Revisiting breast cancer patients who previously tested negative for BRCA mutations using a 12-gene panel

EMQN best practice guidelines for genetic testing in hereditary breast and ovarian cancer

Hereditary Breast and Ovarian Cancer (HBOC) is a genetic condition associated with increased risk of cancers. The past decade has brought about significant changes to hereditary breast and ovarian cancer (HBOC) diagnostic testing with new treatments, testing methods and strategies, and evolving information on genetic associations. These best practice guidelines have been produced to assist clinical laboratories in effectively addressing the complexities of HBOC testing, while taking into account advancements since the last guidelines were published in 2007. These guidelines summarise cancer risk data from recent studies for the most commonly tested high and moderate risk HBOC genes for laboratories to refer to as a guide. Furthermore, recommendations are provided for somatic and germline testing services with regards to clinical referral, laboratory analyses, variant interpretation, and reporting. The guidelines present recommendations where 'must' is assigned to advocate that the recommendation is essential; and 'should' is assigned to advocate that the recommendation is highly advised but may not be universally applicable. Recommendations are presented in the form of shaded italicised statements throughout the document, and in the form of a table in supplementary materials (Table S4). Finally, for the purposes of encouraging standardisation and aiding implementation of recommendations, example report wording covering the essential points to be included is provided for the most common HBOC referral and reporting scenarios. These guidelines are aimed primarily at genomic scientists working in diagnostic testing laboratories.

Homologous Recombination Deficiency in Ovarian, Breast, Colorectal, Pancreatic, Non-Small Cell Lung and Prostate Cancers, and the Mechanisms of Resistance to PARP Inhibitors

Homologous recombination (HR) is a highly conserved DNA repair mechanism that protects cells from exogenous and endogenous DNA damage. Breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) play an important role in the HR repair pathway by interacting with other DNA repair proteins such as Fanconi anemia (FA) proteins, ATM, RAD51, PALB2, MRE11A, RAD50, and NBN. These pathways are frequently aberrant in cancer, leading to the accumulation of DNA damage and genomic instability known as homologous recombination deficiency (HRD). HRD can be caused by chromosomal and subchromosomal aberrations, as well as by epigenetic inactivation of tumor suppressor gene promoters. Deficiency in one or more HR genes increases the risk of many malignancies. Another conserved mechanism involved in the repair of DNA single-strand breaks (SSBs) is base excision repair, in which poly (ADP-ribose) polymerase (PARP) enzymes play an important role. PARP inhibitors (PARPIs) convert SSBs to more cytotoxic double-strand breaks, which are repaired in HR-proficient cells, but remain unrepaired in HRD. The blockade of both HR and base excision repair pathways is the basis of PARPI therapy. The use of PARPIs can be expanded to sporadic cancers displaying the “BRCAness” phenotype. Although PARPIs are effective in many cancers, their efficacy is limited by the development of resistance. In this review, we summarize the prevalence of HRD due to mutation, loss of heterozygosity, and promoter hypermethylation of 35 DNA repair genes in ovarian, breast, colorectal, pancreatic, non-small cell lung cancer, and prostate cancer. The underlying mechanisms and strategies to overcome PARPI resistance are also discussed.

Mutations in exon region of BRCA1-related RING domain 1 gene and risk of breast cancer

Background

BRCA1‐associated RING Domain 1 (BARD1) is an important gene related to breast cancer development. However, the role of BARD1 mutations in breast cancer remains inconclusive. This study is to investigate the relationship between exon mutations of BARD1 gene and the risk of early‐onset breast cancer.

Methods

Totally, 60 cases of early‐onset breast cancer patients (age 30–40 years) and 240 healthy women (age 30–40 years) were enrolled. Exon mutations of BARD1 were detected and analyzed by direct sequencing and SNaPshot.

Results

The risk of breast cancer was increased by 3.475 times in carriers with deletion mutation at rs28997575 site of BARD1 (aOR₁ = 3.475, 95%CI = 1.302–9.276) (p = 0.013). The risk of breast cancer in carriers with GC genotype at rs2229571 site of BARD1 was reduced by 72.6% (aOR₁ = 0.274, 95%CI = 0.134–0.562) (p = 0.001), and that in carriers with CC genotype was reduced by 82.8% (aOR₁ = 0.172, 95%CI = 0.076–0.392) (p = 0.001). After stratification with family history, the difference of rs2229571 site mutation genotype was statistically significant (OR = −2.169, 95%CI = 0.016–0.828, p = 0.032). Additionally, the frequency distribution of breast cancer family history in the case group (15%) was significantly more than that in the control group (6.7%) (p = 0.037).

Conclusion

The deletion mutation at rs28997575 locus of the BARD1 gene can significantly increase the risk of breast cancer. The mutation genotype of rs2229571 locus can significantly reduce the risk of breast cancer. Family history is associated with BARD1 gene polymorphism. A family history of breast cancer may be a risk factor for breast cancer.

Outcomes of retesting in patients with previously uninformative cancer genetics evaluations

Advances in cancer genetics have increased germline pathogenic/likely pathogenic variant (PV/LPV) detection rates. More data is needed to inform which patients with previously uninformative results could benefit most from retesting, especially beyond breast/ovarian cancer populations. Here, we describe retesting outcomes and predictors of PV/LPVs in a cohort of patients unselected by cancer diagnosis. Retrospective chart reviews were conducted for patients at a cancer genetics clinic between 1998 and 2019 who underwent genetic testing (GT) on ≥ 2 dates with ≥ 1 year between tests, with no PV/LPVs on first-line GT. Demographics, retesting indications, and GT details were reviewed to evaluate predictive factors of PV/LPV identification. 139 patients underwent retesting, of whom 24 (17.3%) had a PV/LPV, encompassing 15 genes. 14 PV/LPV carriers (58.3%) only returned for retesting after personal or familial history changes (typically new cancer diagnoses), while 10 (41.7%) retested due to updated GT availability. No specific GT method was most likely to identify PV/LPVs and no specific clinical factors were predictive of a PV/LPV. The identified PV/LPVs were consistent with patients' personal or family histories, but were discordant with the initial referral indication for GT. For 16 (66.7%) PV/LPV carriers, the genetic diagnosis changed clinical management. This study adds to the limited body of literature on retesting outcomes beyond first-line BRCA analysis alone and confirms the utility of multigene panel testing. Retesting certain affected individuals when updated GT is available could result in earlier PV/LPV identification, significantly impacting screening recommendations and potentially reducing cancer-related morbidity and mortality.

The prevalence of ataxia telangiectasia mutated (ATM) variants in patients with breast cancer patients: a systematic review and meta-analysis

Breast cancer is the most common cancer in women, and its high mortality has become one of the biggest health problems globally. Several studies have reported an association between breast cancer and ATM gene variants. This study aimed to demonstrate and analyze the relationship between ATM gene polymorphisms and breast cancer prevalence rate. A systematic literature review was undertaken using the following databases: Medline (PubMed), Web of sciences, Scopus, EMBASE, Cochrane, Ovid, and CINHAL to retrieve all cross-sectional studies between January 1990 and January 2020, which had reported the frequency of ATM variants in patients with breast cancer. A random-effects model was applied to calculate the pooled prevalence with a 95% confidence interval. The pooled prevalence of ATM variants in patients with breast cancer was 7% (95% CI: 5−8%). Also, the pooled estimate based on type of variants was 6% (95% CI: 4−8%; I square: 94%; P: 0.00) for total variants¸ 0% (95% CI: 0−1%; I square: 0%; P: 0.59) for deletion variants, 12% (95% CI: 7−18%; I square: 99%; P: 0.00) for substitution variants, and 2% (95% CI: 4−9%; I square: 67%; P: 0.08) for insertion variants. This meta-analysis showed that there is a significant relationship between ATM variants in breast cancer patients. Further studies are required to determine which of the variants of the ATM gene are associated with BRCA mutations.

TP53 germline mutations in the context of families with hereditary breast and ovarian cancer: a clinical challenge

PURPOSE

TP53germline (g) mutations, associated with the Li-Fraumeni syndrome (LFS), have rarely been reported in the context of hereditary breast and ovarian cancer (HBOC). The prevalence and cancer risks in this target group are unknown and counseling remains challenging. Notably an extensive high-risk surveillance program is implemented, which evokes substantial psychological discomfort. Emphasizing the lack of consensus about clinical implications, we aim to further characterize TP53g mutations in HBOC families.

METHODS

Next-generation sequencing was conducted on 1876 breast cancer (BC) patients who fulfilled the inclusion criteria for HBOC.

RESULTS

(Likely) pathogenic variants in TP53 gene were present in 0.6% of the BC cohort with higher occurrence in early onset BC < 36 years. (1.1%) and bilateral vs. unilateral BC (1.1% vs. 0.3%). Two out of eleven patients with a (likely) pathogenic TP53g variant (c.542G > A; c.375G > A) did not comply with classic LFS/Chompret criteria. Albeit located in the DNA-binding domain of the p53-protein and therefore revealing no difference to LFS-related variants, they only displayed a medium transactivity reduction constituting a retainment of wildtype-like anti-proliferative functionality.

CONCLUSION

Among our cohort of HBOC families, we were able to describe a clinical subgroup, which is distinct from the classic LFS-families. Strikingly, two families did not adhere to the LFS criteria, and functional analysis revealed a reduced impact on TP53 activity, which may suit to the attenuated phenotype. This is an approach that could be useful in developing individualized screening efforts for TP53g mutation carrier in HBOC families. Due to the low incidence, national/international cooperation is necessary to further explore clinical implications. This might allow providing directions for clinical recommendations in the future.

Clinical Contribution of Next-Generation Sequencing Multigene Panel Testing for BRCA Negative High-Risk Patients With Breast Cancer

BACKGROUND

Breast cancer is the most common malignancy in women and thought to be hereditary in 10% of patients. Recent next-generation sequencing studies have increased the detection of pathogenic or likely pathogenic (P/LP) variants in genes other than BRCA1/2 in patients with breast cancer. This study evaluated pathogenic variants, likely pathogenic variants, and variants of unknown significance in 18 hereditary cancer susceptibility genes in patients with BRCA1/2-negative breast cancer.

PATIENTS AND METHODS

This retrospective study included 188 high-risk BRCA1/2-negative patients with breast cancer tested with a multigene cancer panel using next-generation sequencing.

RESULTS

Among 188 proband cases, 18 variants in 21 patients (11.1%) were classified as P/LP in PALB2 (n = 6), CHEK2 (n = 5), MUTYH (n = 4), ATM (n = 3), TP53 (n = 2), BRIP1 (n = 1), and MSH2 (n = 1). Three novel P/LP variants were identified. An additional 28 variants were classified as variants of unknown significance and detected in 30 different patients (15.9%).

CONCLUSION

This is one of the largest study from Turkey to investigate the mutation spectrum in non-BRCA hereditary breast cancer susceptibility genes. A multigene panel test increased the likelihood of identifying a molecular diagnosis in patients with BRCA 1/2-negative breast cancer at risk for a hereditary breast cancer syndrome. More studies are needed to enable the clinical interpretation of these P/LP variants in hereditary patients with breast cancer.

Using Co-segregation and Loss of Heterozygosity Analysis to Define the Pathogenicity of Unclassified Variants in Hereditary Breast Cancer Patients

The use of gene panels introduces a new dilemma in the genetics field due to the high frequency of variants of uncertain significance (VUS). The objective of this study was to provide evidence that may help in the classification of these germline variants in terms of their clinical impact and association with the disease in question. A total of 52 unrelated women at-risk for HBOC and negative for BRCA1/BRCA2 pathogenic variants were evaluated through a gene panel comprising 14 breast and/or ovarian cancer susceptibility genes. Of the 453 germline variants identified, 15 variants (classes 3, 4, and 5) in the ATM, BRIP1, CHEK2, MRE11A, MUTHY, PALB2, RAD50, and RAD51C genes were evaluated via databases, co-segregation studies and loss of heterozygosity in the tumor. The co-segregation analysis allowed the establishment of an association with the presence of variants and the risk of cancer for variant c.316C>T in the BRIP1 gene. Four variants of uncertain significance showed loss of heterozygosity in the tumor (ATM c.4709T>C; CHEK2 c.1036C>T; PALB2 c.1001A>G, and RAD50 c.281T>C), which is an indication of pathogenicity. Thus, the present study provides novel evidence that favors the association of variants in moderate-risk genes with the development of hereditary breast cancer.

Summary of BARD1 Mutations and Precise Estimation of Breast and Ovarian Cancer Risks Associated with the Mutations

Over the last two decades, numerous BARD1 mutations/pathogenic variants (PVs) have been found in patients with breast cancer (BC) and ovarian cancer (OC). However, their role in BC and OC susceptibility remains controversial, and strong evidence-based guidelines for carriers are not yet available. Herein, we present a comprehensive catalog of BARD1 PVs identified in large cumulative cohorts of ~48,700 BC and ~20,800 OC cases (retrieved from 123 studies examining the whole coding sequence of BARD1). Using these resources, we compared the frequency of BARD1 PVs in the cases and ~134,100 controls from the gnomAD database and estimated the effect of the BARD1 PVs on BC and OC risks. The analysis revealed that BARD1 is a BC moderate-risk gene (odds ratio (OR) = 2.90, 95% CIs:2.25–3.75, p < 0.0001) but not an OC risk gene (OR = 1.36, 95% CIs:0.87–2.11, p = 0.1733). In addition, the BARD1 mutational spectrum outlined in this study allowed us to determine recurrent PVs and evaluate the variant-specific risk for the most frequent PVs. In conclusion, these precise estimates improve the understanding of the role of BARD1 PVs in BC and OC predisposition and support the need for BARD1 diagnostic testing in BC patients.

The Myc tag monoclonal antibody 9E10 displays highly variable epitope recognition dependent on neighboring sequence context

Epitope tags are short, linear antibody recognition sequences that enable detection of tagged fusion proteins by antibodies. Epitope tag position and neighboring sequences potentially affect its recognition by antibodies, and such context-dependent differences in tag binding may have a wide-ranging effect on data interpretation. We tested by Western blotting six antibodies that recognize the c-Myc epitope tag, including monoclonal antibodies 9E10, 4A6, 9B11, and 71D10 and polyclonal antibodies 9106 and A-14. All displayed context-dependent differences in their ability to detect N- or C-terminal Myc-tagged proteins. In particular, clone 9E10, the most cited Myc-tag antibody, displayed high context-dependent detection variability, whereas others, notably 4A6 and 9B11, showed much less context sensitivity in their detection of Myc-tagged proteins. The very high context sensitivity of 9E10 was further substantiated by peptide microarray analyses. We conclude that recently developed, purpose-made monoclonal antibodies specific for Myc have much more uniform reactivity in diverse assays and are much less context sensitive than is the legacy antibody 9E10.

Challenges in reporting pathogenic/potentially pathogenic variants in 94 cancer predisposing genes - in pediatric patients screened with NGS panels

The benefit of reporting unsolicited findings in Next Generation Sequencing (NGS) related to cancer genes in children may have implications for family members, nevertheless, could also cause distress. We aimed to retrospectively investigate germline variants in 94 genes implicated in oncogenesis, in patients referred to NGS testing for various rare genetic diseases and reevaluate the utility of reporting different classes of pathogenicity. We used in silico prediction software to classify variants and conducted manual review to examine unsolicited findings frequencies in 145 children with rare diseases, that underwent sequencing - using a 4813 gene panel. The anonymized reanalysis revealed 18250 variants, of which 126 were considered after filtering. Six pathogenic variants (in BRCA1,BMPR1A,FANCA,FANCC,NBN genes) with cancer related phenotype and three unsolicited variants (in BRCA2,PALB2,RAD50 genes) were reported to patients. Additionally, three unsolicited variants in ATR, BLM (in two individuals), and FANCB genes presented potential cancer susceptibility, were not reported to patients. In retrospect, 4.8% (7/145) of individuals in our cohort had unsolicited NGS findings related to cancer. More efforts are needed to create an updatable consensus in reporting variants in cancer predisposing genes, especially for children. Consent process is crucial to inform of both value and risk of additional genetic information.

Identifying sequence variants contributing to hereditary breast and ovarian cancer in BRCA1 and BRCA2 negative breast and ovarian cancer patients

Families with breast and ovarian cancer are often tested for disease associated sequence variants in BRCA1 and BRCA2. Pathogenic sequence variants (PVs) in these two genes are known to increase breast and ovarian cancer risks in females. However, in most families no PVs are detected in these two genes. Currently, several studies have identified other genes involved in hereditary breast and ovarian cancer (HBOC). To identify genetic risk factors for breast and ovarian cancer in a Norwegian HBOC cohort, 101 breast and/or ovarian cancer patients negative for PVs and variants of unknown clinical significance (VUS) in BRCA1/2 were screened for PVs in 94 genes using next-generation sequencing. Sixteen genes were closely scrutinized. Nine different deleterious germline PVs/likely pathogenic variants (LPVs) were identified in seven genes in 12 patients: three in ATM, and one in CHEK2, ERCC5, FANCM, RAD51C, TP53 and WRN. Additionally, 32 different VUSs were identified and these require further characterization. For carriers of PV/LPV in many of these genes, there are no national clinical management programs in Norway. The diversity of genetic risk factors possibly involved in cancer development show the necessity for more knowledge to improve the clinical follow-up of this genetically diverse patient group.

Identification of germline pathogenic variants in DNA damage repair genes by a next-generation sequencing multigene panel in BRCAX patients

BACKGROUND

Approximately 5-10% of breast carcinomas have been related to hereditary conditions and are attributable to pathogenic variants in the BRCA1 and BRCA2 genes, which is referred to as hereditary breast and ovarian cancer (HBOC) syndrome. The inclusion of additional genes that can be related to HBOC syndrome is under intense evaluation due to the high proportion of patients with HBOC criteria who do not present pathogenic mutations in BRCA genes, named BRCAX, despite having high clinical suspicion of hereditary cancer. The main aim is to identify new potentially pathogenic gene variants that may contribute to HBOC to improve the efficiency of routine diagnostic tests in this hereditary condition.

METHODS

A retrospective cohort of 77 HBOC BRCAX patients was analyzed by next-generation sequencing using a targeted multigene panel composed of 25 genes related to hereditary cancer and deficiencies in DNA repair pathways.

RESULTS

We found 9 variants in 7 different genes, which were confirmed by automated sequencing. Six variants were classified as pathogenic or likely pathogenic. Three of them were located in the PALB2 gene, one in the BRIP1 gene, one in the BARD1 gene and 1 in the RAD50 gene. In addition, three variants of uncertain significance (VUS) were detected in the TP53, CHEK2, and CDH1 genes.

CONCLUSIONS

We identified that 8% of BRCAX patients were carriers of pathogenic variants in genes other than BRCA1 and BRCA2. Therefore, wide gene panels, including clinically actionable genes, should be routinely used in the screening of HBOC in our population. We observed differences from other studies in the prevalence of mutated genes, most likely due to differences in the selection criteria of the probands and in the population analyzed. The high incidence of deleterious variant detection in PALB2 supports its significant role in breast cancer susceptibility and reinforces its inclusion in the HBOC genetic diagnostic process.

Survey of primary care physicians' views about breast and ovarian cancer screening for true BRCA1/2 non-carriers

Despite some controversy, true BRCA1/2 non-carriers are generally considered to be at an average risk for breast and ovarian cancer. Primary care physicians are then expected to encourage their non-carrier patients to adopt cancer screening practices appropriate to women of the same age in the general population. This study aimed to describe breast and ovarian cancer screening recommendations that primary care physicians would consider advisable for young true BRCA1/2 non-carriers. One hundred thirty-four family physicians and 123 gynecologists (response rate 45%) completed a cross-sectional mailed survey administered in the Province of Quebec, Canada. The survey included questions about basic genetic knowledge and screening recommendations for two fictitious cases (< 40 years), one carrier and one non-carrier, from a BRCA1/2 mutation-positive family. Screening exams considered advisable did not differ significantly between family physicians and gynecologists. More than 75% of physicians considered the cancer risks of true non-carriers to be comparable with that of the general population and 14% to be a little higher. Still, 53% would prescribe a biennial and or even an annual (27%) mammography to a non-carrier woman before the recommended starting age. Physician considerations of non-carriers' expectations or requests for screening were associated with more screening prescriptions. More than half of primary care physicians would recommend more mammography screenings than expected for a young true BRCA1/2 non-carrier. Personalized cancer risk assessment may help primary care physicians tailor screening of women from BRCA1/2 mutation-positive families and allow these women to make more informed choices regarding cancer risk management options.

Exploring Predictors of Genetic Counseling and Testing for Hereditary Breast and Ovarian Cancer: Findings from the 2015 U.S. National Health Interview Survey

Despite efforts to increase the availability of clinical genetic testing and counseling for Hereditary Breast and Ovarian (HBOC)-related cancers, these services remain underutilized in clinical settings. There have been few efforts to understand the public's use of cancer genetic services, particularly for HBOC-related cancers. This analysis is based on data from the 2015 National Health Interview Survey (NHIS), a U.S.-based nationwide probability sample, to better understand the public's use of HBOC-related clinical cancer genetic services. Bivariate analyses were used to compute percentages and examine the associations of familial cancer risk for three genetic services outcomes (ever had genetic counseling for cancer risk, ever discussed genetic testing for cancer risk with a provider, and ever had genetic testing for cancer risk). Multivariable logistic regression models were used to estimate the association of familial cancer risk and other demographic and health variables with genetic services. Most women (87.67%) in this study were at low risk based on self-reported family history of breast and ovarian cancer, 10.65% were at medium risk, and 1.68% were at high risk. Overall, very small numbers of individuals had ever had genetic counseling (2.78%), discussed genetic testing with their physician (4.55%) or had genetic testing (1.64%). Across all genetic services outcomes, individuals who were at higher familial risk were more likely to have had genetic counseling than those at lower risk (high risk: aOR = 5.869, 95% CI = 2.911-11.835; medium risk: aOR = 4.121, 95% CI = 2.934-5.789), discussed genetic testing (high risk: aOR = 5.133, 95% CI = 2.699-9.764; medium risk: aOR = 3.649, 95% CI = 2.696-4.938), and completed genetic testing (high risk: aOR = 8.531, 95% CI = 3.666-19.851; medium risk aOR = 3.057, 95% CI = 1.835-5.094). Those who perceived themselves as being more likely to develop cancer than the average woman were more likely to engage in genetic counseling (aOR = 1.916, 95% CI = 1.334-2.752), discuss genetic testing (aOR = 3.314, 95% CI = 2.463-4.459) or have had genetic testing (aOR = 1.947, 95% CI = 1.13-3.54). Personal cancer history was also a significant predictor of likelihood to have engaged in genetic services. Our findings highlight: (1) potential under-utilization of cancer genetic services among high risk populations in the U.S. and (2) differences in genetic services use based on individual's characteristics such as self-reported familial risk, personal history, and beliefs about risk of cancer. These results align with other studies which have noted that awareness and use of genetic services are low in the general population and likely not reaching individuals who could benefit most from screening for inherited cancers. Efforts to promote public awareness of familial cancer risk may lead to better uptake of cancer genetic services.

Non-BRCA1/2 Variants Detected in a High-Risk Chilean Cohort With a History of Breast and/or Ovarian Cancer

METHODS

Data were retrospectively collected from the registry of the High-Risk Breast and Ovarian Cancer Program at Clínica Las Condes, Santiago, Chile. Data captured included index case diagnosis, ancestry, family history, and genetic test results.

RESULTS

Three hundred fifteen individuals underwent genetic testing during the study period. The frequency of germline pathogenic and likely pathogenic variants in a breast or ovarian cancer predisposition gene was 20.3%. Of those patients who underwent testing with a panel of both high- and moderate-penetrance genes, 10.5% were found to have pathogenic or likely pathogenic variants in non-BRCA1/2 genes.

CONCLUSION

Testing for non-BRCA1 and -2 mutations may be clinically relevant for individuals who are suspected to have a hereditary breast or ovarian cancer syndrome in Chile. Comprehensive genetic testing of individuals who are at high risk is necessary to further characterize the genetic susceptibility to cancer in Chile.

Current review of TP53 pathogenic germline variants in breast cancer patients outside Li-Fraumeni syndrome

Pathogenic germline variants in TP53 predispose carriers to the multi-cancer Li-Fraumeni syndrome (LFS). Widespread multigene panel testing is identifying TP53 pathogenic variants in breast cancer patients outside the strict clinical criteria recommended for LFS testing. We aimed to assess frequency and clinical implications of TP53 pathogenic variants in breast cancer cohorts ascertained outside LFS. Classification of TP53 germline variants reported in 59 breast cancer studies, and publicly available population control sets was reviewed and identified evidence for misclassification of variants. TP53 pathogenic variant frequency was determined for: breast cancer studies grouped by ascertainment characteristics; breast cancer cohorts undergoing panel testing; and population controls. Early age of breast cancer onset, regardless of family history or BRCA1/BRCA2 previous testing, had the highest pick-up rate for TP53 carriers. Patients at risk of hereditary breast cancer unselected for features of LFS carried TP53 pathogenic variants at a frequency comparable to that of other non-BRCA1/2 breast cancer predisposing genes, and ∼threefold more than reported in population controls. These results have implications for the implementation of TP53 testing in broader clinical settings, and suggest urgent need to investigate cancer risks associated with TP53 pathogenic variants in individuals outside the LFS spectrum.

Validation of CZECANCA (CZEch CAncer paNel for Clinical Application) for targeted NGS-based analysis of hereditary cancer syndromes

Background

Carriers of mutations in hereditary cancer predisposition genes represent a small but clinically important subgroup of oncology patients. The identification of causal germline mutations determines follow-up management, treatment options and genetic counselling in patients’ families. Targeted next-generation sequencing-based analyses using cancer-specific panels in high-risk individuals have been rapidly adopted by diagnostic laboratories. While the use of diagnosis-specific panels is straightforward in typical cases, individuals with unusual phenotypes from families with overlapping criteria require multiple panel testing. Moreover, narrow gene panels are limited by our currently incomplete knowledge about possible genetic dispositions.

Methods

We have designed a multi-gene panel called CZECANCA (CZEch CAncer paNel for Clinical Application) for a sequencing analysis of 219 cancer-susceptibility and candidate predisposition genes associated with frequent hereditary cancers.

Results

The bioanalytical and bioinformatics pipeline was validated on a set of internal and commercially available DNA controls showing high coverage uniformity, sensitivity, specificity and accuracy. The panel demonstrates a reliable detection of both single nucleotide and copy number variants. Inter-laboratory, intra- and inter-run replicates confirmed the robustness of our approach.

Conclusion

The objective of CZECANCA is a nationwide consolidation of cancer-predisposition genetic testing across various clinical indications with savings in costs, human labor and turnaround time. Moreover, the unified diagnostics will enable the integration and analysis of genotypes with associated phenotypes in a national database improving the clinical interpretation of variants.

Preferences for multigene panel testing for hereditary breast cancer risk among ethnically diverse BRCA-uninformative families

Until recently, genetic testing for hereditary breast cancer has primarily focused on pathogenic variants in the BRCA1 and BRCA2 (BRCA) genes. However, advances in DNA sequencing technologies have made simultaneous testing for multiple genes possible. We examined correlates of interest in multigene panel testing and risk communication preferences in an ethnically diverse sample of women who tested negative for BRCA mutations previously but remain at high risk based on their family history (referred to as "BRCA-uninformative") and their at-risk female family members. Two-hundred and thirteen women with a previous breast cancer diagnosis and a BRCA-uninformative test result and their first-degree relatives completed a survey on interest in multigene panel testing, communication preferences, and sociodemographic, psychological, and clinical factors. Stepwise logistic regression was used to identify factors associated with testing interest. Chi-square analyses were used to test differences in risk communication preferences. Interest in multigene panel testing was high (84%) and did not considerably differ by cancer status or ethnicity. In multivariable analysis, factors significantly associated with interest in genetic testing were having had a mammogram in the past 2 years (odds ratio (OR) = 4.04, 95% confidence interval (CI) 1.80-9.02) and high cancer worry (OR = 3.77, 95% CI 1.34-10.60). Overall, the most commonly preferred genetic communication modes were genetic counselors, oncologists, and print materials. However, non-Hispanic women were more likely than Hispanic women to prefer web-based risk communication (p < 0.001). Hispanic and non-Hispanic women from BRCA-uninformative families have a high level of interest in gene panel testing. Cancer-related emotions and communication preferences should be considered in developing targeted genetic risk communication strategies.

Non-BRCA1/2 Breast Cancer Susceptibility Genes: A New Frontier with Clinical Consequences for Plastic Surgeons

Twenty percent of breast cancer cases may be related to a genetic mutation conferring an increased risk of malignancy. The most common and prominent breast cancer susceptibility genes are BRCA1 and BRCA2, found in nearly 40% of such cases. However, continued interest and investigation of cancer genetics has led to the identification of a myriad of different breast cancer susceptibility genes. Additional genes, each with unique significance and associated characteristics, continue to be recognized. Concurrently, advanced genetic testing, while still controversial, has become more accessible and cost-effective. As oncologic and reconstructive advances continue to be made in prophylactic breast reconstructive surgery, patients may present to plastic surgeons with an increasingly more diverse array of genetic diagnoses to discuss breast reconstruction. It is therefore imperative that plastic surgeons be familiar with these breast cancer susceptibility genes and their clinical implications. We, therefore, aim to review the most common non-BRCA1/2 breast cancer susceptibility genetic mutations in an effort to assist plastic surgeons in counseling and managing this unique patient population. Included in this review are syndromic breast cancer susceptibility genes such as TP53, PTEN, CDH1, and STK11, among others. Nonsyndromic breast cancer susceptibility genes herein reviewed include PALB2, CHEK2, and ataxia telangiectasia mutated gene. With this knowledge, plastic surgeons can play a central role in the diagnosis and comprehensive treatment, including successful breast reconstruction, of all patients carrying genetic mutations conferring increased risk for breast malignancies.

Clinical implications of germline mutations in breast cancer: TP53

Purpose

This review describes the prevalence of germline TP53 mutations, the risk of breast cancer and other cancers in mutation carriers and management implications for women with breast cancer and unaffected women.

Methods

Literature review of English language papers available through PubMed.

Results

Women who carry germline mutations in the TP53 gene have a very high risk of breast cancer of up to 85% by age 60 years. Most of these breast cancers are early onset with a median age at diagnosis of 34 years. Approximately 5–8% of women presenting with breast cancer under 30 years old have a germline TP53 gene mutation. Breast cancers in women with TP53 mutations are more likely to be hormone receptor positive and/or Her2 positive. Mastectomy is recommended over lumpectomy in TP53 mutation carriers who have breast cancer so that adjuvant breast radiotherapy can be avoided. Risk-reducing surgery should be considered due to the high contralateral breast cancer risk. Mutation carriers are at high risk of various childhood and adult-onset cancers with a very lifetime risk of malignancy, the commonest malignancies being breast cancer and soft tissue sarcoma. In unaffected female mutation carriers, MRI breast screening or risk-reducing surgery is recommended. The optimal surveillance for other cancers is currently unclear and should ideally be performed as part of a clinical trial.

Conclusions

Identifying a TP53 mutation in a gene panel test is a challenging result for the patient and clinician due to the high risk of second primaries and the lack of consensus about surveillance.

Association between single nucleotide polymorphism rs9534275 and the risk of coronary artery disease and ischemic stroke

BACKGROUND

The present study was to detect the association of single nucleotide polymorphism (SNP) in the breast susceptibility gene 2 (BRCA2) and the risk of coronary artery disease (CAD) and ischemic stroke (IS).

METHODS

Genotypes of the BRCA2 rs9534275 in 1822 unrelated subjects (CAD, 606; IS, 569; and healthy controls, 647) were determined by the polymerase chain reaction and restriction fragment length polymorphism and then confirmed by direct sequencing.

RESULTS

The genotypic and allelic frequencies of rs9534275 were significantly different between the CAD, IS patients and controls (P = 0.033 and P = 0.027; respectively). The GG, GT/GG genotypes and G allele were associated with an increased risk of CAD and IS (CAD: P = 0.005 for GG vs. TT, P = 0.004 for GT/GG vs. TT, P = 0.005 for G vs. T; IS: P = 0.003 for GG vs. TT, P = 0.005 for GT/GG vs. TT; P = 0.002 for G vs. T). The GG, GT and GT/GG genotypes in the CAD, but not in healthy controls and IS patients, were associated with an increased serum total cholesterol (TC) and apolipoprotein B (ApoB) concentration.

CONCLUSIONS

The present study shows that the G allele carriers of BRCA2 rs9534275 were associated with increased serum TC and ApoB levels in the CAD patients and increased risk of CAD and IS.

TRIAL REGISTRATION

Retrospectively registered.

Genetic Testing: Challenges and Changes in Testing for Hereditary Cancer Syndromes

BACKGROUND

The practice of genetic testing for hereditary cancer syndromes has changed dramatically in recent years, and patients often approach oncology nurses requesting information about genetic testing.
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OBJECTIVES

This article aims to explore changes in cancer genetics, the role of genetics professionals in providing comprehensive genetic care, and the implications of these new developments in genetics for oncology nurses.
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METHODS

A literature review was conducted and focused on articles about the updating of genetic tests with panel testing, insurance changes, alternative genetic counseling strategies, and direct-to-consumer genetic testing.
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FINDINGS

Oncology nurses play an important role in identifying and referring patients, including those who have tested negative for hereditary susceptibility genes, to genetics professionals. Genetics professionals can assist with insurance issues, interpretation of test results, clarification when a variant of unknown clinical significance is detected, and recommendations for care based on personal and family history and testing results. Oncology nurses can assist families with understanding the limitations of direct-to-consumer genetic testing.