Despite the progress in understanding the hereditary basis of familial breast and ovarian cancer, hereditary factors known today, such as changes in the BRCA1/2 genes, can only explain part of all familial cases. Recent data suggest that additional genetic and non-genetic components may contribute multifactorially to the disease and modulate disease risk in the presence of risk gene mutation.
Our goal is to further unravel the diverse architecture of breast and ovarian cancer, identify new risk factors and their interactions, and to make this knowledge available to patients through personalized risk prediction and cancer prevention. To achieve these goals, we work closely with international study groups and coordinate the German Consortium Familial Breast and Ovarian Cancer, which has attracted international attention by identifying new risk genes.
One focus of our research is the identification of new genes associated with an increased risk of breast and/or ovarian cancer. Since these additional genes are rarely mutated and probably only moderately increase the risk of disease, large collectives of well characterized patients are necessary to detect significant associations with the phenotype. For this purpose we have entered into national and international collaborations to identify additional risk genes. In the PERSPECTIVE study "personalized risk stratification for the prevention and early detection of breast cancer", which we are conducting with Prof. Jacques Simard (Genome Quebec, Canada) and other cooperation partners from the Netherlands and the USA, new candidate genes were identified by exome-wide analyses. For this purpose, exome sequencing was performed in about 1,500 breast cancer (BC) patients. We aim to genetically validate and functionally characterize the newly identified BC candidate risk genes to explore their putative role in BC pathogenesis by using patient-derived LCLs, mouse ES cells, and CRISPR/Cas9-mediated gene silencing. The results of this study will help to further improve the risk calculation for those seeking advice from families in which no mutation has been detected so far.
Results of our Genome-wide association studies (GWAS) showed that single nucleotide polymorphisms (SNPs) are associated with the risk of developing breast cancer. The risk of individual SNPs is low, so that they are not suitable for risk calculation on an individual basis. However, studies have shown that a combination of several SNPs can have an influence on the risk of developing breast cancer. It is now assumed that the currently known SNPs can explain approximately 18% of the familial breast cancer risk. The multiplicative effect of the variants can be summarized and the so-called PRS can be calculated. At present the calculations of the PRS are based only on models, which are usually limited to BRCA1/2 mutation carriers. A validation of the PRS, especially in familial breast cancer patients, is still pending. Furthermore, it has to be clarified whether the PRS can be applied to mutation carriers of further risk genes and whether a risk stratification of these patients based on the calculation of the PRS is possible. For this project, we are also working closely together with the other German breast cancer centers and international experts (Dr. Karoline Kuchenbäcker, University College London).
The goal of personalized treatment is to administer only those therapies to which patients actually respond. To investigate the effect of germline mutations on therapy response, we are involved in two studies of the German Breast Group (GBG). In the GeparSixto study (NCT01426880), we were able to show by examining the BRCA1/2 germline mutation status in patients with triple-negative breast cancer that BRCA1/2 mutation carriers generally respond well to the neoadjuvant therapy with anthracyclines and taxanes, but do not benefit additionally from the addition of carboplatin. GeparOcto (NCT02125344) is a Phase III clinical trial comparing two different treatment strategies in the treatment of primary breast cancer in high-risk patients. Patients were randomly assigned to one of the two therapeutic arms. In a genetic subproject of the study, we isolate the DNA of the study participants from blood and examine it by means of Next Generation Sequencing (NGS) for pathological germline mutations in the known breast cancer genes BRCA1 and BRCA2 and another 16 potential risk genes suspected to be associated with an increased breast cancer risk. The aim is to gain insight into whether and to what extent the genetic status has an influence on the response to therapy of those affected
Expanding the current understanding of genetic BC and OC predisposition is a prerequisite for the improvement of individualized risk prediction, cancer prevention by intensified surveillance programs and prophylactic measures and targeted therapy.
The translational impact of our data is supported by direct clinical implementation within the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC), as recently shown for new BC/OC risk genes such as BRIP1 and BARD1.
Center for Familial Breast- and Ovarian Cancer
CMMC - PI - assoc. RG 20
+49 221 478 86509
+49 221 478 86510
Center for Familial Breast- and Ovarian Cancer
Kerpener Str. 34