Histopathological characteristics of BRCA1- and BRCA2-associated intraperitoneal cancer: a clinic-based study

The aim of the research was to assess possible histopathological differences between BRCA1- and BRCA2-associated malignant intraperitoneal (ovarian/fallopian tube/peritoneal) tumors and their sporadic counterparts. Dutch families harboring pathogenic BRCA1 or BRCA2 mutations were selected. Included were patients who had had malignant primary ovarian, fallopian tube or peritoneal tumors. Histopathological data was compared with data obtained from the Dutch cancer registry between 1989 and 1993 (reference group). A total of 63 with primary intraperitoneal malignant tumors were identified in 41 families. Non-epithelial malignant tumors were not observed in the study group versus 6% (n = 404) in the reference group (n = 6,789, P = 0.04). These tumors were excluded from further analysis, as were ovarian adenocarcinomas not otherwise specified, since these were detected in 22% of the study group, and in 19% of the reference group (P = 0.76). Serous carcinomas were detected in 94% (47/50) of the women in the study group in contrast to 62% (3,145/5,088) of the reference group (P < 0.01). In the study group, mucinous and endometrioid ovarian adenocarcinomas and serous ovarian borderline tumors each comprised 2.0% of the tumors. Clear cell ovarian carcinomas were not detected. In contrast, these percentages were 16% (P < 0.01), 10% (P = 0.07), 7% (P = 0.16) and 5% (P = 0.12), respectively, in the reference group. In the study group, 6.0% of the carcinomas arose in the fallopian tube versus 1.9% in the reference group (P = 0.03). Four percent of the study group developed primary serous peritoneal carcinomas, versus six percent in the reference group (P = 0.57). Serous carcinoma is the predominant type of intraperitoneal malignancy occurring in women harboring BRCA1 or BRCA2 mutations. Non-epithelial cancer does not seem to be part of the tumor spectrum of BRCA mutation carriers. This suggests, therefore, that serous tumors may be the only subtype related to a BRCA1 or BRCA2 mutation. Furthermore, fallopian tube carcinoma occurred more often in BRCA mutation carriers than in the reference population. This revised version was published online in August 2006 with corrections to the Cover Date.     

Clinical outcome of prophylactic oophorectomy in BRCA1/BRCA2 mutation carriers and events during follow-up

A retrospective study was performed to assess the histopathologic findings in high-risk women undergoing bilateral prophylactic (salpingo)-oophorectomy. The medical files of BRCA1 or BRCA2 mutation carriers and members of a hereditary breast/ovarian cancer (HBOC) family, who had undergone prophylactic surgery, were reviewed. In all, 38 women underwent a bilateral oophorectomy (26 BRCA1, three BRCA2 and nine HBOC, respectively). A total of 90 women underwent bilateral salpingo-oophorectomy (58 BRCA1, six BRCA2, one BRCA1 and 2, 25 HBOC, respectively). At the time of salpingo-oophorectomy, five of 58 BRCA1 carriers (8.6%) were diagnosed with an occult carcinoma: two fallopian tube carcinomas, two ovarian carcinomas and one case was defined as a fallopian tube/ovarian carcinoma. No occult carcinomas were found in the other groups. Of the 38 patients, who underwent a bilateral oophorectomy (mean follow-up 45 months), three of 26 BRCA1 mutation carriers (3.4 in 100 women-years) developed peritoneal papillary serous carcinoma (PPSC) during follow-up. So far, no PPSC have occurred in the 90 women, who underwent a salpingo-oophorectomy (mean follow-up 12 months), including 58 BRCA1 carriers (0 in 60 in women-years). These results contribute to the thesis that BRCA1 germline mutation carriers are not only at risk for ovarian cancer, but also for fallopian tube carcinoma and peritoneal papillary serous carcinoma. Our data suggest that PPSC risk among BRCA2 carriers is lower than among BRCA1 carriers.     

Hereditary ovarian cancer in Ashkenazi Jews

Ovarian cancer is the fourth leading cause of cancer deaths among American women. While women in both the Ashkenazi and non-Ashkenazi populations have an estimated 1.7% lifetime risk of acquiring malignancy, the proportion of hereditary ovarian cancer is much higher in the Ashkenazim. Most of this increased proportion of hereditary ovarian cancer risk is accounted for by inherited mutations in the BRCA1 and BRCA2 genes. In the Ashkenazi Jewish population, 29 to 41% of ovarian cancer is believed to be secondary to inheriting one of three founder mutations in BRCA1 and BRCA2, while only 10% of ovarian cancer is attributed to mutations of these genes in non-Ashkenazim. In the US population in general, it is estimated that between 1 out of 345 and 1 out of 1000 individuals carries a BRCA mutation, compared with approximately 1 in 40 individuals of Ashkenazi Jewish descent. The ovarian cancer risk up to age 70 associated with BRCA mutation carriers has been reported to be as high as 66% for BRCA1 and 27% for BRCA2mutation carriers. Ovarian cancer in Ashkenazi kindreds has served as a model for the study of the histopathology of inherited ovarian cancers as well as for the study of risk reduction and screening among all women at inherited risk of ovarian cancer.     

A review of histopathological subtypes of ovarian cancer in BRCA-related French Canadian cancer families

Pathogenic mutations in BRCA1 and BRCA2 have been reported in about 55–59% of breast and ovarian cancer (HBOC) families of French Canadian descent, where about 70% of families with more than two cases of ovarian cancer were mutation-positive. Given that specific subtypes of ovarian cancer are associated with mutation-positive families, we reviewed the features of 54 HBOC families of French Canadian descent that had histopathologically confirmed cases of invasive ovarian cancer where the BRCA1 and BRCA2 mutation status is known, and 27 families harbored germline mutations. The number of cases and ages of diagnosis of either breast cancers or ovarian cancers did not differ significantly in comparisons of mutation-positive and mutation-negative groups. However, the distribution of histopathological subtypes for the 79 cases of invasive epithelial cancer from the 54 HBOC families differed when grouped according to familial mutation status. The mutation-negative group had significantly more cases of the mucinous subtype of ovarian cancer when compared with the BRCA1 (P = 0.005) and BRCA2 (P = 0.017) mutation-positive groups. The presence of a mucinous subtype ovarian cancer in multiple young age of onset breast and/or ovarian mutation-negative HBOC cancer families warrants further investigation, as these families appear to exhibit features most consistent with BRCA1 and BRCA2 carrier status.     

Prevalence of the BRCA1 founder mutation c.5266dupin Brazilian individuals at-risk for the hereditary breast and ovarian cancer syndrome

About 5-10% of breast and ovarian carcinomas are hereditary and most of these result from germline mutations in the BRCA1 and BRCA2 genes. In women of Ashkenazi Jewish ascendance, up to 30% of breast and ovarian carcinomas may be attributable to mutations in these genes, where 3 founder mutations, c.68_69del (185delAG) and c.5266dup (5382insC) in BRCA1 and c.5946del (6174delT) in BRCA2, are commonly encountered. It has been suggested by some authors that screening for founder mutations should be undertaken in all Brazilian women with breast cancer. Thus, the goal of this study was to determine the prevalence of three founder mutations, commonly identified in Ashkenazi individuals in a sample of non-Ashkenazi cancer-affected Brazilian women with clearly defined risk factors for hereditary breast and ovarian cancer (HBOC) syndrome. Among 137 unrelated Brazilian women from HBOC families, the BRCA1c.5266dup mutation was identified in seven individuals (5%). This prevalence is similar to that encountered in non-Ashkenazi HBOC families in other populations. However, among patients with bilateral breast cancer, the frequency of c.5266dup was significantly higher when compared to patients with unilateral breast tumors (12.1% vs 1.2%, p = 0.023). The BRCA1 c.68_69del and BRCA2 c.5946del mutations did not occur in this sample. We conclude that screening non-Ashkenazi breast cancer-affected women from the ethnically heterogeneous Brazilian populations for the BRCA1 c.68_69del and BRCA2 c.5946del is not justified, and that screening for BRCA1c.5266dup should be considered in high risk patients, given its prevalence as a single mutation. In high-risk patients, a negative screening result should always be followed by comprehensive BRCA gene testing. The finding of a significantly higher frequency of BRCA1 c.5266dup in women with bilateral breast cancer, as well as existence of other as yet unidentified founder mutations in this population, should be further assessed in a larger well characterized high-risk cohort.     

Phenotypic heterogeneity of hereditary gynecologic cancers: a report from the Creighton hereditary cancer registry

To determine the validity of observations suggesting a significant dichotomy of gynecologic cancers determined by linkage to specific genetic defects associated with two major autosomal dominant hereditary cancer syndromes; the Creighton University Hereditary Cancer Registry was searched for female carriers of germ line mutations in BRCA1 and BRCA2, associated with the Hereditary Breast Ovarian Cancer syndrome, and in the mismatch repair (MMR) genes MLH1, MSH2 and MSH6, associated with Lynch syndrome, who were registered with invasive uterine, ovarian, fallopian tube or peritoneal cancers between January 1, 1959 and December 31, 2010. From 217 such cases, a total of 174 subjects, consisting of 95 BRCA1 and BRCA2 mutation carriers and 79 carriers of mutations in MMR genes, were identified who had current signed Health Insurance Portability and Accountability Act forms and complete primary diagnostic pathology reports and clinical records. Data meticulously extracted from these cases were categorized and statistically analyzed. There were highly significant differences between carriers of BRCA1 and BRCA2 mutations and carriers of MMR gene mutations in the proportion of serous carcinomas compared with endometrioid carcinomas of the uterus, including cervix and endometium (p < 0.002), ovaries (p < 0.001) and overall, including fallopian tube and peritoneum cancers (p < 0.001). Endometrioid carcinoma was found in one and transitional carcinoma in another of the 14 BRCA1 mutation carriers with fallopian tube cancer, and endometrioid carcinoma was found in two of four MMR gene mutation carriers with fallopian tube cancers. All other fallopian tube cancers were serous carcinomas. Seven BRCA1 and one BRCA2 mutation carriers were diagnosed with primary peritoneal serous carcinoma; no peritoneal carcinomas were registered in MMR gene mutation carriers. Nine of 14 gynecologic cancers with associated endometriosis in mutation carriers were endometrioid or endometrioid mixed carcinomas compared with just three of other histologic types. Primary breast cancers, that characterize the HBOC syndrome, were much more frequent in BRCA1 and BRCA2 mutation carriers; while multiple gynecologic cancers and associated colorectal and urinary tract cancers, which are features of Lynch syndrome, were more common in MMR gene mutation carriers. Both serous and endometrioid carcinomas were diagnosed in MMR gene mutation carriers at significantly younger ages than in BRCA1 and BRCA2 mutation carriers (p < 0.0006). These findings confirm a clear dichotomy of uterine, ovarian and fallopian tube cancers associated with inheritance of mutations in BRCA1 and BRCA2 contrasted with inheritance of MMR gene mutations. This opens possibilities for new approaches to molecular genetic research into carcinogenic pathways and raises important new considerations regarding counseling, screening, prophylaxis and treatment of mutation carriers.     

Association of the C677T polymorphism in the MTHFR gene with breast and/or ovarian cancer risk in Jewish women

The C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with reduced enzyme activity, hyperhomocysteinaemia and increased risk for atherosclerosis in homozygotes. We examined the frequency of this mutation and its association with disease pattern in 491 Jewish women with either sporadic (n=355; 72%) or hereditary (n=136; 28%) breast and/or ovarian cancer and in 69 asymptomatic BRCA1/2 mutation carriers, genotyped for the three predominant Jewish founder BRCA1/2 mutations (185delAG, 5382insC and 6174delT). 677T homozygotes were equally distributed among women with sporadic breast and/or ovarian cancer (71/355; 20.0%) and among BRCA1/2 mutation carriers (43/205; 21.0%) (P=non-significant). 677T homozygotes were equally distributed among women diagnosed with breast cancer prior to (22/122; 18.0%) and after 42 years of age (42/243; 17.3%). Among BRCA1/2 carriers, the rate of 677T homozygotes in manifesting cancer (32/136; 23.5%) and asymptomatic individuals (11/69; 15.9%) was not significantly different. The rate of 677T homozygotes (24/72; 33.3%) was higher (P=0.0026) among women with bilateral breast cancer and those with both breast and ovarian carcinoma than among those with unilateral breast cancer (64/365; 17.5%). Differences in morbidity (one versus multiple breast/ovarian tumours) are mainly attributed to 677T homozygosity and partly to BRCA1/2 mutations. Confirmation of these data, namely, that the 677T allele is significantly more common in cases of bilateral breast cancer or combined breast and ovarian cancer would have important clinical implications.     

Familial breast and ovarian cancers

About 60% of familial breast and ovarian cancers in Japan involve germline mutations of the BRCA1 or BRCA2 (BRCA1/2) genes. These genes contribute to genetic stability and DNA repair and act as tumor suppressor genes. Mutation analysis of the BRCA1/2 genes has improved our understanding of both common mutation patterns in Japanese patients and the clinicopathological features of BRCA1/2-related cancers. BRCA1-related breast cancers are characterized by poor prognosis, a low rate of estrogen receptor positivity, and histological predominance of solid-tubular carcinoma. BRCA1-related ovarian cancers are associated with a high frequency of serous adenocarcinoma and a good outcome. Further large-scale studies are needed to delineate genotype-phenotype relations and penetrance in BRCA1/2-related breast and ovarian cancers in Japan. The development of systems for clinical genetics in Japan, including genetic counseling, has led to the increased use of genetic testing for the clinical management of BRCA1/2-related cancers. Three options are available for carriers of BRCA1/2 mutations: intensive surveillance, chemoprevention, and prophylactic surgery. Studies done in other countries indicate that prophylactic surgery effectively prevents the development of breast and ovarian cancers in carriers of BRCA1/2 mutations. However, prophylactic mastectomy remains controversial in Japan, and now systematic intensive surveillance is generally performed for the prevention of breast cancer in women at high risk. Early detection of ovarian cancer remains challenging, resulting in increased acceptance of the need for prophylactic oophorectomy in women at risk. This review summarizes experimental and clinical findings about familial breast and ovarian cancers, including data on Japanese patients.     

BRCA2, but not BRCA1, mutations account for familial ovarian cancer in Iceland: a population-based study

A single founder mutation in each of the BRCA genes has been identified in Iceland. The frequency of the BRCA1 G5193A and BRCA2 999del5 mutations in all ovarian cancer patients diagnosed over the period 1991–2000 was determined. Mutation status was correlated with family history, tumour morphology and age at diagnosis. Samples from 86% of cases (179 carcinomas and 74 borderline tumours) were available. In the carcinomas, BRCA1 and BRCA2 mutations were present in 1.2% and 6% of cases, respectively. No BRCA mutations were found in the borderline tumours. Odds Ratio (OR) of developing ovarian cancer was 20.65 for BRCA2 carriers. Family history of breast/ovarian cancer was present for 70% of BRCA2 carriers and approximately 14% for non-carriers with carcinoma. In conclusion, BRCA2 999del5 is present in 6% of ovarian cancer cases in Iceland and is associated with a 20-fold increase in the risk of the disease. The BRCA1 G5193A mutation is too rare to contribute significantly to ovarian cancer in Iceland.     

Nuclear morphometric features in benign breast tissue and risk of subsequent breast cancer

Germ-line mutations in BRCA1 and BRCA2 are responsible for about 30–60% of the hereditary breast and ovarian cancer (HBOC). A large number of point mutations have been described in both genes. However, large deletions and duplications that disrupt one or more exons are overlooked by point mutation detection approaches. Over the past years several rearrangements have been identified in BRCA1, while few studies have been designed to screen this type of mutations in BRCA2. Our aim was to estimate the prevalence of large genomic rearrangements in the BRCA2 gene in Spanish breast/ovarian cancer families. The multiplex ligation-dependent probe amplification (MLPA) was employed to search gross deletions or duplications of BRCA2 in 335 Spanish moderate to high-risk breast/ovarian cancer families previously screened negative for point mutations by conventional methods. Four different and novel large genomic alterations were consistently identified by MLPA in five families, respectively: deletions of exon 2, exons 10–12 and exons 15–16 and duplication of exon 20 (in two families). RT-PCR experiments confirmed the deletion of exons 15–16. All patients harbouring a genomic rearrangement were members of high-risk families, with three or more breast/ovarian cancer cases or the presence of breast cancer in males. We provide evidence that the BRCA2 rearrangements seem to account for a relatively small proportion of familial breast cancer cases in Spanish population. The screening for these alterations as part of the comprehensive genetic testing can be recommended, especially in multiple case breast/ovarian families and families with male breast cancer cases.     

Age and Geographical Distribution in Families with <Emphasis Type="Italic">BRCA1/BRCA2</Emphasis> Mutations in the Slovak Republic

Molecular diagnostics of hereditary breast and/or ovarian cancer is mainly based on detection of BRCA1 and BRCA2 germline mutations in suspected families. The aim of the study was to determine the frequency, age and geographical distribution in 130 Slovak hereditary breast and ovarian cancer (HBOC) families diagnosed within the years 2000-2004. Mutation screening was performed by single-strand conformation polymorphism (SSCP), heteroduplex analysis (HDA) and sequencing of PCR products showing an abnormal migration pattern. Twenty of 130 (15.6%) HBOC suspected families were found to carry mutations in BRCA1 or BRCA2 genes. The glossary data from the National Cancer Registry of Slovakia (NCRS) were compared with the results from HBOC suspected kindreds. Age distribution of breast cancer onset in our study group showed the highest proportion of onset in HBC families within the 5^th decade of life, while NCRS reports at least a ten year later onset. These findings confirmed that cases of breast cancer under 50 years of age can be used as one of the principal criteria to assign a family as a hereditary breast and/or ovarian cancer kindred. In contrast with unselected ovarian cancer cases, about 75% of all HOC index cases were diagnosed between 40 and 49 years of age. To study the geographical distribution of hereditary breast and/or ovarian cancer, Slovakia was divided into three parts. The distribution of HBOC suspected families approximately follows this division, with an increasing number in the western area of the country.     

Risk reducing surgery with peritoneal staging in BRCA1-2 mutation carriers. A prospective study

IntroductionInternational guidelines recommend risk-reducing salpingo-oophorectomy (RRSO) in BRCA1-2 mutations carriers to decrease ovarian cancer occurrence. In this prospective study, we describe the incidence of occult malignancies and the surgical outcomes in asymptomatic BRCA mutation carriers submitted to RRSO.MethodsData on BRCA1-2 carriers undergoing RRSO with peritoneal washing and peritoneal/omental biopsies (PeS), between January 2019 until March 2021, were prospectively collected.ResultsA total of 132 patients were enrolled: 74 BRCA1 and 58 BRCA2 mutation carriers. 31.1% women underwent RRSO and PeS (16.2% of BRCA1 and 50% of BRCA2 carriers), while 68.9% patients were submitted also to concomitant hysterectomy. Almost all the procedures (99.2%) were performed by minimally invasive surgery. Postoperative complications occurred in twelve patients (9.1%): 10 in the concomitant hysterectomy group and two complications in the RRSO group. At the final pathological examination, 6 (4.5%) occult carcinomas were diagnosed: 3 fallopian tube carcinomas, one ovarian carcinoma and two serous tubal intraepithelial carcinomas (STICs), with negative PeS. Median age of occult carcinomas patients at RRSO was 54 (range: 48–79) years. The mean follow up was 20 (range: 7–34) months. During the follow up, no primary peritoneal cancer has been diagnosed.ConclusionsOccult pathologic findings in RRSO occurred in 4.5% (3% invasive carcinomas, STIC 1.5%) among our patients. The routine use of peritoneal biopsies does not improve the detection of occult malignancies. Our data confirm the importance of timely performing RRSO in BRCA1-2 carriers.     

Results of a population-based screening for hereditary breast cancer in a region of North-Central Italy: contribution of BRCA1/2 germ-line mutations

BRCA1/2 mutation status is of paramount importance to identify families at risk of Hereditary Breast and Ovarian Cancer (HBOC). Most HBOC and BRCA1/2 mutation studies have focused on highly selected sub-populations, and few data are available for large population cohorts. For this reason, as part of a regional cancer prevention strategy in North-Central Italy, we set up a population-based screening programme to identify all resident HBOC families, and to determine their BRCA1/2 mutation status. To date, 44 different BRCA1/2 variants have been identified in 55 HBOC families. Of the seven newly reported mutations, only BRCA1 Q284X is clearly deleterious. The analysis of clinical disease characteristics in relation to age of disease onset and family history showed a difference between BRCA1/2 wild type and mutation carrier families. Interestingly, BRCA1/2 mutations were significantly more common in women who developed breast cancer ≤40 years of age than in BRCA1/2 wild type women (50% vs. 29%, respectively, P = 0.005). The family history selection criteria most likely to indicate the presence of deleterious BRCA1/2 mutations are breast cancer ≤35 years (P = 0.012), two first-degree relatives with breast cancer ≤50 years (P = 0.022), and male breast cancer (P = 0.047). The penetrance of BRCA1/2 alterations in our cohort seems to be aligned with other published results. However, new data interpretations have emerged in relation to the clinical criteria and the presence of deleterious mutations. This information shows that a correct and accurate clinical selection could avoid unnecessary molecular tests and could better address genetic analysis and clinical management. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Prevalence of hereditary breast and ovarian cancer (HBOC) predisposition gene mutations among 882 HBOC high‐risk Chinese individuals

Identification of deleterious variants in hereditary breast and ovarian cancer (HBOC) susceptibility genes allows for increased clinical surveillance and early detection, and could predict the response to poly (ADP‐ribose) polymerase (PARP) inhibitor in patients with advanced ovarian carcinomas. To determine the prevalence and clinical prediction factors for HBOC syndrome, 882 selected individuals underwent multigene panel testing for HBOC risk assessment during the period from January 2015 to March 2018. Overall, 176 deleterious mutations were observed in 19.50% (n = 172) of individuals. Twenty‐six of 176 mutations could not be retrieved in related public databases and were considered to be novel. Among patients with ovarian cancer, 115 deleterious mutations were identified in 429 patients (48.6%) with significant enrichment for a family history of breast or ovarian cancer syndrome (P < .05). In the breast cancer subgroup, 31 deleterious mutations were identified in 261 patients. Besides BRCA1 (8; 25.8%) and BRCA2 (11; 35.5%), the most frequently occurring genes, an additional 12 deleterious mutations (38.7%) were found in seven other susceptibility genes. Higher mutation incidence (57.9%) was observed in subjects with histories of breast and ovarian cancer. Our results highlighted the genetic heterogeneity of HBOC and the efficiency of a multigene panel in carrying out risk assessment.     

BRCA1 and BRCA2 mutations in ovarian cancer patients from China: ethnic‐related mutations in BRCA1 associated with an increased risk of ovarian cancer

BRCA1/2 are cancer predisposition genes involved in hereditary breast and ovarian cancer (HBOC). Mutation carriers display an increased sensitivity to inhibitors of poly(ADP‐ribose) polymerase (PARP). Despite a number of small‐size hospital‐based studies being previously reported, there is not yet, to our knowledge, precise data of BRCA1/2 mutations among Chinese ovarian cancer patients. We performed a multicenter cohort study including 916 unselected consecutive epithelial ovarian cancer (EOC) patients from eastern China to screen for BRCA1/2 mutations using the next‐generation sequencing approach. A total of 153 EOC patients were found to carry pathogenic germline mutations in BRCA1/2, accounting for an overall mutation incidence of 16.7% with the predominance in BRCA1 (13.1%) compared with BRCA2 (3.9%). We identified 53 novel pathogenic mutations, among which the c.283_286delCTTG and the c.4573C > T of BRCA1 were both found in two unrelated patients. More importantly, the most common mutation found in this study, c.5470_5477del8 was most likely to be Chinese population‐related without an apparent founder origin. This hot‐spot mutation was presumably associated with an increased risk of ovarian cancer. Taken together, germline BRCA1/2 mutations were common in Chinese EOC patients with distinct mutational spectrum compared to Western populations. Our study contributes to the current understanding of BRCA1/2 mutation prevalence worldwide. We recommend BRCA1/2 genetic testing to all Chinese women diagnosed with EOC to identify HBOC families, to provide genetic counseling and clinical management for at‐risk relatives. Mutation carriers may also benefit from PARP‐targeted therapies.     

BRCA1 and BRCA2 mutation carriers in the Breast Cancer Family Registry: an open resource for collaborative research

The Breast Cancer Family Registry is a resource for interdisciplinary and translational studies of the genetic epidemiology of breast cancer. This resource is available to researchers worldwide for collaborative studies. Herein, we report the results of testing for germline mutations in BRCA1 and BRCA2. We have tested 4,531 probands for mutations in BRCA1 and 4,084 in BRCA2. Deleterious mutations in BRCA1 and BRCA2 were identified for 9.8% of probands tested [233/4,531 (5.1%) for BRCA1 and 193/4,084 (4.7%) for BRCA2]. Of 1,385 Ashkenazi Jewish women tested for only the three founder mutations, 17.4% carried a deleterious mutation. In total, from the proband and subsequent family testing, 1,360 female mutation carriers (788 in BRCA1, 566 in BRCA2, 6 in both BRCA1 and BRCA2) have been identified. The value of the resource has been greatly enhanced by determining the germline BRCA1 and BRCA2 mutation statuses of nearly 6,000 probands.     

Reproductive factors and ovarian cancer risk in Jewish BRCA1 and BRCA2 mutation carriers (United States)

Objective: To determine whether oral contraceptive (OC) use, childbearing, breastfeeding and tubal ligation differ between ovarian cancer cases with and without a BRCA1/2 mutation. Methods: A case-only study of 242 Jewish women with invasive epithelial ovarian cancer. Women were genotyped for three Ashkenazi founder mutations (185delAG and 5382insC in BRCA1 and 6174delT in BRCA2). We obtained data on OC use, childbearing, breastfeeding, gynecologic surgeries and other reproductive factors from each woman. We compared the frequencies of these risk factors in carriers and non-carriers using unconditional logistic-regression, controlling for other covariates. Results: Among the 242 cases, 64 (26.4%) carried one of the BRCA1 founder mutations, and 31 (12.8%) carried the BRCA2 mutation. Although there were no differences in the percent of nulliparous women between carriers and non-carriers, parous BRCA1 carriers reported fewer live births than non-carriers (average of 2.1 versus 2.5 live births, OR = 0.61, 95%CI = 0.39–0.95, adjusted for age at diagnosis, tubal ligation and duration of OC use). Carriers and non-carriers did not differ in their history of breastfeeding, or in their lifetime use of OCs. BRCA1 carriers were more likely than non-carriers to have had a tubal ligation (25.0 versus 10.2%, OR = 3.67, 95%CI = 1.55–8.70, adjusted for age at diagnosis, number of live births and OC duration). Conclusions: In general, OC use, childbearing and breastfeeding do not differ between BRCA1/2 carriers and non-carriers with ovarian cancer. However, the effects of tubal ligation may differ between BRCA1 carriers and non-carriers.     

Hereditary breast cancer in Jews

A family history of breast cancer poses higher risks for Jewish versus non-Jewish women, particularly for early-onset breast cancer. This appears to be due in large part to the high prevalence (2.5%) of three BRCA1 and BRCA2 founder mutations in Ashkenazi Jews. About 4 to 8% of non-Jewish male breast cancer cases versus 19% of Jewish male breast cancer cases carry germline BRCA mutations. Jewish women are disproportionately impacted by BRCA mutations throughout life, with a 10% carrier rate for breast cancer diagnosed at any age and a 21 to 30% carrier rate for breast cancer diagnosed by age 40. Comparable rates in non-Jewish populations are 6.1% for breast cancer diagnosed before age 50. Lifetime penetrance estimates based on genotyping of probands have ranged widely in Jewish and non-Jewish populations. However, a study of 1008 Jewish women with breast cancer which extended genotyping to relatives found high penetrance rates with considerably smaller standard errors. This study and studies of early-onset incident breast cancer in non-Jews have found that at least half of high-risk cases would be missed by family history screening alone. While the carrier rate in non-Jewish populations is too low to consider genetic screening, the carrier rate in Ashkenazi Jews is high and genetic screening poses fewer technical barriers. The high genetic attributable cancer risks of Ashkenazi BRCA founder mutations, the sobering lethality of ovarian and early onset breast cancers, and the increasing clarity about effectiveness of medical interventions make imperative further dialogue and research to keep guidelines for genetic screening up to date.     

BRCA1, TP53, and CHEK2 germline mutations in uterine serous carcinoma

BACKGROUND:

Uterine serous carcinoma (USC) is not recognized as part of any defined hereditary cancer syndrome, and its association with hereditary breast and ovarian carcinoma and Lynch syndrome are uncertain.

METHODS:

Using targeted capture and massively parallel genomic sequencing, 151 subjects with USC were assessed for germline mutations in 30 tumor suppressor genes, including BRCA1 (breast cancer 1, early onset), BRCA2, the DNA mismatch repair genes (MLH1 [mutL homolog 1], MSH2 [mutS homolog 2], MSH6, PMS2 [postmeiotic segregation increased 2]), TP53 (tumor protein p53), and 10 other genes in the Fanconi anemia–BRCA pathway. Ten cases with < 10% serous histology were also assessed.

RESULTS:

Seven subjects (4.6%) carried germline loss‐of‐function mutations: 3 subjects (2.0%) with mutations in BRCA1, 2 subjects (1.3%) with mutations in TP53, and 2 subjects (1.3%) with mutations in CHEK2 (checkpoint kinase 2). One subject with < 10% serous histology had an MSH6 mutation. Subjects with MSH6 and TP53 mutations had neither personal nor family histories suggestive of Lynch or Li‐Fraumeni syndromes. Of the 22 women with USC and a personal history of breast carcinoma, the frequency of BRCA1 mutations was 9%, compared to 0.9% in 119 women with no such history.

CONCLUSIONS:

Approximately 5% of women with USC have germline mutations in 3 different tumor suppressor genes: BRCA1, CHEK2, and TP53. Mutations in DNA mismatch repair genes that cause Lynch syndrome are rare in USC. The germline BRCA1 mutation rate in USC subjects of 2% is higher than expected in a nonfounder population, suggesting that USC is associated with hereditary breast and ovarian carcinoma in a small proportion of cases. Women with USC and breast cancer should be offered genetic testing for BRCA1 and BRCA2 mutations. Cancer 2013. © 2012 American Cancer Society.