Christina Justenhoven

A common coding variant in CASP8 is associated with breast cancer risk

The Breast Cancer Association Consortium (BCAC) has been established to conduct combined case-control analyses with augmented statistical power to try to confirm putative genetic associations with breast cancer. We genotyped nine SNPs for which there was some prior evidence of an association with breast cancer: CASP8 D302H (rs1045485), IGFBP3 −202 C → A (rs2854744), SOD2 V16A (rs1799725), TGFB1 L10P (rs1982073), ATM S49C (rs1800054), ADH1B 3′ UTR A → G (rs1042026), CDKN1A S31R (rs1801270), ICAM5 V301I (rs1056538) and NUMA1 A794G (rs3750913). We included data from 9–15 studies, comprising 11,391–18,290 cases and 14,753–22,670 controls. We found evidence of an association with breast cancer for CASP8 D302H (with odds ratios (OR) of 0.89 (95% confidence interval (c.i.): 0.85–0.94) and 0.74 (95% c.i.: 0.62–0.87) for heterozygotes and rare homozygotes, respectively, compared with common homozygotes; Ptrend = 1.1 × 10−7) and weaker evidence for TGFB1 L10P (OR = 1.07 (95% c.i.: 1.02–1.13) and 1.16 (95% c.i.: 1.08–1.25), respectively; Ptrend = 2.8 × 10−5). These results demonstrate that common breast cancer susceptibility alleles with small effects on risk can be identified, given sufficiently powerful studies.NOTE: In the version of this article initially published, there was an error that affected the calculations of the odds ratios, confidence intervals, between-study heterogeneity, trend test and test for association for SNP ICAM5 V301I in Table 1 (ICAM5 V301I); genotype counts in Supplementary Table 2 (ICAM5; ICR_FBCS and Kuopio studies) and minor allele frequencies, trend test and odds ratios for heterozygotes and rare homozygotes in Supplementary Table 3 (ICAM5; ICR_FBCS and Kuopio studies). The errors in Table 1 have been corrected in the PDF version of the article. The errors in supplementary information have been corrected online.

Risk of estrogen receptor-positive and -negative breast cancer and single-nucleotide polymorphism 2q35-rs13387042

BACKGROUND A recent genome-wide association study identified single-nucleotide polymorphism (SNP) 2q35-rs13387042 as a marker of susceptibility to estrogen receptor (ER)-positive breast cancer. We attempted to confirm this association using the Breast Cancer Association Consortium. METHODS 2q35-rs13387042 SNP was genotyped for 31 510 women with invasive breast cancer, 1101 women with ductal carcinoma in situ, and 35 969 female control subjects from 25 studies. Odds ratios (ORs) were estimated by logistic regression, adjusted for study. Heterogeneity in odds ratios by each of age, ethnicity, and study was assessed by fitting interaction terms. Heterogeneity by each of invasiveness, family history, bilaterality, and hormone receptor status was assessed by subclassifying case patients and applying polytomous logistic regression. All statistical tests were two-sided. RESULTS We found strong evidence of association between rs13387042 and breast cancer in white women of European origin (per-allele OR = 1.12, 95% confidence interval [CI] = 1.09 to 1.15; P(trend) = 1.0 x 10(-19)). The odds ratio was lower than that previously reported (P = .02) and did not vary by age or ethnicity (all P > or = .2). However, it was higher when the analysis was restricted to case patients who were selected for a strong family history (P = .02). An association was observed for both ER-positive (OR = 1.14, 95% CI = 1.10 to 1.17; P = 10(-15)) and ER-negative disease (OR = 1.10, 95% CI = 1.04 to 1.15; P = .0003) and both progesterone receptor (PR)-positive (OR = 1.15, 95% CI = 1.11 to 1.19; P = 5 x 10(-14)) and PR-negative disease (OR = 1.10, 95% CI = 1.06 to 1.15; P = .00002). CONCLUSION The rs13387042 is associated with both ER-positive and ER-negative breast cancer in European women.

One-Carbon Metabolism and Breast Cancer Risk: No Association of MTHFR, MTR, and TYMS Polymorphisms in the GENICA Study from Germany

Neoplastic development and growth are suspected to be influenced by availability and metabolism of folate due to effects on gene expression through DNA methylation and on genome integrity through DNA synthesis and repair ([1][1]-[3][2]). Key enzymatic regulators are methylene-tetrahydrofolate

Expression of xenobiotic and steroid hormone metabolizing enzymes in human breast carcinomas

The potential to metabolize endogenous and exogenous substances may influence breast cancer development and tumor growth. Therefore, the authors investigated the protein expression of Glutathione S‐transferase (GST) isoforms and cytochrome P450 (CYP) known to be involved in the metabolism of steroid hormones and endogenous as well as exogenous carcinogens in breast cancer tissue to obtain new information on their possible role in tumor progression. Expression of GST pi, mu, alpha and CYP1A1/2, 1A2, 3A4/5, 1B1, 2E1 was assessed by immunohistochemistry for primary breast carcinomas of 393 patients from the German GENICA breast cancer collection. The percentages of positive tumors were 50.1 and 44.5% for GST mu and CYP2E1, and ranged from 13 to 24.7% for CYP1A2, GST pi, CYP1A1/2, CYP3A4/5, CYP1B1. GST alpha was expressed in 1.8% of tumors. The authors observed the following associations between strong protein expression and histopathological characteristics: GST expression was associated with a better tumor differentiation (GST mu, p = 0.018) and with reduced lymph node metastasis (GST pi, p = 0.02). In addition, GST mu expression was associated with a positive estrogen receptor and progesterone receptor status (p < 0.001). CYP3A4/5 expression was associated with a positive nodal status (p = 0.018). Expression of CYP1B1 was associated with poor tumor differentiation (p = 0.049). Our results demonstrate that the majority of breast carcinomas expressed xenobiotic and drug metabolizing enzymes. They particularly suggest that GST mu and pi expression may indicate a better prognosis and that strong CYP3A4/5 and CYP1B1 expression may be key features of nonfavourable prognosis.

Family History, Genetic Testing, and Clinical Risk Prediction: Pooled Analysis of CHEK2*1100delC in 1,828 Bilateral Breast Cancers and 7,030 Controls

If breast cancers arise independently in each breast the odds ratio (OR) for bilateral breast cancer for carriers of CHEK2*1100delC should be ∼5.5, the square of the reported OR for a first primary (OR, 2.34). In the subset of bilateral cases with one or more affected relatives, the predicted carrier OR should be ∼9. We have tested these predictions in a pooled set of 1,828 cases with 2 primaries and 7,030 controls from 8 studies. The second primary OR for CHEK2*1100delC carriers was 6.43 (95% confidence interval, 4.33-9.56; P < 0.0001), significantly greater than the published estimate for a first primary (P < 0.001) but consistent with its square. The predicted increase in carrier OR with increasing numbers of affected relatives was seen using bilateral cases from the UK (Ptrend = 0.0003) and Finland (Ptrend = 0.37), although not using those from the Netherlands and Russia (P = 0.001 for heterogeneity between countries). Based on a standard genetic model, we predict lifetime risks for CHEK2*1100delC carrier and noncarrier daughters of bilateral breast cancer cases of 37% and 18%, respectively. Our results imply that clinical management of the daughter of a woman with bilateral breast cancer should depend on her CHEK2*1100delC carrier status. This and other moderate penetrance breast cancer susceptibility alleles, together with family history data, will thus identify increasing numbers of women at potentially very high risk. Before such predictions are accepted by clinical geneticists, however, further population-based evidence is needed on the effect of CHEK2*1100delC and other moderate penetrance alleles in women with a family history of breast cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(1):230–4)

Investigation of Genetic Variants of Genes of the Hemochromatosis Pathway and Their Role in Breast Cancer

Iron overload has been noticed as a feature of human breast cancer. Cellular iron uptake is regulated by the hemochromatosis and transferrin receptor system, mutations of which cause the iron storage disease hereditary hemochromatosis. To understand the role of hemochromatosis and transferrin receptor system mutations in breast cancer, we analyzed 19 sequence variations at HFE, TFR1, TFR2, and FPN1 and compared genotype frequencies between cases and controls in a German population. There were 688 breast cancer patients and 724 population-based and age-matched controls. For genotyping, we applied the Hemochromatosis Strip Assay and TaqMan allelic discrimination analyses. In addition to genotype frequencies, we established frequencies of compound genotypes. The frequencies of HFE at His63Asp, Ser65Cys, and Cys282Tyr, and of TFR1 at Ser142Gly minor alleles in this German population were 15.9%, 1.8%, 5.6%, and 46.0%, respectively. No rare variants at 15 more loci at HFE, TFR2, and FPN1 were observed in breast cancer patients. There were no significant differences of allele and genotype frequencies between cases and controls. Triple and quadruple compound genotypes at HFE_His63_Cys282-TFR1_Ser142Gly and HFE_His63_Ser65_Cys282-TFR1_Ser142Gly showed a nonsignificant increase in cases. Although limited by low numbers, an increased prevalence of the HFE Tyr282 minor allele was observed in breast cancer cases with a high number of affected lymph nodes (P = 0.032). Our data suggest that variants of the hemochromatosis-transferrin receptor system have no direct effect on the incidence of breast cancer in Germany. Possible effects on tumor progression and prognosis remain elusive.

Association of a Common AKAP9 Variant With Breast Cancer Risk: A Collaborative Analysis

Data from several studies have suggested that polymorphisms in A-kinase anchoring proteins (AKAPs), which are key components of signal transduction, contribute to carcinogenesis. To evaluate the impact of AKAP variants on breast cancer risk, we genotyped six nonsynonymous single-nucleotide polymorphisms that were predicted to be deleterious and found two (M463I, 1389G>T and N2792S, 8375A>G) to be associated with an allele dose-dependent increase in risk of familial breast cancer in a German population. We extended the analysis of AKAP9 M463I, which is in strong linkage disequilibrium with AKAP9 N2792S, to 9523 breast cancer patients and 13770 healthy control subjects from seven independent European and Australian breast cancer studies. All statistical tests were two-sided. The collaborative analysis confirmed the association of M463I with increased breast cancer risk. Among all breast cancer patients, the combined adjusted odds ratio (OR) of breast cancer for individuals homozygous for the rare allele TT (frequency = 0.19) compared with GG homozygotes was 1.17 (95% confidence interval [CI] = 1.08 to 1.27, P = .0003), and the OR for TT homozygotes plus GT heterozygotes compared with GG homozygotes was 1.10 (95% CI = 1.04 to 1.17, P = .001). Among the combined subset of 2795 familial breast cancer patients, the respective ORs were 1.27 (95% CI = 1.12 to 1.45, P = .0003) and 1.16 (95% CI = 1.06 to 1.27, P = .001).

Common variants in the UBC9 gene encoding the SUMO-conjugating enzyme are associated with breast tumor grade

UBC9 encodes a protein that conjugates small ubiquitin‐related modifier (SUMO) to target proteins resulting in a change of their localization, activity or stability. Genetic variability may affect expression and activity of UBC9 and may have an impact on breast tumor progression. We investigated associations between UBC9 genotypes and histopathological parameters in 1,021 breast cancer cases of the GENICA collection using a single nucleotide polymorphism (SNP) tagging approach. Genotyping analyses were performed by TaqMan® allelic discrimination. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by ordinal logistic regression. Multiple imputation based on HapMap data was applied to boost the power of the study. The study revealed significant associations of three UBC9 SNPs with histological grade (rs7187167, ptrend = 0.001; rs11248866, ptrend = 0.009; rs8052688, ptrend = 0.008). Model selection identified a recessive penetrance model for rs7187167 as the best representation of tumor grade (global p = 0.001). This model did not improve by inclusion of additional SNPs in linkage disequilibrium. Imputation of SNPs in a 300 kb region around the genotyped SNPs supported rs7187167 as a major contributor to tumor grade. Compared with common allele carriers, rare homozygotes presented less frequently with high grade tumors (G3 vs. G1: OR 0.26, 95% CI 0.11–0.62; G3 vs. G2: OR 0.45, 95% CI 0.23–0.86). In addition to tumor size, nodal status and estrogen receptor status, multivariate analyses confirmed an independent role of rs7187167 as predictor of tumor grade (p = 0.0003). The present results underline the value of genetic variation in UBC9 for breast cancer prognosis.

Breast cancer risk reduction and membrane-bound catechol O-methyltransferase genetic polymorphisms

Catechol O-methyltransferase (COMT)-catalyzed methylation of catecholestrogens has been proposed to play a protective role in estrogen-induced genotoxic carcinogenesis. We have taken a comprehensive approach to test the hypothesis that genetic variation in COMT might influence breast cancer risk. Fifteen COMT single nucleotide polymorphisms (SNPs) selected on the basis of in-depth resequencing of the COMT gene were genotyped in 1,482 DNA samples from a Mayo Clinic breast cancer case control study. Two common SNPs in the distal promoter for membrane-bound (MB) COMT, rs2020917 and rs737865, were associated with breast cancer risk reduction in premenopausal women in the Mayo Clinic study, with allele-specific odds ratios (OR) of 0.70 [95% confidence interval (CI), 0.52-0.95] and 0.68 (95% CI, 0.51-0.92), respectively. These two SNPs were then subjected to functional genomic analysis and were genotyped in an additional 3,683 DNA samples from two independent case control studies (GENICA and GESBC). Functional genomic experiments showed that these SNPs could up-regulate transcription and that they altered DNA-protein binding patterns. Furthermore, substrate kinetic and exon array analyses suggested a role for MB-COMT in catecholestrogen inactivation. The GENICA results were similar to the Mayo case control observations, with ORs of 0.85 (95% CI, 0.72-1.00) and 0.85 (95% CI, 0.72-1.01) for the two SNPs. No significant effect was observed in the GESBC study. These studies showed that two SNPs in the COMT distal promoter were associated with breast cancer risk reduction in two of three case control studies, compatible with the results of functional genomic experiments, suggesting a role for MB-COMT in breast cancer risk.

A Novel Polymorphism in the Promoter Region of ERBB4 Is Associated with Breast and Colorectal Cancer Risk

Purpose: The receptor tyrosine kinase ERBB4/HER4 plays a role in cell division, migration, differentiation, as well as apoptosis, and is frequently overexpressed in breast and colorectal tumors. To understand the role of genetic variations in the regulation of ERBB4 expression, we identified new polymorphisms and investigated their functional implication and risk association with breast and colorectal cancer. Experimental Design: We screened colorectal tumors from 92 patients for genetic variants at the ERBB4 ATG −1000 bp 5′-regulatory region by denaturing high-performance liquid chromatography and sequencing. Variants were subjected to DNA-protein interaction analyses (electrophoretic mobility shift assay), reporter gene assays in breast cancer cell lines MDA134 and MDA157, and immunohistochemical analyses of breast tumors. We established genotype frequencies within a breast cancer case-control collection (1,021 cases, 1,015 population-based controls) and a colorectal cancer case-control collection (459 cases, 569 blood donors) using matrix-assisted laser desorption ionization/time of flight mass spectrometry. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were assessed by multivariate logistic regression. Results: We identified five new germ line variants −815 A>T, −782 G>T, −638 insTC, −267 C>G, and −219 del10bp. Two variants showed in vitro functional effects. The −782T allele showed lower protein binding affinity and lower promoter activity compared with the −782G allele, however, the −815T allele showed higher protein binding affinity and higher promoter activity. The −782T variant was identified as a risk allele for breast and colorectal cancer (OR, 1.59; 95% CI, 1.06-2.34 and OR, 2.21; 95% CI, 1.22-3.99, respectively). Conclusion: The ERBB4 −782 G>T polymorphism, by virtue of its in vitro functional implication and incidence, is a risk factor for breast and colorectal cancer.