BRCA1/2 germline mutations and their clinical importance in Turkish breast cancer patients

Experiences of BRCA1/2 Gene Mutation-Positive Women With Cancer in Communicating Genetic Risk to Their Relatives

BACKGROUND

When a woman is diagnosed with hereditary breast or ovarian cancer, family members may be at high risk of cancers associated with BRCA1/2 gene mutation and benefit from disclosure of the genetic test result. This duty of informing relatives may be distressing, or relatives may not be properly informed.

OBJECTIVE

To qualitatively describe breast cancer patients' experiences communicating genetic risk of cancer to their relatives.

METHODS

Probands with BRCA1/2 gene mutations were recruited from an oncology institute in Istanbul, Turkey, and interviewed by telephone. Qualitative content analysis was conducted to derive central elements of the 30 women's experiences communicating genetic risk to their relatives.

RESULTS

Six themes were identified: response to genetic test results, reason for communication, feelings about communication, reflection after communication, results of communication, and needs.

CONCLUSION

Women with cancer found to have BRCA1/2 gene mutations tended to share their genetic test results within the family. The main motives for sharing test results were the desire to encourage relatives to get tested and moral and ethical convictions. Women needed explicit information regarding cancer risk and risk-reducing strategies to act upon.

IMPLICATIONS FOR PRACTICE

The women's feelings and reflections about the communication process were varied and suggest that personalized genetic risk communication interventions may better support women with BRCA1/2 gene mutations during and after communication with relatives. Long-term follow-up of those women is essential because of the need for informed decision on risk-reducing strategies.

Whole-exome sequencing reveals the etiology of the rare primary hepatic mucoepidermoid carcinoma

Background

Primary hepatic mucoepidermoid carcinoma (HMEC) is extremely rare and the molecular etiology is still unknown. The CRTC1-MAML2 fusion gene was previously detected in a primary HMEC, which is often associated with MEC of salivary gland in the literature.

Methods

A 64-year-old male was diagnosed with HMEC based on malignant squamous cells and mucus-secreting cells in immunohistochemical examination. Fluorescence in situ hybridization (FISH) was used to detect the CRTC1-MAML2 fusion gene in HMEC. Whole-exome sequencing and Sanger sequencing were used to reveal the molecular characteristics of HMEC and analysis was performed with public data. Pedigree investigation was performed to identify susceptibility genes.

Results

Hematoxylin–eosin staining and immunohistochemistry revealed that the tumor cells were composed of malignant epidermoid malignant cells and mucous cells, indicating a diagnosis of HMEC. The CRTC1-MAML2 fusion gene was not detected in the primary HMEC, and somatic mutations in GNAS, KMT2C and ELF3 genes were identified by sequencing. Analyses of public data revealed somatic GNAS alterations in 2.1% hepatobiliary tumors and relation with parasite infection. Heterozygous germline mutations of FANCA, FANCI, FANCJ/BRIP1 and FAN1 genes were also identified. Pedigree investigation verified that mutation of Fanconi’s anemia susceptibility genes were present in the pedigree.

Conclusions

Here we provide the first evidence of the molecular etiology of a rare HMEC associated with germline Fanconi’s anemia gene mutations and somatic GNAS R201H mutation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-021-01086-3.

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.

The NCCN Criterion "Young Age at Onset" Alone is Not an Indicator of Hereditary Breast Cancer in Iranian Population

Because the contribution of genetic factors to the burden of breast cancer is not well investigated in Iran, we aimed to examine the prevalence of mutations in breast cancer susceptibility genes, BRCA1/2 and PALB2, and to investigate the predictive potential of hereditary breast cancer risk criteria for genetic testing in Iranian population. Next-generation sequencing was conducted on a population consisting of 299 and 125 patients with breast cancer, with and without hereditary cancer risk criteria for genetic testing, respectively. The pathogenic mutation frequency rate was 10.7% in patients with hereditary cancer criteria versus 1.6% in no criteria group (P = 0.0017). None of the 107 tested patients with only young age at onset (<40) criterion had a pathogenic mutation. Patients who had only a single heritable risk criterion [OR, 6.15; 95% confidence interval (CI), 1.26-58.59; P = 0.009] and patients with multiple heritable risk criteria (OR, 22.5; 95% CI, 5.19-201.31; P < 0.0001) had higher probabilities of carrying a mutation compared with no criteria group. Our results showed that young age at onset alone is not an indicator of hereditary breast cancer at least in the Iranian population. This is while women with multiple hereditary breast cancer risk criteria were enriched for BRCA1/2 mutations. Given such high risk of identification of a disease-causing mutation, multiple hereditary criteria should be regarded as a strong predictor for a hereditary breast cancer syndrome. These findings are important concerning the optimization of genetic counseling and furthermore establishing criteria for BRCA1/2 testing of the Iranian population.

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

Background

The guidelines recommend considering the BRCA1 and BRCA2 germline mutations in female patients with breast carcinomas. In this retrospective study, the BRCA1/2 mutation prevalence in high-risk breast carcinoma patients in a Turkish population was investigated.

Materials and Methods

In high genetic risk breast carcinoma patients, the BRCA1 and BRCA2 germline mutations were identified by applying next-generation sequencing.

Results

The results showed BRCA1/2 mutations in 19% of the total patients. In those with first-degree relatives with breast carcinoma histories, the BRCA1/2 mutation prevalence was also 19%. In the patients younger than 40 years old, the BRCA1/2 mutation prevalence was 19.5%. In the triple-negative breast carcinoma patients younger than 60 years old, the BRCA1/2 mutation prevalence was 24.2%. In the patients younger than 40 years old with triple-negative breast carcinomas, BRCA1/2 mutation positivity was found in 37.5% of the patients. Overall, in the Turkish population, the BRCA1/2 mutation prevalence ranges from 19% to 37% in patients with high-risk breast carcinomas.

Conclusion

It is recommended to check for BRCA1/2 mutations in all high-risk breast carcinoma patients in the Turkish population.

BRCA1 and BRCA2 germline variants in breast cancer patients from the Republic of Macedonia

PURPOSE

We aimed to establish the spectrum of BRCA1/2 mutations among the breast cancer (BC) patients from the Republic of Macedonia.

METHODS

We used targeted next-generation sequencing (NGS), Sanger DNA sequencing, and multiplex ligation probe amplification analysis (MLPA) to search for point mutations and deletions/duplications involving BRCA1 and BRCA2-coding regions.

RESULTS

We have analyzed a total of 313 BC patients, enriched for family history of cancer, early age of onset and bilateral and/or triple negative (TN) BC. A total of 26 pathogenic mutations were observed in 49 unrelated BC patients (49/313, 15.7%). BRCA2 mutations (27/49, 55.1%) were more common than BRCA1 mutations (22/49, 44.9%). We identified five novel point mutations, one in BRCA1 (c.4352_4356delA) and four in BRCA2 (c.151G>T, c.4707_4708delCA, c.7811_7814delTGTG, and c.9304_9305delG), as well as two novel deletions involving parts of the BRCA1 gene (c.81-?_593+?del and c.5470-?_5530+?del). The most common mutations were c.181T>G, c.5266dupC, and c.3700_3704del5 in BRCA1 and c.7879A>T, c.8317_8330del14 and c.5722_5723delCT in BRCA2 gene. Thus far, BRCA2 c.7879A>T and c.8317_8330del14 mutations have been described in several isolated cases; however, our study is the first one showing that they have a founder effect among Macedonian population. Nine recurrent mutations account for 65.3% of all of the detected mutations allowing for implementation of a fast first-step BRCA1/2 mutational screening strategy in our country.

CONCLUSION

This study provides a comprehensive view of known and novel BRCA1/2 mutations in BC patients from the Republic of Macedonia and contributes to the global spectrum of BRCA1/2 mutations in breast cancer.

Current guidelines for BRCA testing of breast cancer patients are insufficient to detect all mutation carriers

Background

Identification of BRCA mutations in breast cancer (BC) patients influences treatment and survival and may be of importance for their relatives. Testing is often restricted to women fulfilling high-risk criteria. However, there is limited knowledge of the sensitivity of such a strategy, and of the clinical aspects of BC caused by BRCA mutations in less selected BC cohorts. The aim of this report was to address these issues by evaluating the results of BRCA testing of BC patients in South-Eastern Norway.

Methods

1371 newly diagnosed BC patients were tested with sequencing and Multi Ligation Probe Amplification (MLPA). Prevalence of mutations was calculated, and BC characteristics among carriers and non-carriers compared. Sensitivity and specificity of common guidelines for BRCA testing to identify carriers was analyzed. Number of identified female mutation positive relatives was evaluated.

Results

A pathogenic BRCA mutation was identified in 3.1%. Carriers differed from non-carriers in terms of age at diagnosis, family history, grade, ER/PR-status, triple negativity (TNBC) and Ki67, but not in HER2 and TNM status. One mutation positive female relative was identified per mutation positive BC patient. Using age of onset below 40 or TNBC as criteria for testing identified 32-34% of carriers. Common guidelines for testing identified 45-90%, and testing all below 60 years identified 90%. Thirty-seven percent of carriers had a family history of cancer that would have qualified for predictive BRCA testing. A Variant of Uncertain Significance (VUS) was identified in 4.9%.

Conclusions

Mutation positive BC patients differed as a group from mutation negative. However, the commonly used guidelines for testing were insufficient to detect all mutation carriers in the BC cohort. Thirty-seven percent had a family history of cancer that would have qualified for predictive testing before they were diagnosed with BC. Based on our combined observations, we suggest it is time to discuss whether all BC patients should be offered BRCA testing, both to optimize treatment and improve survival for these women, but also to enable identification of healthy mutation carriers within their families. Health services need to be aware of referral possibility for healthy women with cancer in their family.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3422-2) contains supplementary material, which is available to authorized users.

Mutation analysis of the PARKIN, PINK1, DJ1, and SNCA genes in Turkish early-onset Parkinson's patients and genotype-phenotype correlations

OBJECTIVE

Variations in PARK genes (PRKN, PINK1, DJ-1, and SNCA) cause early-onset Parkinson's disease (EOPD) in different populations. In the current study, we aimed to evaluate the frequencies of variations in PARK genes and the effects of these variations on the phenotypes of Turkish EOPD patients.

METHODS

All coding regions and exon-intron boundaries of the PRKN, PINK1, DJ-1, and SNCA genes were screened by heteroduplex analysis followed by direct sequencing of the detected variants in 50 Turkish EOPD patients. These variants were evaluated using SIFT, PolyPhen, HSF, and LOVD web-based programs.

RESULTS

The frequency of EOPD-associated variations in the PRKN gene was 34%. Among these variations, p.A82E in exon 3 and p.Q409X in exon 11 was determined to be pathogenic. We also defined previously unknown cryptic variations, including c.872-35 G>A and c.872-28T>G in exon 8 of PRKN and c.252+30 T>G and c.322+4 A>G in exons 4 and 5 of DJ1, respectively, that were associated with EOPD. Although no significant association was observed between the PARK gene mutations and clinical features (P>0.05), the alterations were related to the clinical symptoms in each patient.

CONCLUSION

An increasing number of studies report that PRKN, PINK1, DJ1 and SNCA mutations are associated with early-onset Parkinson's disease; however, a limited number of studies have been conducted in Turkey. Additionally, our study is the first to evaluate the frequency of SNCA mutations in a Turkish population. The aim of this study was determine the frequency distributions of the PRKN, PINK1, DJ1, and SNCA gene mutations and to analyze the relationships between these genetic variations and the clinical phenotype of EOPD in Turkish patients.

Molecular analysis of a male breast cancer patient with prolonged stable disease under mTOR/PI3K inhibitors BEZ235/everolimus

The mTORC1 inhibitor everolimus (Afinitor/RAD001) has been approved for multiple cancer indications, including ER⁺/HER2⁻ metastatic breast cancer. However, the combination of everolimus with the dual PI3K/mTOR inhibitor BEZ235 was shown to be more efficacious than either everolimus or BEZ235 alone in preclinical models. Herein, we describe a male breast cancer (MBC) patient who was diagnosed with hormone receptor-positive (HR⁺)/HER2⁻ stage IIIA invasive ductal carcinoma and sequentially treated with chemoradiotherapy and hormonal therapy. Upon the development of metastases, the patient began a 200 mg twice-daily BEZ235 and 2.5 mg weekly everolimus combination regimen. The patient sustained a prolonged stable disease of 18 mo while undergoing the therapy, before his tumor progressed again. Therefore, we sought to both better understand MBC and investigate the underlying molecular mechanisms of the patient's sensitivity and subsequent resistance to the BEZ235/everolimus combination therapy. Genomic and immunohistochemical analyses were performed on samples collected from the initial invasive ductal carcinoma pretreatment and a metastasis postprogression on the BEZ235/everolimus combination treatment. Both tumors were relatively quiet genomically with no overlap to recurrent MBC alterations in the literature. Markers of PI3K/mTOR pathway hyperactivation were not identified in the pretreatment sample, which complements previous reports of HR⁺ female breast cancers being responsive to mTOR inhibition without this activation. The postprogression sample, however, demonstrated greater than fivefold increased estrogen receptor and pathogenesis-related protein expression, which could have constrained the PI3K/mTOR pathway inhibition by BEZ235/everolimus. Overall, these analyses have augmented the limited episteme on MBC genetics and treatment.

BRCA1 and BRCA2 sequence variations detected with next-generation sequencing in patients with premature ovarian insufficiency

OBJECTIVE

Although the association between BRCA1 and BRCA2 gene mutations and breast and ovarian cancer is known, there is insufficient data about premature ovarian insufficiency (POI). However, several studies have reported that there might be a relationship between POI and BRCA1 and BRCA2 gene mutation. Therefore, in the present study, we aimed to investigate the role of BRCA1 and BRCA2 gene mutations in the etiology of POI in a Turkish population.

MATERIAL AND METHODS

The cohort was classified into two groups: a study group, consisting of 56 individuals diagnosed with premature ovarian insufficiency (and who were younger than 40 years of age, had an antral follicle count <3-5, and FSH levels >12 IU/I), and a control group, consisting of 45 fertile individuals. A total of 101 individuals were analyzed by next-generation sequencing to detect BRCA1 and BRCA2 gene mutations.

RESULTS

We detected four new variations (p.T1246N and p.R1835Q in BRCA1 and p.I3312V and IVS-7T>A in BRCA2) that had not been reported before.

CONCLUSION

We did not find an association between the BRCA1 and BRCA2 gene mutations and premature ovarian insufficiency. However, larger, functional studies are needed to clarify the association.

Expression status of let-7a and miR-335 among breast tumors in patients with and without germ-line BRCA mutations

The genetic factors of cancer predisposition remain elusive in the majority of familial and/or early-onset cases of breast cancer (BC). This type of BC is promoted by germ-line mutations that inactivate BRCA1 or BRCA2. On the other hand, recent studies have indicated that alterations in the levels of miRNA expression are linked to this disease. Although BRCA1 and BRCA2 gene mutations have been reported to commonly lead to alterations in genes that encode cancer-related proteins, little is known regarding the putative impact of these mutations on noncoding miRNAs. In the present study, we aimed to determine whether miRNA dysregulation is involved in the pathogenesis of BRCA-mutated BC. An expression analysis of 14 human miRNAs previously shown to be related to BC diagnosis, prognosis, and drug resistance was conducted using tissues from 60 familial and/or early-onset patients whose peripheral blood samples had been screened for BRCA1 and BRCA2 mutations through sequence analysis. Let-7a and miR-335 expression levels were significantly downregulated in the tumors of patients with a BRCA mutation compared with those of patients without a BRCA mutation (P = 0.04 and P = 0.02, respectively). Our results defined the associations between the expression status of let-7a and miR-335 and BRCA mutations. The expression analysis of these miRNAs might be used as biomarkers of the BRCA mutation status of early-onset and/or familial BC.