Hereditary ovarian cancer in Poland

Susceptibility Genes Associated with Multiple Primary Cancers

With advancements in treatment and screening techniques, we have been witnessing an era where more cancer survivors harbor multiple primary cancers (MPCs), affecting approximately one in six patients. Identifying MPCs is crucial for tumor staging and subsequent treatment choices. However, the current clinicopathological criteria for clinical application are limited and insufficient, making it challenging to differentiate them from recurrences or metastases. The emergence of next-generation sequencing (NGS) technology has provided a genetic perspective for defining multiple primary cancers. Researchers have found that, when considering multiple tumor pairs, it is crucial not only to examine well-known essential mutations like MLH1/MSH2, EGFR, PTEN, BRCA1/2, CHEK2, and TP53 mutations but also to explore certain pleiotropic loci. Moreover, specific deleterious mutations may serve as regulatory factors in second cancer development following treatment. This review aims to discuss these susceptibility genes and provide an explanation of their functions based on the signaling pathway background. Additionally, the association network between genetic signatures and different tumor pairs will be summarized.

Report on the Effect of the Implementation of an Early Detection and Prevention of Cancer Program on Families at High Hereditary Risk-Concentrating on Patients Undergoing Genetic Diagnostics and Counseling in Central Poland

Over a 46-month period, the objectives of the National Cancer Control Program (NCCP, pol. Narodowy Program Zwalczania Chorób Nowotworowych), coordinated by the Ministry of Health, were pursued by conducting genetic diagnostics on individuals at high risk of developing cancer. A total of 1097 individuals were enrolled in the study, leading to the identification of 128 cases of germline mutations. The implementation of the NCCP led to the identification of genetic mutations in 4.43% of the patients qualified for BRCA1 and BRCA2 screening tests, in 18.18% of those qualified for a comprehensive next-generation sequencing (NGS) panel in cases of breast and ovarian cancer, and in 17.36% of cases of colorectal and endometrial cancer. The research conducted allowed us to establish individualized preventive and therapeutic approaches for mutation carriers. However, the results prove that liberalizing the inclusion criteria for high-throughput diagnostics and the use of broad gene panels could significantly increase the percentage of detected carriers. This publication serves as a summary and discussion of the results obtained from the implementation of the NCCP as well as of the role of genetic consulting in personalized medicine.

Frequency of BRCA1 and BRCA2 mutations in ovarian cancer patients in South-East Poland

Background

Mutations in BRCA1 and BRCA2 genes are well-established risk factors of breast and ovarian cancer. In our former study, we observed that approximately 6% of unselected ovarian cancer patients in the region of Podkarpacie (South-East Poland) carry BRCA1 causative founder variants, which is significantly lower than in other regions of Poland. Therefore, it is deeply justified to do research based on the sequencing of whole BRCA1 and BRCA2 genes.

Methods

We examined 158 consecutive unselected cases of ovarian cancer patients from the region of Podkarpacie. We performed BRCA1 and BRCA2 genes Next-Generation Sequencing study in all cases.

Results

Altogether, in 18 of 158 (11.4%) ovarian cancer patients with BRCA1 or BRCA2 pathogenic mutations were found. BRCA1 pathogenic variants were detected in 11 of the 158 (7.0%) ovarian cancer cases. 10 of 11 (91%) detected BRCA1 mutations were founder mutations, detectable with the standard test used in Poland. BRCA2 pathogenic variants were found in 7 of the 158 (4.4%) cases. No BRCA2 pathogenic variants were founder mutations. The median age of patients at the diagnosis of the 18 hereditary ovarian cancers was 57.5 years.

Conclusions

The frequency of BRCA1 or BRCA2 gene mutation carriers among patients with ovarian cancer from the Podkarpacie region is comparable to other regions of Poland. However, a significantly higher percentage of BRCA2 gene mutations was observed, that were not detectable with a standard test for detection of founder mutations. Diagnostics based only on testing the BRCA1/2 Polish founder mutations is characterized by relatively low sensitivity in the case of ovarian cancer patients from South-East Poland and should be supplemented by NGS study, in particular of the BRCA2 gene.

Association of recurrent mutations in BRCA1, BRCA2, RAD51C, PALB2, and CHEK2 with the risk of borderline ovarian tumor

Background

There are several genes associated with ovarian cancer risk. Molecular changes in borderline ovarian tumor (BOT) indicate linkage of this disease to type I ovarian tumors (low-grade ovarian carcinomas). This study determined the prevalence and association of mutations in BRCA1, BRCA2, PALB2, RAD51C, and CHEK2 with the risk of BOTs.

Methods

The study group consisted of 102 patients with histologically confirmed BOT and 1743 healthy controls. In addition, 167 cases with ovarian cancer G1 were analyzed. The analyses included genotyping of 21 founder and recurrent mutations localized in 5 genes (BRCA1, BRCA2, PALB2, RAD51C, and CHEK2). The risk for developing BOT and low-grade ovarian cancer, as well as the association of tested mutations with survival, was estimated.

Results

The CHEK2 missense mutation (c.470T>C) was associated with 2-times increased risk of BOT (OR=2.05, p=0.03), at an earlier age at diagnosis and about 10% worse rate of a 10-year survival. Mutations in BRCA1 and PALB2 were associated with a high risk of ovarian cancer G1 (OR=8.53, p=0.005 and OR=7.03, p=0.03, respectively) and were related to worse all-cause survival for BRCA1 carriers (HR=4.73, 95%CI 1.45–15.43, p=0.01).

Conclusions

Results suggest that CHEK2 (c.470T>C) may possibly play a role in the pathogenesis of BOT, but due to the low number of BOT patients, obtained results should be considered as preliminary. Larger more in-depth studies are required.

Frequency of germline BRCA1/2 mutations and association with clinicopathological characteristics in Turkish women with epithelial ovarian cancer

AIM

This study aims to determine the frequency of germline BRCA 1/2 mutations in Turkish women with epithelial ovarian cancer (EOC) and evaluate its relationship with clinicopathological characteristics.

METHODS

In this cross-sectional study, all women with recently diagnosed EOC presenting to Zekai Tahir Burak Women's Health Training and Research Hospital Medical Oncology Clinic between 2016 and 2019 were referred for BRCA testing. Peripheral blood samples were obtained from 76 patients applying to Medical Genetics and BRCA1/2 genes were sequenced using next-generation sequencing. The American College of Medical Genetics and Genomics 2015 criteria were followed for classification of genetic variants.

RESULTS

Twenty-four women (31.6%) had pathogenic germline BRCA1/2 mutations. Of these, 17 patients (22.4%) harbored germline BRCA1 mutations and 7 (9.2%) had BRCA2 mutations. When we compared the patients with and without BRCA mutations, there was significant difference in terms of family history (41.7% vs 9.6%, respectively, P = .001). Among all patients, 15 (19.7%) had history of breast or ovarian cancer in first- or second-degree relatives. Germline BRCA1/2 mutations were detected in 66.7% of patients with family history, while these mutations were found in 22.9% of patients without family history (P = .001).

CONCLUSION

In this sample 31.6% of Turkish women with EOC harbored germline BRCA1/2 mutations, which seems higher compared to other ethnic groups except for the Ashkenazi Jews population. All women with EOC should be referred for BRCA testing regardless of family history, age at diagnosis, and histological subtype.

Recurrent Mutations in BRCA1, BRCA2, RAD51C, PALB2 and CHEK2 in Polish Patients with Ovarian Cancer

The aim of the study was to analyze the frequency and magnitude of association of 21 recurrent founder germline mutations in BRCA1, BRCA2, PALB2, RAD51C, and CHEK2 genes with ovarian cancer risk among unselected patients in Poland. We genotyped 21 recurrent germline mutations in BRCA1 (9 mutations), BRCA2 (4 mutations), RAD51C (3 mutations), PALB2 (2 mutations), and CHEK2 (3 mutations) among 2270 Polish ovarian cancer patients and 1743 healthy controls, and assessed the odds ratios (OR) for developing ovarian cancer for each gene. Mutations were detected in 369 out of 2095 (17.6%) unselected ovarian cancer cases and 117 out of 1743 (6.7%) unaffected controls. The ovarian cancer risk was associated with mutations in BRCA1 (OR = 40.79, 95% CI: 18.67-114.78; p = 0.29 × 10^-15), in BRCA2 (OR = 25.98; 95% CI: 1.55-434.8; p = 0.001), in RAD51C (OR = 6.28; 95% CI 1.77-39.9; p = 0.02), and in PALB2 (OR 3.34; 95% CI: 1.06-14.68; p = 0.06). There was no association found for CHEK2. We found that pathogenic mutations in BRCA1, BRCA2, RAD51C or PALB2 are responsible for 12.5% of unselected cases of ovarian cancer. We recommend that all women with ovarian cancer in Poland and first-degree female relatives should be tested for this panel of 18 mutations.

Rare Germline Genetic Variants and the Risks of Epithelial Ovarian Cancer

A family history of ovarian or breast cancer is the strongest risk factor for epithelial ovarian cancer (EOC). Germline deleterious variants in the BRCA1 and BRCA2 genes confer EOC risks by age 80, of 44% and 17% respectively. The mismatch repair genes, particularly MSH2 and MSH6, are also EOC susceptibility genes. Several other DNA repair genes, BRIP1, RAD51C, RAD51D, and PALB2, have been identified as moderate risk EOC genes. EOC has five main histotypes; high-grade serous (HGS), low-grade serous (LGS), clear cell (CCC), endometrioid (END), and mucinous (MUC). This review examines the current understanding of the contribution of rare genetic variants to EOC, focussing on providing frequency data for each histotype. We provide an overview of frequency and risk for pathogenic variants in the known susceptibility genes as well as other proposed genes. We also describe the progress to-date to understand the role of missense variants and the different breast and ovarian cancer risks for each gene. Identification of susceptibility genes have clinical impact by reducing disease-associated mortality through improving risk prediction, with the possibility of prevention strategies, and developing new targeted treatments and these clinical implications are also discussed.

Pathological findings following risk-reducing salpingo-oophorectomy in BRCA mutation carriers: A systematic review and meta-analysis

OBJECTIVE

To evaluate the benefit of risk-reducing salpingo-oophorectomy (RRSO) by estimating the pathological positive rate of occult lesions, including serous tubal intraepithelial carcinoma (STIC) and occult cancers (OCCs).

METHODS

BRCA1/2 mutation carriers who underwent RRSO in a Chinese study center between 2014 and 2018 were included. A literature review was performed, followed by a meta-analysis of the literature to further validate the findings.

RESULTS

Twenty-four BRCA1/2 mutation carriers who underwent RRSO were identified; one patient (4.2%) had STIC, and one patient (4.2%) had occult fallopian tube cancer complicated by STIC. Thirty-four articles were ultimately included in the meta-analysis. Of the reported cases of OCC, 61.3% occurred in the fallopian tubes and 32.3% in the ovaries, and 81.5% were in the early stages. The estimated rate of overall pathological positive events was 5%. The estimated rates of overall STIC events and OCC were 1% and 3%, respectively. The rates of STIC and OCC were 1% and 3%, respectively, for BRCA1 mutation carriers and 1% and 1%, respectively, for BRCA2 mutation carriers. No significant difference was observed between the results of a routine examination of pathological sections and those of the Sectioning and Extensively Examining the Fimbriae (SEE-FIM) protocol.

CONCLUSIONS

This study is the first report of RRSO results in China. In this systematic review, the positive rates of STIC or OCC after RRSO were no more than 3%, which are 200-fold higher than the risk of the general population. The use of a strict SEE-FIM protocol would likely increase positive results.

Germline and somatic mutations of multi-gene panel in Chinese patients with epithelial ovarian cancer: a prospective cohort study

Background

Multiple targeted gene sequencing is seldom performed in both germline and somatic testing for ovarian cancer. This study is to evaluate the specific genetic alterations, including both somatic and germline mutations, in Chinese patients with epithelial ovarian cancer (EOC) in a prospective cohort study.

Materials and methods

Mutations in a customed 21-gene panel that included BRCA1, BRCA2, and 19 other tumor suppressor genes related to homologous recombination (HR) deficiency or non-HR deficiency were detected by targeted exon capture and next-generation sequencing (NGS) technology across all coding exons and exon-intron (±20 base pairs) boundaries. Patients were enrolled consecutively and unselectively without age or family history consideration. Sixty-two unselected patients with epithelial ovarian cancer were enrolled in our study to be tested for paired somatic and germline mutations. All patients were tested using a 21-gene panel that included BRCA1, BRCA2, CHEK2, PALB2, BRIP1, TP53, PTEN, STK11, CDH1, ATM, BARD1, MLH1, MRE11A, MSH2, MSH6, MUTYH, NBN, PMS1, PMS2, RAD50, and RAD51C.

Results

Mutation analysis revealed that 77.4% (48/62) of patients carried one or more of 64 identified genetic alterations, including 19 germline and 45 somatic deleterious mutations. Twelve individuals shared both germline and somatic mutations. BRCA mutants existed in 17 of 62 (27.4%) patients. Of the 64 mutations detected, 46 (74.2%) were in 7 other HR or non-HR genes, including TP53, PTEN, ATM, CHEK2, PALB2, RAD51C, and STK11. In somatic mutation analysis, TP53 showed frequent pathogenic or likely pathogenic mutations in 56.5% (35/62) of enrolled cases, among which six cases harbored a loss of heterozygosity.

Conclusions

This is the first report of multi-gene panel testing for germline and somatic mutations among Chinese EOC patients, which revealed a broader deleterious variants than only BRCA testing.

Registration

Registration No. NCT03015376, clinicaltrials.gov, registered on January 10, 2017.

Electronic supplementary material

The online version of this article (10.1186/s13048-019-0560-y) contains supplementary material, which is available to authorized users.

Frequency of germline mutations in BRCA1 and BRCA2 in ovarian cancer patients and their effect on treatment outcome

Aim of work

Reporting the incidence and the variants of BRCA1/2 mutations in ovarian cancer patients exploring their effects on the treatment outcomes.

Patients and methods

In total, 104 patients with epithelial ovarian cancer were prospectively recruited to the study. Analysis consisted of the sequencing of all the translated exons and immediately adjacent intronic regions of the BRCA1/2 genes. Responses to multiple lines of chemotherapy were assessed, as well as the effect of BRCA gene mutations on progression-free survival (PFS) and overall survival (OS).

Results

Pathogenic BRCA1/2 mutations were found in 21.15% of the patients. BRCA1 mutations represented 68.2% of the total mutations. Two novel BRCA1 mutations were identified. Age at diagnosis was a strong predictor of the presence of a pathogenic BRCA1/2 mutation. Patients with a family history of cancer had a higher incidence of BRCA mutations (P=0.005). As high as 72% of the patients with BRCA mutations were diagnosed at advanced stage. High-grade serous tumors have a higher incidence of pathogenic mutation (P=0.07). Response to neoadjuvant chemotherapy was high (93.9%). All patients underwent surgery which was optimal in 73.1% of the patients. As high as 85.6% of the patients received adjuvant chemotherapy. Relapse rate was 45.2%. Visceral metastasis was more often in BRCA carriers (P=0.01). Patients carrying pathogenic BRCA1/2 mutations had a longer median PFS of 42.43 months (95% CI 32.04–52.83) compared to 22.24 months (95% CI 14.83–29.58) for non-carriers (P=0.08). OS was 64.32 months (95% CI 38.09–90.06) for BRCA mutation patients versus 56.63 months (95% CI 50.05–63.21) (P=0.04) for non-carriers. In multivariate analysis, early stage at diagnosis and optimal debulking were the only independent predictors of better PFS and OS.

Conclusion

We documented a number of pathogenic BRCA1 and 2 mutations in this patients cohort; two novel mutations were detected. BRCA status seemed to affect survival in ovarian cancer patients.

Current Genetic Service Delivery Models for the Provision of Genetic Testing in Europe: A Systematic Review of the Literature

Background: The provision of genetic services, along with research in the fields of genomics and genetics, has evolved in recent years to meet the increasing demand of consumers interested in prediction of genetic diseases and various inherited traits. The aim of this study is to evaluate genetic services in order to identify and classify delivery models for the provision of genetic testing in European and in extra-European countries. Methods: A systematic review of the literature was conducted using five electronic resources. Inclusion criteria were that studies be published in English or Italian during the period 2000-2015 and carried out in European or extra-European countries (Canada, USA, Australia, or New Zealand). Results: 148 genetic programs were identified in 117 articles and were delivered mostly in the UK (59, 40%), USA (35, 24%) or Australia (16, 11%). The programs were available nationally (66; 45%), regionally (49; 33%) or in urban areas (21, 14%). Ninety-six (64%) of the programs were integrated into healthcare systems, 48 (32.21%) were pilot programs and five (3%) were direct-to-consumer genetic services. The genetic tests offered were mainly for BRCA1/2 (59, 40%), Lynch syndrome (23, 16%), and newborn screening (18, 12%). Healthcare professionals with different backgrounds are increasingly engaged in the provision of genetic services. Based on which healthcare professionals have prominent roles in the respective patient care pathways, genetic programs were classified into five models: (i) the geneticists model; (ii) the primary care model; (iii) the medical specialist model; (iv) the population screening programs model; and (v) the direct-to-consumer model. Conclusions: New models of genetic service delivery are currently under development worldwide to address the increasing demand for accessible and affordable services. These models require the integration of genetics into all medical specialties, collaboration among different healthcare professionals, and the redistribution of professional roles. An appropriate model for genetic service provision in a specific setting should ideally be defined according to the type of healthcare system, the genetic test provided within a genetic program, and the cost-effectiveness of the intervention. Only applications with proven efficacy and cost-effectiveness should be implemented in healthcare systems and made available to all citizens.

Routine germline BRCA1 and BRCA2 testing in patients with ovarian carcinoma: analysis of the Scottish real-life experience

OBJECTIVE

To determine the rates of germline BRCA1 and BRCA2 mutations in Scottish patients with ovarian cancer, before and after a change in testing policy.

DESIGN

Retrospective cohort study.

SETTING

Four cancer/genetics centres in Scotland.

POPULATION

Patients with ovarian cancer undergoing germline BRCA1 and BRCA2 (gBRCA1/2) sequencing before 2013 (under the 'old criteria', with selection based solely on family history), after 2013 (under the 'new criteria', with sequencing offered to newly presenting patients with non-mucinous ovarian cancer), and in the 'prevalent population' (who presented before 2013, but were not eligible for sequencing under the old criteria but were sequenced under the new criteria).

METHODS

Clinicopathological and sequence data were collected before and for 18 months after this change in selection criteria.

MAIN OUTCOME MEASURES

Frequency of germline BRCA1, BRCA2, RAD51C, and RAD51D mutations.

RESULTS

Of 599 patients sequenced, 205, 236, and 158 were in the 'old criteria', 'new criteria', and 'prevalent' populations, respectively. The frequency of gBRCA1/2 mutations was 30.7, 13.1, and 12.7%, respectively. The annual rate of gBRCA1/2 mutation detection was 4.2 before and 20.7 after the policy change. A total of 48% (15/31) 'new criteria' patients with gBRCA1/2 mutations had a Manchester score of <15 and would not have been offered sequencing based on family history criteria. In addition, 20 patients with gBRCA1/2 were identified in the prevalent population. The prevalence of gBRCA1/2 mutations in patients aged >70 years was 8.2%.

CONCLUSIONS

Sequencing all patients with non-mucinous ovarian cancer gives a much higher annual gBRCA1/2 mutation detection rate, with the frequency of positive tests still exceeding the 10% threshold upon which many family history-based models operate.

TWEETABLE ABSTRACT

BRCA sequencing all non-mucinous cancer patients increases mutation detection five fold.

Prevalence of two BRCA1 mutations, 5382insC and 300T > G, in ovarian cancer patients from Ukraine

Ovarian cancer is the seventh most common cancer in women worldwide and the leading cause of gynecological malignant diseases-related deaths in women. The most significant risk factor for ovarian cancer is an inherited genetic mutation in one of two genes: breast cancer gene 1 (BRCA1) or breast cancer gene 2 (BRCA2). The germline mutation c.5266dupC (also known as 5382insC or 5385insC) is the most common mutation among Slavic patients with breast and/or ovarian cancer. Missense mutation c.181T > G (also known as 300T > G or p.C61G) is regarded as the founder change in many Central European countries. We screened 306 ovarian cancer patients diagnosed at different ages by mutagenically separated polymerase chain reaction (PCR) and real-time PCR. A total of 25 BRCA1 mutations were detected (18 cases of 5382insC and 7 cases of 300 T > G). The frequency of the BRCA1 5382insC mutation is similar in breast and ovarian cancer patients from Ukraine, but the frequency of 300T > G was estimated in Ukraine at first time.

Frequency of BRCA1 and BRCA2 causative founder variants in ovarian cancer patients in South-East Poland

Background

Causative variants in BRCA1 and BRCA2 are well-established risk factors for breast and ovarian cancer. In Poland, the causative founder variants in the BRCA1 are responsible for a significant proportion of ovarian cancer cases, however, regional differences in the frequencies of various mutations may exist. The spectrum and frequency of BRCA1/2 mutations between ovarian cancer patients have not yet been studied in the region of South-East Poland.

Methods

We examined 158 consecutive unselected cases of ovarian cancer patients from the region of Podkarpacie. We studied 13 Polish causative founder variants in BRCA1 (c.5266dupC, c.4035delA, c.5251C > T, c.181 T > G, c.676delT, c.68_69delAG, c.3700_3704delGTAAA, c.1687C > T, c.3756_3759delGTCT) and in BRCA2 (c.658_659delGT, c.7910_7914delCCTTT, c.3847_3848delGT, c.5946delT).

Results

A BRCA1 causative founder variants were detected in 10 of the 158 (6.3%) ovarian cancer cases. BRCA2 causative founder variants were not observed. The c.5266dupC mutation was detected in 6 patients, c.181 T > G mutation in 3 patients and the c.676delT mutation in 1 patient. The median age of diagnosis of the 10 hereditary ovarian cancers was 55.5 years of age.

Conclusions

The frequency of 13 causative founder variants in Podkarpacie was lower than in other regions of Poland. Testing of three BRCA1 mutations (c.5266dupC, c.181 T > G, c.676delT) should be considered a sensitive test panel.

Prevalence of BRCA1/BRCA2 mutations in a Brazilian population sample at-risk for hereditary breast cancer and characterization of its genetic ancestry

Background

There are very few data about the mutational profile of families at-risk for hereditary breast and ovarian cancer (HBOC) from Latin America (LA) and especially from Brazil, the largest and most populated country in LA.

Results

Of the 349 probands analyzed, 21.5% were BRCA1/BRCA2 mutated, 65.3% at BRCA1 and 34.7% at BRCA2 gene. The mutation c.5266dupC (former 5382insC) was the most frequent alteration, representing 36.7% of the BRCA1 mutations and 24.0% of all mutations identified. Together with the BRCA1 c.3331_3334delCAAG mutation, these mutations constitutes about 35% of the identified mutations and more than 50% of the BRCA1 pathogenic mutations. Interestingly, six new mutations were identified. Additionally, 39 out of the 44 pathogenic mutations identified were not previously reported in the Brazilian population. Besides, 36 different variants of unknown significance (VUS) were identified. Regarding ancestry, average ancestry proportions were 70.6% European, 14.5% African, 8.0% Native American and 6.8% East Asian.

Materials and methods

This study characterized 349 Brazilian families at-risk for HBOC regarding their germline BRCA1/BRCA2 status and genetic ancestry.

Conclusions

This is the largest report of BRCA1/BRCA2 assessment in an at-risk HBOC Brazilian population. We identified 21.5% of patients harboring BRCA1/BRCA2 mutations and characterized the genetic ancestry of a sample group at-risk for hereditary breast cancer showing once again how admixed is the Brazilian population. No association was found between genetic ancestry and mutational status. The knowledge of the mutational profile in a population can contribute to the definition of more cost-effective strategies for the identification of HBOC families.

The First Nationwide Multicenter Prevalence Study of Germline BRCA1 and BRCA2 Mutations in Chinese Ovarian Cancer Patients

OBJECTIVE

Subjects with germline BRCA1/2 mutations (gBRCAm) have an increased risk of developing ovarian cancer and enhanced sensitivity to platinum-containing agents and PARP (poly[ADP-ribose] polymerase) inhibitors. BRCA mutations in Asian patients are poorly understood compared with other populations. We aimed to investigate gBRCAm prevalence and characteristics in Chinese ovarian cancer patients.

METHODS

We conducted the first nationwide multicenter gBRCAm prevalence study in China. Eight hundred twenty-six unselected ovarian cancer patients from 5 clinical centers were enrolled and tested for gBRCAm status. Medical data including age, family history, previous treatments, clinical diagnosis, histopathologic diagnosis, tumor grade, platinum sensitivity, and CA-125 test result were reviewed and collected.

RESULTS

Prevalence rate or gBRCAm was determined as 28.5%, with 20.8% of patients harboring BRCA1 mutation and 7.6% harboring BRCA2 mutation. The group had a higher percentage of high-grade serous (73.0%), late-stage (III and IV [85.5%]) patients and a younger median age at diagnosis (52 years) compared with other reported studies. Twnety-seven BRCA1 and 17 BRCA2 mutations have not been reported previously in public databases or the literature. Statistically significant correlations were observed between gBRCAm status and family history (P < 0.001), gBRCAm status, and tumor stage (P = 0.02). A numerical higher prevalence of gBRCAm in patients with high-grade serous histopathology (30.9%), platinum-sensitive phenotype (34%), and late-line chemotherapy was observed.

CONCLUSIONS

Germline BRCA1/2 mutations is common in Chinese ovarian cancer patients. This study implies that all ovarian patients should be tested for gBRCAm status regardless of family history and histopathology.

Epidemiology of ovarian cancer: a review

Ovarian cancer (OC) is the seventh most commonly diagnosed cancer among women in the world and the tenth most common in China. Epithelial OC is the most predominant pathologic subtype, with five major histotypes that differ in origination, pathogenesis, molecular alterations, risk factors, and prognosis. Genetic susceptibility is manifested by rare inherited mutations with high to moderate penetrance. Genome-wide association studies have additionally identified 29 common susceptibility alleles for OC, including 14 subtype-specific alleles. Several reproductive and hormonal factors may lower risk, including parity, oral contraceptive use, and lactation, while others such as older age at menopause and hormone replacement therapy confer increased risks. These associations differ by histotype, especially for mucinous OC, likely reflecting differences in etiology. Endometrioid and clear cell OC share a similar, unique pattern of associations with increased risks among women with endometriosis and decreased risks associated with tubal ligation. OC risks associated with other gynecological conditions and procedures, such as hysterectomy, pelvic inflammatory disease, and polycystic ovarian syndrome, are less clear. Other possible risk factors include environmental and lifestyle factors such as asbestos and talc powder exposures, and cigarette smoking. The epidemiology provides clues on etiology, primary prevention, early detection, and possibly even therapeutic strategies.

Epidemiology of ovarian cancer: a review

Ovarian cancer (OC) is the seventh most commonly diagnosed cancer among women in the world and the tenth most common in China. Epithelial OC is the most predominant pathologic subtype, with five major histotypes that differ in origination, pathogenesis, molecular alterations, risk factors, and prognosis. Genetic susceptibility is manifested by rare inherited mutations with high to moderate penetrance. Genome-wide association studies have additionally identified 29 common susceptibility alleles for OC, including 14 subtype-specific alleles. Several reproductive and hormonal factors may lower risk, including parity, oral contraceptive use, and lactation, while others such as older age at menopause and hormone replacement therapy confer increased risks. These associations differ by histotype, especially for mucinous OC, likely reflecting differences in etiology. Endometrioid and clear cell OC share a similar, unique pattern of associations with increased risks among women with endometriosis and decreased risks associated with tubal ligation. OC risks associated with other gynecological conditions and procedures, such as hysterectomy, pelvic inflammatory disease, and polycystic ovarian syndrome, are less clear. Other possible risk factors include environmental and lifestyle factors such as asbestos and talc powder exposures, and cigarette smoking. The epidemiology provides clues on etiology, primary prevention, early detection, and possibly even therapeutic strategies.

Epidemiology of ovarian cancer: a review

Ovarian cancer (OC) is the seventh most commonly diagnosed cancer among women in the world and the tenth most common in China. Epithelial OC is the most predominant pathologic subtype, with five major histotypes that differ in origination, pathogenesis, molecular alterations, risk factors, and prognosis. Genetic susceptibility is manifested by rare inherited mutations with high to moderate penetrance. Genome-wide association studies have additionally identified 29 common susceptibility alleles for OC, including 14 subtype-specific alleles. Several reproductive and hormonal factors may lower risk, including parity, oral contraceptive use, and lactation, while others such as older age at menopause and hormone replacement therapy confer increased risks. These associations differ by histotype, especially for mucinous OC, likely reflecting differences in etiology. Endometrioid and clear cell OC share a similar, unique pattern of associations with increased risks among women with endometriosis and decreased risks associated with tubal ligation. OC risks associated with other gynecological conditions and procedures, such as hysterectomy, pelvic inflammatory disease, and polycystic ovarian syndrome, are less clear. Other possible risk factors include environmental and lifestyle factors such as asbestos and talc powder exposures, and cigarette smoking. The epidemiology provides clues on etiology, primary prevention, early detection, and possibly even therapeutic strategies.

Epidemiology of Patients with Ovarian Cancer with and Without a BRCA1/2 Mutation

Ovarian cancer survival rates have improved only slightly in recent decades; however, treatment of this disease is expected to undergo rapid change as strategies incorporating molecular-targeted therapies enter clinical practice. Carriers of deleterious mutations (defined as a harmful mutation) in either the BRCA1 or BRCA2 gene (BRCAm) have a significantly increased risk of developing ovarian cancer. Epidemiology data in large (>500 patients) unselected ovarian cancer populations suggest that the expected incidence rate for BRCAm in this population is 12-14 %. Patients with a BRCAm are typically diagnosed at a younger age than those without a BRCAm. Associations with BRCAm vary according to ethnicity, with women of Ashkenazi Jewish descent being 10 times more likely to have a BRCAm than the general population. In terms of survival, patients with invasive epithelial ovarian cancer who have a BRCAm may have improved overall survival compared with patients who do not carry a BRCAm. Although genetic testing for BRCAm remains relatively uncommon in ovarian cancer patients, testing is becoming cheaper and increasingly accessible; however, this approach is not without numerous social, ethical and policy issues. Current guidelines recommend BRCAm testing in specific ovarian cancer patients only; however, with the emergence of treatments that are targeted at patients with a BRCAm, genetic testing of all patients with high-grade serous ovarian cancer may lead to improved patient outcomes in this patient population. Knowledge of BRCAm status could, therefore, help to inform treatment decisions and identify relatives at increased risk of developing cancer.

The biological effects and clinical implications of BRCA mutations: where do we go from here?

BRCA1 and BRCA2 are tumour-suppressor genes encoding proteins that are essential for the repair of DNA double-strand breaks by homologous recombination (HR). Cells that lack either BRCA1 or BRCA2 repair these lesions by alternative, more error-prone mechanisms. Individuals carrying germline pathogenic mutations in BRCA1 or BRCA2 are at highly elevated risk of developing breast and/or ovarian cancer. Genetic testing for germline pathogenic mutations in BRCA1 and BRCA2 has proved to be a valuable tool for determining eligibility for cancer screening and prevention programmes. In view of increasing evidence that the HR DNA repair pathway can also be disrupted by sequence variants in other genes, screening for other BRCA-like defects has potential implications for patient care. Additionally, there is a growing argument for directly testing tumours for pathogenic mutations in BRCA1, BRCA2 and other genes involved in HR-DNA repair as inactivation of these genes may be strictly somatic. Tumours in which HR-DNA repair is altered are most likely to respond to emerging targeted therapies, such as inhibitors of poly-ADP ribose polymerase. This review highlights the biological role of pathogenic BRCA mutations and other associated defects in DNA damage repair mechanisms in breast and ovarian cancer, with particular focus on implications for patient management strategies.

The Prevalence of Founder Mutations among Individuals from Families with Familial Pancreatic Cancer Syndrome

PURPOSE

Familial pancreatic cancer describes families with at least two first-degree relatives with pancreatic cancer that do not fulfil the criteria of other inherited tumor syndromes with increased risks of pancreatic cancer. Although much has been learned regarding the aggregation of pancreatic cancer in some families, the genetic basis for this familial aggregation is poorly understood. This study evaluated the prevalence of 10 Polish founder mutations in four genes among individuals from families with diagnosed familial pancreatic cancer syndrome and assessed their possible association with the familial pancreatic cancer (FPC) risk in Poland.

MATERIALS AND METHODS

In this study, 400 FPC individuals and 4,000 control subjects were genotyped for founder mutations in BRCA1 (5382insC, 4153delA, C61G), CHEK2 (1100delC, IVS2+1G>A, del5395, I157T), NBS1 (657del5), and PALB2 (509_510delGA, 172_175delTTGT) genes.

RESULTS

A statistically significant association was observed between the 172_175delTTGT mutation of the PALB2 gene and an increased risk of FPC syndrome (odds ratio [OR], 10.05; p=0.048). In addition, an increased risk of cancer was observed in the FPC family members with a BRCA1 mutation (OR, 6.72; p=0.006). Novel associations were found between the FPC family members with cancer and CHEK2 mutations (OR, 2.26; p=0.008) with a noticeable contribution of the missense variant, I157T of CHEK2 (OR, 2.17; p=0.026).

CONCLUSION

The founder mutations in the genes, BRCA1, PALB2, and CHEK2, cause a small percentage of familial pancreatic cancer syndrome in the Polish population. Following confirmation in larger studies, these mutations can be added to the panel of genes to be tested in families with a diagnosis of FPC syndrome.

Detection of somatic BRCA1/2 mutations in ovarian cancer - next-generation sequencing analysis of 100 cases

The overall prevalence of germline BRCA1/2 mutations is estimated between 11% and 15% of all ovarian cancers. Individuals with germline BRCA1/2 alterations treated with the PARP1 inhibitors (iPARP1) tend to respond better than patients with wild-type BRCA1/2. Additionally, also somatic BRCA1/2 alterations induce the sensitivity to iPARP1. Therefore, the detection of both germline and somatic BRCA1/2 mutations is required for effective iPARP1 treatment. The aim of this study was to identify the frequency and spectrum of germline and somatic BRCA1/2 alterations in a group of Polish patients with ovarian serous carcinoma. In total, 100 formalin-fixed paraffin-embedded (FFPE) ovarian serous carcinoma tissues were enrolled to the study. Mutational analysis of BRCA1/2 genes was performed by using next-generation sequencing. The presence of pathogenic variants was confirmed by Sanger sequencing. In addition, to confirm the germline or somatic status of the mutation, the nonneoplastic tissue was analyzed by bidirectional Sanger sequencing. In total, 27 (28% of patient samples) mutations (20 in BRCA1 and 7 in BRCA2) were identified. For 22 of 27 patients, nonneoplastic cells were available and sequencing revealed the somatic character of two BRCA1 (2/16; 12.5%) and two BRCA2 (2/6; 33%) mutations. Notably, we identified six novel frameshift or nonsense BRCA1/2 mutations. The heterogeneity of the detected mutations confirms the necessity of simultaneous analysis of BRCA1/2 genes in all patients diagnosed with serous ovarian carcinoma. Moreover, the use of tumor tissue for mutational analysis allowed the detection of both somatic and germline BRCA1/2 mutations.

Do founder mutations characteristic of some cancer sites also predispose to pancreatic cancer?

Understanding of the etiology and risk of pancreatic cancer (PaCa) is still poorly understood. This study evaluated the prevalence of 10 Polish founder mutations in four genes among PaCa patients and assessed their possible association with the risk of disease in Poland. In the study 383 PaCa patients and 4,000 control subjects were genotyped for founder mutations in: BRCA1 (5382insC, 4153delA, C61G), CHEK2 (1100delC, IVS2 + 1G > A, del5395, I157T), NBS1 (657del5) and PALB2 (509_510delGA, 172_175delTTGT). A statistically significant association between the 657del5 mutation and an increased risk of pancreatic cancer was observed for NBS1 gene. The Slavic NBS1 gene mutation (657delACAAA) was detected in 8 of 383 (2.09%) unselected cases compared with 22 of 4,000 (0.55%) controls (OR: 3.80, p = 0.002). The PALB2 509_510delGA and 172_175delTTGT mutations combined were seen in 2 (0.52%) unselected cases of PaCa and in 8 (0.20%) of 4,000 controls (OR: 2.61, p = 0.49). For BRCA1, the three mutations combined were detected in 4 of 383 (1.04%) PaCa patients and in 17 of 4,000 (0.42%) controls (OR: 2.46, p = 0.20). CHEK2 mutations were not associated with the risk of pancreatic cancer (OR: 1.11, p = 0.72). The founder mutation in NBS1 (657del5) was associated with an increased risk of PaCa in heterozygous carriers, indicating that this mutation appears to predispose to cancer of the pancreas. By identifying pancreatic cancer risk groups, founder mutation testing in Poland should be considered for people at risk for PaCa.

Prevalence of BRCA1/2 germline mutations in 21 401 families with breast and ovarian cancer

PURPOSE

To characterise the prevalence of pathogenic germline mutations in BRCA1 and BRCA2 in families with breast cancer (BC) and ovarian cancer (OC) history.

PATIENTS AND METHODS

Data from 21 401 families were gathered between 1996 and 2014 in a clinical setting in the German Consortium for Hereditary Breast and Ovarian Cancer, comprising full pedigrees with cancer status of all individual members at the time of first counselling, and BRCA1/2 mutation status of the index patient.

RESULTS

The overall BRCA1/2 mutation prevalence was 24.0% (95% CI 23.4% to 24.6%). Highest mutation frequencies were observed in families with at least two OCs (41.9%, 95% CI 36.1% to 48.0%) and families with at least one breast and one OC (41.6%, 95% CI 40.3% to 43.0%), followed by male BC with at least one female BC or OC (35.8%; 95% CI 32.2% to 39.6%). In families with a single case of early BC (<36 years), mutations were found in 13.7% (95% CI 11.9% to 15.7%). Postmenopausal unilateral or bilateral BC did not increase the probability of mutation detection. Occurrence of premenopausal BC and OC in the same woman led to higher mutation frequencies compared with the occurrence of these two cancers in different individuals (49.0%; 95% CI 41.0% to 57.0% vs 31.5%; 95% CI 28.0% to 35.2%).

CONCLUSIONS

Our data provide guidance for healthcare professionals and decision-makers to identify individuals who should undergo genetic testing for hereditary breast and ovarian cancer. Moreover, it supports informed decision-making of counselees on the uptake of genetic testing.

Clinical features and outcomes of germline mutation BRCA1-linked versus sporadic ovarian cancer patients

Background

The role of germline mutations in BRCA1 and BRCA2 genes in the risk of the development of ovarian cancer is clinically well established. BRCA1/2 testing seems to have increasing role in clinical management in patients with advanced ovarian cancer who require treatment with poly(ADP-ribose) polymerase inhibitors.

Methods

Between 2002 – 2008, 125 consecutive patients with ovarian cancer were categorized as having three founder mutations in the BRCA1 gene in Poland as: 5382insC [exon 20], 4153delA [exon 11.17], and 300 T > G [exon 5]. PFS (progression free survival) and OS (overall survival) were determined by Kaplan-Meier analysis with log rank test, univariate comparisons, and multivariate regression analysis using Cox proportional hazards model.

Results

Of the 125 patients, the founder mutations of BRCA1 were reported in 17 patients (13.6 %). The median OS was longer for BRCA mutated patients (not reached vs 35.6 months, p = 0.041). PFS was similar for both kinds of ovarian cancer. In multivariate analysis, age ≥70 years, suboptimal surgery, and BRCA1 wild type were poor prognostic factors. The BRCA1 mutation reduced the likelihood of death in ovarian cancer by 86 % (HR 0.14; CI: 0.032-0.650, p = 0.012).

Conclusion

In conclusion, we found better overall survival for ovarian cancer patients with BRCA1 germline mutations in comparison with patients without these mutations (sporadic) ovarian cancer. Thus, BRCA1 germline mutations appear to be an independent prognostic factor for ovarian cancer.

BRCA1 founder mutations compared to ovarian cancer in Belarus

In Belarus and other Slavic countries, founder mutations in the BRCA1 gene are responsible for a significant proportion of breast cancer cases, but the data on contribution of these mutations to ovarian cancers are limited. To estimate the proportion of ovarian cancers in Belarus, which are dependent on BRCA1 Slavic founder mutations, we sought the presence of three most frequent mutations (BRCA1: 5382insC, C61G and, 4153delA) in 158 consecutive unselected cases of ovarian cancer. One of the three founder mutations was present in 25 of 158 unselected cases of ovarian cancer (15.8 %). We recommend that all cases of ovarian cancer in Belarus be offered genetic testing for these founder mutations. Furthermore, genetic testing of the Belarusian population will provide the opportunity to prevent a significant proportion of ovarian cancer.

High prevalence of BRCA1 stop mutation c.4183C>T in the Tyrolean population: implications for genetic testing

Screening for founder mutations in BRCA1 and BRCA2 has been discussed as a cost-effective testing strategy in certain populations. In this study, comprehensive BRCA1 and BRCA2 testing was performed in a routine diagnostic setting. The prevalence of the BRCA1 stop mutation c.4183C>T, p.(Gln1395Ter), was determined in unselected breast and ovarian cancer patients from different regions in the Tyrol. Cancer registry data were used to evaluate the impact of this mutation on regional cancer incidence. The mutation c.4183C>T was detected in 30.4% of hereditary BRCA1-associated breast and ovarian cancer patients in our cohort. It was also identified in 4.1% of unselected (26% of unselected triple negative) Tyrolean breast cancer patients and 6.8% of unselected ovarian cancer patients from the Lower Inn Valley (LIV) region. Cancer incidences showed a region-specific increase in age-stratified breast and ovarian cancer risk with standardized incidence ratios of 1.23 and 2.13, respectively. We, thus, report a Tyrolean BRCA1 founder mutation that correlates to a local increase in the breast and ovarian cancer risks. On the basis of its high prevalence, we suggest that targeted genetic analysis should be offered to all women with breast or ovarian cancer and ancestry from the LIV region.

Genetic polymorphisms and gene-dosage effect in ovarian cancer risk and response to paclitaxel/cisplatin chemotherapy

Background

Ovarian malignancies are often diagnosed in advanced stage and at the same time resistance to treatment, both intrinsic and developed during treatment, is sometimes observed. These facts underscore the need for new markers of ovarian cancer risk, as well as markers of treatment effectiveness.

Methods

In this study we genotyped 225 ovarian cancer patients, 64 breast and ovarian cancer patients and 348 healthy controls. In total, 12 polymorphic variants and 2 deletions in PGR, ABCB1, ABCG2, GSTT1, GSTM1, GSTP1, ATM, TP53 and ATP7B genes were analyzed using ASA-PCR, RFLP-PCR, multiplex-PCR and sequencing.

Results

Ten genetic polymorphisms were significantly associated with the risk of developing ovarian carcinoma in at least one of the groups under study. Impact of PGR gene polymorphisms on ovarian cancer risk was specific only for the group of the BRCA1 mutation carriers (in presence of p.Val660Leu variant- OR 2,82; p = 0,010), which confirms the difference in modulation of ovarian cancer risk between sporadic and hereditary malignancies, including the breast-ovarian cancer group (as a cancer-prone group). The analyses showed also the importance of ATP7B gene in ovarian carcinogenesis, both studied variants of which significantly modulated the ovarian cancer risk in all groups excluding the group with BRCA1 mutation. Cumulative risk analysis revealed 3 unfavorable variants that increased significantly the risk of developing ovarian cancer (p.Ile1145 = ABCB1+ p.Asp1853Asn ATM+ p.Ser406Ala ATP7B- OR 7,47; p = 0,002) and significantly modified the progression free survival (PFS) of the patients, and also two favorable genotypes which protected against ovarian cancer (p.Arg952Lys ATP7B+ p.Arg72Pro TP53- OR 0,50; p = 0,008). PFS analysis for carriers of favorable versus unfavorable genotypes emphasized the impact of the regulation of cell cycle (p.Asp1853Asn ATM) and active transport of xenobiotics (p.Ser894Ala/Thr ABCB1) on the risk of disease progression (HR 3,81; p = 0,010) after paclitaxel/cisplatin chemotherapy.

Conclusions

The unfavorable genetic variants could facilitate carcinogenic process and once their carriers developed malignancy, their chances of survival were smaller. Our analyses also showed a strong gene-dosage effect with the decrease of progression-free survival for the carriers of two unfavorable genetic factors.

Mutational analysis of BRCA1/2 in a group of 134 consecutive ovarian cancer patients. Novel and recurrent BRCA1/2 alterations detected by next generation sequencing

The importance of proper mutational analysis of BRCA1/2 in individuals at risk for hereditary breast and ovarian cancer syndrome is widely accepted. Standard genetic screening includes targeted analysis of recurrent, population-specific mutations. The purpose of the study was to establish the frequency of germline BRCA1/2 mutations in a group of 134 unrelated patients with primary ovarian cancer. Next generation sequencing analysis revealed a presence of 20 (14.9 %) mutations, where 65 % (n = 13) were recurrent BRCA1 alterations included in the standard diagnostic panel in northern Poland. However, the remaining seven BRCA1/2 mutations (35 %) would be missed by the standard approach and were detected in unique patients. A substantial proportion (n = 5/12; 41 %) of mutation-positive individuals with complete family history reported no incidence of breast or ovarian cancer in their relatives. This observation, together with the raising perspectives for personalized therapy targeting BRCA1/2 signaling pathways indicates the necessity of comprehensive genetic screening in all ovarian cancer patients. However, due to the limited sensitivity of the standard genetic screening presented in this study (65 %) an application of next generation sequencing in molecular diagnostics of BRCA1/2 genes should be considered.

Multiple primary cancers as a guide to heritability

There are approximately 100 genes which when mutated are known to predispose to one or more forms of cancer. Currently, genetic testing is offered for many of these, either as single genes or as multi-gene panels. Features of hereditary cancer include a positive family history of cancer, early age of onset and the appearance of multiple primary cancers in one individual. In some cases multiple cancers may be of the same site (e.g., bilateral breast cancer) and in other cases they may be at different sites. Various combinations of cancer sites may be indicative of specific cancer syndromes such as the breast ovarian cancer syndrome. Genetic testing should be offered to individuals who have experienced multiple primary cancers in some circumstances, the genetic counselor should review the ages of sites of cancer, their pathologic features and the family history of cancer as part of the pre-test evaluation.

BRCA1- and BRCA2-related mutations: therapeutic implications in ovarian cancer

Ovarian cancer is the deadliest among gynecologic cancers. Hereditary cancer related to BRCA1/2 gene mutations account for ~10%-12% of ovarian cancers. The BRCA1/2 proteins are important in homologous recombination (HR) repair of DNA. Patients with BRCA1/2 mutations have been reported to have improved chemosensitivity to platinum agents, longer disease-free intervals, and longer survivals than nonhereditary counterparts. Recent interest in poly(ADP-ribosyl) polymerase (PARP) proteins which are key components of base excision repair, has led to the development of PARP inhibitors; tumors arising in BRCA1/2 mutation carriers and/or with HR deficiency (HRD) are particularly sensitive to the action of these drugs. As 60%-80% of all advanced ovarian cancers are high-grade serous type, exhibiting HRD in at least 50% (referred as BRCAness) future antitumor strategies may depend on identifying these defects through molecular testing. Once HRD becomes amenable to routine testing, a larger group of ovarian cancer patients than are currently considered for PARP inhibitor trials, may benefit from such targeted therapy.

High frequency of allelic loss at the BRCA1 locus in ovarian cancers: clinicopathologic and molecular associations

BRCA1 dysfunction may occur by different mechanisms that are rarely evaluated concomitantly. We aimed to analyze BRCA1 germline mutations, loss of heterozygosity (LOH) and promoter methylation in unselected ovarian carcinomas in the context of their clinicopathologic characteristics and other molecular changes. BRCA1 mutations were analyzed in 257 carcinomas using single-strand conformation polymorphism (SSCP), heteroduplex, and sequencing methods. LOH at the BRCA1 locus was screened for in 180 cancers. Methylation analysis was performed for 241 tumors using quantitative methylation specific PCR (qMSP). BRCA1 alterations, comprising germline mutations, allelic loss, and/or aberrant promoter methylation, were found in 77.6% (125/161) of ovarian carcinomas. Patients with germline mutations were younger than non-carriers (P < 0.0001). Germline mutations and LOH were associated with advanced stages (P=0.009, P < 0.0001), high tumor grade (P=0.005, P < 0.0001), and TP53 mutations (P=0.003, P < 0.0001, for mutations and LOH, respectively). LOH was also associated with the serous histological type (P=0.004) and PIK3CA amplification (P=0.003). Aberrant promoter methylation was associated with LOH (P=0.017) and absence of germline mutations (P=0.037). The high frequency of LOH at the BRCA1 locus suggests that LOH may be an important mechanism of BRCA1 deficiency in ovarian carcinomas. Tumors with various BRCA1 alterations have a similar phenotype of high-grade, high-stage carcinomas with frequent TP53 mutations.

Genotype-phenotype correlations among BRCA1 4153delA and 5382insC mutation carriers from Latvia

BACKGROUND

Mutations in the high penetrance breast and ovarian cancer susceptibility gene BRCA1 account for a significant percentage of hereditary breast and ovarian cancer cases. Genotype-phenotype correlations of BRCA1 mutations located in different parts of the BRCA1 gene have been described previously; however, phenotypic differences of specific BRCA1 mutations have not yet been fully investigated. In our study, based on the analysis of a population-based series of unselected breast and ovarian cancer cases in Latvia, we show some aspects of the genotype-phenotype correlation among the BRCA1 c.4034delA (4153delA) and c.5266dupC (5382insC) founder mutation carriers.

METHODS

We investigated the prevalence of the BRCA1 founder mutations c.4034delA and c.5266dupC in a population-based series of unselected breast (n = 2546) and ovarian (n = 795) cancer cases. Among the BRCA1 mutation carriers identified in this analysis we compared the overall survival, age at diagnosis and family histories of breast and ovarian cancers.

RESULTS

We have found that the prevalence of breast and ovarian cancer cases (breast: ovarian cancer ratio) differs significantly among the carriers of the c.5266dupC and c.4034delA founder mutations (OR = 2.98, 95%CI = 1.58 to 5.62, P < 0.001). We have also found a difference in the prevalence of breast and ovarian cancer cases among the 1st and 2nd degree relatives of the c.4034delA and c.5266dupC mutation carriers. In addition, among the breast cancer cases the c.4034delA mutation has been associated with a later age of onset and worse clinical outcomes in comparison with the c.5266dupC mutation.

CONCLUSIONS

Our data suggest that the carriers of the c.4034delA and c.5266dupC founder mutations have different risks of breast and ovarian cancer development, different age of onset and prognosis of breast cancer.

High frequency and allele-specific differences of BRCA1 founder mutations in breast cancer and ovarian cancer patients from Belarus

Breast cancer and ovarian cancer are common malignancies in Belarus accounting for about 3500 and 800 new cases per year, respectively. For breast cancer, the rates and age of onset appear to vary significantly in regions differentially affected by the Chernobyl accident. We assessed the frequency and distribution of three BRCA1 founder mutations 5382insC, 4153delA and Cys61Gly in two hospital-based series of 1945 unselected breast cancer patients and of 201 unselected ovarian cancer patients from Belarus as well as in 1019 healthy control females from the same population. Any of these mutations were identified in 4.4% of the breast cancer patients, 26.4% of the ovarian cancer patients and 0.5% of the controls. In the breast cancer patients, BRCA1 mutations were strongly associated with earlier age at diagnosis, with oestrogen receptor (ER) negative tumours and with a first-degree family history of breast cancer, although only 35% of the identified BRCA1 mutation carriers had such a family history. There were no marked differences in the regional distribution of BRCA1 mutations, so that the significant differences in age at diagnosis and family history of breast cancer patients from areas afflicted by the Chernobyl accident could not be explained by BRCA1. We next observed a higher impact and a shifted mutational spectrum of BRCA1 in the series of Byelorussian ovarian cancer patients where the three founder mutations accounted for 26.4% (53/201). While the Cys61Gly mutation appeared underrepresented in ovarian cancer as compared with breast cancer cases from the same population (p = 0.01), the 4153delA mutation made a higher contribution to ovarian cancer than to breast cancer (p < 0.01). BRCA1 mutations were significantly enriched among ovarian cancer cases with a first-degree family history of breast or ovarian cancer, whereas the median age at ovarian cancer diagnosis was not different between mutation carriers and non-carriers. Taken together, these results identify three BRCA1 founder mutations as key components of inherited breast and ovarian cancer susceptibility in Belarus and might have implications for cancer prevention, treatment and genetic counselling in this population.

The contribution of founder mutations in BRCA1 to breast and ovarian cancer in Lithuania

We evaluated the prevalence of BRCA1 founder mutations in unselected cases of breast, ovarian and colon cancer from Lithuania. We identified a founder mutation (4153delA, 5382insC or C61G) in 6% of 235 unselected cases of breast cancer and in 19% of 43 unselected cases of ovarian cancer. Only one patient with a mutation was identified among 178 cases of colon cancer. No mutation was identified among 422 newborn controls. This data indicates that the genetic burden of breast and ovarian cancer attributable to BRCA1 mutations in Lithuania is very high and supports the recommendation that all cases of breast and ovarian cancer in Lithuania be offered genetic testing.

On the origin and diffusion of BRCA1 c.5266dupC (5382insC) in European populations

The BRCA1 mutation c.5266dupC was originally described as a founder mutation in the Ashkenazi Jewish (AJ) population. However, this mutation is also present at appreciable frequency in several European countries, which raises intriguing questions about the origins of the mutation. We genotyped 245 carrier families from 14 different population groups (Russian, Latvian, Ukrainian, Czech, Slovak, Polish, Danish, Dutch, French, German, Italian, Greek, Brazilian and AJ) for seven microsatellite markers and confirmed that all mutation carriers share a common haplotype from a single founder individual. Using a maximum likelihood method that allows for both recombination and mutational events of marker loci, we estimated that the mutation arose some 1800 years ago in either Scandinavia or what is now northern Russia and subsequently spread to the various populations we genotyped during the following centuries, including the AJ population. Age estimates and the molecular evolution profile of the most common linked haplotype in the carrier populations studied further suggest that c.5266dupC likely entered the AJ gene pool in Poland approximately 400-500 years ago. Our results illustrate that (1) BRCA1 c.5266dupC originated from a single common ancestor and was a common European mutation long before becoming an AJ founder mutation and (2) the mutation is likely present in many additional European countries where genetic screening of BRCA1 may not yet be common practice.

Founder BRCA1/2 mutations in the Europe: implications for hereditary breast-ovarian cancer prevention and control

Detection of mutations in hereditary breast and ovarian cancer-related BRCA1 and BRCA2 genes is an effective method of cancer prevention and early detection. Different ethnic and geographical regions have different BRCA1 and BRCA2 mutation spectrum and prevalence. Along with the emerging targeted therapy, demand and uptake for rapid BRCA1/2 mutations testing will increase in a near future. However, current patients selection and genetic testing strategies in most countries impose significant lag in this practice. The knowledge of the genetic structure of particular populations is important for the developing of effective screening protocol and may provide more efficient approach for the individualization of genetic testing. Elucidating of founder effect in BRCA1/2 genes can have an impact on the management of hereditary cancer families on a national and international healthcare system level, making genetic testing more affordable and cost-effective. The purpose of this review is to summarize current evidence about the BRCA1/2 founder mutations diversity in European populations.

Moving Toward Personalized Medicine: Treatment-Focused Genetic Testing of Women Newly Diagnosed With Ovarian Cancer

Objectives:

The presence of a germline BRCA mutation defines a genotype-specific group of women whose invasive ovarian cancer is associated with an increasingly well-defined prognostic and chemosensitivity biological profile. To determine the criteria that may be used to select patients for BRCA treatment-focused genetic testing, we performed a systemic literature search of studies that assessed BRCA1 and BRCA2 mutation frequency in women with ovarian cancer unselected for family history. The results are discussed with regard to the added clinical value gained by identifying a germline BRCA mutation at the time of the ovarian cancer diagnosis.

Methods:

BRCA-related studies were identified in the CD-ROM databases PubMed (including MEDLINE), PsychINFO, and CINAHL and included in the review if they met the following criteria: they (a) assessed mutation frequency in women with ovarian cancer who were unselected for family history and ethnicity, (b) were published in a peer-review journal, (c) between January 1997 and October 2009, and (d) in the English language.

Results:

Studies investigating the prevalence of BRCA1 or BRCA2 mutations in ovarian cancer patients unselected for family history or ethnicity have found a pathological BRCA mutation rate of approximately 3% to 17%. Without a significant family history, specific features that may be used to target treatment-focused BRCA testing in the ovarian cancer setting include young age at onset (<50 years), high-grade serous tumor histology, and specific ethnicity associated with known BRCA founder mutations.

Conclusions:

We believe that given the growing appreciation of the prognostic significance of BRCA mutations and the differential chemosensitivity shown by these tumors, as well as the potential of novel agents such as poly(ADP-ribose) polymerase inhibitors, the identification of a germline BRCA mutation concurrent with a new diagnosis of ovarian cancer will significantly impact on tailoring personalized ovarian management in the future.

Preventing future cancers by testing women with ovarian cancer for BRCA mutations

PURPOSE

Women with ovarian cancer have a 10% probability of carrying a BRCA mutation. If a mutation is identified, unaffected family members can undergo genetic testing and cancer risk-reducing strategies. We estimated the net health benefits and cost-effectiveness of different criteria for BRCA mutation testing in women with ovarian cancer, and the downstream benefits for their first-degree relatives (FDRs).

METHODS

We developed a Markov Monte Carlo simulation model to compare four criteria for BRCA testing in women with ovarian cancer: no testing (reference); only if personal history of breast cancer, family history of breast/ovarian cancer, or Ashkenazi Jewish ancestry; only if invasive serous cancer; any invasive nonmucinous epithelial cancer. Net health benefit was life expectancy for FDRs and primary outcome was the incremental cost-effectiveness ratio (ICER). The model estimated the number of future breast and ovarian cancer cases in FDRs.

RESULTS

BRCA testing based on personal/family history and ancestry could prevent future cases in FDRs with an ICER of $32,018 per year of life (LY) gained compared with the reference strategy. BRCA testing based on serous or any nonmucinous epithelial ovarian cancer could prevent more cancer cases, but at ICERs of $128,465 and $148,363 per LY gained, respectively.

CONCLUSION

BRCA testing of women with ovarian cancer based on personal/family history of cancer or Ashkenazi Jewish ancestry is a cost-effective strategy to prevent future breast and ovarian cancers among FDRs. More inclusive testing strategies prevent additional cancer cases but at significant cost.

BRCA1 and BRCA2 germline mutations in Korean ovarian cancer patients

PURPOSE

To evaluate the proportion of Korean ovarian cancer patients with a strong family history and the genetic status in such patients.

METHODS AND PATIENTS

Pedigree analysis and genetic counseling were performed on 337 ovarian cancer patients in the National Cancer Center Korea between January 2005 and June 2008. Patients with a strong family history were defined as (1) patients with double primary ovarian and breast cancer and (2) ovarian cancer patients with one or more first-degree relatives with breast or ovarian cancer. Lymphocyte specimens from peripheral blood were processed for BRCA1 and BRCA2 by direct sequencing.

RESULTS

Sixteen percent (54/337) of patients had a strong family history. Of the 54 patients with a strong family history, 40 patients (74%) accepted the genetic test. Thirteen deleterious mutations (11 in BRCA1 and 2 in BRCA2) were identified (33%). Twenty-three of 283 patients (8%) without a strong family history underwent genetic testing and two deleterious mutations in BRCA1 were identified (9%). Eight of 15 mutations (53%) were novel, and c.1041delAGCinsT and c.2081insC in the BRCA1 gene were recurrent in two patients.

CONCLUSIONS

The proportion of Korean ovarian cancer patients with a strong family history was significant, and the prevalence of BRCA1 and BRCA2 mutations in such patients was high.

The contribution of BRCA1 and BRCA2 to ovarian cancer

Germline mutations of the BRCA1 and BRCA2 genes confer a high life-time risk of ovarian cancer. They represent the most significant and well characterised genetic risk factors so far identified for the disease. The frequency with which BRCA1/2 mutations occur in families containing multiple cases of ovarian cancer or breast and ovarian cancer, and in population-based ovarian cancer series varies geographically and between different ethnic groups. There are differences in the frequency of common mutations and in the presence of specific founder mutations in different populations. BRCA1 and BRCA2 are responsible for half of all families containing two or more ovarian cancer cases. In population-based studies, BRCA1 and BRCA2 mutations are present in 5-15% of all ovarian cancer cases. Often, individuals in which mutations are identified in unselected cases have no family history of either ovarian or breast cancer. The ability to identify BRCA1/2 mutations has been one of the few major success stories over the last few years in the clinical management of ovarian cancer. Currently, unaffected individuals can be screened for mutations if they have a family history of the disease. If a mutation is identified in the family, and if an individual is found be a mutation carrier, they can be offered clinical intervention strategies that can dramatically reduce their ovarian cancer risks. In some populations with frequent founder mutations screening may not be dependent on whether a mutation is identified in an affected relative.