A deep intronic recurrent CHEK2 variant c.1009-118_1009-87delinsC affects pre-mRNA splicing and contributes to hereditary breast cancer predisposition

Germline CHEK2 pathogenic variants confer an increased risk of female breast cancer (FBC). Here we describe a recurrent germline intronic variant c.1009-118_1009-87delinsC, which showed a splice acceptor shift in RNA analysis, introducing a premature stop codon (p.Tyr337PhefsTer37). The variant was found in 21/10,204 (0.21%) Czech FBC patients compared to 1/3250 (0.03%) controls (p = 0.04) and in 4/3639 (0.11%) FBC patients from an independent German dataset. In addition, we found this variant in 5/2966 (0.17%) Czech (but none of the 443 German) ovarian cancer patients, three of whom developed early-onset tumors. Based on these observations, we classified this variant as likely pathogenic.

Clinical implications of incorporating genetic and non-genetic risk factors in CanRisk-based breast cancer risk prediction

BACKGROUND

Breast cancer (BC) risk prediction models consider cancer family history (FH) and germline pathogenic variants (PVs) in risk genes. It remains elusive to what extent complementation with polygenic risk score (PRS) and non-genetic risk factor (NGRFs) data affects individual intensified breast surveillance (IBS) recommendations according to European guidelines.

METHODS

For 425 cancer-free women with cancer FH (mean age 40·6 years, range 21-74), recruited in France, Germany and the Netherlands, germline PV status, NGRFs, and a 306 variant-based PRS (PRS306) were assessed to calculate estimated lifetime risks (eLTR) and estimated 10-year risks (e10YR) using CanRisk. The proportions of women changing country-specific European risk categories for IBS recommendations, i.e. ≥20 % and ≥30 % eLTR, or ≥5 % e10YR were determined.

FINDINGS

Of the women with non-informative PV status, including PRS306 and NGRFs changed clinical recommendations for 31·0 %, (57/184, 20 % eLTR), 15·8 % (29/184, 30 % eLTR) and 22·4 % (41/183, 5 % e10YR), respectively whereas of the women tested negative for a PV observed in their family, clinical recommendations changed for 16·7 % (25/150), 1·3 % (2/150) and 9·5 % (14/147). No change was observed for 82 women with PVs in high-risk genes (BRCA1/2, PALB2). Combined consideration of eLTRs and e10YRs identified BRCA1/2 PV carriers benefitting from IBS <30 years, and women tested non-informative/negative for whom IBS may be postponed.

INTERPRETATION

For women who tested non-informative/negative, PRS and NGRFs have a considerable impact on IBS recommendations. Combined consideration of eLTRs and e10YRs allows personalizing IBS starting age.

FUNDING

Horizon 2020, German Cancer Aid, Federal Ministry of Education and Research, Köln Fortune.

Implementing mainstream genetic counseling within the area-wide network of the German Consortium Hereditary Breast and Ovarian Cancer (GC-HBOC): Satisfaction of primary care providers with the provided state-of-the-art training by the Cologne Center

The German Cancer Society (Deutsche Krebsgesellschaft DKG) has published a position paper to address the challenges of cancer patient care in the era of genomic medicine. The German Consortium Hereditary Breast and Ovarian Cancer (GC-HBOC) has implemented this recommendation in its care concept for families at risk. Core elements are the outcome-oriented evaluation of structured and standardized clinical measures and reporting recommendations derived therefrom to primary care providers and patients. A cross-sector network with certified breast cancer and gynecological cancer centers was founded in 2015, starting from the Cologne Center of the GC-HBOC. To guarantee the knowledge transfer for mainstream genetic counseling, the Cologne center has established an educational program for physicians and specialized nurses in order to pilot trans-sectoral knowledge transfer on risk assessment and risk-stratified care. It consists of face-to-face lectures with written knowledge test, attending a genetic case conference and genetic counseling sessions with the opportunity to counsel under supervision. The lectures were accompanied by a structured evaluation of the participants' satisfaction and feedback of the needs in mainstream genetic counseling. Thereby, the network ensures that genetic counseling and testing is provided according to state-of-the-art knowledge and allows physicians to participate in knowledge-generating care outside the university setting and patients to receive care close to home. After multiple feedback cycles to improve the educational program, the GC-HBOC, in cooperation with the German Cancer Society, has now adopted this concept and developed a common and uniform online curriculum funded by the Federal Ministry of Health. https://www.krebsgesellschaft.de/fortbildung-familiaerer-krebs.html.

Pathogenic germline variants in SMARCA4 and further cancer predisposition genes in early onset ovarian cancer

To assess the role of germline pathogenic variants (PVs) in SMARCA4 and further established ovarian cancer (OC) predisposition genes in early onset OC, we investigated a clinical cohort of 206 unrelated OC index patients with an age at diagnosis of OC ≤40 years using an extended panel of 24 (candidate) cancer predisposition genes. PVs in established OC predisposition genes were most frequent in patients with high grade serous OC (21/62, 33.9%), comparatively rare in patients with epithelial OC other than high grade serous (5/74, 6.8%) or borderline ovarian tumours (2/39, 5.1%) and absent in mucinous OC (0/27). We demonstrate that germline PVs in SMARCA4 unlikely predispose for early onset OC other than SCCOHT.

Long‑term survival of a BRCA2 mutation carrier following second ovarian cancer relapse using PARPi therapy: A case report

BRCA1/2 mutation carriers have lifelong increased risks of developing breast and ovarian cancer. Due to the lack of efficient ovarian cancer screening, patients mainly present when the tumors are at an advanced stage, and the long-term survival is poor. The application of poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) has been used in personalized cancer treatment. Specific strategies to improve the outcome of patients are available and mainly include targeting of BRCA1 or BRCA2 mutations. The aim of the present study was to report the case of a 67-year old BRCA2 mutation carrier, who was enrolled in 2010 in one of the first PARPi studies (ICEBERG2). The patient exhibited second ovarian cancer (OC) relapse following a platinum-free interval of 5 months. The third-line treatment with olaparib monotherapy was initiated in January 2011, without prior surgery or chemotherapy, and achieved a persistent response. The patient demonstrated an unprecedented long-term survival of >9 years under PARPi monotherapy after the second relapse of OC. The data of the present case report support the use of PARPi as a well-tolerated and effective long-term treatment, even for patients with unfavourable prognostic characteristics, such as platinum resistance, without immediately preceding optimal cytoreduction. However, further studies are required to provide more insight into the selection of patients for favourable maintenance treatment.

Polygenic risk scores indicate extreme ages at onset of breast cancer in female BRCA1/2 pathogenic variant carriers

Background

Clinical management of women carrying a germline pathogenic variant (PV) in the BRCA1/2 genes demands for accurate age-dependent estimators of breast cancer (BC) risks, which were found to be affected by a variety of intrinsic and extrinsic factors. Here we assess the contribution of polygenic risk scores (PRSs) to the occurrence of extreme phenotypes with respect to age at onset, namely, primary BC diagnosis before the age of 35 years (early diagnosis, ED) and cancer-free survival until the age of 60 years (late/no diagnosis, LD) in female BRCA1/2 PV carriers.

Methods

Overall, estrogen receptor (ER)-positive, and ER-negative BC PRSs as developed by Kuchenbaecker et al. for BC risk discrimination in female BRCA1/2 PV carriers were employed for PRS computation in a curated sample of 295 women of European descent carrying PVs in the BRCA1 (n=183) or the BRCA2 gene (n=112), and did either fulfill the ED criteria (n=162, mean age at diagnosis: 28.3 years, range: 20 to 34 years) or the LD criteria (n=133). Binomial logistic regression was applied to assess the association of standardized PRSs with either ED or LD under adjustment for patient recruitment criteria for germline testing and localization of BRCA1/2 PVs in the corresponding BC or ovarian cancer (OC) cluster regions.

Results

For BRCA1 PV carriers, the standardized overall BC PRS displayed the strongest association with ED (odds ratio (OR) = 1.62; 95% confidence interval (CI): 1.16–2.31, p<0.01). Additionally, statistically significant associations of selection for the patient recruitment criteria for germline testing and localization of pathogenic PVs outside the BRCA1 OC cluster region with ED were observed. For BRCA2 PV carriers, the standardized PRS for ER-negative BC displayed the strongest association (OR = 2.27, 95% CI: 1.45–3.78, p<0.001).

Conclusions

PRSs contribute to the development of extreme phenotypes of female BRCA1/2 PV carriers with respect to age at primary BC diagnosis. Construction of optimized PRS SNP sets for BC risk stratification in BRCA1/2 PV carriers should be the task of future studies with larger, well-defined study samples. Furthermore, our results provide further evidence, that localization of PVs in BC/OC cluster regions might be considered in BC risk calculations for unaffected BRCA1/2 PV carriers.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12885-022-09780-1).

Large scale multifactorial likelihood quantitative analysis of BRCA1 and BRCA2 variants: An ENIGMA resource to support clinical variant classification

The multifactorial likelihood analysis method has demonstrated utility for quantitative assessment of variant pathogenicity for multiple cancer syndrome genes. Independent data types currently incorporated in the model for assessing BRCA1 and BRCA2 variants include clinically calibrated prior probability of pathogenicity based on variant location and bioinformatic prediction of variant effect, co-segregation, family cancer history profile, co-occurrence with a pathogenic variant in the same gene, breast tumor pathology, and case-control information. Research and clinical data for multifactorial likelihood analysis were collated for 1,395 BRCA1/2 predominantly intronic and missense variants, enabling classification based on posterior probability of pathogenicity for 734 variants: 447 variants were classified as (likely) benign, and 94 as (likely) pathogenic; and 248 classifications were new or considerably altered relative to ClinVar submissions. Classifications were compared with information not yet included in the likelihood model, and evidence strengths aligned to those recommended for ACMG/AMP classification codes. Altered mRNA splicing or function relative to known nonpathogenic variant controls were moderately to strongly predictive of variant pathogenicity. Variant absence in population datasets provided supporting evidence for variant pathogenicity. These findings have direct relevance for BRCA1 and BRCA2 variant evaluation, and justify the need for gene-specific calibration of evidence types used for variant classification.

Prevalence of pathogenic BRCA1/2 germline mutations among 802 women with unilateral triple-negative breast cancer without family cancer history

Background

There is no international consensus up to which age women with a diagnosis of triple-negative breast cancer (TNBC) and no family history of breast or ovarian cancer should be offered genetic testing for germline BRCA1 and BRCA2 (gBRCA) mutations. Here, we explored the association of age at TNBC diagnosis with the prevalence of pathogenic gBRCA mutations in this patient group.

Methods

The study comprised 802 women (median age 40 years, range 19–76) with oestrogen receptor, progesterone receptor, and human epidermal growth factor receptor type 2 negative breast cancers, who had no relatives with breast or ovarian cancer. All women were tested for pathogenic gBRCA mutations. Logistic regression analysis was used to explore the association between age at TNBC diagnosis and the presence of a pathogenic gBRCA mutation.

Results

A total of 127 women with TNBC (15.8%) were gBRCA mutation carriers (BRCA1: n = 118, 14.7%; BRCA2: n = 9, 1.1%). The mutation prevalence was 32.9% in the age group 20–29 years compared to 6.9% in the age group 60–69 years. Logistic regression analysis revealed a significant increase of mutation frequency with decreasing age at diagnosis (odds ratio 1.87 per 10 year decrease, 95%CI 1.50–2.32, p < 0.001). gBRCA mutation risk was predicted to be > 10% for women diagnosed below approximately 50 years.

Conclusions

Based on the general understanding that a heterozygous mutation probability of 10% or greater justifies gBRCA mutation screening, women with TNBC diagnosed before the age of 50 years and no familial history of breast and ovarian cancer should be tested for gBRCA mutations. In Germany, this would concern approximately 880 women with newly diagnosed TNBC per year, of whom approximately 150 are expected to be identified as carriers of a pathogenic gBRCA mutation.

BRIP1 loss-of-function mutations confer high risk for familial ovarian cancer, but not familial breast cancer

Background

Germline mutations in the BRIP1 gene have been described as conferring a moderate risk for ovarian cancer (OC), while the role of BRIP1 in breast cancer (BC) pathogenesis remains controversial.

Methods

To assess the role of deleterious BRIP1 germline mutations in BC/OC predisposition, 6341 well-characterized index patients with BC, 706 index patients with OC, and 2189 geographically matched female controls were screened for loss-of-function (LoF) mutations and potentially damaging missense variants. All index patients met the inclusion criteria of the German Consortium for Hereditary Breast and Ovarian Cancer for germline testing and tested negative for pathogenic BRCA1/2 variants.

Results

BRIP1 LoF mutations confer a high OC risk in familial index patients (odds ratio (OR) = 20.97, 95% confidence interval (CI) = 12.02–36.57, P < 0.0001) and in the subgroup of index patients with late-onset OC (OR = 29.91, 95% CI = 14.99–59.66, P < 0.0001). No significant association of BRIP1 LoF mutations with familial BC was observed (OR = 1.81 95% CI = 1.00–3.30, P = 0.0623). In the subgroup of familial BC index patients without a family history of OC there was also no apparent association (OR = 1.42, 95% CI = 0.70–2.90, P = 0.3030). In 1027 familial BC index patients with a family history of OC, the BRIP1 mutation prevalence was significantly higher than that observed in controls (OR = 3.59, 95% CI = 1.43–9.01; P = 0.0168). Based on the negative association between BRIP1 LoF mutations and familial BC in the absence of an OC family history, we conclude that the elevated mutation prevalence in the latter cohort was driven by the occurrence of OC in these families. Compared with controls, predicted damaging rare missense variants were significantly more prevalent in OC (P = 0.0014) but not in BC (P = 0.0693) patients.

Conclusions

To avoid ambiguous results, studies aimed at assessing the impact of candidate predisposition gene mutations on BC risk might differentiate between BC index patients with an OC family history and those without. In familial cases, we suggest that BRIP1 is a high-risk gene for late-onset OC but not a BC predisposition gene, though minor effects cannot be excluded.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0935-9) contains supplementary material, which is available to authorized users.

Abstract P3-08-01: TruRisk® based next-generation sequencing in BRCA1/2-negative breast and ovarian cancer families reveal high mutation prevalence in additional risk genes

Background: 24% of familial breast cancer (BC) and/or ovarian cancer (OC) cases analyzed within the framework of the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC) are due to pathogenic BRCA1/2 mutations. However, the mutation prevalence of non-BRCA1/2 genes associated with familial BC and/or BC/OC is largely unknown. Methods: Here, we present the first NGS data generated using the GC-HBOC-designed TruRisk® gene panel. In this study a cohort of 2028 BRCA1/2 and CHEK2 c.1100delC negative index cases was analyzed which comprises consecutive patients from BC families and BC/OC families complying the inclusion criteria of the GC-HBOC. Sequencing was performed on MiSeq, NextSeq, or HiSeq devices (Illumina) using customized SureSelect XT enrichment (Agilent). Data analysis was carried out using the SeqPilot software (version 4.2.2), SophiaDDM (Version 3.5.0.12-p5.0.0) as well as an in house bioinformatics pipeline (Cologne Center for Genomics, varpipe_v2.X). The analysis of copy number variations (CNV) based on NGS-data is currently in process and not yet included in the present mutation prevalence. Results: By focusing on 22 BC/OC associated genes (ATM, BARD1, BRIP1, CDH1, CHEK2, FAM175A, FANCM, MLH1, MRE11A, MSH2, MSH6, NBN, PALB2, PMS2, PTEN, RAD50, RAD51C, RAD51D, RINT1, STK11, TP53, XRCC2), we identified 71 different deleterious variants in 104 unrelated mutation carriers derived from 2028 BC and BC/OC families (8%). Interestingly, we identified a high prevalence of ATM mutations (n=29, 1.4%) in the familial cases. Additionally mutations in PALB2 (n=27), NBN (n=9), CHEK2 (n=14), BARD1 (n=9), BRIP1 (n=10), RAD51C (n=11) were frequently observed and we confirmed FANCM (n=17) as a novel BC predisposing gene. No mutations in MLH1, MRE11A, PTEN, RAD51D, STK11 and XRCC2 were identified in our collective. Conclusions: Due to the unexpectedly high mutation prevalence in familial cases, our study highlights the importance of these genes to be included in BC/OC routine diagnostics. In contrast we found low occurrence or absence of mutations for a subset of our gene selection which requires further investigation to optimize the gene panel for diagnostic purposes. Nevertheless this approach confirms the TruRisk® gene panel as a reliable tool for this comprehensive analysis.

Citation Format: Keupp K, Richters L, Bülow L, Kröber S, Ernst C, Blümcke B, Versmold B, Waha A, Driesen J, Baasner A, Altmüller J, Thiele H, Nuernberg P, Wappenschmidt B, Neidhardt G, Rhiem K, Schmutzler R, Hahnen E, Hauke J. TruRisk® based next-generation sequencing in BRCA1/2-negative breast and ovarian cancer families reveal high mutation prevalence in additional risk genes [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-08-01.

Comprehensive allelotype and genetic anaysis of 466 human nervous system tumors

Brain tumors pose a particular challenge to molecular oncology. Many different tumor entities develop in the nervous system and some of them appear to follow distinct pathogenic routes. Molecular genetic alterations have increasingly been reported in nervous system neoplasms. However, a considerable number of affected genes remain to be identified. We present here a comprehensive allelotype analysis of 466 nervous system tumors based on loss of heterozygosity (LOH) studies with 129 microsatellite markers that span the genome. Specific alterations of the EGFR, CDK4, CDKN2A, TP53, DMBT1, NF2, and PTEN genes were analyzed in addition. Our data point to several novel genetic loci associated with brain tumor development, demonstrate relationships between molecular changes and histopathological features, and further expand the concept of molecular tumor variants in neuro-oncology. This catalogue may provide a valuable framework for future studies to delineate molecular pathways in many types of human central nervous system tumors.