression of four steroid receptor co-activators (steroid receptor co-activator 1 (SRC-1), transcription intermediary factor 2 (TIF 2), protein 300 kDa/CREB binding protein (p300/CBP), amplified in breast cancer 1 (AIB1)), and of the co-repressor nuclear receptor co-repressor (NCoR), in malignant breast tissues and in matching normal breast biopsies of the same individuals. Protein expression was analyzed by immunohistochemistry and was compared to prognostic parameters such as lymph node involvement, tumor grading and receptor status. All members of the co-regulatory protein family were detected in both, benign and matching malignant tissue samples, except for AIB1, which was found to be expressed exclusively in malignant epithelium. AIB1 was preferentially present in carcinomas with high tumor grade (r = 0.48, p = 0.014), and was co-expressed with p300/CBP (r = 0.54, p = 0.006). TIF 2 correlated significantly to nodal status (r = 0.46, p = 0.025). Furthermore, protein levels of ER-β, p300/CBP and AIB1 were higher in invasive ductal carcinomas than in normal mammary tissue. The tumoral ER-α protein expression was significantly correlated with that of PgR (r = 0.61, p = 0.001) and NCoR (r = 0.4, p = 0.043), whereas ER-β expression was associated with SRC-1 (r = 0.68, p ≤ 0.001), TIF 2 (r = 0.64, p = 0.001) and NCoR (r = 0.48, p = 0.014) protein levels in malignant specimens. In our hands, 20% of ER-β positive tumors did not express ER-α protein, thereby suggesting that a substantial fraction of ER-beta positive tumors is falsely considered to be ‘estrogen receptor negative’ if only ER-α specific antibodies are employed in the histological assessment of the ER status.

Co-expression of ErbB-family members in human breast cancer: Her-2/neu is the preferred dimerization candidate in nodal-positive tumors

Over-expression of members of the ErbB-receptor family has been associated with malignant transformation. The amplification of Her-2/neu in tumor tissue is now an established prognostic factor in breast cancer. In order to initiate signal transduction, ErbB-receptor monomers need to form homo- or heterodimers. The composition of these dimers is thought to influence both quality and quantity of downstream signaling pathways, and to determine the biological response. We have investigated the protein expression pattern of the four ErbB-receptors EGFR, Her-2/neu, Her-3 and Her-4, and correlated it with their putative ligands EGF, TGF-α and HRG in 74 women with invasive breast cancer. Using western blot-analysis on cell membrane isolates, we detected the co-expression of all four ErbB-family members in 79.7% of cases, and of all of the three investigated ligands in 82.4%. We did not observe a correlation between EGFR and Her-2/neu or Her-4 protein expression, EGFR and Her-3 (p = 0.005), and Her-3 and Her-4 (p = 0.05) were clearly co-expressed. The strongest overall correlation, was found between Her-2/neu and Her-3 (p < 0.001) and between Her-2/neu and Her-4 (p = 0.001). This was particularly true in nodal-positive tumors (p <0.001 and p = 0.002) whereas in nodal-negative tumors the co-expression was either less significant (Her-2/neu and Her-3; p = 0.01) or not significant (Her-2/neu and Her-4). The co-expression of EGFR/Her-3 was associated with the expression of all ligands, whereas the Her-2/neu/Her-3 was correlated with HRG (p = 0.002), thereby indicating a functional relation between specific receptor-dimer combinations and putative ligands. Taken together, we have performed the first comprehensive survey of ErbB-system expression in breast cancer, and have demonstrated the presence of a co-regulated receptor/ligand system in vivo. We have further shown that Her-2/neu is the preferred co-expression partner in nodal-positive tumors and thus the most likely dimerization candidate in malignant breast tumors.

Presence of nanobacteria in psammoma bodies of ovarian cancer: evidence for pathogenetic role in intratumoral biomineralization

Aims:u2002 The presence of laminated, calcified extracellular debris known as psammoma bodies is a well‐known histomorphological feature of ovarian adenocarcinomas and other human malignancies. Biomineralization has recently been found to be associated with a group of extremely small Gram‐negative bacteria capable of precipitating calcium salts. The aim of the present study was to evaluate a possible pathogenic link between the development of psammoma bodies and nanobacteria infection.

Occult ovarian cancers identified at risk-reducing salpingo-oophorectomy in a prospective cohort of BRCA1/2 mutation carriers

Risk-reducing salpingo-oophorectomy (RRSO) is widely used for cancer risk reduction in BRCA1 or BRCA2 (BRCA1/2) mutation carriers. Occult ovarian/fallopian tube cancers (OOC) detected at the time of RRSO have been reported in several studies with wide variability in reported prevalence. We estimated the prevalence of OOC in a prospective cohort of 647 BRCA1/2 mutation carriers from 18 centers (PROSE consortium) who underwent RRSO between 2001 and 2008. OOC was detected in 16 of 647 women (2.5%). The mean age at RRSO was 51.7 in those with OOC versus 46.6 in those without OOC (Pxa0=xa00.017). Twelve of the 16 OOCs (75%) were diagnosed in women with BRCA1 mutations. Thirty-eight percent of women with OOC had stage 1 cancer versus none of the women in the PROSE database diagnosed with ovarian cancer outside of screening. Among 385 women (60%) in whom pathology reports were available for central review, 246 (64%) RRSOs were performed at participating PROSE centers while 139 (36%) were performed at local sites. Ovarian and fallopian tube tissues removed at major genetics referral centers were significantly more likely to have been examined in toto compared to specimens obtained at non-referral centers (75% vs. 30%, Pxa0<xa00.001). Our results confirm that OOC may be found at the time of RRSO in BRCA1/2 mutation carriers and suggest that OOC are of a more favorable stage than cancers found outside RRSO. An unacceptably high proportion of pathologic examinations did not adequately examine ovaries and fallopian tubes obtained at RRSO.

A head-to-head comparison between technetium-99m-tetrofosmin and technetium-99m-MIBI scintigraphy to evaluate suspicious breast lesions

Abstract. The aim of this study was to assess the diagnostic value of technetium-99m-tetrofosmin and technetium-99m-MIBI in a head-to-head comparison. Both radiopharmaceuticals are routinely used for detecting breast cancer. In a prospective, open, diagnostic trial, the two radiopharmaceuticals were administered randomly on different days to the same 101 women suffering from 103 breast tumours. Planar images and single photon emission computer tomography (SPET) were performed. After histological examination of the tumours, sensitivity, specificity and positive and negative predictive value were compared. 99mTc-tetrofosmin and 99mTc-MIBI showed low sensitivity in planar images (44% vs 46%, respectively). SPET improved sensitivity (70% vs 69%, respectively). Specificity in planar images was 83% and 87%, and it was even lower using SPET (70% vs 78%, respectively). Positive predictive value in planar images was 76% vs 81%, and it was not changed by SPET. Negative predictive value was low in planar images (54% vs 57%, respectively), but it was improved by using SPET (65% vs 67%, respectively). In conclusion, 99mTc-tetrofosmin and 99mTc-MIBI scintigraphy show similar diagnostic value in assessing suspicious breast lesions.

Impact of AdipoR1 expression on breast cancer development.

OBJECTIVEnAdiponectin serum levels have been shown to be inversely correlated with breast cancer risk. The protein is believed to act through adiponectin receptor 1 (AdipoR1) and has been suggested to play an important role in cancer development. While AdipoR1 is known to be expressed in invasive tumors, its role in DCIS remains elusive. We therefore investigated AdipoR1 expression in both invasive and preinvasive breast cancer.nnnMETHODSnTissue microarrays were established from paraffin-embedded archived tissues which contained 104 invasive breast cancers with adjacent preinvasive component (DCIS) as well as 96 preinvasive breast cancers. AdipoR1 expression was investigated by immunohistochemistry and correlated with clinical and tumor parameters.nnnRESULTSnAdipoR1 was detected in stromal and epithelial components of both invasive and preinvasive breast cancer. However, stromal and epithelial immunoreactivity for AdipoR1 was significantly higher in invasive breast cancer compared to preinvasive DCIS (p<0.001 and p=0.009). Within DCIS, AdipoR1 expression was inversely correlated with tumor size (r=-0.238, p=0.033). Menopausal status showed no influence on AdipoR1 expression.nnnCONCLUSIONSnThe altered expression of AdipoR1 in invasive breast cancer compared to DCIS suggests that the receptor-binding protein adiponectin might exert growth inhibitory effects that are overcome in transformation of preinvasive to invasive breast cancer.

Elevated CSF1 serum concentration predicts poor overall survival in women with early breast cancer

Colony-stimulating factor 1 (CSF1) is a key regulator of mammary gland development, and a modulator of tissue macrophages. Expression of the CSF1 receptor gene C-FMS (CSF1R) is strongly associated with poor outcome in breast cancer and results in tumor cell invasiveness and pro-metastatic behavior in vitro. However, CSF1s role as a predictive factor in breast cancer remains unclear. We have prospectively measured circulating CSF1 using ELISA in 572 women with early breast cancer and in 688 women with benign breast lesions, and correlated these concentrations with overall survival (OS), nodal status, and other clinical and histological parameters. Serum CSF1 concentrations were significantly elevated in patients with early breast cancer when compared with those with benign tumors (P<0.0001). Within breast cancer patients, CSF1 was higher in women with axillary lymph nodes (P=0.03). Serum CSF1 correlated with tumor size (P=0.002), age (P<0.001), and Ki67 expression (P=0.006). Log CSF1 serum concentrations were predictive of poor survival in both univariate (hazard ratio (HR): 3.77, 95% CI: 1.65-8.65, P=0.002) and multivariate analyses (HR: 3.1, 95% CI: 1.03-9.33, P=0.04). Post- but not premenopausal women with CSF1 serum concentrations >873u200a pg/ml experienced a significantly poorer outcome (P=0.004 log-rank test). Serum CSF1 concentrations are elevated in women with malignant breast tumors. In early breast cancer, elevated serum CSF1 is associated with nodal involvement, and in postmenopausal women also with poor OS.