Germline Mutations in BRCA1 and BRCA2 in Breast Cancer Patients with High Genetic Risk in Turkish Population

Breast Cancer High-Penetrance Genes BRCA1 and BRCA2 Mutations Using Next-Generation Sequencing Among Iraqi Kurdish Women

Background BRCA1 and BRCA2 genes are the main high-penetrance genes that are responsible for most cases of inherited breast cancer. The present study aimed to detect the frequencies of inherited breast cancer caused by BRCA1 and BRCA2 genes among Kurdish breast cancer patients, including all the exome of these two genes, using next-generation sequencing (NGS). Methodology Seventy women who were diagnosed with breast cancer and registered at Nanakali Hospital in Erbil, Iraq, were included. Blood samples were collected for molecular testing (polymerase chain reaction (PCR)) targeting all exomes of BRCA1 and BRCA2 genes. All exome regions are sequenced by NGS using the Miseq system (Illumina Inc., San Diego, CA). Obtained data were visualized using Integrative Genomics Viewer (IGV 2.3 Software, Broad Institute, Cambridge, MA). Data were interpreted based on the National Center for Biotechnology Information (NCBI), Clinically Relevant Variation (ClinVar) archives, and other databases. Results Among 70 samples, more than forty-two variants have been detected, 20 on BRCA1 and 22 on BRCA2. Regarding clinical significance, six (14.28%) variants were pathogenic, four of them on the BRCA1 gene, which were: c.3607C>T, c.3544C>T, c.68_69del, and c.224_227delAAAG, and two pathogenic variants were on BRCA2 gene: c.100G>T, and c.1813delA. Also, two (4.76%) variants were conflict interpretations of pathogenicity, one (2.38%) was a variant of uncertain significant VUS, and the rest 29 (69%) variants were benign. In addition, four new variants (three in BRCA1 and one in BRCA2 gene), never previously reported, were identified. Conclusions In conclusion, analyzing the BRCA1/2 genes provide a better prediction for the risk of developing breast cancer in the future. Variant types and frequencies differ among different populations and ethnicities, the common mutations worldwide may not be prevalent in the Kurdish population. The current research findings will be useful for future screening studies of these two genes in the Kurdish population.

Factors associated with psychological distress during genetic counseling in high-risk women with breast cancer in Turkey

PURPOSE

This study aims to shed light on the rather neglected area of research of psychological distress in women facing genetic counselling in Turkey, where few institutions providing such counselling exist.

METHODS

105 breast cancer patients presenting for genetic testing completed a sociodemographic and clinical questionnaire as well as validated structured questionnaires including the Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory (STAI-S/T) and the Health Motivation Sub-dimension of Champion's Health Belief Model Scale.

RESULTS

69.5% of the participants had lost a family member from cancer; 80% said the term "cancer" elicited negative thoughts (e.g., death, fear, and incurable disease). 62.9% and 37.1% attributed cancer to stress or sorrow, and genetic susceptibility, respectively. There was a negative association between health motivation and BDI scores (r:-0.433, p < 0.001). Married individuals had higher BDI and STAI-S scores (p = 0.001, p = 0.01 respectively), as well as lower STAI-T scores (p = 0.006). BDI, STAI-S and STAI-T scores were higher in those refusing genetic testing (p < 0.001, p < 0.001, p = 0.003 respectively) and those with metastases (p = 0.03, p = 0.01, p = 0.03 respectively). Furthermore, individuals with low health motivation were more likely to exhibit high BDI scores (p < 0.001) and low STAI-T scores (p = 0.02).

CONCLUSION

Common perceptions and beliefs about cancer and genetic testing during genetic counselling were found to have a negative impact on distress in high-risk women with breast cancer. The negative relationship between psychological distress and health motivation may reduce patients' compliance with genetic counselling recommendations. A comprehensive psychological evaluation should be considered as an important part of genetic counselling.

BRCA Mutations and MicroRNA Expression Patterns in the Peripheral Blood of Breast Cancer Patients

Breast cancer (BC) persists as the predominant malignancy globally, standing as the foremost cause of cancer-related mortality among women. Despite notable advancements in prevention and treatment, encompassing the incorporation of targeted immunotherapies, a continued imperative exists for the development of innovative methodologies. These methodologies would facilitate the identification of women at heightened risk, enhance the optimization of therapeutic approaches, and enable the vigilant monitoring of emergent treatment resistance. Circulating microRNAs (miRNAs), found either freely circulating in the bloodstream or encapsulated within extracellular vesicles, have exhibited substantial promise for diverse clinical applications. These applications range from diagnostic and prognostic assessments to predictive purposes. This study aimed to explore the potential associations between BRCA mutations and specific miRNAs (miR-21, miR-155, miR-126, and miR-200c) expression that are known to be dysregulated in BC patient samples. Our findings indicate a robust correlation between miRNA expression status and disease subtypes. We found a correlation between the expression status of miRNAs and distinct disease subtypes. Intriguingly, however, no significant associations were discerned between disease status, subtypes, or miRNA expression levels and the presence of BRCA mutations. To advance the validation of miRNAs as clinically relevant biomarkers, additional investigations within larger and meticulously selected patient cohorts are deemed imperative. These microRNA entities hold the potential to emerge as groundbreaking and readily accessible tools, poised for seamless integration into the landscape of clinical practice.

Exploring the contrasts: in-depth analysis of human and canine mammary tumors - discoveries at the frontier

We have examined genomic and transcriptomic abnormalities in human and canine samples to evaluate the canine model's validity for breast cancer research, emphasizing similarities and differences. Both species commonly utilize serum tumor markers and noncoding microRNAs. Immunohistochemistry and immunocytochemistry were employed to illustrate and compare results based on histological diagnoses. In addition to these factors, similarities exist in spontaneous tumor occurrence, age of onset, hormonal influences, and disease progression, including tumor size, clinical stage, and lymph node involvement. Molecular traits such as hormone receptor status, Epidermal Growth Factor Receptor (EGFR), and proliferation markers (Ki67) further endorse the canine model's utility in breast cancer studies. The advancement of technologies facilitates the identification of new cancer-associated molecules, both coding and non-coding genes, underscoring their potential as prognostic/diagnostic biomarkers and therapeutic targets.

Frequency of germline pathogenic variants in breast cancer predisposition genes among young Turkish breast cancer patients

PURPOSE

One of the most important risk factors for hereditary breast and ovarian cancer is young age. We aim to report the frequency of pathogenic/likely pathogenic variants in breast cancer predisposing genes in young (≤ 40 years old) breast cancer patients who undergone 26-gene inherited cancer panel at our Breast Health Center.

METHODS

Medical records of breast cancer patients who were referred to genetic counseling based on NCCN criteria and were ≤ 40 years of age are reviewed. The frequency of germline pathogenic/likely pathogenic variants who undergone 26-gene inherited cancer panel was analyzed.

RESULTS

Among 414 breast cancer patients who were ≤ 40 years of age, 308 undergone 26-gene inherited cancer panel and 108 had next generation sequencing (NGS)-based BRCA 1 and 2 genetic testing. Median age was 35 (22-40), Family history in first degree relatives was present in 14% of patients. Forty-five percent of patients met one of the NCCN criteria for genetic testing, 41% of them met two criteria, and 14% of patients fulfilled ≥ 3 criteria. Seventy pathogenic/likely pathogenic variants (PV/LPV) were found in 65 (21%) patients. PV/LPs in BRCA genes and non-BRCA genes represented 53% and 44% of all PV/LPVs, accounting for 12% and 10% of patients in the study cohort respectively. Two PVs were present in 5 patients and eleven PVs were novel. The most common PVs were in BRCA 1 (n:18), BRCA 2 (n:19), ATM (n:7), CHEK2 (n:7) and TP53 (n:5) genes. Thirty-one percent of the patients with triple-negative tumors and 25% of the patients with hormone receptor-positive tumors had PV/LPVs with panel testing. Family history in first degree relatives (p = 0.029), the number of met NCCN criteria (p = 0.036) and axillary nodal involvement (p = 0.000) were more common in patients with PVs. When combined with patient group (n:106) who had only BRCA1 and 2 gene testing, 16% of Turkish breast cancer patients ≤ 40 years of age had PVs in BRCA genes.

CONCLUSION

One fifth of Turkish breast cancer patients ≤ 40 years of age had at least one PV/LPV in breast cancer predisposing genes with 26-gene inherited cancer panel. The frequency of PV/LPVs was higher in triple-negative young-onset patients compared to hormone receptor and Her-2 positive subtypes. Our findings regarding to frequency PV/LPVs in BRCA 1/2 and non-BRCA genes in young-onset breast cancer patients are in line with the literature.

Management of breast cancer patients with BRCA gene mutations in Jordan: perspectives and challenges

BACKGROUND

This paper explores and discusses local challenges oncologists face for diagnosing and managing breast cancer patients with BRCA gene mutations in Jordan.

METHODS

A task force involving key opinion leaders, experts in the management of breast cancer, and stakeholders in healthcare systems where genetic testing is available in Jordan discussed current evidence and local real-life practice. The task force then formulated recommendations to achieve better patient outcomes and satisfaction based on evidence-based medicine and their clinical experience in BRCA-mutated breast cancer management.

RESULTS AND CONCLUSION

Eligibility of patients for genetic testing, physician acceptance and willingness to integrate genetic testing into routine practice is encouraging but remains restricted by testing availability and financial coverage. Until more data is available, genetic testing should be targeted for breast cancer patients based on tumor subtypes, as well as family and personal history of cancer, as per international guidelines. Whenever possible, genetic testing should aim to detect all actionable genes through a multigene panel including BRCA1/2. Major challenges faced in clinical practice in Jordan include fear of genetic discrimination and social stigmatization, as well as hesitancy toward risk-reducing surgery. Pre-testing counseling is therefore critical to promote acceptance of genetic testing. Since geneticists are in short supply in Jordan, genetic counseling can be offered through a specially trained genetic counselor or through a hybrid system that includes oncologist-based counselling. In addition to cancer prevention, germline genetic testing may assist in the selection of specific anti-cancer therapy, such as PARP inhibitors, in patients with BRCA1/2 mutation. Nationwide initiatives are also needed to ensure access to PARP inhibition therapy and provide financial coverage for genetic screening, mastectomies and reconstructive surgery across Jordan.

Analysis of pathogenic variants in BRCA1 and BRCA2 genes using next-generation sequencing in women with triple negative breast cancer from South India

BACKGROUND

The frequency of triple-negative breast cancer (TNBC) incidence varies among different populations suggesting the involvement of genetic components towards TNBC development. Previous studies have reported that BRCA1/2 germline mutations confer a lifetime risk of developing TNBC. However, there is hardly any information regarding the common pathogenic variants (PVs) in BRCA1/2 genes that contribute to TNBC in the Indian population. Hence, we screened for PVs in BRCA1/2 and their association with clinico-pathological features in TNBC patients.

METHODS AND RESULTS

The study recruited 59 TNBC patients without hereditary breast and ovarian cancer (HBOC) from South India. The entire BRCA1 and BRCA2 genes were sequenced for the 59 patients using the Illumina HiSeq X Ten sequencer. Among the 59 TNBC genomic DNA samples sequenced, BRCA mutations were identified in 8 patients (13.6%), BRCA1 mutations in 6 patients, and BRCA2 mutations in 2 patients. Among the 6 BRCA1 mutations, three were c.68_69delAG (185delAG) mutation. Remarkably, all the TNBC patients with BRCA mutations exhibited higher-grade tumors (grade 2 or 3). However, among all the BRCA mutation carriers, only one patient with a BRCA2 mutation (p.Glu1879Lys) developed metastasis.

CONCLUSION

Our data advocates that South Indian women with higher grade TNBC tumors and without HBOC could be considered for BRCA mutation screening, thereby enabling enhanced decision-making and preventive therapy.

Prevalence of specific and recurrent/founder pathogenic variants in BRCA genes in breast and ovarian cancer in North Africa

Background

Elucidation of specific and recurrent/founder pathogenic variants (PVs) in BRCA (BRCA1 and BRCA2) genes can make the genetic testing, for breast cancer (BC) and/or ovarian cancer (OC), affordable for developing nations.

Methods

To establish the knowledge about BRCA PVs and to determine the prevalence of the specific and recurrent/founder variants in BRCA genes in BC and/or OC women in North Africa, a systematic review was conducted in Morocco, Algeria, and Tunisia.

Results

Search of the databases yielded 25 relevant references, including eleven studies in Morocco, five in Algeria, and nine in Tunisia. Overall, 15 studies investigated both BRCA1 and BRCA2 genes, four studies examined the entire coding region of the BRCA1 gene, and six studies in which the analysis was limited to a few BRCA1 and/or BRCA2 exons. Overall, 76 PVs (44 in BRCA1 and32 in BRCA2) were identified in 196 BC and/or OC patients (129 BRCA1 and 67 BRCA2 carriers). Eighteen of the 76 (23.7%) PVs [10/44 (22.7%) in BRCA1 and 8/32 (25%) in BRCA2] were reported for the first time and considered to be novel PVs. Among those identified as unlikely to be of North African origin, the BRCA1 c.68_69del and BRCA1 c.5266dupC Jewish founder alleles and PVs that have been reported as recurrent/founder variants in European populations (ex: BRCA1 c.181T>G, BRCA1 c1016dupA). The most well characterized PVs are four in BRCA1 gene [c.211dupA (14.7%), c.798_799detTT (14%), c.5266dup (8.5%), c.5309G>T (7.8%), c.3279delC (4.7%)] and one in BRCA2 [c.1310_1313detAAGA (38.9%)]. The c.211dupA and c.5309G>T PVs were identified as specific founder variants in Tunisia and Morocco, accounting for 35.2% (19/54) and 20.4% (10/49) of total established BRCA1 PVs, respectively. c.798_799delTT variant was identified in 14% (18/129) of all BRCA1 North African carriers, suggesting a founder allele. A broad spectrum of recurrent variants including BRCA1 3279delC, BRCA1 c.5266dup and BRCA2 c.1310_1313detAAGA was detected in 42 patients. BRCA1 founder variants explain around 36.4% (47/129) of BC and outnumber BRCA2 founder variants by a ratio of ≈3:1.

Conclusions

Testing BC and/or OC patients for the panel of specific and recurrent/founder PVs might be the most cost-effective molecular diagnosis strategy.

A Review of Breast Cancer Risk Factors in Adolescents and Young Adults

Simple Summary

Cancer diagnosed in patients between the ages of 15 and 39 deserves special consideration. Diagnoses within this cohort of adolescents and young adults include childhood cancers which present at an older age than expected, or an early presentation of cancers that are typically observed in older adults, such as breast cancer. Cancers within this age group are associated with worse disease-free and overall survival rates, and the incidence of these cases are rising. Knowing an individual’s susceptibility to disease can change their clinical management and allow for the risk-testing of relatives. This review discusses the risk factors that contribute to breast cancer in this unique cohort of patients, including inherited genetic risk factors, as well as environmental and lifestyle factors. We also describe risk models that allow clinicians to quantify a patient’s lifetime risk of developing disease.

Abstract

Cancer in adolescents and young adults (AYAs) deserves special consideration for several reasons. AYA cancers encompass paediatric malignancies that present at an older age than expected, or early-onset of cancers that are typically observed in adults. However, disease diagnosed in the AYA population is distinct to those same cancers which are diagnosed in a paediatric or older adult setting. Worse disease-free and overall survival outcomes are observed in the AYA setting, and the incidence of AYA cancers is increasing. Knowledge of an individual’s underlying cancer predisposition can influence their clinical care and may facilitate early tumour surveillance strategies and cascade testing of at-risk relatives. This information can further influence reproductive decision making. In this review we discuss the risk factors contributing to AYA breast cancer, such as heritable predisposition, environmental, and lifestyle factors. We also describe a number of risk models which incorporate genetic factors that aid clinicians in quantifying an individual’s lifetime risk of disease.

Clinical and Pathological Characteristics of Patients with High-Risk Breast Cancer Based on BRCA Mutation Profiles: A Retrospective Study

Objective

This study aimed to determine the differences in clinicopathological features of Turkish patients with high-risk breast cancer based on the mutation status of two breast cancer susceptibility genes (BRCA1/2) .

Materials and Methods

This study enrolled patients with invasive breast cancer who have been evaluated for BRCA1/2 mutations due to the presence of high-risk factors admitted to two tertiary referral centers in Turkey. Clinical and histopathological features were analyzed in BRCA1 mutation carriers, BRCA2 mutation carriers, and non-carriers.

Results

A total of 302 patients with a mean age of 44.2±9.9 (22-82) years were included. BRCA1/2 mutation was found in 75 (24%) patients, of whom 41 (13.6%) were BRCA1 mutation carriers and 37 (12.3%) were BRCA2 mutation carriers. Moreover, 104 (34.4%) and 4 (1.3%) patients had family history of breast and ovarian carcinoma, respectively. The rates of triple negativity (56.1%), histologic grade 3 (65.9%), and lymphovascular invasion (78%) were significantly higher in BRCA1 mutation carriers than in non-carriers and BRCA2 mutation carriers. Furthermore, 87% of triple-negative BRCA1 mutation carriers had histologic grade 3 tumors compared with 38.9% in non-triple-negative BRCA1 mutation carriers, and the difference was significant.

Conclusion

Findings of this study showed that BRCA1-related breast cancers represent a distinct group with unique pathological features, which are usually associated with a poor prognosis.

Identification of a novel germline BRCA2 variant in a Chinese breast cancer family

Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer-related deaths in women worldwide. In this study, a large Chinese pedigree with breast cancer including a proband and two female patients was recruited and a familial history of breast cancer was collected by questionnaire. Clinicopathological assessments and neoadjuvant therapy-related information were obtained for the proband. Blood samples were taken, and gDNA was extracted. The BRCA1/2 and PALB2 genes were screened using next-generation sequencing by a targeted gene panel. We have successfully identified a novel, germline heterozygous, missense mutation of the gene BRCA2: c.7007G>T, p.R2336L, which is likely to be pathogenic in the proband and her elder sister who both had breast cancer. Furthermore, the risk factors for developing breast cancer in this family are discussed. Thus, genetic counselling and long-term follow-up should be provided for this family of breast cancer patients as well as carriers carrying a germline variant of BRCA2: c.7007G>T (p.R2336L).

Nutrition in the Prevention of Breast Cancer: A Middle Eastern Perspective

This paper reviews the escalating burden of breast cancer (BC) in the Middle East (ME) and the prevalence of modifiable risk factors and underscores opportunities to promote the prevention of the disease. Similar to more developed countries, BC is the most frequent cancer among women in countries of the ME, accounting for one-third of total cancer cases and 24% of total cancer deaths. Average age at BC diagnosis appears to be a decade earlier in Middle Eastern countries compared to the Western countries, and its incidence is predicted to further increase. Although incidence rates of BC are still lower in Middle Eastern countries than Western ones, mortality rates are similar and at times even higher. It is estimated that 30% of BC cases are due to environmental and lifestyle factors, such as obesity and diet and hence can be preventable. The ME suffers from surging rates of obesity, with eight of its countries ranking among the highest worldwide in obesity prevalence among adults aged 18 and above. ME countries with the highest prevalence of obesity that are among the top 20 worldwide include United Arab Emirates (UAE), Lebanon, Egypt, Libya, Qatar, Saudi Arabia, Jordan, and Kuwait with rates ranging from 30% in UAE to 37% in Kuwait. In parallel, studies in the ME have consistently showed a shift in dietary intake whereby traditional diets, rich in fruits and vegetables, are progressively eroding and being replaced by westernized diets high in energy and fat. Accumulating evidence is reporting convincing association between consumption of such westernized diets and higher BC risk. Addressing these risk factors and studying their association with BC in terms of their nature and magnitude in Middle Eastern countries could provide the basis for intervention strategies to lower the risk and alleviate the burden of BC in these countries.