Validation of the BOADICEA model in a prospective cohort of BRCA1/2 pathogenic variant carriers.

BACKGROUND: No validation has been conducted for the BOADICEA multifactorial breast cancer risk prediction model specifically in BRCA1/2 pathogenic variant (PV) carriers to date. Here, we evaluated the performance of BOADICEA in predicting 5-year breast cancer risks in a prospective cohort of BRCA1/2 PV carriers ascertained through clinical genetic centres. METHODS: We evaluated the model calibration and discriminatory ability in the prospective TRANsIBCCS cohort study comprising 1614 BRCA1 and 1365 BRCA2 PV carriers (209 incident cases). Study participants had lifestyle, reproductive, hormonal, anthropometric risk factor information, a polygenic risk score based on 313 SNPs and family history information. RESULTS: The full multifactorial model considering family history together with all other risk factors was well calibrated overall (E/O=1.07, 95% CI: 0.92 to 1.24) and in quintiles of predicted risk. Discrimination was maximised when all risk factors were considered (Harrell's C-index=0.70, 95% CI: 0.67 to 0.74; area under the curve=0.79, 95% CI: 0.76 to 0.82). The model performance was similar when evaluated separately in BRCA1 or BRCA2 PV carriers. The full model identified 5.8%, 12.9% and 24.0% of BRCA1/2 PV carriers with 5-year breast cancer risks of <1.65%, <3% and <5%, respectively, risk thresholds commonly used for different management and risk-reduction options. CONCLUSION: BOADICEA may be used to aid personalised cancer risk management and decision-making for BRCA1 and BRCA2 PV carriers. It is implemented in the free-access CanRisk tool (https://www.canrisk.org/).

Delineating genotype and parent-of-origin effect on the phenotype in MSH6-associated Lynch syndrome.

BACKGROUND: This study investigates the potential influence of genotype and parent-of-origin effects (POE) on the clinical manifestations of Lynch syndrome (LS) within families carrying (likely) disease-causing MSH6 germline variants. PATIENTS AND METHODS: A cohort of 1615 MSH6 variant carriers (310 LS families) was analyzed. Participants were categorized based on RNA expression and parental inheritance of the variant. Hazard ratios (HRs) were calculated using weighted Cox regression, considering external information to address ascertainment bias. The findings were cross-validated using the Prospective Lynch Syndrome Database (PLSD) for endometrial cancer (EC). RESULTS: No significant association was observed between genotype and colorectal cancer (CRC) risk (HR = 1.06, 95% confidence interval [CI]: 0.77-1.46). Patients lacking expected RNA expression exhibited a reduced risk of EC (Reference Cohort 1: HR = 0.68, 95% CI: 0.43-1.03; Reference Cohort 2: HR = 0.63, 95% CI: 0.46-0.87). However, these results could not be confirmed in the PLSD. Moreover, no association was found between POE and CRC risk (HR = 0.78, 95% CI: 0.52-1.17) or EC risk (Reference Cohort 1: HR = 0.93, 95% CI: 0.65-1.33; Reference Cohort 2: HR = 0.8, 95% CI: 0.64-1.19). DISCUSSION AND CONCLUSION: No evidence of POE was detected in MSH6 families. While RNA expression may be linked to varying risks of EC, further investigation is required to explore this observation.

Long-term outcome of high-grade serous carcinoma established in risk-reducing salpingo-oophorectomy specimens in asymptomatic BRCA1/2 germline pathogenic variant carriers.

OBJECTIVE: The aim of this study was to describe the long-term outcome of asymptomatic BRCA1/2 germline pathogenic variant (GPV) carriers with high-grade serous carcinoma (HGSC) in their risk-reducing salpingo-oophorectomy (RRSO) specimen. METHODS: In a previously described cohort of asymptomatic BRCA1/2 GPV carriers derived from the Hereditary Breast and Ovarian cancer in the Netherlands (HEBON) study, women with HGSC at RRSO were identified. Main outcome was ten-year disease-free survival (DFS). Secondary outcomes were time to recurrence, ten-year disease-specific survival (DSS), ten-year overall survival (OS). Patient, disease and treatment characteristics associated with recurrence were described. RESULTS: The 28 included women with HGSC at RRSO were diagnosed at a median age of 55.3 years (range: 33.5-74.3). After staging, eighteen women had (FIGO) stage I, three stage II and five had stage III disease. Two women did not undergo surgical staging and were classified as unknown stage. After a median follow-up of 13.5 years (range: 9.1-24.7), six women with stage I (33%), one woman with stage II (33%), two women with stage III (40%) and none of the women with unknown stage developed a recurrence. Median time to recurrence was 6.9 years (range: 0.8-9.2 years). Ten-year DFS was 68%, ten-year DSS was 88% and ten-year OS was 82%. CONCLUSION: Most asymptomatic BRCA1/2 GPV carriers with HGSC at RRSO were diagnosed at an early stage. Nevertheless, after a median follow-up of 13.5 years, nine of the 28 women with HGSC at RRSO developed a recurrence after a median of 6.9 years.

Clinical applicability of the Polygenic Risk Score for breast cancer risk prediction in familial cases.

BACKGROUND: Common low-risk variants are presently not used to guide clinical management of familial breast cancer (BC). We explored the additive impact of a 313-variant-based Polygenic Risk Score (PRS313) relative to standard gene testing in non-BRCA1/2 Dutch BC families. METHODS: We included 3918 BC cases from 3492 Dutch non-BRCA1/2 BC families and 3474 Dutch population controls. The association of the standardised PRS313 with BC was estimated using a logistic regression model, adjusted for pedigree-based family history. Family history of the controls was imputed for this analysis. SEs were corrected to account for relatedness of individuals. Using the BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) V.5 model, lifetime risks were retrospectively calculated with and without individual PRS313. For 2586 cases and 2584 controls, the carrier status of pathogenic variants (PVs) in ATM, CHEK2 and PALB2 was known. RESULTS: The family history-adjusted PRS313 was significantly associated with BC (per SD OR=1.97, 95% CI 1.84 to 2.11). Including the PRS313 in BOADICEA family-based risk prediction would have changed screening recommendations in up to 27%, 36% and 34% of cases according to BC screening guidelines from the USA, UK and the Netherlands (National Comprehensive Cancer Network, National Institute for Health and Care Excellence, and Netherlands Comprehensive Cancer Organisation), respectively. For the population controls, without information on family history, this was up to 39%, 44% and 58%, respectively. Among carriers of PVs in known moderate BC susceptibility genes, the PRS313 had the largest impact for CHEK2 and ATM. CONCLUSIONS: Our results support the application of the PRS313 in risk prediction for genetically uninformative BC families and families with a PV in moderate BC risk genes.

Discordant Staining Patterns and Microsatellite Results in Tumors of MSH6 Pathogenic Variant Carriers.

Diagnosis of Lynch syndrome (LS) caused by a pathogenic germline MSH6 variant may be complicated by discordant immunohistochemistry (IHC) and/or by a microsatellite stable (MSS) phenotype. This study aimed to identify the various causes of the discordant phenotypes of colorectal cancer (CRC) and endometrial cancer (EC) in MSH6-associated LS. Data were collected from Dutch family cancer clinics. Carriers of a (likely) pathogenic MSH6 variant diagnosed with CRC or EC were categorized based on an microsatellite instability (MSI)/IHC test outcome that might fail to result in a diagnosis of LS (eg, retained staining of all 4 mismatch repair proteins, with or without an MSS phenotype, and other staining patterns). When tumor tissue was available, MSI and/or IHC were repeated. Next-generation sequencing (NGS) was performed in cases with discordant staining patterns. Data were obtained from 360 families with 1763 (obligate) carriers. MSH6 variant carriers with CRC or EC (n = 590) were included, consisting of 418 CRCs and 232 ECs. Discordant staining was reported in 77 cases (36% of MSI/IHC results). Twelve patients gave informed consent for further analysis of tumor material. Upon revision, 2 out of 3 MSI/IHC cases were found to be concordant with the MSH6 variant, and NGS showed that 4 discordant IHC results were sporadic rather than LS-associated tumors. In 1 case, somatic events explained the discordant phenotype. The use of reflex IHC mismatch repair testing, the current standard in most Western countries, may lead to the misdiagnosis of germline MSH6 variant carriers. The pathologist should point out that further diagnostics for inheritable colon cancer, including LS, should be considered in case of a strong positive family history. Germline DNA analysis of the mismatch repair genes, preferably as part of a larger gene panel, should therefore be considered in potential LS patients.

Sexual functioning more than 15 years after premenopausal risk-reducing salpingo-oophorectomy.

BACKGROUND: Women with a BRCA1/2 pathogenic variant are advised to undergo premenopausal risk-reducing salpingo-oophorectomy after completion of childbearing, to reduce their risk of ovarian cancer. Several studies reported less sexual pleasure 1 to 3 years after a premenopausal oophorectomy. However, the long-term effects of premenopausal oophorectomy on sexual functioning are unknown. OBJECTIVE: This study aimed to study long-term sexual functioning in women at increased familial risk of breast or ovarian cancer who underwent a risk-reducing salpingo-oophorectomy either before the age of 46 years (premenopausal group) or after the age of 54 years (postmenopausal group). Subgroup analyses were performed in the premenopausal group, comparing early (before the age of 41 years) and later (at ages 41-45 years) premenopausal risk-reducing salpingo-oophorectomy. STUDY DESIGN: Between 2018 and 2021, 817 women with a high familial risk of breast or ovarian cancer from an ongoing cohort study were invited to participate in our study. Because of a large difference in age in the study between the premenopausal and postmenopausal salpingo-oophorectomy groups, we restricted the comparison of sexual functioning between the groups to 368 women who were 60 to 70 years old at completion of the questionnaire (226 in the premenopausal group and 142 in the postmenopausal group). In 496 women with a premenopausal risk-reducing salpingo-oophorectomy, we compared the sexual functioning between women in the early premenopausal group (n=151) and women in the later premenopausal group (n=345). Differences between groups were analyzed using multiple regression analyses, adjusting for current age, breast cancer history, use of hormone replacement therapy, body mass index, chronic medication use (yes or no), and body image. RESULTS: Mean times since risk-reducing salpingo-oophorectomy were 20.6 years in the premenopausal group and 10.6 years in the postmenopausal group (P<.001). The mean age at questionnaire completion was 62.7 years in the premenopausal group, compared with 67.0 years in the postmenopausal group (P<.001). Compared with 48.9% of women in the postmenopausal group, 47.4% of women in the premenopausal group were still sexually active (P=.80). Current sexual pleasure scores were the same for women in the premenopausal group and women in the postmenopausal group (mean pleasure score, 8.6; P=.99). However, women in the premenopausal group more often reported substantial discomfort than women in the postmenopausal group (35.6% vs 20.9%; P=.04). After adjusting for confounders, premenopausal risk-reducing salpingo-oophorectomy was associated with substantially more discomfort during sexual intercourse than postmenopausal risk-reducing salpingo-oophorectomy (odds ratio, 3.1; 95% confidence interval, 1.04-9.4). Moreover, after premenopausal risk-reducing salpingo-oophorectomy, more severe complaints of vaginal dryness were observed (odds ratio, 2.6; 95% confidence interval, 1.4-4.7). Women with a risk-reducing salpingo-oophorectomy before the age of 41 years reported similar pleasure and discomfort scores as women with a risk-reducing salpingo-oophorectomy between ages 41 and 45 years. CONCLUSION: More than 15 years after premenopausal risk-reducing salpingo-oophorectomy, the proportion of sexually active women was comparable with the proportion of sexually active women with a postmenopausal risk-reducing salpingo-oophorectomy. However, after a premenopausal risk-reducing salpingo-oophorectomy, women experienced more vaginal dryness and more often had substantial sexual discomfort during sexual intercourse. This did not lead to less pleasure with sexual activity.

Long-term effects of premenopausal risk-reducing salpingo-oophorectomy on cognition in women with high familial risk of ovarian cancer: A cross-sectional study.

OBJECTIVE: To examine the effect of a premenopausal risk-reducing salpingo-oophorectomy (RRSO) in women at increased risk of ovarian cancer on objective and subjective cognition at least 10 years after RRSO. DESIGN: A cross-sectional study with prospective follow-up, nested in a nationwide cohort. SETTING: Multicentre in the Netherlands. POPULATION OR SAMPLE: 641 women (66% BRCA1/2 pathogenic variant carriers) who underwent either a premenopausal RRSO ≤ age 45 (n = 436) or a postmenopausal RRSO ≥ age 54 (n = 205). All participants were older than 55 years at recruitment. METHODS: Participants completed an online cognitive test battery and a questionnaire on subjective cognition. We used multivariable regression analyses, adjusting for age, education, breast cancer, hormone replacement therapy, cardiovascular risk factors and depression. MAIN OUTCOME MEASURES: The influence of RRSO on objective and subjective cognition of women with a premenopausal RRSO compared with women with a postmenopausal RRSO. RESULTS: After adjustment, women with a premenopausal RRSO (mean time since RRSO 18.2 years) performed similarly on objective cognitive tests compared with women with a postmenopausal RRSO (mean time since RRSO 11.9 years). However, they more frequently reported problems with reasoning (odds ratio [OR] 1.8, 95% confidence interval [95% CI] 1.1-3.1) and multitasking (OR 1.9, 95% CI 1.1-3.4) than women with a postmenopausal RRSO. This difference between groups disappeared in an analysis restricted to women of comparable ages (60-70 years). CONCLUSIONS: Reassuringly, approximately 18 years after RRSO, we found no association between premenopausal RRSO and objective cognition.

An alternative approach to establishing unbiased colorectal cancer risk estimation in Lynch syndrome.

PURPOSE: Biallelic pathogenic variants in the mismatch repair (MMR) genes cause a recessive childhood cancer predisposition syndrome known as constitutional mismatch repair deficiency (CMMRD). Family members with a heterozygous MMR variant have Lynch syndrome. We aimed at estimating cancer risk in these heterozygous carriers as a novel approach to avoid complicated statistical methods to correct for ascertainment bias. METHODS: Cumulative colorectal cancer incidence was estimated in a cohort of PMS2- and MSH6-associated families, ascertained by the CMMRD phenotype of the index, by using mutation probabilities based on kinship coefficients as analytical weights in a proportional hazard regression on the cause-specific hazards. Confidence intervals (CIs) were obtained by bootstrapping at the family level. RESULTS: The estimated cumulative colorectal cancer risk at age 70 years for heterozygous PMS2 variant carriers was 8.7% (95% CI 4.3-12.7%) for both sexes combined, and 9.9% (95% CI 4.9-15.3%) for men and 5.9% (95% CI 1.6-11.1%) for women separately. For heterozygous MSH6 variant carriers these estimates are 11.8% (95% CI 4.5-22.7%) for both sexes combined, 10.0% (95% CI 1.83-24.5%) for men and 11.7% (95% CI 2.10-26.5%) for women. CONCLUSION: Our findings are consistent with previous reports that used more complex statistical methods to correct for ascertainment bias. These results underline the need for MMR gene-specific surveillance protocols for Lynch syndrome.

Role of germline aberrations affecting CTNNA1, MAP3K6 and MYD88 in gastric cancer susceptibility.

BACKGROUND: In approximately 10% of all gastric cancer (GC) cases, a heritable cause is suspected. A subset of these cases have a causative germline CDH1 mutation; however, in most cases the cause remains unknown. Our objective was to assess to what extent these remaining cases may be explained by germline mutations in the novel candidate GC predisposing genes CTNNA1, MAP3K6 or MYD88. METHODS: We sequenced a large cohort of unexplained young and/or familial patients with GC (n=286) without a CDH1germline mutation for germline variants affecting CTNNA1, MAP3K6 and MYD88 using a targeted next-generation sequencing approach based on single-molecule molecular inversion probes. RESULTS: Predicted deleterious germline variants were not encountered in MYD88, but recurrently observed in CTNNA1 (n=2) and MAP3K6 (n=3) in our cohort of patients with GC. In contrast to deleterious variants in CTNNA1, deleterious variants in MAP3K6 also occur frequently in the general population. CONCLUSIONS: Based on our results MAP3K6 should no longer be considered a GC predisposition gene, whereas deleterious CTNNA1 variants are confirmed as an infrequent cause of GC susceptibility. Biallelic MYD88 germline mutations are at most a very rare cause of GC susceptibility as no additional cases were identified.

Ovarian stimulation for IVF and risk of primary breast cancer in BRCA1/2 mutation carriers.

BACKGROUND: The effect of in vitro fertilisation (IVF) on breast cancer risk for BRCA1/2 mutation carriers is rarely examined. As carriers may increasingly undergo IVF as part of preimplantation genetic diagnosis (PGD), we examined the impact of ovarian stimulation for IVF on breast cancer risk in BRCA1/2 mutation carriers. METHODS: The study population consisted of 1550 BRCA1 and 964 BRCA2 mutation carriers, derived from the nationwide HEBON study and the nationwide PGD registry. Questionnaires, clinical records and linkages with the Netherlands Cancer Registry were used to collect data on IVF exposure, risk-reducing surgeries and cancer diagnosis, respectively. Time-dependent Cox regression analyses were conducted, stratified for birth cohort and adjusted for subfertility. RESULTS: Of the 2514 BRCA1/2 mutation carriers, 3% (n = 76) were exposed to ovarian stimulation for IVF. In total, 938 BRCA1/2 mutation carriers (37.3%) were diagnosed with breast cancer. IVF exposure was not associated with risk of breast cancer (HR: 0.79, 95% CI: 0.46-1.36). Similar results were found for the subgroups of subfertile women (n = 232; HR: 0.73, 95% CI: 0.39-1.37) and BRCA1 mutation carriers (HR: 1.12, 95% CI: 0.60-2.09). In addition, age at and recency of first IVF treatment were not associated with breast cancer risk. CONCLUSION: No evidence was found for an association between ovarian stimulation for IVF and breast cancer risk in BRCA1/2 mutation carriers.

Novel BRCA1 and BRCA2 Tumor Test as Basis for Treatment Decisions and Referral for Genetic Counselling of Patients with Ovarian Carcinomas.

With the recent introduction of Poly(ADP-ribose) polymerase inhibitors, a promising novel therapy has become available for ovarian carcinoma (OC) patients with inactivating BRCA1 or BRCA2 mutations in their tumor. To select patients who may benefit from these treatments, assessment of the mutation status of BRCA1 and BRCA2 in the tumor is required. For reliable evaluation of germline and somatic mutations in these genes in DNA derived from formalin-fixed, paraffin-embedded (FFPE) tissue, we have developed a single-molecule molecular inversion probe (smMIP)-based targeted next-generation sequencing (NGS) approach. Our smMIP-based NGS approach provides analysis of both strands of the open reading frame of BRCA1 and BRCA2, enabling the discrimination between real variants and formalin-induced artefacts. The single molecule tag enables compilation of unique reads leading to a high analytical sensitivity and enabling assessment of the reliability of mutation-negative results. Multiplex ligation-dependent probe amplification (MLPA) and Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) were used to detect exon deletions of BRCA1 and methylation of the BRCA1 promoter, respectively. Here, we show that this combined approach allows the rapid and reliable detection of both germline and somatic aberrations affecting BRCA1 and BRCA2 in DNA derived from FFPE OCs, enabling improved hereditary cancer risk assessment and clinical treatment of ovarian cancer patients.

Accuracy of Hereditary Diffuse Gastric Cancer Testing Criteria and Outcomes in Patients With a Germline Mutation in CDH1.

BACKGROUND & AIMS: Germline mutations in the cadherin 1, type 1, E-cadherin gene (CDH1) cause a predisposition to gastric cancer. We evaluated the ability of the internationally accepted hereditary diffuse gastric cancer (HDGC) criteria to identify individuals with pathogenic mutations in CDH1, and assessed their outcomes. The criteria were as follows: families with 2 or more cases of gastric cancer, with at least 1 patient diagnosed with diffuse gastric cancer (DGC) before age 50; families with 3 or more cases of DGC; families with 1 DGC before the age of 40; and families with a history of DGC and lobular breast cancer, with 1 diagnosis before the age of 50. METHODS: We collected results of a CDH1 mutation analysis of 578 individuals from 499 families tested in The Netherlands between 1999 and 2014 (118 families met the HDGC criteria for testing and 236 did not; there were 145 families with incomplete data and/or availability of only first-degree relatives). Data were linked with family histories and findings from clinical and pathology analyses. The Kaplan-Meier method and Cox regression analysis were used to evaluate the overall survival of patients with and without CDH1 mutations. RESULTS: In a cohort study in The Netherlands, the HDGC criteria identified individuals with a germline CDH1 mutation with a positive predictive value of 14% and 89% sensitivity. There were 18 pathogenic CDH1 mutations in 499 families (4%); 16 of these mutations were detected in the 118 families who met the HDGC criteria for testing. One pathogenic CDH1 mutation was detected in the 236 families who did not meet HDGC criteria and 1 in the 145 families with incomplete data and/or availability of only first-degree relatives. No CDH1 mutations were found in the 67 families whose members developed intestinal-type gastric cancer, or in the 22 families whose families developed lobular breast cancer. Among patients who fulfilled the HDGC criteria and had pathogenic CDH1 mutations, 36% survived for 1 year and 4% survived for 5 years; among patients who fulfilled the HDGC criteria but did not carry pathogenic CDH1 mutations, 48% survived for 1 year and 13% survived for 5 years (P = .014 for comparative survival analysis between patients with and without a CDH1 mutation). CONCLUSIONS: All individuals with a CDH1 mutation had a personal or family history of diffuse gastric cancer. Patients with gastric cancer and germline CDH1 mutations had shorter survival times than patients who met the HDGC criteria but did not have CDH1 mutations.

The effect of genotypes and parent of origin on cancer risk and age of cancer development in PMS2 mutation carriers.

PURPOSE: Lynch syndrome (LS), a heritable disorder with an increased risk of primarily colorectal cancer (CRC) and endometrial cancer (EC), can be caused by mutations in the PMS2 gene. We wished to establish whether genotype and/or parent-of-origin effects (POE) explain (part of) the reported variability in severity of the phenotype. METHODS: European PMS2 mutation carriers (n = 381) were grouped and compared based on RNA expression and whether the mutation was inherited paternally or maternally. RESULTS: Mutation carriers with loss of RNA expression (group 1) had a significantly lower age at CRC diagnosis (51.1 years vs. 60.0 years, P = 0.035) and a lower age at EC diagnosis (55.8 years vs. 61.0 years, P = 0.2, nonsignificant) compared with group 2 (retention of RNA expression). Furthermore, group 1 showed slightly higher, but nonsignificant, hazard ratios (HRs) for both CRC (HR: 1.31, P = 0.38) and EC (HR: 1.22, P = 0.72). No evidence for a significant parent-of-origin effect was found for either CRC or EC. CONCLUSIONS: PMS2 mutation carriers with retention of RNA expression developed CRC 9 years later than those with loss of RNA expression. If confirmed, this finding would justify a delay in surveillance for these cases. Cancer risk was not influenced by a parent-of-origin effect.Genet Med 18 4, 405-409.

Colorectal cancer risk variants on 11q23 and 15q13 are associated with unexplained adenomatous polyposis.

BACKGROUND: Colorectal adenomatous polyposis is associated with a high risk of colorectal cancer (CRC) and is frequently caused by germline mutations in APC or MUTYH. However, in about 20-30% of patients no underlying gene defect can be identified. In this study, we tested if recently identified CRC risk variants play a role in patients with >10 adenomas. METHODS: We analysed a total of 16 SNPs with a reported association with CRC in a cohort of 252 genetically unexplained index patients with >10 colorectal adenomas and 745 controls. In addition, we collected detailed clinical information from index patients and their first-degree relatives (FDRs). RESULTS: We found a statistically significant association with two of the variants tested: rs3802842 (at chromosome 11q23, OR=1.60, 95% CI 1.3 to 2.0) and rs4779584 (at chromosome 15q13, OR=1.50, 95% CI 1.2 to 1.9). The majority of index patients (84%) had between 10 and 100 adenomas and 15% had >100 adenomas. Only two index patients (1%), both with >100 adenomas, had FDRs with polyposis. Forty-one per cent of the index patients had one or more FDRs with CRC. CONCLUSIONS: These SNPs are the first common, low-penetrant variants reported to be associated with adenomatous polyposis not caused by a defect in the APC, MUTYH, POLD1 and POLE genes. Even though familial occurrence of polyposis was very rare, CRC was over-represented in FDRs of polyposis patients and, if confirmed, these relatives will therefore benefit from surveillance.

Breast and ovarian cancer risks in a large series of clinically ascertained families with a high proportion of BRCA1 and BRCA2 Dutch founder mutations.

BACKGROUND: BRCA1 or BRCA2 mutations confer increased risks of breast and ovarian cancer, but risks have been found to vary across studies and populations. METHODS: We ascertained pedigree data of 582 BRCA1 and 176 BRCA2 families and studied the variation in breast and ovarian cancer risks using a modified segregation analysis model. RESULTS: The average cumulative breast cancer risk by age 70 years was estimated to be 45% (95% CI 36 to 52%) for BRCA1 and 27% (95% CI 14 to 38%) for BRCA2 mutation carriers. The corresponding cumulative risks for ovarian cancer were 31% (95% CI 17 to 43%) for BRCA1 and 6% (95% CI 2 to 11%) for BRCA2 mutation carriers. In BRCA1 families, breast cancer relative risk (RR) increased with more recent birth cohort (p heterogeneity = 0.0006) and stronger family histories of breast cancer (p heterogeneity < 0.001). For BRCA1, our data suggest a significant association between the location of the mutation and the ratio of breast to ovarian cancer (p<0.001). By contrast, in BRCA2 families, no evidence was found for risk heterogeneity by birth cohort, family history or mutation location. CONCLUSIONS: BRCA1 mutation carriers conferred lower overall breast and ovarian cancer risks than reported so far, while the estimates of BRCA2 mutations were among the lowest. The low estimates for BRCA1 might be due to older birth cohorts, a moderate family history, or founder mutations located within specific regions of the gene. These results are important for a more accurate counselling of BRCA1/2 mutation carriers.

Relevance and efficacy of breast cancer screening in BRCA1 and BRCA2 mutation carriers above 60 years: a national cohort study.

Annual MRI and mammography is recommended for BRCA1/2 mutation carriers to reduce breast cancer mortality. Less intensive screening is advised ≥60 years, although effectiveness is unknown. We identified BRCA1/2 mutation carriers without bilateral mastectomy before age 60 to determine for whom screening ≥60 is relevant, in the Rotterdam Family Cancer Clinic and HEBON: a nationwide prospective cohort study. Furthermore, we compared tumour stage at breast cancer diagnosis between different screening strategies in BRCA1/2 mutation carriers ≥60. Tumours >2 cm, positive lymph nodes, or distant metastases at detection were defined as "unfavourable." Of 548 BRCA1/2 mutation carriers ≥60 years in 2012, 395 (72%) did not have bilateral mastectomy before the age of 60. Of these 395, 224 (57%) had a history of breast or other invasive carcinoma. In 136 BRCA1/2 mutation carriers, we compared 148 breast cancers (including interval cancers) detected ≥60, of which 84 (57%) were first breast cancers. With biennial mammography 53% (30/57) of carcinomas were detected in unfavourable stage, compared to 21% (12/56) with annual mammography (adjusted odds ratio: 4·07, 95% confidence interval [1.79-9.28], p = 0.001). With biennial screening 40% of breast cancers were interval cancers, compared to 20% with annual screening (p = 0.016). Results remained significant for BRCA1 and BRCA2 mutation carriers, and first breast cancers separately. Over 70% of 60-year old BRCA1/2 mutation carriers remain at risk for breast cancer, of which half has prior cancers. When life expectancy is good, continuation of annual breast cancer screening of BRCA1/2 mutation carriers ≥60 is worthwhile.

The counselees' self-reported request for psychological help in genetic counseling for hereditary breast/ovarian cancer: not only psychopathology matters.

BACKGROUND: Several studies have shown that counselees do not experience psychopathological levels of distress after DNA test result disclosure. However, it has not systematically been studied whether the absence of psychopathology also means that counselees do not want to receive help. Their self-reported request for help may be related not only with psychopathology/distress but also with other psychological needs (e.g., surgery decisions), genetics-specific needs (e.g., feeling vulnerable/stigmatized), and existential concerns (e.g., meaning in life). METHODS: Questionnaires were filled in by Dutch cancer patients, before and after disclosure of BRCA1/2 test results for hereditary breast/ovarian cancer: pathogenic mutation results (n = 30), uninformative results (n = 202), or unclassified variants (n = 16). Newly developed questions measured request for help, psychopathology was estimated with factor analyses on distress/psychopathology instruments, and several validated questionnaires measured other needs/concerns. RESULTS: One-third of all counselees who reported a request for psychological help had actually received help. The level of psychopathology correlated between 0.34 and 0.44 with this self-reported need-for-help. Other needs, genetics-specific distress, and existential concerns correlated strongly/moderately with the counselees' self-reported need-for-help. Examples of other needs were intention to undergo surgery, inaccuracy of their interpretation, the impact of cancer, and family communication difficulties. Genetics-specific distress was for instance feeling vulnerable to develop cancer, stigma, and lack of mastery. Existential concerns were, among others, lack of purpose in life, low self-acceptance, and an unfulfilled wish for certainty. CONCLUSIONS: The request for help is related to multiple factors. Referral to psychosocial professionals may be improved by not only discussing psychopathology during genetic-counseling sessions but also by other needs and existential concerns. Questions about other needs and existential issues may be added to psychological screening instruments.

High-Grade Serous Carcinoma at Risk-Reducing Salpingo-Oophorectomy in Asymptomatic Carriers of BRCA1/2 Pathogenic Variants: Prevalence and Clinical Factors.

PURPOSE: To investigate the prevalence of and clinical factors associated with high-grade serous carcinoma (HGSC) at risk-reducing salpingo-oophorectomy (RRSO) in asymptomatic BRCA1/2-pathogenic variant (PV) carriers. PATIENTS AND METHODS: We included BRCA1/2-PV carriers who underwent RRSO between 1995 and 2018 from the Hereditary Breast and Ovarian cancer in the Netherlands study. All pathology reports were screened, and histopathology reviews were performed for RRSO specimens with epithelial abnormalities or where HGSC developed after normal RRSO. We then compared clinical characteristics, including parity and oral contraceptive pill (OCP) use, for women with and without HGSC at RRSO. RESULTS: Of the 2,557 included women, 1,624 had BRCA1, 930 had BRCA2, and three had both BRCA1/2-PV. The median age at RRSO was 43.0 years (range: 25.3-73.8) for BRCA1-PV and 46.8 years (27.6-77.9) for BRCA2-PV carriers. Histopathologic review confirmed 28 of 29 HGSCs and two further HGSCs from among 20 apparently normal RRSO specimens. Thus, 24 (1.5%) BRCA1-PV and 6 (0.6%) BRCA2-PV carriers had HGSC at RRSO, with the fallopian tube identified as the primary site in 73%. The prevalence of HGSC in women who underwent RRSO at the recommended age was 0.4%. Among BRCA1/2-PV carriers, older age at RRSO increased the risk of HGSC and long-term OCP use was protective. CONCLUSION: We detected HGSC in 1.5% (BRCA1-PV) and 0.6% (BRCA2-PV) of RRSO specimens from asymptomatic BRCA1/2-PV carriers. Consistent with the fallopian tube hypothesis, we found most lesions in the fallopian tube. Our results highlight the importance of timely RRSO with total removal and assessment of the fallopian tubes and show the protective effects of long-term OCP.

ENIGMA CHEK2gether Project: A Comprehensive Study Identifies Functionally Impaired CHEK2 Germline Missense Variants Associated with Increased Breast Cancer Risk.

PURPOSE: Germline pathogenic variants in CHEK2 confer moderately elevated breast cancer risk (odds ratio, OR ∼ 2.5), qualifying carriers for enhanced breast cancer screening. Besides pathogenic variants, dozens of missense CHEK2 variants of uncertain significance (VUS) have been identified, hampering the clinical utility of germline genetic testing (GGT). EXPERIMENTAL DESIGN: We collected 460 CHEK2 missense VUS identified by the ENIGMA consortium in 15 countries. Their functional characterization was performed using CHEK2-complementation assays quantifying KAP1 phosphorylation and CHK2 autophosphorylation in human RPE1-CHEK2-knockout cells. Concordant results in both functional assays were used to categorize CHEK2 VUS from 12 ENIGMA case-control datasets, including 73,048 female patients with breast cancer and 88,658 ethnicity-matched controls. RESULTS: A total of 430/460 VUS were successfully analyzed, of which 340 (79.1%) were concordant in both functional assays and categorized as functionally impaired (N = 102), functionally intermediate (N = 12), or functionally wild-type (WT)-like (N = 226). We then examined their association with breast cancer risk in the case-control analysis. The OR and 95% CI (confidence intervals) for carriers of functionally impaired, intermediate, and WT-like variants were 2.83 (95% CI, 2.35-3.41), 1.57 (95% CI, 1.41-1.75), and 1.19 (95% CI, 1.08-1.31), respectively. The meta-analysis of population-specific datasets showed similar results. CONCLUSIONS: We determined the functional consequences for the majority of CHEK2 missense VUS found in patients with breast cancer (3,660/4,436; 82.5%). Carriers of functionally impaired missense variants accounted for 0.5% of patients with breast cancer and were associated with a moderate risk similar to that of truncating CHEK2 variants. In contrast, 2.2% of all patients with breast cancer carried functionally wild-type/intermediate missense variants with no clinically relevant breast cancer risk in heterozygous carriers.

Spectrum and Frequency of Germline FANCM Protein-Truncating Variants in 44,803 European Female Breast Cancer Cases.

FANCM germline protein truncating variants (PTVs) are moderate-risk factors for ER-negative breast cancer. We previously described the spectrum of FANCM PTVs in 114 European breast cancer cases. In the present, larger cohort, we report the spectrum and frequency of four common and 62 rare FANCM PTVs found in 274 carriers detected among 44,803 breast cancer cases. We confirmed that p.Gln1701* was the most common PTV in Northern Europe with lower frequencies in Southern Europe. In contrast, p.Gly1906Alafs*12 was the most common PTV in Southern Europe with decreasing frequencies in Central and Northern Europe. We verified that p.Arg658* was prevalent in Central Europe and had highest frequencies in Eastern Europe. We also confirmed that the fourth most common PTV, p.Gln498Thrfs*7, might be a founder variant from Lithuania. Based on the frequency distribution of the carriers of rare PTVs, we showed that the FANCM PTVs spectra in Southwestern and Central Europe were much more heterogeneous than those from Northeastern Europe. These findings will inform the development of more efficient FANCM genetic testing strategies for breast cancer cases from specific European populations.