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Background: To estimate the incidence of primary peritoneal cancer after preventive bilateral oophorectomy in women with a BRCA1 or BRCA2 mutation., Methods: A total of 6310 women with a BRCA1 or BRCA2 mutation who underwent a preventive bilateral oophorectomy were followed for a mean of 7.8 years from oophorectomy. The 20-year cumulative incidence of peritoneal cancer post-oophorectomy was estimated using the Kaplan-Meier method. A left-truncated Cox proportional hazards analysis was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) associated with the age at oophorectomy, year of oophorectomy, and family history of ovarian cancer as well as hormonal and reproductive risk factors., Results: Fifty-five women developed primary peritoneal cancer (n = 45 in BRCA1, 8 in BRCA2, and 2 in women with a mutation in both genes). Their mean age at oophorectomy was 48.9 years. The annual risk of peritoneal cancer was 0.14% for women with a BRCA1 mutation and 0.06% for women with a BRCA2 mutation. The 20-year cumulative risk of peritoneal cancer from the date of oophorectomy was 2.7% for BRCA1 carriers and 0.9% for BRCA2 mutation carriers. There were no peritoneal cancers in BRCA1 carriers who had the operation before age 35 or in BRCA2 carriers who had the operation before age 45., Conclusions: For BRCA1 mutation carriers, the annual risk of peritoneal cancer for 20 years post-oophorectomy is 0.14% per year. The risk is lower for BRCA2 carriers (0.06% per year)., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Knowledge of the genetic landscape of a specific population group is vital for population-specific diagnosis and treatment of familial breast cancer. Although BRCA-related diagnostic testing has long been implemented in South Africa, the genotyping approach previously failed for the SA Indian population as it was based on other SA population groups. Because this population is uniquely admixed, the lack of population-specific data resulted in the implementation of comprehensive mutation screens for BRCA1/2. A total of 223 female patients were screened for clinically actionable variants. High-resolution melting analysis (HRMA) was used to screen 88 patients for DNA alterations in the coding and splice site boundaries of BRCA1 exons 2-9, BRCA1 exons 11-23, BRCA2 exons 2-9 and BRCA2 exons 12-27. The protein truncation test (PTT) was used to screen the three larger exons (BRCA1 exon 10 and BRCA2 exons 10 and 11) for protein termination changes. Multiplex ligation-dependent probe amplification (MLPA) was used to determine the presence of larger indels and possible copy number differences. Next Generation Sequencing (NGS) was performed on the remaining 135 samples. All potential variants were confirmed by performing Sanger DNA sequencing. The search revealed 28 different pathogenic heterozygotic variants, together with nine variants of unknown significance (VUS). The results suggested that the SA Indian population represents a different genetic admixture compared to that of mainland India, as only five pathogenic variants corresponded to those reported for mainland India. Familial breast cancer testing for SA Indian patients should therefore be performed as comprehensively as possible as the pathogenic variants seem to be family- rather than population-specific. Furthermore, predictive testing of family members will contribute to relieve the financial burden on the country's healthcare system, as increased surveillance and appropriate management could prevent disease., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to declare., (Copyright © 2021. Published by Elsevier Inc.)

The MRN complex, composed of MRE11A, RAD50, and NBN, mediates vital molecular functions to maintain genomic stability and hence protect against related disorders. Germline mutations in the MRN genes predispose to three different syndromes: ataxia-telangiectasia-like disorder (MRE11A deficiency), Nijmegen breakage syndrome (NBS; NBN deficiency), and NBS-like disorder (RAD50 deficiency). The potential cancer component of these syndromes in addition to the close physical and functional proximity of the MRN complex to BRCA1 has promoted the MRN genes as candidate risk genes for developing breast cancer. This notion has been challenged by independent large-scale population-based studies. Despite having their two-decade old candidacy as breast cancer genes close to being refuted, it has recently been reported that the MRN genes rise to have potential new roles in clonal hematopoiesis. In this article, we discuss the history and current status of MRN genes' clinical utility in breast cancer and then focus on their recently uncovered and less understood roles in clonal hematopoiesis that likely predispose to health-related disorders such as hematologic malignancies and/or cardiovascular morbid events., (©2021 American Association for Cancer Research.)

Inactivating mutations in SMARCA4 and concurrent epigenetic silencing of SMARCA2 characterize subsets of ovarian and lung cancers. Concomitant loss of these key subunits of SWI/SNF chromatin remodeling complexes in both cancers is associated with chemotherapy resistance and poor prognosis. Here, we discover that SMARCA4/2 loss inhibits chemotherapy-induced apoptosis through disrupting intracellular organelle calcium ion (Ca 2+ ) release in these cancers. By restricting chromatin accessibility to ITPR3, encoding Ca 2+ channel IP3R3, SMARCA4/2 deficiency causes reduced IP3R3 expression leading to impaired Ca 2+ transfer from the endoplasmic reticulum to mitochondria required for apoptosis induction. Reactivation of SMARCA2 by a histone deacetylase inhibitor rescues IP3R3 expression and enhances cisplatin response in SMARCA4/2-deficient cancer cells both in vitro and in vivo. Our findings elucidate the contribution of SMARCA4/2 to Ca 2+ -dependent apoptosis induction, which may be exploited to enhance chemotherapy response in SMARCA4/2-deficient cancers., (© 2021. The Author(s).)

Hereditary non-polyposis colorectal cancer, now known as Lynch syndrome (LS) is one of the most common cancer predisposition syndromes and is caused by germline pathogenic variants (GPVs) in DNA mismatch repair (MMR) genes. A common founder GPV in PMS2 in the Canadian Inuit population, NM_000535.5: c.2002A>G, leads to a benign missense (p.I668V) but also acts as a de novo splice site that creates a 5 bp deletion resulting in a truncated protein (p.I668*). Individuals homozygous for this GPV are predisposed to atypical constitutional MMR deficiency with a delayed onset of first primary malignancy. We have generated mice with an equivalent germline mutation (Pms2c.1993A>G) and demonstrate that it results in a splicing defect similar to those observed in humans. Homozygous mutant mice are viable like the Pms2 null mice. However, unlike the Pms2 null mice, these mutant mice are fertile, like humans homozygous for this variant. Furthermore, these mice exhibit a significant increase in microsatellite instability and intestinal adenomas on an Apc mutant background. Rectification of the splicing defect in human and murine fibroblasts using antisense morpholinos suggests that this novel mouse model can be valuable in evaluating the efficacy aimed at targeting the splicing defect in PMS2 that is highly prevalent among the Canadian Inuits., (© 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

The nuclease MRE11A is often included in genetic test panels for hereditary breast and ovarian cancer (HBOC) due to its BRCA1-related molecular function in the DNA repair pathway. However, whether MRE11A is a true predisposition gene for HBOC is still questionable. We determined to investigate this notion by dissecting the molecular genetics of the c.1516G > T;p.E506* truncating MRE11A variant, that we pinpointed in two unrelated French-Canadian (FC) HBOC patients. We performed a case-control study for the variant in ~ 2500 breast, ovarian, and endometrial cancer patients from the founder FC population of Quebec. Furthermore, we looked for the presence of second somatic alterations in the MRE11A gene in the tumors of the carriers. In summary, these investigations suggested that the identified variant is not associated with an increased risk of developing breast or ovarian cancer. We finally performed a systematic review for all the previously reported MRE11A variants in breast and ovarian cancer. We found that MRE11A germline variants annotated as pathogenic on ClinVar often lacked evidence for such classification, hence misleading the clinical management for affected patients. In summary, our report suggests the lack of clinical utility of MRE11A testing in HBOC, at least in the White/Caucasian populations.

Embryonal rhabdomyosarcomas (ERMS) account for 2-3% of cancers in pediatric and adolescent populations. They are rarer in adults. We and others have reported that ERMS arising in the uterine cervix may harbor mutations in the gene encoding the microRNA biogenesis enzyme, DICER1, but a large series of cases has not been published. In the uterus, distinguishing ERMS from adenosarcoma can be very challenging, even for expert pathologists, and DICER1 alterations have been identified in a variable subset of uterine adenosarcomas. We hypothesized that DICER1 genetic testing may be useful in distinguishing between ERMS and adenosarcoma. We conducted a central pathology review-based study of 64 tumors initially thought to be uterine ERMS or adenosarcoma; 19 neoplasms had a consensus diagnosis of ERMS, 27 of adenosarcoma and for 18, no consensus diagnosis was reached. The median age at diagnosis was 30 years (range 2.5-69) for ERMS, 57.5 years (range 27-82) for adenosarcoma, and 65.5 years (range 32-86) for no consensus cases. In our series, the DICER1 mutation prevalence differed between the three groups: DICER1 alterations were present in 18/19 (95%) ERMS, 7/27 (26%) adenosarcomas (p < 0.001), and 4/18 (22%) no consensus cases. A germline alteration was present in 6/12 ERMS patients tested versus 0/6 adenosarcoma patients. Thus, although DICER1 mutations are near ubiquitous in uterine ERMS and are significantly less common in uterine adenosarcoma, DICER1 testing is only of value in distinguishing between the two neoplasms when a DICER1 mutation is absent, as this is helpful in excluding ERMS. On review of the clinical and radiological features of the single DICER1 wild-type cervical ERMS, this was thought most likely to be of vaginal origin. Given the significant prevalence of DICER1 germline pathogenic variants in uterine ERMS, all patients with this diagnosis should be referred to a genetics service.

Background: Pathogenic variants that occur in the familial breast cancer genes (BRCA1/2) lead to truncated ineffective proteins in the majority of cases. These variants are mostly represented by small deletions/insertions, nonsense- and splice-site variants, although some larger pathogenic rearrangements occur. Currently, their contribution to familial breast cancer (BC) and ovarian cancer (OVC) in South Africa (SA) is unknown., Methods: Seven hundred and forty-four patients affected with BC or OVC were screened for larger genomic rearrangements (LGRs) by means of multiplex ligation-dependent probe amplification or Next Generation Sequencing using the Oncomine™ BRCA research assay., Results: The patients represented mostly medium to high-risk families, but also included lower risk patients without a family history of the disease, diagnosed at an early age of onset (< 40 years). Eight LGRs were detected (1.1%); seven in BRCA1 with a single whole gene deletion (WGD) detected for BRCA2. These eight LGRs accounted for 8.7% of the 92 BRCA1/2 pathogenic variants identified in the 744 cases. The pathogenic LGRs ranged from WGDs to the duplication of a single exon., Conclusions: Larger rearrangements in BRCA1/2 contributed to the overall mutational burden of familial BC and OVC in SA. Almost a quarter of all pathogenic variants in BRCA1 were LGRs (7/30, 23%). The spectrum observed included two WGDs, one each for BRCA1 and BRCA2.

DICER1 syndrome is a pleiotropic tumor predisposition syndrome characterized by a distinctive constellation of neoplastic and dysplastic lesions, which are generally rare and affect children and young adults. Germline pathogenic variants in the DICER1 gene are the underlying cause of the syndrome; variants are typically inherited in an autosomal dominant pattern but may arise de novo in the germline or in a somatic mosaic distribution. The encoded DICER1 protein is a key component of the microRNA processing pathway. In this Mutation Update, we present a comprehensive review of all DICER1 genetic alterations reported in articles published before January 31st, 2019. A total of 1,136 DICER1 alterations were catalogued from 808 individuals and the tumors that occurred in these persons. We provide an inventory of these DICER1 alterations and discuss them with respect to their provenance, distribution across the gene, associated phenotypes and ages of onset, and penetrance. We also address approaches to classification of DICER1 variants of uncertain significance and discuss the clinical significance of DICER1 variant identification., (© 2019 Wiley Periodicals, Inc.)

Purpose: Constitutional mismatch repair deficiency (CMMRD) is a highly penetrant cancer predisposition syndrome caused by biallelic mutations in mismatch repair (MMR) genes. As several cancer syndromes are clinically similar, accurate diagnosis is critical to cancer screening and treatment. As genetic diagnosis is confounded by 15 or more pseudogenes and variants of uncertain significance, a robust diagnostic assay is urgently needed. We sought to determine whether an assay that directly measures MMR activity could accurately diagnose CMMRD., Patients and Methods: In vitro MMR activity was quantified using a 3'-nicked G-T mismatched DNA substrate, which requires MSH2-MSH6 and MLH1-PMS2 for repair. We quantified MMR activity from 20 Epstein-Barr virus-transformed lymphoblastoid cell lines from patients with confirmed CMMRD. We also tested 20 lymphoblastoid cell lines from patients who were suspected for CMMRD. We also characterized MMR activity from patients with neurofibromatosis type 1, Li-Fraumeni syndrome, polymerase proofreading-associated cancer syndrome, and Lynch syndrome., Results: All CMMRD cell lines had low MMR activity (n = 20; mean, 4.14 ± 1.56%) relative to controls (n = 6; mean, 44.00 ± 8.65%; P < .001). Repair was restored by complementation with the missing protein, which confirmed MMR deficiency. All cases of patients with suspected CMMRD were accurately diagnosed. Individuals with Lynch syndrome (n = 28), neurofibromatosis type 1 (n = 5), Li-Fraumeni syndrome (n = 5), and polymerase proofreading-associated cancer syndrome (n = 3) had MMR activity that was comparable to controls. To accelerate testing, we measured MMR activity directly from fresh lymphocytes, which yielded results in 8 days., Conclusion: On the basis of the current data set, the in vitro G-T repair assay was able to diagnose CMMRD with 100% specificity and sensitivity. Rapid diagnosis before surgery in non-neoplastic tissues could speed proper therapeutic management.

Context: DICER1 syndrome is a rare autosomal-dominantly inherited disorder that predisposes to a variety of cancerous and noncancerous tumors of mostly pediatric and adolescent onset, including differentiated thyroid carcinoma (DTC). DTC has been hypothesized to arise secondarily to the increased prevalence of thyroid hyperplastic nodules in syndromic patients., Objective: To determine somatic alterations in DICER1-associated DTC and to study patient outcomes., Design: Retrospective series., Setting: Tertiary referral centers., Patients: Ten patients with germline pathogenic DICER1 variants and early-onset DTC., Methods: Somatic DICER1 mutation analysis, extensive somatic DNA variant and gene fusion analyses were performed on all tumors., Results: Median age at DTC diagnosis was 13.5 years and there was no recurrent or metastatic disease (median follow-up, 8 years). All thyroid specimens showed diffuse nodular hyperplasia with at least one focus suspicious of DTC but without infiltrative growth, extrathyroidal extension, vascular invasion, or lymph node metastasis. Most of the individual nodules (benign and malignant) sampled from the 10 tumors harbored distinct DICER1 RNase IIIb hotspot mutations, indicating a polyclonal composition of each tumor. Furthermore, nine of 10 DICER1-related DTCs lacked well-known oncogenic driver DNA variants and gene rearrangements., Conclusion: On the basis of our clinical, histological, and molecular data, we consider that most DICER1-related DTCs form a low-risk subgroup. These tumors may arise within one of multiple benign monoclonal nodules; thus, hemi-thyroidectomy or, more likely, total thyroidectomy may often be required. However, radioiodine treatment may be unnecessary given the patients' ages and the tumors' low propensity for metastases.

Background: To evaluate the predictors of mortality, including ER status, in women with a BRCA2 mutation and breast cancer., Methods: Eligible participants were identified from within two longitudinal cohorts. These patients were selected because they were diagnosed with breast cancer between 1975 and 2015 and carried a BRCA2 mutation. Data were abstracted from the medical record and pathology report. We analysed the effects of ER status and other variables on breast cancer specific survival using a Cox proportional hazards model., Results: Three hundred ninety women with breast cancer and a BRCA2 mutation were included in the analysis. The mean follow-up time was 12.3 years (range 1-39 years) and 89 subjects died (22.8%). In the multivariate analysis, women with ER-positive tumours were more likely to die than women with ER-negative tumours (HR 2.08, 95% CI 0.99-4.36, p = 0.05), and this was of borderline significance. For the 233 women with ER-positive tumours the 20-year survival rate was 62.2%, compared to 83.7% for 58 women with ER-negative tumours (p = 0.03)., Conclusions: The majority of women with a BRCA2 mutation present with ER-positive breast cancer, and for these women, prognosis may be worse than for BRCA2 carriers with ER-negative breast cancer.

We describe a family in which four siblings exhibited multiple or classic colonic polyposis with or without colorectal carcinoma (CRC). One female developed three primary tumors, including CRC and carcinomas of the ovary and breast. Whole-exome sequencing of germline DNA from affected and unaffected individuals revealed a novel missense mutation in the exonuclease domain of POLE (c.833C>A; p.Thr278Lys) associated with a highly penetrant, autosomal-dominant inheritance pattern. Functional studies in yeast and demonstration of a high mutational burden in the available tumors confirmed the pathogenicity of the novel variant. Prominent POLE-deficient somatic mutational signatures were seen in the CRCs, but in contrast, a mutational signature typical of concomitant tumoral loss of POLE and mismatch-repair function (POLE-exo * /MSI) was noted in the breast cancer. The breast cancer also showed distinctive pathological characteristics that reflect the presence of both the germline POLE variant and the secondary somatic MMR alterations., (© 2018 Wiley Periodicals, Inc.)

Purpose: In the general population, an early age at first full-term birth confers protection against the risk of developing breast cancer. The relationship between age at first birth and breast cancer risk is not clear for women with a mutation in the BRCA1 or BRCA2 gene. Thus, we undertook a case-control study of women with a BRCA1 or BRCA2 mutation to study the effects of age at first full-term birth matched for other reproductive factors., Methods: Information about reproductive factors, including age at first birth as well as medical history, was collected from a routinely administered research questionnaire. There were 2,295 matched pairs of women with a BRCA1 or BRCA2 mutation included in the final analysis., Results: There was no significant difference in the mean age at first full-term birth among the BRCA1 (24.9 vs. 25.2; P = 0.10) or BRCA2 mutation carriers (26.5 vs. 26.6 years; P = 0.80). Findings were similar in the analysis limited to cases who were diagnosed with breast cancer prior to age 45., Conclusion: This matched analysis of a large number of BRCA mutation carriers suggests that age at first birth has little influence on BRCA1 or BRCA2 breast cancer risk.

Importance: Prophylactic bilateral salpingo-oophorectomy is recommended for BRCA1 mutation carriers to prevent ovarian cancer. Whether or not hormone replacement therapy (HRT) initiated after oophorectomy is associated with an increased risk of breast cancer has not been evaluated in a prospective study., Objective: To determine the association between HRT use and BRCA1-associated breast cancer., Design, Setting, and Participants: A prospective, longitudinal cohort study of BRCA1 and BRCA2 mutation carriers from 80 participating centers in 17 countries was conducted between 1995 and 2017 with a mean follow-up of 7.6 years. Participants had sought genetic testing for a BRCA1 or BRCA2 mutation because of a personal or family history of breast and/or ovarian cancer. Carriers of BRCA1 mutation with no personal medical history of cancer who underwent bilateral oophorectomy following enrollment were eligible for the cohort study., Exposures: A follow-up questionnaire was administered every 2 years to obtain detailed information on HRT use. A left-truncated Cox proportional hazard analysis was used to estimate the hazard ratios (HRs) and 95% CIs associated with the initiation of HRT use postoophorectomy., Main Outcomes and Measures: Incident breast cancer., Results: A total of 872 BRCA1 mutation carriers with a mean postoophorectomy follow-up period of 7.6 years (range, 0.4-22.1) were included in this study. Mean (SD) age of participants was 43.4 (8.5) years. Among these, 92 (10.6%) incident breast cancers were diagnosed. Overall, HRT use after oophorectomy was not associated with an increased risk of breast cancer. The HR was 0.97 (95% CI, 0.62-1.52; P = .89) for ever use of any type of HRT vs no use; however, the effects of estrogen alone and combination hormonal therapy were different. After 10 years of follow-up, the cumulative incidence of breast cancer among women who used estrogen-alone HRT was 12% compared with 22% among women who used estrogen plus progesterone HRT (absolute difference, 10%; log rank P = .04)., Conclusions and Relevance: These findings suggest that use of estrogen after oophorectomy does not increase the risk of breast cancer among women with a BRCA1 mutation and should reassure BRCA1 mutation carriers considering preventive surgery that HRT is safe. The possible adverse effect of progesterone-containing HRT warrants further study.

Objectives: For women at high risk of developing ovarian cancer, it is important to provide an accurate recommendation for the optimal age for preventive surgery in order to maximize the preventative effect while delaying symptoms associated with early surgical menopause. The goal of the current study was to estimate age-specific incidence rates of ovarian cancer among women with a BRCA1 or BRCA2 mutation., Methods: From our international registry, we identified 5689 women with no previous diagnosis of ovarian or fallopian tube cancer or preventive oophorectomy. Women were followed from the date of completion of the baseline questionnaire until either a diagnosis of ovarian or fallopian tube cancer, prophylactic oophorectomy, death or last follow-up. The annual and cumulative incidence rates of ovarian cancer were estimated., Results: Over a mean follow-up period of 4.7 years (ranges 0-22.6), 195 incident ovarian or fallopian tube cancers were diagnosed (169 [86%] ovarian cancers, 22 [11%] fallopian tube cancers and four [2%] cancers that involved both the ovaries and fallopian tubes). Of these, 45 (23%) cancers were diagnosed at preventive surgery (occult cancers). The cumulative risk of ovarian cancer to age 80 was 49% for BRCA1 and 21% for BRCA2 mutation carriers. The mean age at diagnosis was 51.3 years (ranges 33-84) among women with a BRCA1 mutation and 61.4 years (ranges 44-80) among women with a BRCA2 mutation., Conclusion: Based on a cumulative risk of 0.55% to age 35 for BRCA1 mutation carriers and of 0.56% to age 45 for BRCA2 mutation carriers, we recommend bilateral salpingo-oophorectomy before age 40, but ideally by age 35, for women with a BRCA1 mutation and by age 45 for those with a BRCA2 mutation to maximize prevention and to minimize adverse effects., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Physical activity is inversely associated with the risk of breast cancer among women in the general population. It is not clear whether or not physical activity is associated with the risk of BRCA-associated breast cancer., Methods: We conducted a case-control study of 443 matched pairs of BRCA mutation carriers to evaluate the association between physical activity and breast cancer risk. Moderate and vigorous physical activities at ages 12-13, ages 14-17, ages 18-22, ages 23-29 and ages 30-34 were determined using the Nurses' Health Study II Physical Activity Questionnaire. We estimated mean metabolic equivalent task hours/week for moderate, vigorous and total physical activities overall (ages 12-34), during adolescence (ages 12-17) and during early adulthood (ages 18-34). Logistic regression analysis was used to estimate the odds ratios (OR) and 95% confidence intervals (CI) for total, moderate and strenuous recreational physical activities and breast cancer risk, by menopausal status., Results: Overall, there was no significant association between total physical activity and subsequent breast cancer risk (OR Q4 vs. Q1  = 1.01, 95% CI 0.69-1.47; P-trend = 0.72). Moderate physical activity between ages 12-17 was associated with a 38% decreased risk of premenopausal breast cancer (OR Q4 vs. Q1  = 0.62; 95% CI 0.40-0.96; P-trend = 0.01). We found no association between exercise and breast cancer diagnosed after menopause., Conclusions: These findings suggest that early-life physical activity is associated with a reduced risk of premenopausal breast cancer among BRCA mutation carriers., Impact: Future prospective analyses, complemented by mechanistic evidence, are warranted in this high-risk population.

Context: Papillary thyroid carcinoma (PTC) is a common malignancy in adolescence and is molecularly and clinically distinct from adult PTC. Mutations in the DICER1 gene are associated with thyroid abnormalities, including multinodular goiter and differentiated thyroid carcinoma., Objective: In this study, we sought to characterize the prevalence of DICER1 variants in pediatric PTC, specifically in tumors without conventional PTC oncogenic alterations., Patients: Patients (N = 40) who underwent partial or total thyroidectomy and who were <18 years of age at the time of surgery were selected., Design: The 40 consecutive thyroidectomy specimens (30 malignant, 10 benign) underwent genotyping for 17 PTC-associated variants, as well as full sequencing of the exons and exon-intron boundaries of DICER1., Results: Conventional alterations were found in 12 of 30 (40%) PTCs (five BRAFV600E, three RET/PTC1, four RET/PTC3). Pathogenic DICER1 variants were identified in 3 of 30 (10%) PTCs and in 2 of 10 (20%) benign nodules, all of which lacked conventional alterations and did not recur during follow-up. DICER1 alterations thus constituted 3 of 18 (16.7%) PTCs without conventional alterations. The three DICER1-mutated carcinomas each had two somatic DICER1 alterations, whereas two follicular-nodular lesions arose in those with germline DICER1 mutations and harbored characteristic second somatic RNase IIIb "hotspot" mutations., Conclusions: DICER1 is a driver of pediatric thyroid nodules, and DICER1-mutated PTC may represent a distinct class of low-risk malignancies. Given the prevalence of variants in children, we advocate for inclusion of DICER1 sequencing and gene dosage determination in molecular analysis of pediatric thyroid specimens.

Objective: We previously identified a pathogenic germline DICER1 variant in a child with transposition of the great arteries who was a member of a family with DICER1 syndrome. In view of a report linking Dicer1 knockout in murine cardiomyocytes to cardiac outflow defects, we investigated the involvement of DICER1 in transposition of the great arteries., Design: We used Fluidigm access array followed by next generation sequencing to screen for variants in the coding exons, their exon/intron boundaries and the 3' untranslated region of DICER1 in patient DNA., Cases: Germline DNA was collected from 129 patients with either sporadic or familial forms of transposition of the great arteries from two sites in Australia and Italy., Results: Most cases (85%) did not have any germline DICER1 variants. In the remaining 15% of cases, we identified 16 previously reported variants (5 synonymous, 6 intronic, and 5 missense) and 2 novel variants (1 intronic and 1 missense). None of the identified variants were predicted to be pathogenic., Conclusions: Here, we report that neither likely pathogenic nor pathogenic variants in DICER1 appear to play a major role in transposition of the great arteries., (© 2018 Wiley Periodicals, Inc.)

Most common breast cancer susceptibility variants have been identified through genome-wide association studies (GWAS) of predominantly estrogen receptor (ER)-positive disease. We conducted a GWAS using 21,468 ER-negative cases and 100,594 controls combined with 18,908 BRCA1 mutation carriers (9,414 with breast cancer), all of European origin. We identified independent associations at P < 5 × 10 -8 with ten variants at nine new loci. At P < 0.05, we replicated associations with 10 of 11 variants previously reported in ER-negative disease or BRCA1 mutation carrier GWAS and observed consistent associations with ER-negative disease for 105 susceptibility variants identified by other studies. These 125 variants explain approximately 16% of the familial risk of this breast cancer subtype. There was high genetic correlation (0.72) between risk of ER-negative breast cancer and breast cancer risk for BRCA1 mutation carriers. These findings may lead to improved risk prediction and inform further fine-mapping and functional work to better understand the biological basis of ER-negative breast cancer.

Biallelic inactivation of BRCA1 or BRCA2 is associated with a pattern of genome-wide mutations known as signature 3. By analyzing ∼1,000 breast cancer samples, we confirmed this association and established that germline nonsense and frameshift variants in PALB2, but not in ATM or CHEK2, can also give rise to the same signature. We were able to accurately classify missense BRCA1 or BRCA2 variants known to impair homologous recombination (HR) on the basis of this signature. Finally, we show that epigenetic silencing of RAD51C and BRCA1 by promoter methylation is strongly associated with signature 3 and, in our data set, was highly enriched in basal-like breast cancers in young individuals of African descent.

Ovarian Sertoli-Leydig cell tumors (SLCTs) are uncommon sex cord-stromal tumors associated with both germ-line and somatic DICER1 mutations, the frequency of which has varied widely in different studies (0% to 62.5%). The current World Health Organization Classification includes 3 histologic types of SLCTs (well-differentiated, moderately differentiated, and poorly differentiated); heterologous elements and/or retiform patterns may be present in moderately and poorly differentiated neoplasms. We investigated the frequency of DICER1 mutations in a series of 38 ovarian tumors initially diagnosed as SLCTs, and explored whether identified mutations were associated with specific morphologic features. Specialist pathology review performed blinded to molecular results confirmed 34 tumors to be SLCTs (22 moderately differentiated, 8 poorly differentiated; 4 well-differentiated), while the remaining 4 neoplasms were considered not to represent SLCTs. Of the 34 cases diagnosed as SLCTs, 30 (88%) harbored ≥1 DICER1 mutation. All 30 moderately differentiated/poorly differentiated SLCTs contained mutations, but we did not find deleterious DICER1 mutations in the 4 well-differentiated SLCTs. Our study reports the highest DICER1 mutation frequency to date in SLCTs, with 100% of moderately differentiated and poorly differentiated tumors being DICER1-mutated. This suggests that DICER1 mutation may be a defining feature of these neoplasms. Although the number of cases is limited, well-differentiated SLCTs appear to be DICER1-independent. Moderately differentiated and poorly differentiated SLCT components often coexist with each other and form part of a spectrum, while well-differentiated SLCTs usually occur in pure form, suggesting that fundamentally, these represent 2 separate and independent tumor types with a different pathogenesis. We suggest that all patients with ovarian SLCTs undergo germ-line DICER1 mutation testing.

Objective: Preventive breast surgery and MRI screening are offered to unaffected BRCA mutation carriers. The clinical benefit of these two modalities has not been evaluated among mutation carriers with a history of ovarian cancer. Thus, we sought to determine whether or not BRCA mutation carriers with ovarian cancer would benefit from preventive mastectomy or from MRI screening., Methods: First, the annual mortality rate for ovarian cancer patients was estimated for a cohort of 178 BRCA mutation carriers from Ontario, Canada. Next, the actuarial risk of developing breast cancer was estimated using an international registry of 509 BRCA mutation carriers with ovarian cancer. A series of simulations was conducted to evaluate the reduction in the probability of death (from all causes) associated with mastectomy and with MRI-based breast surveillance. Cox proportional hazards models were used to evaluate the impacts of mastectomy and MRI screening on breast cancer incidence as well as on all-cause mortality., Results: Twenty (3.9%) of the 509 patients developed breast cancer within ten years following ovarian cancer diagnosis. The actuarial risk of developing breast cancer at ten years post-diagnosis, conditional on survival from ovarian cancer and other causes of mortality was 7.8%. Based on our simulation results, among all BRCA mutation-carrying patients diagnosed with stage III/IV ovarian cancer at age 50, the chance of dying before age 80 was reduced by less than 1% with MRI and by less than 2% with mastectomy. Greater improvements in survival with MRI or mastectomy were observed for women who had already survived 10years after ovarian cancer, and for women with stage I or II ovarian cancer., Conclusions: Among BRCA mutation-carrying ovarian cancer patients without a personal history of breast cancer, neither preventive mastectomy nor MRI screening is warranted, except for those who have survived ovarian cancer without recurrence for ten years and for those with early stage ovarian cancer., (Copyright © 2017 Elsevier Inc. All rights reserved.)

We here examined whether Nestin, by protein and mRNA levels, could be a predictor of BRCA1 related breast cancer, a basal-like phenotype, and aggressive tumours. Immunohistochemical staining of Nestin was done in independent breast cancer hospital cohorts (Series I-V, total 1257 cases). Also, TCGA proteomic data (n = 103), mRNA microarray data from TCGA (n = 520), METABRIC (n = 1992), and 6 open access breast cancer datasets (n = 1908) were analysed. Patients with Nestin protein expression in tumour cells more often had BRCA1 germline mutations (OR 8.7, p < 0.0005, Series III), especially among younger patients (<40 years at diagnosis) (OR 16.5, p = 0.003). Nestin protein positivity, observed in 9-28% of our hospital cases (Series I-IV), was independently associated with reduced breast cancer specific survival (HR = 2.0, p = 0.035) and was consistently related to basal-like differentiation (by Cytokeratin 5, OR 8.7-13.8, p < 0.0005; P-cadherin OR 7.0-8.9, p < 0.0005; EGFR staining, OR 3.7-8.2, p ≤ 0.05). Nestin mRNA correlated significantly with Nestin protein expression (ρ = 0.6, p < 0.0005), and high levels were seen in the basal-like intrinsic subtype. Gene expression signalling pathways linked to high Nestin were explored, and revealed associations with stem-like tumour features. In summary, Nestin was strongly associated with germline BRCA1 related breast cancer, a basal-like phenotype, reduced survival, and stemness characteristics.

Purpose: Cis-acting regulatory SNPs resulting in differential allelic expression (DAE) may, in part, explain the underlying phenotypic variation associated with many complex diseases. To investigate whether common variants associated with DAE were involved in breast cancer susceptibility among BRCA1 and BRCA2 mutation carriers, a list of 175 genes was developed based of their involvement in cancer-related pathways., Methods: Using data from a genome-wide map of SNPs associated with allelic expression, we assessed the association of ~320 SNPs located in the vicinity of these genes with breast and ovarian cancer risks in 15,252 BRCA1 and 8211 BRCA2 mutation carriers ascertained from 54 studies participating in the Consortium of Investigators of Modifiers of BRCA1/2., Results: We identified a region on 11q22.3 that is significantly associated with breast cancer risk in BRCA1 mutation carriers (most significant SNP rs228595 p = 7 × 10 -6 ). This association was absent in BRCA2 carriers (p = 0.57). The 11q22.3 region notably encompasses genes such as ACAT1, NPAT, and ATM. Expression quantitative trait loci associations were observed in both normal breast and tumors across this region, namely for ACAT1, ATM, and other genes. In silico analysis revealed some overlap between top risk-associated SNPs and relevant biological features in mammary cell data, which suggests potential functional significance., Conclusion: We identified 11q22.3 as a new modifier locus in BRCA1 carriers. Replication in larger studies using estrogen receptor (ER)-negative or triple-negative (i.e., ER-, progesterone receptor-, and HER2-negative) cases could therefore be helpful to confirm the association of this locus with breast cancer risk., Competing Interests: The authors declare that they have no conflict of interest. Ethical approval Study participants were recruited through the CIMBA Initiative, following the approval of the corresponding protocol by the Institutional Review Board or Ethics Committee at each participating center. Written informed consent was obtained from all study participants.

The analytical power of modern methods for DNA analysis has outstripped our capability to interpret and understand the data generated. To make good use of this genomic data in a biomedical setting (whether for research or diagnosis), it is vital that we understand the mechanisms through which mutations affect biochemical pathways and physiological systems. This lies at the centre of what genetics is all about, and it is the reason why genetics and genomics should go hand in hand whenever possible. In this Annual Review Issue of The Journal of Pathology, we have assembled a collection of 16 expert reviews covering a wide range of topics. Through these, we illustrate the power of genetic analysis to improve our understanding of normal physiology and disease pathology, and thereby to think in rational ways about clinical management. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Background: The rarity of mutations in PALB2, CHEK2 and ATM make it difficult to estimate precisely associated cancer risks. Population-based family studies have provided evidence that at least some of these mutations are associated with breast cancer risk as high as those associated with rare BRCA2 mutations. We aimed to estimate the relative risks associated with specific rare variants in PALB2, CHEK2 and ATM via a multicentre case-control study., Methods: We genotyped 10 rare mutations using the custom iCOGS array: PALB2 c.1592delT, c.2816T>G and c.3113G>A, CHEK2 c.349A>G, c.538C>T, c.715G>A, c.1036C>T, c.1312G>T, and c.1343T>G and ATM c.7271T>G. We assessed associations with breast cancer risk (42 671 cases and 42 164 controls), as well as prostate (22 301 cases and 22 320 controls) and ovarian (14 542 cases and 23 491 controls) cancer risk, for each variant., Results: For European women, strong evidence of association with breast cancer risk was observed for PALB2 c.1592delT OR 3.44 (95% CI 1.39 to 8.52, p=7.1×10 -5 ), PALB2 c.3113G>A OR 4.21 (95% CI 1.84 to 9.60, p=6.9×10 -8 ) and ATM c.7271T>G OR 11.0 (95% CI 1.42 to 85.7, p=0.0012). We also found evidence of association with breast cancer risk for three variants in CHEK2, c.349A>G OR 2.26 (95% CI 1.29 to 3.95), c.1036C>T OR 5.06 (95% CI 1.09 to 23.5) and c.538C>T OR 1.33 (95% CI 1.05 to 1.67) (p≤0.017). Evidence for prostate cancer risk was observed for CHEK2 c.1343T>G OR 3.03 (95% CI 1.53 to 6.03, p=0.0006) for African men and CHEK2 c.1312G>T OR 2.21 (95% CI 1.06 to 4.63, p=0.030) for European men. No evidence of association with ovarian cancer was found for any of these variants., Conclusions: This report adds to accumulating evidence that at least some variants in these genes are associated with an increased risk of breast cancer that is clinically important., Competing Interests: Conflicts of Interest: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Dysembryoplastic neuroepithelial tumor (DNET) is a benign brain tumor associated with intractable drug-resistant epilepsy. In order to identify underlying genetic alterations and molecular mechanisms, we examined three family members affected by multinodular DNETs as well as 100 sporadic tumors from 96 patients, which had been referred to us as DNETs. We performed whole-exome sequencing on 46 tumors and targeted sequencing for hotspot FGFR1 mutations and BRAF p.V600E was used on the remaining samples. FISH, copy number variation assays and Sanger sequencing were used to validate the findings. By whole-exome sequencing of the familial cases, we identified a novel germline FGFR1 mutation, p.R661P. Somatic activating FGFR1 mutations (p.N546K or p.K656E) were observed in the tumor samples and further evidence for functional relevance was obtained by in silico modeling. The FGFR1 p.K656E mutation was confirmed to be in cis with the germline p.R661P variant. In 43 sporadic cases, in which the diagnosis of DNET could be confirmed on central blinded neuropathology review, FGFR1 alterations were also frequent and mainly comprised intragenic tyrosine kinase FGFR1 duplication and multiple mutants in cis (25/43; 58.1 %) while BRAF p.V600E alterations were absent (0/43). In contrast, in 53 cases, in which the diagnosis of DNET was not confirmed, FGFR1 alterations were less common (10/53; 19 %; p < 0.0001) and hotspot BRAF p.V600E (12/53; 22.6 %) (p < 0.001) prevailed. We observed overexpression of phospho-ERK in FGFR1 p.R661P and p.N546K mutant expressing HEK293 cells as well as FGFR1 mutated tumor samples, supporting enhanced MAP kinase pathway activation under these conditions. In conclusion, constitutional and somatic FGFR1 alterations and MAP kinase pathway activation are key events in the pathogenesis of DNET. These findings point the way towards existing targeted therapies.

Background: Somatic mosaicism is being increasingly recognised as an important cause of non-Mendelian presentations of hereditary syndromes. A previous whole-exome sequencing study using DNA derived from peripheral blood identified mosaic mutations in DICER1 in two children with overgrowth and developmental delay as well as more typical phenotypes of germline DICER1 mutation. However, very-low-frequency mosaicism is difficult to detect, and thus, causal mutations can go unnoticed. Highly sensitive, cost-effective approaches are needed to molecularly diagnose these persons. We studied four children with multiple primary tumours known to be associated with the DICER1 syndrome, but in whom germline DICER1 mutations were not detected by conventional mutation detection techniques., Methods and Results: We observed the same missense mutation within the DICER1 RNase IIIb domain in multiple tumours from different sites in each patient, raising suspicion of somatic mosaicism. We implemented three different targeted-capture technologies, including the novel HaloPlex(HS) (Agilent Technologies), followed by deep sequencing, and confirmed that the identified mutations are mosaic in origin in three patients, detectable in 0.24-31% of sequencing reads in constitutional DNA. The mosaic origin of patient 4's mutation remains to be unequivocally established. We also discovered likely pathogenic second somatic mutations or loss of heterozygosity (LOH) in tumours from all four patients., Conclusions: Mosaic DICER1 mutations are an important cause of the DICER1 syndrome in patients with severe phenotypes and often appear to be accompanied by second somatic truncating mutations or LOH in the associated tumours. Furthermore, the molecular barcode-containing HaloPlex(HS) provides the sensitivity required for detection of such low-level mosaic mutations and could have general applicability., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

The current standard model for identifying carriers of high-risk mutations in cancer-susceptibility genes (CSGs) generally involves a process that is not amenable to population-based testing: access to genetic tests is typically regulated by health-care providers on the basis of a labour-intensive assessment of an individual's personal and family history of cancer, with face-to-face genetic counselling performed before mutation testing. Several studies have shown that application of these selection criteria results in a substantial proportion of mutation carriers being missed. Population-based genetic testing has been proposed as an alternative approach to determining cancer susceptibility, and aims for a more-comprehensive detection of mutation carriers. Herein, we review the existing data on population-based genetic testing, and consider some of the barriers, pitfalls, and challenges related to the possible expansion of this approach. We consider mechanisms by which population-based genetic testing for cancer susceptibility could be delivered, and suggest how such genetic testing might be integrated into existing and emerging health-care structures. The existing models of genetic testing (including issues relating to informed consent) will very likely require considerable alteration if the potential benefits of population-based genetic testing are to be fully realized.

Many BRCA1 mutation carriers undergo elective surgical oophorectomy (often before menopause) to manage their elevated risk of developing ovarian cancer. It is important to clarify whether or not the use of hormone replacement therapy (HRT) to mitigate the symptoms associated with surgical or natural menopause is safe in women with an inherited BRCA1 mutation and no personal history of breast or ovarian cancer. We conducted a case-control analysis of 432 matched pairs of women with a BRCA1 mutation. Detailed information on HRT use after menopause (duration, type, age at first/last use, formulation) was obtained from a research questionnaire administered at the time of study enrollment. Conditional logistic regression was used to estimate the odds ratio (OR) and 95 % confidence intervals (CI) associated with HRT use. The mean duration of HRT use after menopause was 4.3 years among the cases and 4.4 years among the controls (P = 0.83). The adjusted OR for breast cancer comparing all women who ever used HRT to those who never used HRT was 0.80 (95 % CI 0.55-1.16; P = 0.24). Findings did not differ by type of menopause (natural vs. surgical), by recency of use, by duration of use, and by formulation type. These findings suggest that a short course of HRT should not be contra-indicated for BRCA1 mutation carriers who have undergone menopause and who have no personal history of cancer.

Aim: To measure weight gain among unaffected women with a BRCA1 or BRCA2 mutation after undergoing an oophorectomy., Patients & Methods: We compared the bodyweight of women with (n = 405) and without an oophorectomy (n = 741) at baseline as well as the rate of weight change prior to and following surgery among 1454 BRCA mutation carriers who had an oophorectomy., Results: There was a small and non-significant difference in bodyweight between BRCA mutation carriers who had an oophorectomy compared with those women who did not (151.5 vs 149.1 pounds; p = 0.26). There was an increase in bodyweight with increasing age, but this relationship did not differ prior to and following surgery (p comparing the slope parameters = 0.78)., Conclusion: Oophorectomy is not associated with significant weight gain in high-risk women.

Given the adverse effect of alcohol in the development of breast cancer among women in the general population, we evaluated whether a similar association exists among women with a BRCA1 or BRCA2 mutation. Information regarding baseline daily alcohol consumption was abstracted from a research questionnaire for 3067 BRCA mutation carriers enrolled in a prospective cohort study. Women were followed biennially until the date of the last follow-up questionnaire, date of breast cancer diagnosis, date of prophylactic bilateral mastectomy, or date of death. Cox proportional hazards models were used to estimate relative risks (RRs) and 95 % confidence intervals (CIs) for invasive breast cancer associated with alcohol consumed at or prior to completion of the baseline questionnaire. After a mean of 5.4 years of follow-up, we observed 259 incident cases of primary invasive breast cancer. Compared with non-users, the adjusted RRs were 1.06 (95 % CI 0.78-1.44) for ever use and 1.08 (0.79-1.47) for current alcohol use. For women in the highest versus lowest quintile of cumulative alcohol consumption, the RR was 0.94 (95 % CI 0.63-1.40; P trend = 0.65). Our findings suggest that alcohol consumption is not a risk factor for breast cancer among women with a BRCA1 or BRCA2 mutation.

Embryonal rhabdomyosarcoma (ERMS), a soft tissue sarcoma, is one of the most common pediatric cancers. Certain ERMSs are associated with the DICER1 syndrome, a tumor predisposition syndrome caused by germ-line DICER1 mutations. Characteristic somatic mutations have also been identified in DICER1-associated tumor types. These "hotspot" mutations affect the catalytic activity of the DICER1 ribonuclease IIIb domain. Primary ovarian ERMS (oERMS) is extremely rare. We present a case of a 6-year-old girl with an oERMS harboring 2 DICER1 mutations. The girl also exhibited other DICER1 phenotypes: cystic nephroma (CN) and multinodular goiter. Somatic investigations of the CN identified a hotspot DICER1 mutation different from that in the oERMS. Significantly, the CN presented at 12 years of age, which is much older than the previously reported age range of susceptibility. This report documents the occurrence of DICER1 mutations in a case of oERMS, expanding the spectrum of DICER1-associated tumors., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Inherited mutations in DNA mismatch repair genes predispose to different cancer syndromes depending on whether they are mono-allelic or bi-allelic. This supports a causal relationship between expression level in the germline and phenotype variation. As a model to study this relationship, our study aimed to define the pathogenic characteristics of a recurrent homozygous coding variant in PMS2 displaying an attenuated phenotype identified by clinical genetic testing in seven Inuit families from Northern Quebec., Methods: Pathogenic characteristics of the PMS2 mutation NM&#95;000535.5:c.2002A>G were studied using genotype-phenotype correlation, single-molecule expression detection and single genome microsatellite instability analysis., Results: This PMS2 mutation generates a de novo splice site that competes with the authentic site. In homozygotes, expression of the full-length protein is reduced to a level barely detectable by conventional diagnostics. Median age at primary cancer diagnosis is 22 years among 13 NM&#95;000535.5:c.2002A>G homozygotes, versus 8 years in individuals carrying bi-allelic truncating mutations. Residual expression of full-length PMS2 transcript was detected in normal tissues from homozygotes with cancers in their 20s., Conclusions: Our genotype-phenotype study of c.2002A>G illustrates that an extremely low level of PMS2 expression likely delays cancer onset, a feature that could be exploited in cancer preventive intervention., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers., Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals., Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk., Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare, aggressive tumor that primarily affects young women. SCCOHT has recently been identified as a monogenic disorder caused by germline and/or somatic SMARCA4 mutations. We describe a 15-year-old Caucasian female with a SCCOHT harboring a previously unreported somatic mutation in the SMARCA4 gene (c.1757delA; p.K586.fs) with loss of heterozygosity. No germline mutation was identified. Subsequent immunohistochemical staining confirmed loss of SMARCA4 protein. These molecular findings will aid with SCCOHT diagnosis through immunohistochemical staining for SMARCA4 and in the future may have implications for the management of this disease., (© 2014 Wiley Periodicals, Inc.)

Background: Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls) is an international consortium of 62 centres in 20 countries evaluating the use of targeted PCa screening in men with BRCA1/2 mutations., Objective: To report the first year's screening results for all men at enrollment in the study., Design, Setting and Participants: We recruited men aged 40-69 yr with germline BRCA1/2 mutations and a control group of men who have tested negative for a pathogenic BRCA1 or BRCA2 mutation known to be present in their families. All men underwent prostate-specific antigen (PSA) testing at enrollment, and those men with PSA >3 ng/ml were offered prostate biopsy., Outcome Measurements and Statistical Analysis: PSA levels, PCa incidence, and tumour characteristics were evaluated. The Fisher exact test was used to compare the number of PCa cases among groups and the differences among disease types., Results and Limitations: We recruited 2481 men (791 BRCA1 carriers, 531 BRCA1 controls; 731 BRCA2 carriers, 428 BRCA2 controls). A total of 199 men (8%) presented with PSA >3.0 ng/ml, 162 biopsies were performed, and 59 PCas were diagnosed (18 BRCA1 carriers, 10 BRCA1 controls; 24 BRCA2 carriers, 7 BRCA2 controls); 66% of the tumours were classified as intermediate- or high-risk disease. The positive predictive value (PPV) for biopsy using a PSA threshold of 3.0 ng/ml in BRCA2 mutation carriers was 48%-double the PPV reported in population screening studies. A significant difference in detecting intermediate- or high-risk disease was observed in BRCA2 carriers. Ninety-five percent of the men were white, thus the results cannot be generalised to all ethnic groups., Conclusions: The IMPACT screening network will be useful for targeted PCa screening studies in men with germline genetic risk variants as they are discovered. These preliminary results support the use of targeted PSA screening based on BRCA genotype and show that this screening yields a high proportion of aggressive disease., Patient Summary: In this report, we demonstrate that germline genetic markers can be used to identify men at higher risk of prostate cancer. Targeting screening at these men resulted in the identification of tumours that were more likely to require treatment., (Copyright © 2014 European Association of Urology. All rights reserved.)

Women with a genetic predisposition to breast cancer may be at increased risk of cancer after exposure to ionizing radiation. It is unclear whether mammography screening increases the risk of breast cancer among BRCA1 and BRCA2 carriers. We identified 2,346 women with a BRCA1 (n = 1844) or BRCA2 (n = 502) mutation and no breast cancer, and we reviewed their history of mammography exposure. These women were followed for an average of 5.3 years and were observed for new breast cancer diagnoses. At study entry, 1808 women (77.1 %) reported ever having had a mammogram; of these, 204 women (11.2 %) reported having had a mammogram before age 30. We estimated the hazard ratios for the development of invasive breast cancer, conditional on the number of prior mammograms and on the age at first mammogram. Hazard ratios were estimated and stratified by gene (BRCA1 or BRCA2), relative to women with no exposure. We observed no significant association between prior mammography exposure and breast cancer risk for BRCA1 carriers (HR 0.79; 95 % CI 0.53-1.19; P = 0.26) or for BRCA2 carriers (HR 0.90; 95 % CI 0.35-2.34; P = 0.83). An early age at first mammogram (<30 years) did not increase breast cancer risk among BRCA1 carriers (HR 0.75; 95 % CI 0.41-1.37; P = 0.35) or among BRCA2 carriers (HR 0.69; 95 % CI 0.19-2.48; P = 0.57). Exposure to mammography in women with BRCA1 and BRCA2 mutations is not associated with an increased risk of breast cancer.

Whole-exome sequencing (WES) is revolutionizing medical diagnostics and taxonomy. In less than 5 years since its first use, WES has revealed unexpected molecular drivers of numerous cancers. Here, we describe our use of WES to uncover the true nature of an enigmatic pathological entity, small-cell carcinoma of the ovary, hypercalcaemic type (SCCOHT), which has resisted definitive characterisation since it was first described in 1979. We conducted WES using three families with SCCOHT and identified deleterious mutations in the chromatin-remodelling gene SMARCA4 (encoding BRG1) in all cases. Follow-up of these findings, using both Sanger sequencing and WES of formalin-fixed paraffin-embedded tumours, showed that virtually all SCCOHTs we studied lacked functional SMARCA4/BRG1. Notably, this gene, and the related SMARCB1 gene, is mutated in most, if not all, atypical teratoid/rhabdoid tumours and malignant rhabdoid tumours. Other groups have similar findings. We review the relationship between these three neoplasms, discuss how they were distinguished from morphologically similar neoplasms, consider their similarities and show how WES has revealed that SCCOHTs are in fact rhabdoid tumours. We propose that SCCOHT be renamed 'malignant rhabdoid tumour of the ovary' (MRTO) to reflect these observations., (Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Women with a mutation in BRCA1 or BRCA2 face a lifetime risk of breast cancer of approximately 80 %. Tamoxifen treatment of the first cancer has been associated with a reduction in the risk of a subsequent contralateral cancer. We studied 1,504 women with a known BRCA1 or BRCA2 mutation, 411 women with bilateral breast cancer (cases) and 1,093 women with unilateral breast cancer (controls) in a matched case-control study. Control women were of similar age and had a similar age of diagnosis of first breast cancer as the cases. For each woman who used tamoxifen, the starting and stopping dates were abstracted and the duration of tamoxifen use was calculated. Three hundred and thirty-one women had used tamoxifen (22 %); of these 84 (25 %) had completed four or more years of tamoxifen, the remainder stopped prematurely or were current users. For women with up to 1 year of tamoxifen use, the odds ratio for contralateral breast cancer was 0.37 (95 % CI 0.20-0.69; p = 0.001) compared to women with no tamoxifen use. Among women with 1-4 years of tamoxifen use the odds ratio was 0.53 (95 % CI 0.32-0.87; p = 0.01). Among women with four or more years of tamoxifen use the odds ratio was 0.83 (95 % CI 0.44-1.55; p = 0.55). Short-term use of tamoxifen for chemoprevention in BRCA1 and BRCA2 mutation carriers may be as effective as a conventional 5-year course of treatment.

Individuals harboring germ-line DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 Syndrome or pleuropulmonary blastoma-familial tumor and dysplasia syndrome [online Mendelian inheritance in man (OMIM) #601200]. In addition, specific somatic mutations in the DICER1 RNase III catalytic domain have been identified in several DICER1-associated tumor types. Pituitary blastoma (PitB) was identified as a distinct entity in 2008, and is a very rare, potentially lethal early childhood tumor of the pituitary gland. Since the discovery by our team of an inherited mutation in DICER1 in a child with PitB in 2011, we have identified 12 additional PitB cases. We aimed to determine the contribution of germ-line and somatic DICER1 mutations to PitB. We hypothesized that PitB is a pathognomonic feature of a germ-line DICER1 mutation and that each PitB will harbor a second somatic mutation in DICER1. Lymphocyte or saliva DNA samples ascertained from ten infants with PitB were screened and nine were found to harbor a heterozygous germ-line DICER1 mutation. We identified additional DICER1 mutations in nine of ten tested PitB tumor samples, eight of which were confirmed to be somatic in origin. Seven of these mutations occurred within the RNase IIIb catalytic domain, a domain essential to the generation of 5p miRNAs from the 5' arm of miRNA-precursors. Germ-line DICER1 mutations are a major contributor to PitB. Second somatic DICER1 "hits" occurring within the RNase IIIb domain also appear to be critical in PitB pathogenesis.

Purpose: The purposes of this study were to estimate the reduction in risk of ovarian, fallopian tube, or peritoneal cancer in women with a BRCA1 or BRCA2 mutation after oophorectomy, by age of oophorectomy; to estimate the impact of prophylactic oophorectomy on all-cause mortality; and to estimate 5-year survival associated with clinically detected ovarian, occult, and peritoneal cancers diagnosed in the cohort., Patients and Methods: Women with a BRCA1 or BRCA2 mutation were identified from an international registry; 5,783 women completed a baseline questionnaire and ≥ one follow-up questionnaires. Women were observed until either diagnosis of ovarian, fallopian tube, or peritoneal cancer, death, or date of most recent follow-up. Hazard ratios (HRs) for cancer incidence and all-cause mortality associated with oophorectomy were evaluated using time-dependent survival analyses., Results: After an average follow-up period of 5.6 years, 186 women developed either ovarian (n = 132), fallopian (n = 22), or peritoneal (n = 32) cancer, of whom 68 have died. HR for ovarian, fallopian, or peritoneal cancer associated with bilateral oophorectomy was 0.20 (95% CI, 0.13 to 0.30; P < .001). Among women who had no history of cancer at baseline, HR for all-cause mortality to age 70 years associated with an oophorectomy was 0.23 (95% CI, 0.13 to 0.39; P < .001)., Conclusion: Preventive oophorectomy was associated with an 80% reduction in the risk of ovarian, fallopian tube, or peritoneal cancer in BRCA1 or BRCA2 carriers and a 77% reduction in all-cause mortality., (© 2014 by American Society of Clinical Oncology.)

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is the most common undifferentiated ovarian malignancy in women under 40 years of age. We sequenced the exomes of six individuals from three families with SCCOHT. After discovering segregating deleterious germline mutations in SMARCA4 in all three families, we tested DNA from a fourth affected family, which also carried a segregating SMARCA4 germline mutation. All the familial tumors sequenced harbored either a somatic mutation or loss of the wild-type allele. Immunohistochemical analysis of these cases and additional familial and non-familial cases showed loss of SMARCA4 (BRG1) protein in 38 of 40 tumors overall. Sequencing of cases with available DNA identified at least one germline or somatic deleterious SMARCA4 mutation in 30 of 32 cases. Additionally, the SCCOHT cell line BIN-67 had biallelic deleterious mutations in SMARCA4. Our findings identify alterations in SMARCA4 as the major cause of SCCOHT, which could lead to improvements in genetic counseling and new treatment approaches.