BRCA1 and BRCA2 mutations among ovarian cancer patients from Colombia

Germline Genetic Variants in Cancer Predisposition Genes in Patients From Latin America and the Caribbean

The importance of having region-specific data when planning health interventions has become evident in recent years. Nonetheless, several world regions, including Latin America and the Caribbean (LAC), still face significant challenges. These regions need to develop strategies specifically designed to consider the inherent characteristics of their population composite and sociodemographic characteristics. More than 20% of the global cancer incidence arises in LAC. Yet, treatment, prevention, and follow-up guidelines in the area are frequently based on studies that mainly include patients from North America, Europe, and Asia. As personalized approaches become ubiquitous in medical practice, the amount of information emerging from LAC has risen considerably. In this review, we seek to present a comprehensive summary of the frequency of germline genetic variants in hereditary cancer syndromes in patients from LAC. The data highlight relevant differences in variants associated with LAC patients, including founder and recurrent variants, while showcasing potential features that might be relevant in oncology practices.

Genomic ancestry and cancer among Latin Americans

Latin American populations, characterized by intricate admixture patterns resulting from the intermingling of ancestries from European, Native American (NA) Asian, and African ancestries which result in a vast and complex genetic landscape, harboring unique combinations of novel variants. This genetic diversity not only poses challenges in traditional population genetics methods but also opens avenues for a deeper understanding of its implications in health. In cancer, the interplay between genetic ancestry, lifestyle factors, and healthcare disparities adds a layer of complexity to the varying incidence and mortality rates observed across different Latin American subpopulations. This complex interdependence has been unveiled through numerous studies, whether conducted on Latin American patients residing on the continent or abroad, revealing discernible differences in germline composition that influence divergent disease phenotypes such as higher incidence of Luminal B and Her2 breast tumors, EGFR and KRAS mutated lung adenocarcinomas in addition to an enrichment in BRCA1/2 pathogenic variants and a higher than expected prevalence of variants in colorectal cancer associated genes such as APC and MLH1. In prostate cancer novel risk variants have also been solely identified in Latin American populations. Due to the complexity of genetic divergence, inputs from each individual ancestry seem to carry independent contributions that interplay in the development of these complex disease phenotypes. By understanding these unique population characteristics, genomic ancestries hold a promising avenue for tailoring prognostic assessments and optimizing responses to oncological interventions.

Prognostic factors and the role of primary debulking in operable stage IVB ovarian cancer with supraclavicular lymph node metastasis: a retrospective study in Chinese patients

BACKGROUND

Recent studies showed heterogeneity in stage IVB patients. However, few studies focused on the prognosis of supraclavicular metastatic ovarian cancer. This study aimed to explore the prognostic factors and the role of primary debulking in IVB ovarian cancer patients with supraclavicular lymph node metastasis.

METHODS

We retrospectively analyzed patients newly diagnosed as primary epithelial ovarian cancer with supraclavicular lymph node metastasis from January 2015 to July 2020. Supraclavicular lymph node metastasis was defined as either the pathological diagnosis by supraclavicular lymph node biopsy, or the radiological diagnosis by positron emission tomography-computed tomography (PET-CT).

RESULTS

In 51 patients, 37 was diagnosed with metastatic supraclavicular lymph nodes by histology, 46 by PET-CT, and 32 by both methods. Forty-four (86.3%) with simultaneous metastatic paraaortic lymph nodes (PALNs) by imaging before surgery or neoadjuvant chemotherapy were defined as "continuous-metastasis type", while the other 7 (13.7%) defined as "skip-metastasis type". Nineteen patients were confirmed with metastatic PALNs by histology. Thirty-four patients were investigated for BRCA mutation, 17 had germline or somatic BRCA1/2 mutations (g/sBRCAm). With a median follow-up of 30.0 months (6.3-63.4 m), 16 patients (31.4%) died. The median PFS and OS of the cohort were 17.3 and 48.9 months. Survival analysis showed that "continuous-metastasis type" had longer OS and PFS than "skip-metastasis type" (OS: 50.0/26.6 months, PFS: 18.5/7.2months, p=0.005/0.002). BRCA mutation carriers also had longer OS and PFS than noncarriers (OS: 57.4 /38.5 m, p=0.031; PFS: 23.6/15.2m, p=0.005). Multivariate analysis revealed only metastatic PALNs was independent prognostic factor for OS (p=0.040). Among "continuous-metastasis type" patients, 22 (50.0%) achieved R0 abdominopelvic debulking, who had significantly longer OS (55.3/42.3 months, p =0.034) than those with residual abdominopelvic tumors.

CONCLUSIONS

In stage IVB ovarian cancer patients with supraclavicular lymph nodes metastasis, those defined as "continuous-metastasis type" with positive PALNs had better prognosis. For them, optimal abdominopelvic debulking had prognostic benefit, although metastatic supraclavicular lymph nodes were not resected. Higher BRCA mutation rate than the general population of ovarian cancer patients was observed in patients with IVB supraclavicular lymph node metastasis, leading to better survival as expected.

Germline mutations in BRCA1 and BRCA2 among Brazilian women with ovarian cancer treated in the Public Health System

BACKGROUND

Germline mutations in BRCA1 and BRCA2 genes are among the main causes of hereditary ovarian cancer. Identifying these mutations may reduce cancer risk, facilitate early detection, and enable personalized treatment. However, genetic testing is limited in the Brazilian Public Health System, and data regarding germline mutations in many regions are scarce. Therefore, the study aimed to investigate the prevalence of germline mutations in BRCA1 and BRCA2 in women with ovarian cancer treated in the Public Health System in Pernambuco, Brazil.

METHODS

A cross-sectional study was conducted in the Hereditary Cancer Program from two reference oncological centers in Pernambuco. Women (n = 45) with high-grade serous ovarian cancer underwent genetic counseling and DNA sequencing for BRCA1 and BRCA2 genes.

RESULTS

The prevalence of deleterious mutations in the BRCA1 and BRCA2 genes was 33%. Of the 15 germline mutations found, 13 were in BRCA1 and 2 in BRCA2; two mutations of unknown clinical significance were also found in BRCA2. Mutations c.5266dupC and c.2215 A > T were the most frequent; each was mutation observed in three patients. Additionally, the mutations c.7645dupT and c.921dupT were reported for the first time.

CONCLUSION

One in three women showed a pathogenic mutation, demonstrating a significant prevalence of germline mutations in this sample. Additionally, the small sample revealed an interesting number of mutations, indicating the need to explore more regions of the country.

BRCA1 and BRCA2 germline mutations in Chinese Hakka breast cancer patients

OBJECTIVE

To investigate the prevalence of BRCA1/2 gene variants and evaluate the clinical and pathological characteristics associated with these variants in Chinese Hakka breast cancer patients.

METHODS

A total of 409 breast cancer patients were analyzed based on next-generation sequencing results, with 337 categorized as non-carriers and 72 as carriers of BRCA1/2 variants. Data on the patients' BRCA1/2 gene mutation status, clinical and pathological characteristics, as well as menstrual and reproductive information, were collected, analyzed, compared, and tabulated. Logistic regression analysis was performed to explore the relationship between clinical characteristics and pathogenic variants.

RESULTS

Among the patients, 72 were identified as carriers of pathogenic or likely pathogenic variants in BRCA1/2, while 337 had likely benign or benign mutations. The BRCA1 c.2635G > T (p. Glu879*) variant was detected at a high frequency, accounting for 12.5% (4/32) of the BRCA1 mutations, while the c.5164_5165del (p.Ser1722Tyrfs*4) variant was common among the BRCA2 mutations, accounting for 17.5% (7/40). It was observed that a higher proportion of BRCA1 carriers had the triple-negative breast cancer subtype, whereas more BRCA2 carriers exhibited estrogen receptor (ER) + and progesterone receptor (PR) + subtypes. Multivariate logistic regression analysis revealed that a family history of cancer (OR = 2.36, 95% CI = 1.00-5.54), bilateral cancer (OR = 4.78, 95% CI 1.61-14.20), human epidermal growth factor receptor 2 (HER2)- (OR = 8.23, 95% CI 3.25-20.84), and Ki67 ≥ 15% (OR = 3.88, 95% CI 1.41-10.65) were associated with BRCA1/2 mutations, with the age at diagnosis, age at menarche, and premenopausal status serving as covariates.

CONCLUSIONS

The most common pathogenic variant of the BRCA1 and BRCA2 in breast cancer patients was c.2635G > T and c.5164_5165del, respectively. Additionally, a family history of cancer, bilateral cancer, HER2-, and Ki67 ≥ 15% were identified as independent predictors of BRCA1/2 pathogenic variants.

Sociodemographic, Clinical, and Variation Outcomes for Breast Cancer and Breast Cancer-Related Mutations in a Ten-Year Cohort From Neiva, Huila, Colombia

Background Some breast cancer cases are related to inherited mutations, and this is the reason why early mutation screening is emerging as an area of focus for cost-effective care. However, breast cancer-related mutations vary according to race, ethnicity, geographic origin, and healthcare access. Surveillance for familial breast cancer is not performed routinely in Colombia. Our main aim in this study was to describe a cohort of breast cancer patients, carrying founder breast cancer gene (BRCA) mutations, which were followed up for up to 10 years (2010-2019) in Neiva, Colombia. Methods We performed a retrospective description from an outpatient care center in Huila, Colombia, a region with high breast cancer rates. This study included patients with both a breast cancer diagnosis and an incident genetic mutation for breast cancer (detected during a breast cancer consultation). We captured information from patient medical records. Descriptive analyses were performed. Results A total of 105 patients met the study's inclusion criteria and were included patients with the BRCA1 mutation and three with BRCA2 mutations. They had a median age of 45 years (IQR, 36 to 51 years). Relatives with a breast cancer history were found in 74 carriers (70.5%). Most patients had a report of Breast Imaging-Reporting and Data System (BIRADS) ≥ 4. A TNM (tumor, node, metastasis) changed reclassification was observed in anatomical vs. prognostic classification. Median follow-up was of 74 months (IQR, 44 to 130), overall observed mortality was 22.9%, and specific mortality was 19.1%. Conclusion Women with breast cancer who carry a mutation related to breast cancer are usually younger than age 50 at diagnosis. Developing strategies and specific policies for this population is needed, and a prevalent BRCA1 c.3331_3334delCAAG mutation could be used as a cost-effective first approach. Among these patients, a risk-increased reclassification was observed.

Hereditary gynecologic tumors and precision cancer medicine

Gynecologic cancers are more often caused by genetic factors than other cancers. Genetic testing has become a promising avenue for the prevention, prognosis, and treatment of cancers. This review describes molecular features of gynecologic tumors linked to hereditary syndromes, gives an overview of the current state of clinical management, and clarifies the role of gynecology in the treatment of hereditary tumors. Typical hereditary gynecologic tumors include hereditary breast and ovarian cancer, Lynch syndrome, Peutz-Jeghers syndrome, and Cowden syndrome. Multigene panel testing, which analyzes a preselected subset of genes for genetic variants, has recently become the first-choice test because it can provide more accurate risk assessment than a single test. Furthermore, comprehensive genomic cancer profiling enables personalized cancer treatment and aids in germline findings.

A case–control study of BRCA1 founder mutations 185delAG and 5382insC in a cohort of Egyptian ovarian cancer patients using pyrosequencing technique

Background

Ovarian cancer (OC) is considered a leading cause of death among women with gynecological malignancies. OC, like breast cancer, shows a familial predisposition to germline mutations in genes BRCA1 or BRCA2, which have proved to play important roles in the incidence and progression of cancers. In Arab countries there are limited data concerning BRCA1 or BRCA2 founder mutations associated with familial ovarian cancer (FOC). Therefore, the aim of this pilot study was to assess two common founder mutations of BRCA1 (185delAG and 5382insC) in a cohort of Egyptian patients with FOC. The study included fifty female patients with FOC and twenty healthy controls. Clinical, laboratory, and pathological findings were assessed as well as response to therapy. Genetic testing for BRCA1 (185delAG and 5382insC) mutations was performed on peripheral blood samples using a short-fragment sequencer (pyrosequencer).

Results

The BRCA1 185delAG mutation was not observed in either the FOC patients or the controls. However, the carrier frequency of heterozygous BRCA1 5382insC mutation was 8%. All the FOC patients with a BRCA1 5382insC mutation had a positive family history of cancer (p = 0.009). All carriers of the BRCA1 5382insC mutation showed a preliminary good response to chemotherapy. The majority of carrier patients were diagnosed at an advanced stage of the disease with high-grade tumors and distant metastasis (75% of cases).

Conclusion

The frequency of the BRCA1 5382insC mutation in FOC patients was 8%. The strong association between the mutation and the positive family history suggests that a wider screening for BRCA1 founder mutations would be valuable in predicting high-risk individuals.

Hereditary breast cancer and ancestry in the Madeira archipelago: an exploratory study

Access to genetic testing and counselling in remote areas such as the Madeira archipelago, in the Northern Atlantic Ocean, may be complex. Different counselling methods, including telegenetics, should be explored. In this study, we characterise the Hereditary Breast/Ovarian Cancer (HBOC) families with Madeira ancestry enrolled in our programme. Of a total of 3,566 index patients tested between January 2000 and June 2018, 68 had Madeira ancestry and 22 were diagnosed with a pathogenic germline variant (PV). As in the whole group, BRCA2 PV were more frequent in Madeira patients (68.4%: c.9382C>T (26.3%), c.658_659del (21%), c.156_157insAlu (10.5%), c.793+1G>A (5.3%) and c.298A>T (5.3%). However, the most frequently diagnosed PV in Madeira patients was the BRCA1 c.3331_3334del (31.6%). BRCA1/2 detection rates were 27.9% and 10.5% for Madeira and the whole group, respectively. This study is the first characterisation of HBOC patients with Madeira ancestry. A distinct pattern of BRCA1/2 variants was observed, and the geographic clustering of BRCA1 c.3331_3334del variant may support the possibility of a founder mutation previously described in Northern Portugal. The high detection rate observed reinforces the need to reduce gaps in access to genetic testing in Madeira and other remote areas. According to current guidelines, timely identification of HBOC patients can contribute to their ongoing care and treatment.

Genetic epidemiology of BRCA1- and BRCA2-associated cancer across Latin America

The prevalence and contribution of BRCA1/2 (BRCA) pathogenic variants (PVs) to the cancer burden in Latin America are not well understood. This study aims to address this disparity. BRCA analyses were performed on prospectively enrolled Latin American Clinical Cancer Genomics Community Research Network participants via a combination of methods: a Hispanic Mutation Panel (HISPANEL) on MassARRAY; semiconductor sequencing; and copy number variant (CNV) detection. BRCA PV probability was calculated using BRCAPRO. Among 1,627 participants (95.2% with cancer), we detected 236 (14.5%) BRCA PVs; 160 BRCA1 (31% CNVs); 76 BRCA2 PV frequency varied by country: 26% Brazil, 9% Colombia, 13% Peru, and 17% Mexico. Recurrent PVs (seen ≥3 times), some region-specific, represented 42.8% (101/236) of PVs. There was no ClinVar entry for 14% (17/125) of unique PVs, and 57% (111/196) of unique VUS. The area under the ROC curve for BRCAPRO was 0.76. In summary, we implemented a low-cost BRCA testing strategy and documented a significant burden of non-ClinVar reported BRCA PVs among Latin Americans. There are recurrent, population-specific PVs and CNVs, and we note that the BRCAPRO mutation probability model performs adequately. This study helps address the gap in our understanding of BRCA-associated cancer in Latin America.

Differences in Ovarian and Other Cancers Risks by Population and BRCA Mutation Location

Hereditary breast and ovarian cancer is caused by a germline mutation in BRCA1 or BRCA2 genes. The frequency of germline BRCA1/2 gene mutation carriers and the ratio of germline BRCA1 to BRCA2 mutations in BRCA-related cancer patients vary depending on the population. Genotype and phenotype correlations have been reported in BRCA mutant families, however, the correlations are rarely used for individual risk assessment and management. BRCA genetic testing has become a companion diagnostic for PARP inhibitors, and the number of families with germline BRCA mutation identified is growing rapidly. Therefore, it is expected that analysis of the risk of developing cancer will be possible in a large number of BRCA mutant carriers, and there is a possibility that personal and precision medicine for the carriers with specific common founder mutations will be realized. In this review, we investigated the association of ovarian cancer risk and BRCA mutation location, and differences of other BRCA-related cancer risks by BRCA1/2 mutation, and furthermore, we discussed the difference in the prevalence of germline BRCA mutation in ovarian cancer patients. As a result, although there are various discussions, there appear to be differences in ovarian cancer risk by population and BRCA mutation location. If it becomes possible to estimate the risk of developing BRCA-related cancer for each BRCA mutation type, the age at risk-reducing salpingo-oophorectomy can be determined individually. The decision would bring great benefits to young women with germline BRCA mutations.

Development and Pilot Implementation of the Genomic Risk Assessment for Cancer Implementation and Sustainment (GRACIAS) Intervention in Mexico

PURPOSE

Genomic cancer risk assessment (GCRA) is standard-of-care practice that uses genomic tools to identify individuals with increased cancer risk, enabling screening for early detection and cancer prevention interventions. GCRA is not available in most of Mexico, where breast cancer (BC) is the leading cause of cancer death and ovarian cancer has a high mortality rate.

METHODS

Guided by an implementation science framework, we piloted the Genomic Risk Assessment for Cancer Implementation and Sustainment (GRACIAS) intervention, combining GCRA training, practice support, and low-cost BRCA1/2 (BRCA) gene testing at four centers in Mexico. The RE-AIM model was adapted to evaluate GRACIAS intervention outcomes, including reach, the proportion of new patients meeting adapted National Comprehensive Cancer Network criteria who participated in GCRA. Barriers to GCRA were identified through roundtable sessions and semistructured interviews.

RESULTS

Eleven clinicians were trained across four sites. Mean pre-post knowledge score increased from 60% to 67.2% (range 53%-86%). GCRA self-efficacy scores increased by 31% (95% CI, 6.47 to 55.54; P = .02). Participant feedback recommended Spanish content to improve learning. GRACIAS promoted reach at all sites: 77% in Universidad de Guadalajara, 86% in Instituto Nacional de Cancerología, 90% in Tecnológico de Monterrey, and 77% in Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Overall, a pathogenic BRCA variant was identified in 15.6% (195 of 1,253) of patients. All trainees continue to provide GCRA and address barriers to care.

CONCLUSION

We describe the first project to use implementation science methods to develop and deliver an innovative multicomponent implementation intervention, combining low-cost BRCA testing, comprehensive GCRA training, and practice support in Mexico. Scale-up of the GRACIAS intervention will promote risk-appropriate care, cancer prevention, and reduction in related mortality.

Haplotype analysis of the internationally distributed BRCA1 c.3331_3334delCAAG founder mutation reveals a common ancestral origin in Iberia

BACKGROUND

The BRCA1 c.3331_3334delCAAG founder mutation has been reported in hereditary breast and ovarian cancer families from multiple Hispanic groups. We aimed to evaluate BRCA1 c.3331_3334delCAAG haplotype diversity in cases of European, African, and Latin American ancestry.

METHODS

BC mutation carrier cases from Colombia (n = 32), Spain (n = 13), Portugal (n = 2), Chile (n = 10), Africa (n = 1), and Brazil (n = 2) were genotyped with the genome-wide single nucleotide polymorphism (SNP) arrays to evaluate haplotype diversity around BRCA1 c.3331_3334delCAAG. Additional Portuguese (n = 13) and Brazilian (n = 18) BC mutation carriers were genotyped for 15 informative SNPs surrounding BRCA1. Data were phased using SHAPEIT2, and identical by descent regions were determined using BEAGLE and GERMLINE. DMLE+ was used to date the mutation in Colombia and Iberia.

RESULTS

The haplotype reconstruction revealed a shared 264.4-kb region among carriers from all six countries. The estimated mutation age was ~ 100 generations in Iberia and that it was introduced to South America early during the European colonization period.

CONCLUSIONS

Our results suggest that this mutation originated in Iberia and later introduced to Colombia and South America at the time of Spanish colonization during the early 1500s. We also found that the Colombian mutation carriers had higher European ancestry, at the BRCA1 gene harboring chromosome 17, than controls, which further supported the European origin of the mutation. Understanding founder mutations in diverse populations has implications in implementing cost-effective, ancestry-informed screening.

Breast cancer in six families from Tolima and Huila: BRCA1 3450del4 mutation

Introduction: Breast cancer is a worldwide public health problem; between 5% and 10% of the cases present familial aggregation explained by genes of high risk such as BRCA1 and BRCA2. The founding origin of the deletion BRCA1 3450del4 in Colombia has been previously reported. Objective: To carry out in six families from Tolima and Huila departments a descriptive analysis of the presence of the BRCA1 3450del4 mutation associated with breast cancer and familial aggregation. Materials and methods: We conducted a descriptive and cross-sectional study of six index cases with breast cancer positive for BRCA1 3450del4 that fulfilled three of the criteria established by Jalkh, et al. The genealogical trees were made using the information of the interview data (GenoPro™, version 2016). The mutation was typified in healthy and affected relatives who agreed to participate. Results: Thirty of the 78 individuals selected by convenience in the six families presented the mutation BRCA1 3450del4 six of whom developed breast cancer, one, ovarian cancer, one ovarian and breast cancer, and one prostate cancer; 21 did not present any type of neoplasm at the time of the study. Of the 30 individuals carrying the pathogenic variant, six were men, 24 were women, and 13 of these were under 30. Conclusions: In this study of families with the deletion BRCA1 3450del4 in Tolima and Huila we confirmed its association with familial aggregation of breast cancer.

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.

BRCA1 and BRCA2 mutations in a sample of breast and ovarian cancer families from the Colombian pacific

Introduction:

Breast cancer is the most common neoplasia of women from all over the world especially women from Colombia. 5%­10% of all cases are caused by hereditary factors, 25% of those cases have mutations in the BRCA1/BRCA2 genes.

Objective:

The purpose of this study was to identify the mutations associated with the risk of familial breast and/or ovarian cancer in a population of Colombian pacific.

Methods:

58 high-risk breast and/or ovarian cancer families and 20 controls were screened for germline mutations in BRCA1 and BRCA2, by Single Strand Conformation Polymorphism (SSCP) and sequencing.

Results:

Four families (6.9%) were found to carry BRCA1 mutations and eight families (13.8%) had mutations in BRCA2. In BRCA1, we found three Variants of Uncertain Significance (VUS), of which we concluded, using in silico tools, that c.81­12C>G and c.3119G>A (p.Ser1040Asn) are probably deleterious, and c.3083G>A (p.Arg1028His) is probably neutral. In BRCA2, we found three variants of uncertain significance: two were previously described and one novel mutation. Using in silico analysis, we concluded that c.865A>G (p.Asn289Asp) and c.6427T>C (p.Ser2143Pro) are probably deleterious and c.125A>G (p.Tyr42Cys) is probably neutral. Only one of them has previously been reported in Colombia. We also identified 13 polymorphisms (4 in BRCA1 and 9 in BRCA2), two of them are associated with a moderate increase in breast cancer risk (BRCA2 c.1114A>C and c.8755­66T>C).

Conclusion:

According to our results, the Colombian pacific population presents diverse mutational spectrum for BRCA genes that differs from the findings in other regions in the country.

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.

A Multi-Center Study of BRCA1 and BRCA2 Germline Mutations in Mexican-Mestizo Breast Cancer Families Reveals Mutations Unreported in Latin American Population

The presence of germline and somatic deleterious mutations in the BRCA1 and BRCA2 genes has important clinical consequences for breast cancer (BC) patients. Analysis of the mutational status in BRCA genes is not yet common in public Latin American institutions; thus, our objective was to implement high-performance technology with highly reliable results with the possibility of analyzing several patients simultaneously, therefore reducing cost and work time. A prospective cohort of 252 unrelated sporadic breast cancer patients from the Mexican-mestizo population were analyzed using next generation sequencing (NGS) based on ion semiconductor sequencing. We found 28 pathogenic mutations (25 in BRCA1 and 13 in BRCA2), 11 of which had not been reported previously in Hispanic or Latin American populations. A total of 38 patients were positive for a pathogenic mutation representing 15% of our Mexican women cohort with breast cancer; 25 for BRCA1; and 13 for BRCA2. Our results revealed that there are mutations not analyzed by mutations panels, and our findings support the suitability of massive sequencing approaches in the public institutions of developing countries. Hence, BRCA screening should be offered to patients with breast cancer regardless of their family history of cancer in order to identify unaffected family carriers.

Mutational analysis of BRCA1 and BRCA2 genes in women with familial breast cancer from different regions of Colombia

Purpose

The main risk factor for familial breast cancer is the presence of mutations in BRCA1 and BRCA2 genes. The prevalence of mutations in these genes is heterogeneous and varies according to geographical origin of studied families. In Colombia mutations in these genes have been mainly studied on patients from Andean region. Bogotá and Medellin presented its own battery of mutations. This study aims to identify mutations in BRCA1–2 genes in women with familial breast cancer from different regions of Colombia.

Methods

One hundred four families with a history of breast cancer were sampled in different regions of Colombia, and the BRCA1 gene and exon 11 of the BRCA2 gene were sequenced. To predict the possible effects of sequence alterations found in protein function, different bioinformatics tools were used.

Results

A total of 33 variants were found; 18 in BRCA1 and 15 in BRCA2, of which 15 are unique variants of Colombia. In silico analysis established that alterations p.Thr790Ala, p.Arg959Lys and p.Glu1345Lys in the BRCA1 gene and variants p.Leu771Phe, p.Asn818Lys, p.Val859Ser*22 and p.Lys1032Ile in the BRCA2 gene are considered likely pathogenic. Both the mutations as the variants of unknown clinical significance, in their great majority, presented a specific region distribution and they were different from those reported in previous studies.

Conclusions

In this study we report the BRCA1 and BRCA2 spectrum of mutations and their distribution by regions in Colombia. Our results may help to design a diagnostic test including recurrent mutations for screening high risk to breast cancer families in Colombia.

Pathogenic and likely pathogenic variants in PALB2, CHEK2, and other known breast cancer susceptibility genes among 1054 BRCA-negative Hispanics with breast cancer

BACKGROUND

Breast cancer (BC) is the most common cancer and related cause of mortality among Hispanics, yet susceptibility has been understudied. BRCA1 and BRCA2 (BRCA) mutations explain less than one-half of hereditary BC, and the proportion associated with other BC susceptibility genes is unknown.

METHODS

Germline DNA from 1054 BRCA-mutation-negative Hispanic women with hereditary BC (BC diagnosed at age <51 years, bilateral BC, breast and ovarian cancer, or BC diagnosed at ages 51-70 years with ≥2 first-degree or second-degree relatives who had BC diagnosed at age <70 years), 312 local controls, and 887 multiethnic cohort controls was sequenced and analyzed for 12 known and suspected, high-penetrance and moderate-penetrance cancer susceptibility genes (ataxia telangiectasia mutated [ATM], breast cancer 1 interacting protein C-terminal helicase 1 [BRIP1], cadherin 1 [CDH1], checkpoint kinase 2 [CHEK2], nibrin [NBN], neurofibromatosis type 1 [NF1], partner and localizer of BRCA2 [PALB2], phosphatase and tensin homolog [PTEN], RAD51 paralog 3 [RAD51C], RAD51D, serine/threonine kinase 11 [STK11], and TP53).

RESULTS

Forty-nine (4.6%) pathogenic or likely pathogenic variants (PVs) in 47 of 1054 participants (4.5%), including 21 truncating frameshift, 20 missense, 5 nonsense, and 4 splice variants, were identified in CHEK2 (n = 20), PALB2 (n = 18), ATM (n = 5), TP53 (n = 3), BRIP1 (n = 2), and CDH1 and NF1 (both n = 1) and none were identified in NBN, PTEN, STK11, RAD51C, or RAD51D. Nine participants carried the PALB2 c.2167_2168del PV (0.85%), and 14 carried the CHEK2 c.707T>C PV (1.32%).

CONCLUSIONS

Of 1054 BRCA-negative, high-risk Hispanic women, 4.5% carried a PV in a cancer susceptibility gene, increasing understanding of hereditary BC in this population. Recurrent PVs in PALB2 and CHEK2 represented 47% (23 of 49) of the total, suggesting a founder effect. Accurate classification of variants was enabled by carefully controlling for ancestry and the increased identification of at-risk Hispanics for screening and prevention.

Direct Genetics Referral Pathway for High-Grade Serous Ovarian Cancer Patients: The "Opt-Out" Process

PURPOSE

In order to meet a clinical need for better pathways to access genetic testing for ovarian cancer patients, we implemented and reviewed an opt-out referral process for genetic consultation whereby a referral is automatically sent to genetics following a pathological diagnosis of HGSC.

METHODS

Following implementation of the opt-out referral process, each month a list of new cases of HGSC was generated from the synoptic pathology report and forwarded directly to the Cancer Genetics clinic. Using an advanced directive, patients were automatically referred for genetic counselling two months after surgery. If the patient declined genetic counselling (opted-out) after discussion with their surgeon within the two months after surgery, the Genetic Counsellor was informed and the patient was removed from the referral process.

RESULTS

Between January 1, 2015, and December 31, 2017, 168 women were diagnosed with HGSC, of whom 167 received a referral for genetic consultation. In only one case the referral was cancelled by the surgeon, resulting in a referral rate of 99.4%. By the end of the study period, 133 women attended a genetics consultation appointment and 125 (94%) agreed to proceed with genetic testing. Among those who completed genetic testing, 15% tested positive for a BRCA1 or BRCA2 gene mutation. Of the women who tested positive for a BRCA1/2 mutation, 56% had no family history of breast or ovarian cancer.

CONCLUSIONS

The opt-out referral process described in this study is s a feasible, effective, and patient-centred approach to increase access to BRCA1/2 testing for patients with ovarian cancer.

A multi-gene panel study in hereditary breast and ovarian cancer in Colombia

Germline mutations in BRCA1 and BRCA2 account for approximately 50% of inherited breast and ovarian cancers. Three founder mutations in BRCA1/2 have been reported in Colombia, but the pattern of mutations in other cancer susceptibility genes is unknown. This study describes the frequency and type of germline mutations in hereditary breast and/or ovarian cancer genes in a referral cancer center in Colombia. Eighty-five women referred to the oncogenetics unit of the Instituto de Cancerologia Las Americas in Medellin (Colombia), meeting testing criteria for hereditary breast and ovarian cancer syndrome (NCCN 2015), who had germline testing with a commercial 25-gene hereditary cancer panel, were included in the analysis. Nineteen patients (22.4%) carried a deleterious germline mutation in a cancer susceptibility gene: BRCA1 (7), BRCA2 (8), PALB2 (1), ATM (1), MSH2 (1) and PMS2 (1). The frequency of mutations in BRCA1/2 was 17.6%. One BRCA2 mutation (c.9246dupG) was recurrent in five non-related individuals and is not previously reported in the country. Seventeen mutation-carriers had a diagnosis of breast cancer (median age of diagnosis of 36 years) and two of ovarian cancer. All BRCA1 mutation-carriers with breast cancer had triple negative tumors (median age of diagnosis of 31 years). Variants of unknown significance were reported in 35% of test results. This is the first report of a multi-gene study for hereditary breast and/or ovarian cancer in a Latin American country. We found a high frequency and a wide spectrum of germline mutations in cancer susceptibility genes in Colombian patients, some of which were not previously reported in the country. We observed a very low frequency of known Colombian founder BRCA1/2 mutations (1.2%) and we found mutations in other genes such as PALB2, ATM, MSH2 and PMS2. Our results highlight the importance of performing multi-gene panel testing, including comprehensive BRCA1/2 analysis (full gene sequencing and large rearrangement analysis), in high-risk breast and/or ovarian cancer patients in Colombia.

Prevalence of BRCA1 and BRCA2 pathogenic and likely pathogenic variants in non-selected ovarian carcinoma patients in Brazil

Background

BRCA1/2 pathogenic (P) and likely pathogenic (LP) germline variants are frequent among patients with ovarian carcinoma. However, these variants have not been extensively characterized in patients with ovarian cancer in Brazil.

Methods

In this retrospective study we evaluated clinical characteristics and BRCA1/2 genetic test results from patients with ovarian carcinoma who underwent genetic counseling at A.C.Camargo Cancer Center (Brazil) between 2015 and 2017 and had performed germline genetic testing of BRCA1/2 genes.

Results

Among 158 patients, 33 P and LP variants and were found (20.8%), 27 in BRCA1 and six in BRCA2, and six variants of unknown clinical significance (VUS). Thirteen percent of the patients did not have Multiplex Ligation-dependent Probe Amplification (MLPA) results. Three P variants in BRCA1 were found in more than one patient: c.5266dupC (p.Gln1756Profs*74), c.3331_3334delCAAG (p.Gln1111Asnfs5*), and c.211A > G (p.Arg71Gly). One LP variant in BRCA1 had not been previously described, c.4153_4154delCT (p.Leu1385Ilefs*5). Patients with previous diagnosis of breast cancer were carriers of P or LP variant in 8 of 12 cases (66.7%), and patients with a family history of ovarian or breast cancer in first- or second-degree relatives were carriers of P or LP variant in 26.7% of cases compared to 16.9% for patients without family history (p = 0.166).

Conclusion

Prevalence of BRCA1/2 germline P and LP variants is slightly higher than previously described by the largest occidental studies, with a high prevalence of variant c.5266dupC (p.Gln1756Profs*74) in BRCA1 observed. Moreover, we identified a new LP variant.

BRCA1 and BRCA2 mutations and clinical interpretation in 398 ovarian cancer patients: comparison with breast cancer variants in a similar population

Background

Ovarian cancer is the leading cause of death worldwide among gynecologic malignancies. The recent approval of inhibitors of poly (ADP-ribose) polymerase (iPARP) in the treatment of ovarian cancer in the presence of a BRCA1/2 mutation has sparked the analysis of women with such diagnosis, which can further benefit from the detection of carriers in the family. Germline sequence and large rearrangements for BRCA1/2 were tested in 398 consecutive epithelial ovarian cancer (EOC) patients.

The aim of this study was to identify the frequency and spectrum of germline BRCA1/2 pathogenic alterations in a cohort of patients with ovarian serous carcinoma, with a view to adequately selecting patients for prevention through family counseling and correlating this frequency with platinum sensitivity as a guidance to identify patients eligible for iPARP in our population.

Results

A total of 96 patients carried a pathogenic germline mutation, accounting for an overall 24.1% mutation incidence. Among mutation carriers, BRCA1 showed 62.5% incidence, BRCA2 rendered 36.5%, and one patient exhibited a mutation in both genes. Three pathogenic mutations were recurrent mutations detected five, three, and four times and represented 12.5% of the mutated samples. Worth highlighting, a 50% mutation incidence was detected when breast and ovarian cancer coexisted in the same patient. Novel mutations amounted to 9.4% of the total mutations, as compared to 4.7% in breast cancer. Forty out of 60 BRCA1 mutations were beyond the ovarian cancer cluster region (OCCR), in stark contrast with 22 out of 36 BRCA2 mutations being inside the OCCR. Taken together, germline BRCA1/2 mutations in EOC patients showed a distinct mutational spectrum compared to our previously published data on breast cancer patients.

Conclusions

In sum, our study provides novel data on ovarian BRCA1/2 mutation prevalence worldwide, enhances adequate patient selection for family counseling and prevention, and sheds light on the benefits of iPARP treatment.

Electronic supplementary material

The online version of this article (10.1186/s40246-018-0171-5) contains supplementary material, which is available to authorized users.

Mutational spectrum in a worldwide study of 29,700 families with BRCA1 or BRCA2 mutations

The prevalence and spectrum of germline mutations in BRCA1 and BRCA2 have been reported in single populations, with the majority of reports focused on White in Europe and North America. The Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) has assembled data on 18,435 families with BRCA1 mutations and 11,351 families with BRCA2 mutations ascertained from 69 centers in 49 countries on six continents. This study comprehensively describes the characteristics of the 1,650 unique BRCA1 and 1,731 unique BRCA2 deleterious (disease-associated) mutations identified in the CIMBA database. We observed substantial variation in mutation type and frequency by geographical region and race/ethnicity. In addition to known founder mutations, mutations of relatively high frequency were identified in specific racial/ethnic or geographic groups that may reflect founder mutations and which could be used in targeted (panel) first pass genotyping for specific populations. Knowledge of the population-specific mutational spectrum in BRCA1 and BRCA2 could inform efficient strategies for genetic testing and may justify a more broad-based oncogenetic testing in some populations.

Genetics, tumor features and treatment response of breast cancer in Latinas

Breast cancer is a heterogeneous and genetic disease that has variability according to ethnicity and race with respect to incidence, clinical characteristics and prognosis. The incidence of breast cancer is lower but mortality is higher in Latinas than Caucasians in the US series. Risk factors appear to have different prevalence and impact in Latinas. Breast cancer in Latinas has particular clinic-pathological features including younger age, higher rates of triple-negative subtype and advanced stages. Molecular studies find that Latinas from every region have a specific BRCA incidence and a recurrent mutation, as well as differences in activity of molecular pathways. Treatment response rates and toxicity have also been compared, and no difference was found between Latinas and other ethnic groups.

Prevalence of pathogenic germline variants detected by multigene sequencing in unselected Japanese patients with ovarian cancer

Pathogenic germline BRCA1, BRCA2 (BRCA1/2), and several other gene variants predispose women to primary ovarian, fallopian tube, and peritoneal carcinoma (OC), although variant frequency and relevance information is scarce in Japanese women with OC. Using targeted panel sequencing, we screened 230 unselected Japanese women with OC from our hospital-based cohort for pathogenic germline variants in 75 or 79 OC-associated genes. Pathogenic variants of 11 genes were identified in 41 (17.8%) women: 19 (8.3%; BRCA1), 8 (3.5%; BRCA2), 6 (2.6%; mismatch repair genes), 3 (1.3%; RAD51D), 2 (0.9%; ATM), 1 (0.4%; MRE11A), 1 (FANCC), and 1 (GABRA6). Carriers of BRCA1/2 or any other tested gene pathogenic variants were more likely to be diagnosed younger, have first or second-degree relatives with OC, and have OC classified as high-grade serous carcinoma (HGSC). After adjustment for these variables, all 3 features were independent predictive factors for pathogenic variants in any tested genes whereas only the latter two remained for variants in BRCA1/2. Our data indicate similar variant prevalence in Japanese patients with OC and other ethnic groups and suggest that HGSC and OC family history may facilitate genetic predisposition prediction in Japanese patients with OC and referring high-risk patients for genetic counseling and testing.

Mutations in BRCA1, BRCA2 and other breast and ovarian cancer susceptibility genes in Central and South American populations

Breast cancer (BC) is the most common malignancy among women worldwide. A major advance in the understanding of the genetic etiology of BC was the discovery of BRCA1 and BRCA2 (BRCA1/2) genes, which are considered high-penetrance BC genes. In non-carriers of BRCA1/2 mutations, disease susceptibility may be explained of a small number of mutations in BRCA1/2 and a much higher proportion of mutations in ethnicity-specific moderate- and/or low-penetrance genes. In Central and South American populations, studied have focused on analyzing the distribution and prevalence of BRCA1/2 mutations and other susceptibility genes that are scarce in Latin America as compared to North America, Europe, Australia, and Israel. Thus, the aim of this review is to present the current state of knowledge regarding pathogenic BRCA variants and other BC susceptibility genes. We conducted a comprehensive review of 47 studies from 12 countries in Central and South America published between 2002 and 2017 reporting the prevalence and/or spectrum of mutations and pathogenic variants in BRCA1/2 and other BC susceptibility genes. The studies on BRCA1/2 mutations screened a total of 5956 individuals, and studies on susceptibility genes analyzed a combined sample size of 11,578 individuals. To date, a total of 190 different BRCA1/2 pathogenic mutations in Central and South American populations have been reported in the literature. Pathogenic mutations or variants that increase BC risk have been reported in the following genes or genomic regions: ATM, BARD1, CHECK2, FGFR2, GSTM1, MAP3K1, MTHFR, PALB2, RAD51, TOX3, TP53, XRCC1, and 2q35.

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.

Prevalence and Penetrance of BRCA1 and BRCA2 Germline Mutations in Colombian Breast Cancer Patients

Pathogenic BRCA1/2 germline mutations confer high risks of breast and ovarian cancer to women of European ancestry. Characterization of BRCA1/2 mutations in other ethnic groups is also medically important. We comprehensively screened 68 Colombian breast/ovarian cancer families for small-range mutations, 221 families for large-genomic rearrangements, and 1,022 unselected breast cancer cases for Colombian founder mutations in BRCA1/2. The risk of cancer among relatives of mutation carriers and the mutation penetrance were estimated by survival analysis. Identified BRCA2 mutations included 6310delGA and the recurrent 1991del4 mutations. A novel large BRCA2 deletion was found in 0.9% of the screened families. Among unselected breast cancer cases, 3.3% tested positive for BRCA1/3450del4, 2.2% for BRCA1/A1708E, 1.1% for BRCA2/3034del4, and 0.4% for BRCA2/1991del4. Female relatives of carriers of BRCA1/2 founder mutations showed a 5.90 times higher risk of breast cancer, when the woman herself carried a BRCA1 mutation compared to a non-carrier (95% CI 2.01–17.3). The estimated cumulative risk of breast cancer by age 70 years for BRCA1 mutations carriers was 14% (95% CI 5–38) compared to 3% for the general Colombian population (relative risk of breast cancer 4.05). Together with known founder mutations, reported novel variants may ease a cost-effective BRCA1/2 screening in women with Colombian ancestry.

Genomic Disparities in Breast Cancer Among Latinas

BACKGROUND

Breast cancer is the most common cancer diagnosed among Latinas in the United States and the leading cause of cancer-related death among this population. Latinas tend to be diagnosed at a later stage and have worse prognostic features than their non-Hispanic white counterparts. Genetic and genomic factors may contribute to observed breast cancer health disparities in Latinas.

METHODS

We provide a landscape of our current understanding and the existing gaps that need to be filled across the cancer prevention and control continuum.

RESULTS

We summarize available data on mutations in high and moderate penetrance genes for inherited risk of breast cancer and the associated literature on disparities in awareness of and uptake of genetic counseling and testing in Latina populations. We also discuss common genetic polymorphisms and risk of breast cancer in Latinas. In the treatment setting, we examine tumor genomics and pharmacogenomics in Latina patients with breast cancer.

CONCLUSIONS

As the US population continues to diversify, extending genetic and genomic research into this underserved and understudied population is critical. By understanding the risk of breast cancer among ethnically diverse populations, we will be better positioned to make treatment advancements for earlier stages of cancer, identify more effective and ideally less toxic treatment regimens, and increase rates of survival.

Genetics Consultation Rates Following a Diagnosis of High-Grade Serous Ovarian Carcinoma in the Canadian Province of Ontario

OBJECTIVE

In 2001, the province of Ontario expanded cancer genetic testing eligibility to include all women with high-grade serous ovarian carcinoma (HGSC) of the ovary, fallopian tube, and peritoneum. The aim of this study was to determine the proportion of women who attended genetics counseling for consideration of BRCA1/2 gene analysis. We also sought to examine if regional differences in consultation rate exist across administrative health regions in the province of Ontario.

METHODS

We identified all women with a pathological diagnosis of HGSC in the province of Ontario between 1997 until 2011. Our primary outcome was the 2-year rate of genetics consultation following a diagnosis of HGSC. We compared consultation rates over time and geographical regions and applied multiple logistic regression to identify predictors of genetics consultation.

RESULTS

Of the 5412 women with a diagnosis of HGSC over the study period, 6.6% were seen for genetics consultation within 2 years of diagnosis. Factors predictive of genetics consultation included history of breast cancer (odds ratio [OR], 3.56; 95% confidence interval [CI], 1.87-6.78), era of diagnosis (2009-2011 vs 1997-2000; OR, 10.59; 95% CI, 5.02-22.33), and younger age at diagnosis (OR, 0.95; 95% CI, 0.94-0.97 for each additional year). No regional differences in consultation rate were seen.

CONCLUSIONS

Despite an increasing rate across eras, a small proportion of women with HGSC undergo genetics consultation. Efforts are required to increase cancer genetics consultation in patients with HGSC in the province of Ontario.

Genetic Cancer Risk Assessment for Breast Cancer in Latin America

In Latin America, breast cancer is the most common malignancy in women, and limited available data suggest that up to 15% of all breast cancer cases in the region are hereditary. Genetic cancer risk assessment and counseling is a critical component of the appropriate clinical care of patients with hereditary breast cancer and their families. Unfortunately, genetic services are underdeveloped across Latin America, and access to genetic testing and counseling is very scarce in the region. Barriers contributing to the access to genetic care are high cost and lack of insurance coverage for genetic tests, insufficient oncogenetics training or expertise, nonexistence of genetic counseling as a clinical discipline, and lack of supportive healthcare policies. In this review, we highlight relevant initiatives undertaken in several Latin American countries aimed at creating genetic cancer risk assessment programs. Additionally, we present a review of the scientific literature on the current status of breast cancer genomics in Latin America, with specific emphasis on demographic indicators, access to cancer genetic care, training and strategies to improve outcomes, and international collaborations.

Hereditary cancer syndromes in Latino populations: genetic characterization and surveillance guidelines

Hereditary cancer predisposition syndromes comprise approximately 10% of diagnosed cancers; however, familial forms are believed to account for up to 30% of some cancers. In Hispanics, the most commonly diagnosed hereditary cancers include colorectal cancer syndromes such as, Lynch Syndrome, Familial Adenomatous Polyposis, and hereditary breast and ovarian cancer syndromes. Although the incidence of hereditary cancers is low, patients diagnosed with hereditary cancer syndromes are at high-risk for developing secondary cancers. Furthermore, the productivity loss that occurs after cancer diagnosis in these high-risk patients has a negative socio-economic impact. This review summarizes the genetic basis, phenotype characteristics, and the National Comprehensive Cancer Network's screening, testing, and surveillance guidelines for the leading hereditary cancer syndromes. The aim of this review is to promote a better understanding of cancer genetics and genetic testing in Hispanic patients.

Germline mutations in BRCA1 and BRCA2 in epithelial ovarian cancer patients in Brazil

Background

Approximately 8–15% epithelial ovarian cancer patients are BRCA1 or BRCA2 germline mutation carriers. Brazilian inhabitants may have peculiar genetic characteristics associated with ethnic diversity, and studies focusing on the entire BRCA1/BRCA2 gene sequencing in Brazilian ovarian cancer patients are still lacking. The aim of this study was to evaluate BRCA1/2 mutations, through entire gene sequencing, in a Brazilian population of women with epithelial ovarian cancer.

Methods

In a cross sectional study performed in one reference centre for cancer treatment in São Paulo, Brazil, 100 patients diagnosed with epithelial ovarian cancer unselected for family history of breast and/or ovarian cancer were included. The complete coding sequence of BRCA1/2 genes was evaluated through Next-Generation or capillary sequencing. Large deletions were investigated through Multiplex Ligation-dependent Probe Amplification (MLPA).

Results

Nineteen pathogenic mutations (BRCA1: n = 17 and BRCA2: n = 2) featuring 14 different mutations, including two large deletions in BRCA1 (exon 1–2 deleted and exon 5–7 deleted) were identified. Three mutations were detected more than once (c.3331_3334delCAAG, c.5266dupC and c.4484G > T). Two novel frameshift mutations were identified, one in BRCA1 (c.961_962delTG) and one in BRCA2 (c.1963_1963delC). BRCA1/2 mutations were seen in 35.5% of the patients with first and/or second-degree relatives with breast and/or ovarian cancer. Nineteen variants of uncertain significance (VUS) were detected (BRCA1: n = 2 and BRCA2: n = 17), including five distinct missense variants (BRCA1: c.5348 T > C; BRCA2: c.2350A > G, c.3515C > T, c.7534C > T, and c.8351G > A).

Conclusions

Among epithelial ovarian cancer patients unselected for family history of cancer, 19% were BRCA1/2 germline mutation carriers. Almost ¾ of the BRCA mutations, including two large deletions, were detected only once. Our work emphasizes the need of entire gene sequencing and MLPA screening in Brazil.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2966-x) contains supplementary material, which is available to authorized users.

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 Genetics of Breast Cancer: What the Surgical Oncologist Needs to Know

This article summarizes the impact of germline predisposition to breast cancer on the surgical management of breast cancer and breast cancer risk. Surgical implications of germline predisposition to breast cancer are now more nuanced due to the application of increasingly more complicated next-generation sequencing-based tests. The rapid pace of change will continue to challenge paradigms for genetic cancer risk assessment, which can influence the medical and surgical management of breast cancer risk as well as strategies for screening and for risk reduction.

Prevalence of Hispanic BRCA1 and BRCA2 mutations among hereditary breast and ovarian cancer patients from Brazil reveals differences among Latin American populations

Germline mutations in BRCA1 or BRCA2 (BRCA) are responsible for 5-15% of breast (BC) and ovarian cancers (OC), predisposing to the development of early onset and often multiple primary tumors. Since mutation carriers can benefit from risk-reducing interventions, the identification of individuals with hereditary breast and ovarian cancer (HBOC) syndrome has a significant clinical impact. We assessed whether a panel assay for recurrent Hispanic BRCA mutations (HISPANEL) has an adequate breadth of coverage to be suitable as a cost effective screening tool for HBOC in a cohort of patients from Southern Brazil. A multiplex, PCR-based panel was used to genotype 232 unrelated patients for 114 germline BRCA mutations, finding deleterious mutations in 3.5% of them. This mutation prevalence is within the range detected by the HISPANEL among BC patients unselected for family history in other Latin American settings. The HISPANEL would have accounted for 27% of the BRCA mutations detected by complete sequencing in a comparison cohort (n = 193). This prevalence may be region-specific since significant differences in population structure exist in Brazil. Comprehensive analysis of BRCA in a larger set of HBOC patients from different Brazilian regions is warranted, and the results could inform customization of the HISPANEL as an affordable mutation screening tool.

Founder and Recurrent Mutations in BRCA1 and BRCA2 Genes in Latin American Countries: State of the Art and Literature Review

BACKGROUND

Numerous epidemiological factors affect the probability of developing breast or ovarian cancer, but no predictor is as determinant as inheriting a mutation in BRCA1 or BRCA2. The concept of the founder effect explains the reduced genetic variability in some populations, according to the theory that new populations can be formed from a reduced number of individuals, so the new population would carry only a small fraction of the genetic variability of the original population. The main purpose of this review is to provide an update on the state of the art in founder mutations and some recurrent mutations that have recently been described in Latin America.

METHODS

A literature search was performed in the electronic databases of PUBMED, EMBASE, LILACS, and BIREME using the terms BRCA1, BRCA2, founder mutation, Latin American population, and Hispanic. Sixty-two papers were identified, of which 38 were considered relevant for this review. Each result is shown per country.

RESULTS

In Latin America, clear founder effects have been reported in Mexico (BRCA1 del exons 9-12), Brazil (BRCA1 5382insC and BRCA2 c.156_157insAlu), and Colombia (BRCA1 3450del4, A1708E, and BRCA2 3034del4) and in Latinas residing in Southern California (BRCA1 185delAG, IVS5+1G>A, S955x, and R1443x). Of these, mutation BRCA1 3450del4 has also been reported in Brazil and Chile, whereas mutation BRCA2 3034del4 has been reported in Argentina and Peru. These data support the idea that although most Hispanic populations are the result of a mixture between Europeans, Africans, and Amerindians, the relative proportion of each genetic component varies throughout the Hispanic populations, making it necessary to identify the mutations characteristic of each population to generate mutation profiles adjusted to each one of them.

CONCLUSION

In Latin American countries, and even among regions of the same country, there is great heterogeneity of ancestors. Therefore, Latinas should not be analyzed like other population groups without taking into account their genetic ancestry. The presence of founder mutations in specific population groups represents a cost-effective analysis. The importance of determining the founder mutations lies mainly in the decrease in costs. If we manage to decrease costs, screenings could be offered more widely and cover a larger number of women.

IMPLICATIONS FOR PRACTICE

Hispanic and African-American populations are four to five times less likely than other populations worldwide to receive screening for BRCA mutations, a main reason being the high costs of these tools. The present study seeks to identify the prevalent mutations and the founder effect in the BRCA gene in the Hispanic population to address specific panels for this population group in the future and develop strategies for population screening.

The spectrum of BRCA1 and BRCA2 alleles in Latin America and the Caribbean: a clinical perspective

Hereditary cancer predisposition gene testing allows the identification of individuals at high risk of cancer that may benefit from increased surveillance, chemoprevention, and prophylactic surgery. In order to implement clinical genetic strategies adapted to each population's needs and intrinsic genetic characteristic, this review aims to present the current status of knowledge about the spectrum of BRCA pathogenic variants in Latin American populations. We have conducted a comprehensive review of 33 studies published between 1994 and 2015 reporting the prevalence and/or spectrum of BRCA1 (OMIM 113705) and BRCA2 (OMIM 600185) variants. The combined sample size for these studies consisted of 4835 individuals from 13 countries in Latin America and the Caribbean, as well as in Hispanics in the United States. A total of 167 unique pathogenic variants have been reported in the existing literature. In unselected breast cancer cases, the prevalence ranged from 1.2 to 27.1%. Some countries presented a few recurrent pathogenic variants, while others were characterized by diverse, non-recurrent variants. The proportion of BRCA pathogenic variants shared between Hispanics in the United States and Latin American populations was estimated at 10.4%. Within Latin America and the Caribbean, 8.2% of the BRCA variants reported were present in more than one country. Countries with high prevalence of BRCA pathogenic variants may benefit from more aggressive testing strategies, while testing of recurrent variant panels might present a cost-effective solution for improving genetic testing in some, but not all, countries.

The sooner the better: Genetic testing following ovarian cancer diagnosis

OBJECTIVE

As treatment based genetic testing becomes a reality, it is important to assess the attitudes and preferences of women newly diagnosed with ovarian cancer regarding genetic testing. The objective of this study was to determine when women with a diagnosis of high grade serous ovarian cancer would prefer to undergo genetic testing and factors that influence this preference.

METHODS

Women over 18years of age with a known diagnosis of high grade serous ovarian cancer diagnosed between October 2010-2013 were identified via the Princess Margaret Cancer Center Registry. Participants completed a questionnaire, which obtained preferences and attitudes towards genetic testing, cancer history, and demographic information.

RESULTS

120 of the 355 women identified (33.8%) completed the questionnaires. The median age at time of ovarian cancer diagnosis was 57years (range 35-84). The majority of participants in this study were offered (94.6%) and pursued (84.8%) genetic testing. In this cohort, testing was most frequently offered at diagnosis (41.8%) or during treatment (19.1%). In this study, women with high grade serous ovarian cancer felt that genetic testing should be offered before or at the time of diagnosis (67.8%). Having a family history of breast or ovarian cancer was significantly (p=0.012) associated with preferring genetic testing at an earlier time point in the disease course.

CONCLUSIONS

Our results demonstrate that women with high grade serous ovarian cancer acknowledge the personal and clinical utility of genetic testing and support test implementation at the time of cancer diagnosis.

Germline mutations in BRCA1, BRCA2, CHEK2 and TP53 in patients at high-risk for HBOC: characterizing a Northeast Brazilian Population

Considering the importance of BRCA1, BRCA2, CHEK2 and TP53 in the development of hereditary early-onset breast and ovarian cancer and that the genetic susceptibility profile of the Northeast population from Brazil has never been analyzed, this study aimed to verify the frequency of mutations of clinical significance in these genes in high-risk hereditary breast and ovarian cancer (HBOC) syndrome patients from that region. DNA samples from 106 high-risk unrelated patients mostly from Bahia, the biggest state in the Northeast region, were analyzed. These patients underwent full BRCA1 gene sequencing, screening for common founder mutations in the BRCA2, CHEK2 and TP53 genes and genetic ancestry analysis with nine ancestry informative markers. The positive results were confirmed by two sequencing reactions. Three mutations of clinical significance were found: BRCA1 p.R71G (4.71%), 3450del4 (3.77%) and TP53 p.R337H (0.94%). The genetic ancestry analysis showed a high European ancestry contribution (62.2%) as well as considerable African (31.2%) and Amerindian (6.6%) ancestry contributions (r²=0.991); this degree of heterogeneity was also significant in the population structure analysis (r=0.604). This population is highly admixed with a different spectrum of genetic susceptibility, with the Galician founder mutation BRCA1 p.R71G accounting for 50% of all identified mutations in high-risk HBOC patients. TP53 p.R337H was also significantly frequent; thus, the combined screening of BRCA1/2 and TP53 should be offered to high-risk HBOC patients from Northeast Brazil.

Prevalence and impact of founder mutations in hereditary breast cancer in Latin America

Approximately 10% of all cancers are considered hereditary and are primarily caused by germline, high penetrance mutations in cancer predisposition genes. Although most cancer predisposition genes are considered molecularly heterogeneous, displaying hundreds of different disease-causing sequence alterations, founder mutations have been identified in certain populations. In some Latin American countries, founder mutations associated with increased risk of breast and other cancers have been described. This is particularly interesting considering that in most of these countries, populations are highly admixed with genetic contributions from native populations and from the in-flux of several distinct populations of immigrants. In this article, we present a review of the scientific literature on the subject and describe current data available on founder mutations described in the most common breast cancer predisposition genes: BRCA1, BRCA2 and TP53.

Prevalence of BRCA1 and BRCA2 mutations in unselected breast cancer patients from medellín, Colombia

BACKGROUND

Approximately 5% of all breast cancers can be attributed to a mutation in the BRCA1 or BRCA2 gene. The genetic component of breast cancer in Colombia has been, for the most part, studied on cases from the Bogota region. Five different founder mutations were in two studies of breast cancer patients in the Bogota region. It is important that the frequency of mutations be established among unselected cases of breast cancer of other regions of Colombia in order to estimate the genetic burden of this cancer in Colombia and to plan genetic services. The aim of this study was to establish the mutation frequencies of the BRCA genes in breast cancer patients unselected for family history or age, from Medellin, Colombia.

METHODS

We enrolled 280 unselected women with breast cancer from a large public hospital in Medellin, Colombia. A detailed family history from each patient and a blood sample was obtained and processed for DNA analysis. Mutations in BRCA1 and BRCA2 were sought using a combination of techniques including a panel of recurrent Hispanic BRCA mutations which consists of fifty BRCA1 mutations and forty-six BRCA2 mutations, including the five recurrent Colombian BRCA mutations. All mutations were confirmed by direct sequencing.

RESULTS

Genetic testing was successfully completed for 244 of the 280 cases (87%). Among the 244 cases, three deleterious mutations were identified (two in BRCA1 and one in BRCA2) representing 1.2% of the total. The average age of breast cancer in the mutation-positive cases was 34 years. The two BRCA1 mutations were known founder mutations (3450del4 in exon 11 and A1708E in exon 18). The BRCA2 mutation was in exon 11 (5844del5) and has not been previously reported in individuals of Colombian descent. Among the three mutation-positive families was a breast cancer family and two families with no history of breast or ovarian cancer.

CONCLUSION

The frequency of BRCA mutations in unselected breast cancer cases from the Medellin region of Colombia is low and is approximately 1.2%.

A comprehensive focus on global spectrum of BRCA1 and BRCA2 mutations in breast cancer

Breast cancer (BC) is the most common cancer of women all over the world. BRCA1 and BRCA2 gene mutations comprise the most important genetic susceptibility of BC. Except for few common mutations, the spectrum of BRCA1 and BRCA2 mutations is heterogeneous in diverse populations. 185AGdel and 5382insC are the most important BRCA1 and BRCA2 alterations which have been encountered in most of the populations. After those Ashkenazi founder mutations, 300T>G also demonstrated sparse frequency in African American and European populations. This review affords quick access to the most frequent alterations among various populations which could be helpful in BRCA screening programs.

Timing of referral for genetic counseling and genetic testing in patients with ovarian, fallopian tube, or primary peritoneal carcinoma

OBJECTIVE

The objective of this study was to assess patients' preferences of the timing of referral for genetic counseling and testing in relation to the diagnosis, treatment, and recurrence of ovarian, tubal, or primary peritoneal cancers.

METHODS

Ninety-two patients who underwent counseling and testing by 1 certified genetic counselor were identified. An introductory letter, consent form, and questionnaire were mailed to gather information regarding factors influencing the decision to undergo genetic counseling and testing and opinions regarding optimal timing. Medical records were reviewed for demographic and clinical data.

RESULTS

Of 47 consenting women, 45 underwent testing. Eight (18%) were found to have a genetic mutation. Women lacked consensus about the optimal time for referral for and to undergo genetic testing, although women with stage I disease preferred testing after completion of chemotherapy. Most women were comfortable receiving the results by phone, but one third preferred an office visit.

CONCLUSIONS

Patients' views regarding the best time to be referred for and undergo counseling and testing varied greatly. Because of the high mortality of this disease, clinicians should discuss referral early and personalize the timing to each patient. The subset of patients who prefer results disclosure during an office visit should be identified at the time of their initial counseling.

Planning cancer control in Latin America and the Caribbean

Non-communicable diseases, including cancer, are overtaking infectious disease as the leading health-care threat in middle-income and low-income countries. Latin American and Caribbean countries are struggling to respond to increasing morbidity and death from advanced disease. Health ministries and health-care systems in these countries face many challenges caring for patients with advanced cancer: inadequate funding; inequitable distribution of resources and services; inadequate numbers, training, and distribution of health-care personnel and equipment; lack of adequate care for many populations based on socioeconomic, geographic, ethnic, and other factors; and current systems geared toward the needs of wealthy, urban minorities at a cost to the entire population. This burgeoning cancer problem threatens to cause widespread suffering and economic peril to the countries of Latin America. Prompt and deliberate actions must be taken to avoid this scenario. Increasing efforts towards prevention of cancer and avoidance of advanced, stage IV disease will reduce suffering and mortality and will make overall cancer care more affordable. We hope the findings of our Commission and our recommendations will inspire Latin American stakeholders to redouble their efforts to address this increasing cancer burden and to prevent it from worsening and threatening their societies.