BRCA mutations: Implications of genetic testing in ovarian Cancer

Ovarian cancer (OC) is one of the most lethal gynecological cancers with a 5?year survival rate that ranges from 30% to 40%. Breast cancer genes (BRCA1 and BRCA2) play a key role in maintaining genomic stability. Mutations in BRCA1/2 genes lead to the accumulation of double?strand breaks, resulting in tumorigenesis. The risk of developing OC in women with BRCA1 and BRCA2 mutations is 39% and 11%, respectively, by 70 years of age. BRCA1/2 mutation testing is thus important to identify women at greatest risk of developing OC in addition to its impact on diagnosis, prognosis, and targeted therapy. Genetic testing is required to identify the BRCA mutations and thus select patients who can benefit from polyadenosine diphosphate (ADP)杛ibose polymerase (PARP) inhibitor therapy. Tumor BRCA mutation testing can detect both germline and somatic mutations allowing implementation of preventive strategies on a broader population. Various international guidelines recommend BRCA1/2 mutation genetic testing in all OC patients irrespective of age and family history. This review focuses on the role of BRCA mutation testing in OC

Prevalence and oncologic outcomes of BRCA1/2 mutation and variant of unknown significance in epithelial ovarian carcinoma patients in Korea

OBJECTIVE: BRCA mutational status is important in the management of ovarian cancer, but there is a lack of evidence supporting genetic testing in Asian populations. This study was performed to investigate the prevalence and prognostic outcomes of BRCA1/2 mutation and variant of unknown significance (VUS) in Korean patients diagnosed with epithelial ovarian cancer (EOC). METHODS: Among patients newly diagnosed with EOC between January 2007 and January 2017, those tested for germline BRCA1/2 mutation were studied, regardless of family history. Overall survival (OS) and progression-free survival (PFS) were compared between the patients with and without BRCA1/2 mutation and VUS. RESULTS: A total of 313 patients underwent BRCA testing: 88 patients had a BRCA1/2 mutation and 48 patients had a BRCA1/2 VUS (28.1% and 15.3%, respectively). There were no significant associations between BRCA1/2 mutation, BRCA1/2 wild-type, or BRCA1/2 VUS with age at diagnosis, histologic distribution, or residual disease status after primary cytoreductive surgery. BRCA1 mutation, including BRCA1 VUS, showed no difference in PFS or OS compared to BRCA1 wild-type. In contrast, BRCA2 mutation showed longer PFS than that of BRCA2 wild-type (P=0.04) or BRCA2 VUS (P=0.02). BRCA2 mutation, including BRCA2 VUS, did not show any difference in OS compared to BRCA2 wild-type. CONCLUSION: BRCA mutation and BRCA VUS had similar clinical characteristics and survival outcomes, except that BRCA2 mutation showed better PFS. The results of this study will help to understand the prognostic significance of BRCA mutation and VUS in Korean patients.

Genes de predisposición al cáncer de mama / Breast Cancer Predisposition Genes

Resumen El cáncer de mama es una enfermedad con una importante incidencia y mortalidad entre las mujeres. Los factores genéticos en su génesis aún no han sido reconocidos completamente, pero se admite el importante papel que juegan los genes de predisposición como el BRCA1 y BRCA2, y otros genes de reciente aparición, en las formas hereditarias y principalmente en el fenotipo triple negativo. El cáncer de mama hereditario representa entre un 5-10 % del total de casos de esta patología. BRCA1 y BRCA2 son genes de gran tamaño, y su principal función es mantener la integridad cromosómica, reparando rupturas de doble cadena del ADN por medio de recombinación homóloga. Los otros genes de predisposición en su mayoría cumplen una función en el mantenimiento y reparación del DNA. Actualmente existen pruebas para detección de mutaciones de estos genes en pacientes en riesgo, las cuales permiten implementar intervenciones médicas tempranas, el respaldo psicológico a la persona y la obtención de un diagnóstico más confiable; lo cual a largo plazo podría reducir los altos costos del cáncer. Entre las terapias disponibles para estos pacientes se encuentran desde cirugías preventivas como la mastectomía bilateral y la salpingo-ooforectomía hasta tratamientos farmacológicos como el uso de tamoxifeno, anticonceptivos orales o los recientes inhibidores de la PARP (Poly ADP Ribose Poymerase). Esta revisión pretende hacer énfasis en las características biológicas, genéticas, diagnósticas y terapéuticas del cáncer de mama hereditario para todo el personal de salud.

Abstract Breast cancer is a disease with a significant incidence and mortality among women. Genetic factors in its genesis have not yet been fully recognized, but the important role of predisposing genes such as BRCA1 and BRCA2, and other newly discovered genes in hereditary forms and mainly in the triple negative phenotype are recognized. Hereditary breast cancer represents between 5-10 % of the total cases of this pathology. BRCA1 and BRCA2 are large genes, and their main function is to maintain chromosomal integrity, repairing double strand breaks of DNA by means of homologous recombination. The other predisposing genes, for the most part, play a role in the maintenance and repair of DNA. Currently, there are tests to detect mutations of these genes in patients at risk, implementing early medical interventions, psychological support to the person and obtaining a more reliable diagnosis; which in the long run could reduce the high costs of cancer. Among the available therapies for these patients are preventive surgeries such as bilateral mastectomy and salpingo-oophorectomy, pharmacological treatments such as the use of tamoxifen, oral contraceptives or the recent PARP inhibitors (Poly ADP Ribose Poymerase). The objective of this review is to emphasize the biological, genetic, diagnostic and therapeutic aspects of hereditary breast cancer for all health workers.

GENETIC AND DEMOGRAPHIC FACTORS OF A BRAZILIAN POPULATION SAMPLE AT-RISK OF HEREDITARY BREAST AND OVARIAN CANCER / Fatores genéticos e demográficos de uma amostra da população brasileira sob risco de síndrome de câncer de mama e ovário hereditários

Objective: Genetic-related breast cancer has a tendency to manifest earlier and to be more aggressive than sporadic cancer. There are few studies evaluating the prevalence and incidence of hereditary breast and ovarian cancer (HBOC) among Brazilians. In order to improve assistance, efforts to characterize the population at risk of HBOC could help to formulate locally designed guidelines. Methodology: Descriptive retrospective study in Hospital Erasto Gaertner's service of Oncogenetics, in Curitiba, state of Paraná, Brazil. We included individuals at-risk for HBOC, according to the National Comprehensive Cancer Network (NCCN) criteria, who had performed genetic tests for HBOC. We collected complete family history, presented as heredograms. We excluded families with inappropriate family history. Results: Of the 27 patients analyzed (total of 25 families), 7% were asymptomatic, 8% had ovarian cancer and 85% had breast cancer. Mutations were found in 29.6%, 6 cases of BRCA1, 1 of BRCA2 and 1 of TP53. Triple negative was the most common reported subtype, representing 60% of breast cancers; among patients with identified pathogenic variants, 2 were BRCA2 mutated and 1 TP53 mutated. The mean age of diagnosis was 40 years for those identified as probands on heredograms; in the generation above, it was 52,5, and in the below, 33, suggesting the antecipation phenomena Two new mutations were identified in Brazilian population, both in BRCA1: c.4258 G>A and c.5345 G>A. The most frequent NCCN criteria were number 2, 9, 8 and 4. Estimated penetrance was 22%. Conclusion: This is the first descriptive study in the population at-risk for HBOC in the state of Paraná. We could identify two new pathogenic variants of BRCA1 in Brazilian population. A comprehensive family history was included in the study, depicted as heredograms of each family. Despite the low number of patients, the main results are in agreement with previous studies

Objetivo: Os carcinomas de mama hereditários têm a tendência de se manifestar precocemente e serem mais agressivos do que os esporádicos. São poucos os estudos que avaliam a prevalência e a incidência da síndrome de câncer de mama e ovário hereditário (SCMOH) na população brasileira. No intuito de melhorar a assistência prestada, a análise das características encontradas na população em risco para SCMOH ajudaria a formulação de protocolos regionais para a abordagem desses pacientes. Metodologia: Estudo descritivo retrospectivo realizado no serviço de Oncogenética do Hospital Erasto Gaertner em Curitiba, Paraná. Incluímos indivíduos em risco para SCMOH pelos critérios estabelecidos pela National Comprehensive Cancer Network (NCCN) e que realizaram testes genéticos para SCMOH. Coletamos o histórico familiar completo, apresentado na forma de heredograma. Foram excluídas famílias com histórico familiar inapropriado. Resultados: Das 27 pacientes analisadas (total de 25 famílias), 7% eram assintomáticas, 8% tiveram câncer de ovário e 85%, câncer de mama. Mutações foram encontradas em 29,6%, sendo 6 casos de BRCA1, 1 de BRCA2 e 1 de TP53. Tumores triplo negativos foram os mais encontrados entre os subtipos, representando 60% dos carcinomas de mama; dentre os pacientes com variantes patogênicas, 2 eram de mutações em BRCA2 e 1 em TP53. A média de idade entre as pacientes foi de 40 anos entre probandas dos heredogramas; na geração superior, foi de 52,5 anos e na inferior, de 33, sugerindo o fenômeno de antecipação. Duas novas mutações foram descritas na população brasileira, as duas sendo em BRCA1: c.4258 G>A e c.5345 G>A. Os critérios NCCN mais encontrados foram os de número 2, 9, 8 e 4. A penetrância estimada foi de 22%. Conclusão: Este foi o primeiro estudo descritivo de uma população em risco para SCMOH no estado do Paraná. Encontramos duas novas mutações que não haviam sido descritas na população brasileira até então. Foi realizada a análise detalhada do histórico familiar das pacientes, sendo descrita e detalhada em heredogramas para cada família. Apesar do baixo número de indivíduos analisados, os resultados principais foram de acordo com o encontrado em estudos prévios

Prevalence of germline BRCA mutations among women with carcinoma of the peritoneum or fallopian tube / 부인종양

OBJECTIVE: The aim of the present study was to assess the frequency of germline mutations in patients with peritoneal carcinoma (PC) or the fallopian tube carcinoma (FTC), using a multi-gene panel. METHODS: Twenty-six patients diagnosed with either PC or FTC between January 2013 and December 2016 were recruited consecutively. Germline DNA was sequenced using a 6-gene next generation sequencing (NGS) panel following genetic counseling. Surgico-medical information was obtained from hospital records. Genetic variations were detected using the panel and were cross-validated by Sanger direct sequencing. RESULTS: Germline BRCA1/2 mutations were identified in 6 patients (23.1%). Four were detected in patients with PC and 2 were in FTC patients. No mutations were detected in TP53, PTEN, CDH1, or PALB2. We identified 11 variant of uncertain significance (VUS) in 9 patients; 2 in BRCA1, 3 in BRCA2, 2 in TP53, and 4 in CDH1. We also detected a CDH1 c.2164+16->A VUS in 3 patients. CONCLUSION: The prevalence of germline BRCA1/2 mutations in patients with PC or FTC is comparable to that of BRCA1/2 mutations in epithelial ovarian cancer patients.

Frecuencia de las mutaciones en los genes BRCA en mujeres con agregación familiar de cáncer de glándula mamaria/ovario

OBJETIVO:Reunir evidencias de la variación en la frecuencia de las mutaciones de BRCA1 y BRCA2 y la historia familiar en pacientes con cáncer de glándula mamaria (CGM) y cáncer de ovario (CO) de diferentes orígenes geográficos.MÉTODO:En este trabajo se realizó una revisión sistemática, siguiendo los parámetros del protocolo PRISMA, para estimar la prevalencia de mutaciones en los genes BRCA 1/2 en pacientes con CGM y CO, la incidencia de la historia familiar y la prevalencia observada en casos esporádicos en este tipo de cáncer.RESULTADOS:Se observa una heterogeneidad en la frecuencia de las mutaciones de estos genes en los estudios de historia familiar, con una variación entre 0.0 y 0.48 en pacientes y familiares con CGM y CO similares a los previamente reportados.DISCUSIÓN: Este amplio rango de la frecuencia se debe al origen de la población estudiada, el número de individuos analizados y la metodología de genotipificación utilizada. La revisión revela que el CGM y CO familiar es dos veces más frecuente, en comparación con los casos de esta misma patología con origen esporádico.CONCLUSIONES:Este tipo de estudios moleculares les permite a las personas que presentan historia familiar con CGM y CO realizarse análisis precoces y chequeos para prevenir en un futuro el desarrollo de alguna de estas neoplasias.

OBJECTIVE:Collect evidence about the frequency variation of BRCA1 and BRCA2 mutations and family history in patients with mammary gland cancer (MGC) and ovarian cancer (OC) from different geographical backgrounds.METHOD: This paper presents a systematic review using the PRISMA protocol parameters to estimate the prevalence of mutations in BRCA 1/2 genes in patients with MGC and OC, the incidence of family history and the observed prevalence in sporadic cases with this type of cancer.RESULTS:Heterogeneity is observed in the frequency of mutations of these genes in studies of family history ranging between 0.0 and 0.48 in patients and families with MGC and OC similar to those previously reported.DISCUSSION:This wide range of frequency is due to the origin of the studied population, the number of individuals analyzed and genotyping methodology used. The review reveals that the family MGC and OC is twice as common compared with cases of the same disease of a sporadic origin.CONCLUSIONS: This type of molecular studies allows other people who have family history of MGC and OC to perform early analysis and tests to prevent the future development of this neoplasia.

Effect of BRCA2 mutation on familial breast cancer survival: A systematic review and meta-analysis / 华中科技大学学报（医学）（英德文版）

Reports of BRCA2 genetic mutations on the prognosis of familial breast cancer (BC) patients have been contradictory. True difference in survival, if it exists, would have important implications for genetic counseling and in treatment of hereditary BC. The purpose of this study was to compare overall survival rate (OSR) among BRCA2 mutation carriers, non-carriers and sporadic BC patients. We searched the PUBMED and EMBASE databases and retrieved 4529 articles using keywords that included breast cancer, BRCA, prognosis and survival. Nine articles were selected for systematic review and among them 6 were included in our meta-analysis. We used the fixed and random effect models to calculate the summary odds ratio (OR) and corresponding 95% confidence interval (CI). BRCA2 mutation carriers had significantly higher long-term OSR than non-carriers (OR=0.69 [95% CI=0.5-0.95]), while both short-term and long-term OSR of BRCA2 mutation carriers did not differ from those of patients with sporadic disease (OR=1.11 [95% CI=0.74-1.65]; 0.85 [95% CI=0.38-1.94], respectively). For BC-specific survival rate (BCSSR), BRCA2 mutation carriers had a similar BCSSR to the non-carriers (OR=0.61 [95% CI=0.28-1.34]). There was no significant difference in disease-free survival (DFS) between BRCA2 mutation carriers and patients with sporadic disease. Our results suggest that BRCA2 mutation increases long-term OSR in hereditary BC, which reminds us a new prospect of management of the disease.

Risk Reducing Surgery in Carriers with Double Heterozygosity for BRCA1 and BRCA2 Mutations

Among the treatment options for BRCA mutation carriers, risk reducing surgery is the most effective. However, this procedure has been rarely performed in Korea. Interestingly, our case showed double heterozygosity for BRCA1 and BRCA2 mutations. The patient was diagnosed with left renal cancer and left breast cancer at 45-years-of-age, 4 years before risk reducing surgery. The patient received left radical nephrectomy and left partial mastectomy with axillary lymph node dissection. After pretest counseling, the patient underwent genetic testing that identified BRCA1 and BRCA2 mutations. After post-test counseling, the patient decided on intensive surveillance. At 49-years-of-age, the patient was newly diagnosed with contralateral breast cancer. Treatment options were discussed once again. We performed bilateral total mastectomy with immediate reconstruction and prophylactic bilateral salpingo-oophorectomy after multidisciplinary discussion. The patient has been satisfied with the results of surgery. We think this procedure is a recommendable treatment option for BRCA mutation carriers.

Incidental Detection of Ductal Carcinoma In Situ of the Breast from Bilateral Prophylactic Mastectomy of Asymptomatic BRCA2 Mutation Carrier: A Case Report / 한국유방암학회지

In women at high-risk for breast cancer with a BRCA mutation, bilateral prophylactic mastectomy (BPM) may achieve a risk reduction. A 35-year-old woman had a strong family history of breast and ovarian cancer. She had a regular checkup and found masses in both breasts that confirmed intraductal papillomas and atypical ductal hyperplasia after vacuum assisted mass excision. When she was referred to our clinic, the genetic testing for BRCA mutation was recommended to her sister that managed for ovarian cancer. It was resulted in the positive for the BRCA2 mutation, so she had checked the genetic testing which resulted in the same as the mutation. After sufficient counseling, she decided to undergo BPM and immediate reconstruction. She is satisfied with the result of surgery. This is the first report of BPM of asymptomatic BRCA2 mutation carrier in Korea and BPM should be considered as a risk-reducing option for BRCA mutation carriers.

Single-Port Access Laparoscopic Prophylactic Bilateral Salpingo-Oophorectomy in BRCA-Positive Breast Cancer Patient: A Case Report / 한국유방암학회지

For women with a BRCA 1/2 mutation, prophylactic bilateral salpingo-oophorectomy (BSO) is known to reduce the risk of developing both ovarian and breast cancer. The increasing interest in hereditary breast cancer has recently resulted in frequent genetic testing for high-risk patients. Since breast surgeons frequently encounter BRCA-positive breast cancer patients or carriers in the outpatient clinic, it is a prerequisite that the decision of the patients and doctors should be based on a thorough understanding of the objective risk, the medical assessment and the various treatment options, including surgery and anti-cancer therapy. The risk for the ovarian cancer also makes up an important part of genetic counseling; therefore, the breast surgeons should be well aware of this. This report presents the first experience with performing single-port access laparoscopic prophylactic BSO for a BRCA-positive breast cancer patient, and this procedure was technically feasible and the patient had minimal scar. However, a future investigation is needed to properly assess the cosmetic outcome in this approach.

Germline Mutation of BRCA2 Gene in Korean Breast / Ovarian Cancer Families / 대한암학회지

PURPOSE: Recent discovery of BRCA1 and BRCA2 genes has made it possible to perform presymptomatic diagnosis in hereditary breast/ovarian cancer families. We have previously reported germline mutations of the BRCA1 gene in Korean hereditary breast/ovarian cancer families. In that study two out of 13 families were found to have germline mutations in BRCA1 gene. One was a nonsense mutation in codon 1815, and the other was a frameshift mutation due to 2 base-pair deletion in codon 1701 of BRCA1 gene. This study was intended to identify germline mutations of the BRCA2 gene in Korean breast/ovarian cancer families. MATERIALS AND METHODS: Peripheral blood DNA was obtained from 10 breast cancer patients registered at the Korean Hereditary Tumor Registry with positive family history of breast and/or ovarian cancer. Exons 11 and 27 of the BRCA2 gene(together accounting for 50% of the coding region of the BRCA2 gene) were amplified by polymerase chain reaction(PCR) and screened for mutations by in vitro transcription/translation method. For confirmation of the mutations, automatic sequencing of the PCR products displaying abnormal truncated protein bands was perfomed. RESULT: We identified an abnormal truncated protein in the exon 11 of the BRCA2 gene from a member of hereditary breast cancer family, SNU-B4. Sequencing analysis revealed a 4 bp deletion in codons 1248-49 of the exon 11, resulting in frameshift that led to premature stop codon and truncation of the protein product. CONCLUSION: We have identified a germline mutation from a Korean hereditary breast cancer family. So far only one case of the same mutation has been registered in Database of BRCA2 mutation (BIC) by a commercial genetic diagnosis company, Myriad Genetics, Inc. Identification of the germline mutation in BRCA2 gene should aid in the accurate presymptomatic diagnosis of the at-risk members in this family.