Screening for ATM sequence alterations in African-American women diagnosed with breast cancer

Challenges to genetic testing for germline mutations associated with breast cancer among African Americans Authors

Inequities in preventive cancer screening, diagnosis, treatment, and inferior cancer outcomes continue to pose challenges across the cancer continuum. While the exact reasons for these inferior outcomes are unknown, multiple barriers to various domains of social determinants of health (SDOH) play a vital role, leading to inequities in cancer care. These include barriers to transportation, housing, and food insecurities, contributing to delays in preventive screening and treatment. Furthermore, aggressive biologies also exist across various racial profiles with accompanying germline mutations. For example, African Americans (AAs) have a higher incidence of triple-negative breast cancer subtype and a high prevalence of BRCA1/2 gene mutations, increasing the risk of multiple cancers, warranting high-risk screening for these populations. Unfortunately, other barriers, such as financial insecurities, low health literacy rates, and lack of awareness, lead to delays in cancer screening and genetic testing, even with available high-risk screening and risk reduction procedures. In addition, physicians receive minimal interdisciplinary training to address genetic assessment, interpretation of the results, and almost no additional training in addressing the unique needs of racial minorities, leading to suboptimal delivery of genetic assessment provision resources among AAs. In this review, we discuss the confluence of factors and barriers limiting genetic testing among AAs and highlight the prevalence of germline mutations associated with increased risk of breast cancer among AAs, reflecting the need for multi-panel germline testing as well as education regarding hereditary cancer risks in underserved minorities.

Breast Cancer Germline Genetic Counseling and Testing for Populations of African Heritage Globally: A Scoping Review on Research, Practice, and Bioethical Considerations

PURPOSE

Despite the disproportionately high risk of breast cancer among women of African heritage, little is known about the facilitators and barriers to implementing germline genetic testing and counseling (GT/C).

METHODS

This scoping review followed guidelines recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. Published manuscripts from database inception through 2021 were sourced from PubMed, Cumulative Index to Nursing and Allied Health Literature via EBSCO, Embase, Cochrane Library, and Scopus. Search terms were used to retrieve articles addressing (1) African heritage, (2) breast cancer, and (3) GT or GC. The screening involved abstract and title review and full-text review. Data were extracted for all articles meeting the inclusion criteria.

RESULTS

A total of 154 studies were included. Most studies that took place were conducted in the United States (71.4%), and most first authors (76.9%) were from the United States. GT was conducted in 73 (49.7%) studies. BRCA1/BRCA2 were the most commonly studied genes for germline mutations. GC was conducted in 49 studies (33.3%), and perspectives on GC were evaluated in 43 (29.3%). The use of racial/ethnic categories varied broadly, although African American was most common (40.1%). Racism was mentioned in three studies (2.0%).

CONCLUSION

There is a growing body of literature on GT/C for breast cancer in women of African heritage. Future studies on GT/C of African populations should consider increased clarity around racial/ethnic categorizations, continued community engagement, and intentional processes for informed consent.

The association between ATM variants and risk of breast cancer: a systematic review and meta-analysis

Background

Ataxia telangiectasia-mutated (ATM) gene contributes to repair damaged DNA and to regulate cell cycle; therefore, ATM variants seem to increase breast cancer risk; however, the results are controversial. So we conducted a systematic review and meta-analysis to clarify the pooled association between various ATM variants and the risk of breast cancer.

Methods

The relevant studies were searched through Scopus, Web of Science, PubMed and Cochrane. Stratified and subgroup analyses were performed to explore heterogeneity between studies and assess effects of study quality. The pooled estimates logarithm with standard error logarithm of odds ratio and relative risk with confidence interval were calculated.

Results

This study revealed that there is association between ATM variants and the risk of breast cancer; according to the seven adjusted case-control studies, OR of this association was estimated as 1.67 (95%CI: 0.73–3.82), according to nine unadjusted case-control studies, the crude OR was 2.27 (95% CI: 1.17–4.40) and according to two cohorts, the RR was estimated as 1.68 (95% CI: 1.17–2.40).

Conclusions

The ATM variants are associated with an increased risk of breast cancer that ATM V2424G mutation is detected as the most predisposing factor while ATM D1853V, L546V, and S707P variants have the least predictive ability.

Polymorphism rs1801516 (G > A) in the ATM gene is not associated with overall cancer risk: an updated meta-analysis

Objective

The ataxia telangiectasia mutated (ATM) gene contains a functional single nucleotide polymorphism (SNP) rs1801516 (G > A) that may be associated with cancer risk. This meta-analysis aimed to interrogate the relationship between rs1801516 and cancer occurrence and disease etiology.

Methods

We retrieved and identified the available case–control studies that met the inclusion criteria from the PubMed, Web of Science, and Embase databases. Odds ratio (OR) and 95% confidence intervals (CIs) were used to measure the association between rs1801516 and cancer risk. Additionally, we performed sensitivity, subgroup, and publication bias analyses.

Results

After inclusion criteria were met, the meta-analysis included 29 studies, with 9,453 cancer patients (cases) and 14,646 controls. No association was found between rs1801516 and cancer risk (pooled OR = 0.911; 95% CI, 0.740–1.123). Concordantly, no association was found between rs1801516 and cancer risk after subgroup analysis by source of controls, cancer type, or ethnicity, which confirmed the finding of the dominant model that this SNP is not involved in the occurrence of cancer.

Conclusions

Through this meta-analysis, we found no association between rs1801516 and cancer occurrence as a risk factor. These data provide useful information for future case–control studies on cancer etiology.

Association between ATM rs1801516 polymorphism and cancer susceptibility: a meta-analysis involving 12,879 cases and 18,054 controls

Background

Ataxia telangiectasia mutated (ATM) gene plays a key role in response to DNA lesions and is related to the invasion and metastasis of malignancy. Epidemiological studies have indicated associations between ATM rs1801516 polymorphism and different types of cancer, but their results are inconsistent. To further evaluate the effect of ATM rs1801516 polymorphism on cancer risk, we conducted this meta-analysis.

Methods

Studies were identified according to specific inclusion criteria by searching PubMed, Web of Science, and Embase databases. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) under recessive, dominant, codominant, and overdominant models of inheritance were calculated to estimate the association between rs1801516 polymorphism and cancer risk.

Results

A total of 37 studies with 12,879 cases and 18,054 controls were included in our study. No significant association was found between rs1801516 polymorphism and cancer risk in overall comparisons (AA vs GG + GA: OR = 0.91, 95% CI, 0.78–1.07; AA+GA vs GG: OR = 1.00, 95% CI, 0.90–1.11; AA vs GG: OR = 0.89, 95% CI, 0.75–1.06; GA vs GG: OR = 1.01, 95% CI, 0.91–1.13; GG + AA vs GA: OR = 1.00, 95% CI, 0.88–1.10). However, after subgroup analyses by region-specified population, significant associations were found in European (AA vs GG + GA: OR = 0.79, 95% CI, 0.65–0.96, P = 0.017; AA vs GG: OR = 0.79, 95% CI, 0.65–0.96, P = 0.017), South American (AA+GA vs GG: OR = 2.15, 95% CI, 1.37–3.38, P = 0.001; GA vs GG: OR = 2.19, 95% CI, 1.38–3.47, P = 0.001; GG + AA vs GA: OR = 0.46, 95% CI, 0.29–0.72, P = 0.001), and Asian (AA vs GG + GA: OR = 7.45, 95% CI, 1.31–42.46, P = 0.024; AA vs GG: OR = 7.40, 95% CI, 1.30–42.19, P = 0.024). Subgroup analyses also revealed that compared with subjects carrying a GG genotype, those carrying a homozygote AA had a decreased risk for breast cancer (AA vs GG: OR = 0.76, 95% CI, 0.59–0.98, P = 0.035), and the homozygote AA was associated with decreased cancer risk in subjects with family history (AA vs GG: OR = 0.68, 95% CI, 0.47–0.98, P = 0.039).

Conclusions

ATM rs1801516 polymorphism is not associated with overall cancer risk in total population. However, for subgroup analyses, this polymorphism is especially associated with breast cancer risk; in addition, it is associated with overall cancer risk in Europeans, South Americans, Asians, and those with family history.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4941-1) contains supplementary material, which is available to authorized users.

ATM in breast and brain tumors: a comprehensive review

The ATM gene is mutated in the syndrome, ataxia-telangiectasia (AT), which is characterized by predisposition to cancer. Patients with AT have an elevated risk of breast and brain tumors Carrying mutations in ATM, patients with AT have an elevated risk of breast and brain tumors. An increased frequency of ATM mutations has also been reported in patients with breast and brain tumors; however, the magnitude of this risk remains uncertain. With the exception of a few common mutations, the spectrum of ATM alterations is heterogeneous in diverse populations, and appears to be remarkably dependent on the ethnicity of patients. This review aims to provide an easily accessible summary of common variants in different populations which could be useful in ATM screening programs. In addition, we have summarized previous research on ATM, including its molecular functions. We attempt to demonstrate the significance of ATM in exploration of breast and brain tumors and its potential as a therapeutic target.

Gene-environment interaction for polymorphisms in ataxia telangiectasia-mutated gene and radiation exposure in carcinogenesis: results from two literature-based meta-analyses of 27120 participants

Purpose

We conducted two meta-analyses of ATM genetic polymorphisms and cancer risk in individuals with or without radiation exposure to determine whether there was a joint effect between the ATM gene and radiation exposure in carcinogenesis.

Results

rs1801516, which was the only ATM polymorphism investigated by more than 3 studies of radiation exposure, was eligible for the present study. The meta-analysis of 23333 individuals without radiation exposure from 24 studies showed no association between the rs1801516 polymorphism and cancer risk, without heterogeneity across studies. The meta-analysis of 3787 individuals with radiation exposure from 6 studies showed a significant association between the rs1801516 polymorphism and a decreased cancer risk, with heterogeneity across studies. There was a borderline-significant difference between the ORs of the two meta-analyses (P = 0.066), and the difference was significant when only Caucasians were included (P = 0.011).

Materials and methods

Publications were identified by searching PubMed, EMBASE, Web of Science, and CNKI databases. Odds ratios (ORs) were calculated to estimate the association between ATM genetic polymorphisms and cancer risk. Tests of interaction were used to compare differences between the ORs of the two meta-analyses.

Conclusions

Our meta-analyses confirmed the presence of a gene-environment interaction between the rs1801516 polymorphism and radiation exposure in carcinogenesis, whereas no association was found between the rs1801516 polymorphism and cancer risk for individuals without radiation exposure. The heterogeneity observed in the meta-analysis of individuals with radiation exposure might be due to gene-ethnicity or gene-gene interactions. Further studies are needed to elucidate sources of the heterogeneity.

Association between ATM 5557G>A polymorphism and breast cancer risk: a meta-analysis

Epidemiological studies have evaluated the association between ATM 5557G>A (p.D1853N) polymorphism and breast cancer risk. However, the results remain conflicting rather than conclusive. To derive a more precise estimation of the relationship, we performed this meta-analysis. Systematic searches of PubMed and Medline databases were performed. A total of nine studies included 3155 cases and 2752 controls were identified. When all nine studies were pooled into the meta-analysis, there was no evidence for significant association between 5557G>A mutation and breast cancer risk(for G/A vs. G/G: OR = 1.05, 95% CI = 0.83-1.34; for A/A vs. G/G: OR = 0.77, 95% CI = 0.58-1.03; for dominant model: OR = 1.04, 95% CI = 0.82-1.31; for recessive model: OR = 0.87, 95% CI = 0.69-1.09). In the subgroup analyses by family history and ethnicity, significant associations were found among Amerindians (for G/A vs. G/G: OR = 2.19, 95% CI = 1.38-3.47; for dominant model: OR = 2.15, 95% CI = 1.37-3.38). In summary, the meta-analysis suggest that ATM 5557G>A polymorphism is associated with increased breast cancer risk among Amerindians. However, due to the small subjects included in analysis and the selection bias existed in some studies, the results for Amerindians should be interpreted with caution.

Germline ATM mutational analysis in BRCA1/BRCA2 negative hereditary breast cancer families by MALDI-TOF mass spectrometry

Biallelic inactivation of ATM gene causes the rare autosomal recessive disorder Ataxia-telangiectasia (A-T). Female relatives of A-T patients have a two-fold higher risk of developing breast cancer (BC) compared with the general population. ATM mutation carrier identification is laborious and expensive, therefore, a more rapid and directed strategy for ATM mutation profiling is needed. We designed a case-control study to determine the prevalence of 32 known ATM mutations causing A-T in Spanish population in 323 BRCA1/BRCA2 negative hereditary breast cancer (HBC) cases and 625 matched Spanish controls. For the detection of the 32 ATM mutations we used the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technique. We identified one patient carrier of the c.8264_8268delATAAG ATM mutation. This mutation was not found in the 625 controls. These results suggest a low frequency of these 32 A-T causing mutations in the HBC cases in our population. Further case-control studies analyzing the entire coding and flanking sequences of the ATM gene are warranted in Spanish BC patients to know its implication in BC predisposition.

Rare, evolutionarily unlikely missense substitutions in ATM confer increased risk of breast cancer

The susceptibility gene for ataxia telangiectasia, ATM, is also an intermediate-risk breast-cancer-susceptibility gene. However, the spectrum and frequency distribution of ATM mutations that confer increased risk of breast cancer have been controversial. To assess the contribution of rare variants in this gene to risk of breast cancer, we pooled data from seven published ATM case-control mutation-screening studies, including a total of 1544 breast cancer cases and 1224 controls, with data from our own mutation screening of an additional 987 breast cancer cases and 1021 controls. Using an in silico missense-substitution analysis that provides a ranking of missense substitutions from evolutionarily most likely to least likely, we carried out analyses of protein-truncating variants, splice-junction variants, and rare missense variants. We found marginal evidence that the combination of ATM protein-truncating and splice-junction variants contribute to breast cancer risk. There was stronger evidence that a subset of rare, evolutionarily unlikely missense substitutions confer increased risk. On the basis of subset analyses, we hypothesize that rare missense substitutions falling in and around the FAT, kinase, and FATC domains of the protein may be disproportionately responsible for that risk and that a subset of these may confer higher risk than do protein-truncating variants. We conclude that a comparison between the graded distributions of missense substitutions in cases versus controls can complement analyses of truncating variants and help identify susceptibility genes and that this approach will aid interpretation of the data emerging from new sequencing technologies.