Breast cancer susceptibility testing: past, present and future

Interdisciplinary risk counseling for hereditary breast and ovarian cancer: real-world data from a specialized center

Purpose

Hereditary breast and ovarian cancer has long been established to affect a considerable number of patients and their families. By identifying those at risk ideally before they have been diagnosed with breast and/or ovarian cancer, access to preventive measures, intensified screening and special therapeutic options can be obtained, and thus, prognosis can be altered beneficially. Therefore, a standardized screening and counseling process has been established in Germany under the aegis of the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC). As one of these specialized clinics, the HBOC-Center at Charité offers genetic counseling as well as genetic analysis based on the GC-HBOC standards. This analysis aims first at depicting this process from screening through counseling to genetic analysis as well as the patient collective and second at correlating the results of genetic analysis performed. Thus, real-world data from an HBOC-Center with a substantial patient collective and a high frequency of pathogenic variants in various genes shall be presented.

Methods

The data of 2531 people having been counseled at the HBOC-Center at Charité in 2016 and 2017 were analyzed in terms of patient and family history as well as pathogenic variants detected during genetic analysis with the TruRisk® gene panel when genetic analysis was conducted. This standardized analysis is compiled and regularly adjusted by the GC-HBOC. The following genes were included at time of research: BRCA1, BRCA2, ATM, CDH1, CHEK2, PALB2, RAD51C, RAD51D, NBN, and TP53.

Results

Genetic analysis was conducted in 59.8% of all cases meeting the criteria for genetic analysis and 286 pathogenic variants were detected among 278 (30.3%) counselees tested using the TruRisk® gene panel. These were primarily found in the genes BRCA1 (44.8%) and BRCA2 (28.3%) but also in CHEK2 (12.2%), ATM (5.6%) and PALB2 (3.5%). The highest prevalence of pathogenic variants was seen among the families with both ovarian and breast cancer (50.5%), followed by families with ovarian cancer only (43.2%) and families with breast cancer only (35.6%)—these differences are statistically significant (p < 0.001). Considering breast cancer subtypes, the highest rate of pathogenic variants was detected among patients with triple-negative breast cancer (40.7%) and among patients who had had been diagnosed with triple-negative breast cancer before the age of 40 (53.4%)—both observations proved to be statistically significant (p = 0.003 and p = 0.001).

Conclusion

Genetic counseling and analysis provide the foundation in the prevention and therapy of hereditary breast and ovarian cancer. The rate of pathogenic variants detected is associated with family history as well as breast cancer subtype and age at diagnosis, and can reach considerable dimensions. Therefore, a standardized process of identification, genetic counseling and genetic analysis deems mandatory.

Concurrent Prophylactic Mastectomy, Immediate Reconstruction, and Salpingo-Oophorectomy in High-Risk Patients: A Case Series

Purpose

There are limited data on coordinated breast and gynecological risk-reduction surgery for high-risk patients in Canada. Therefore, this study aims to evaluate the patient demographics, surgical details, and outcomes of prophylactic mastectomy (PM) with immediate reconstruction and bilateral salpingo-oophorectomy (BSO) in high-risk patients.

Methods

We conducted a retrospective chart review at an academic center of patients who concurrently underwent PM with immediate reconstruction and laparoscopic BSO over a 7-year period (March 2010-February 2017) were identified.

Results

A total of 16 patients underwent PM with immediate reconstruction and concurrent BSO. The mean age at the time of surgery was 46.2 ± 6.6 years. Thirteen (81%) patients were carriers of the BRCA1 or BRCA2 mutation. Two patients had prophylactic surgical therapy for BRCA1 mutation and 14 (87.5%) patients had prior oncological treatment. The most common type of procedures performed were skin-sparing, nipple-sparing mastectomy (56.2%) and reconstruction with acellular dermal matrix and implants (43.8%). All patients underwent laparoscopic BSO. The average combined case time was 282.5 ± 81.3 minutes with an average postoperative hospital stay of 1.3 ± 0.5 days. Six (37.5%) patients presented with 30-day postoperative complications, with higher rates in the alloplastic group. There were no gynecological complications.

Conclusions

In conclusion, our results demonstrate that a combined multidisciplinary surgical approach did not increase length of stay or 30-day complication rates. Furthermore, concurrent risk-reducing strategies are an effective option for patients at high risk of breast or ovarian cancer.

Cancer Genetics

For most individuals, cancer development is multifactorial; however, up to 10% of all cancers are related to an inherited genetic mutation. As health care shifts to having a greater emphasis on prevention, care providers, including general surgeons, will need to play a role in identifying patients at high risk for cancer development. Genetic testing provides a tool to determine those patients with a genetic mutation and to whom appropriate preventive care and treatment may be offered. It is imperative for general surgeons to understand the role genetics plays in the care of individual patients and their relatives.

Precision Medicine from a Public Health Perspective

Over the past decade, precision medicine (PM) approaches have received significant investment to create new therapies, learn more about disease processes, and potentially prevent diseases before they arise. However, in many ways, PM investments may come at the expense of existing public health measures that could have a greater impact on population health. As we tackle burgeoning public health concerns, such as obesity, and chronic diseases, such as cancer, it is not clear whether PM is aligned with public health or in conflict with its goals. We summarize the areas of promise demonstrated by PM, discuss the limitations of each of these areas from a population health perspective, and discuss how we can approach PM in a manner that is congruent with the core aims of public health.

Familial breast cancer: Genetic counseling over time, including patients´ expectations and initiators considering the Angelina Jolie effect

Purpose

The German Consortium for hereditary breast/ovarian cancer (GC-HBOC) aims for nationwide access to professional, individualized yet structured care for families at high risk. The identification of such families remains key for optimal care. Our study evaluates counselees’ characteristics, referral practices, expectations and motivations in respect to their first genetic consultation. The impact of the Angelina Jolie Effect (AJE) was prospectively assessed.

Methods

All counselees could participate through a questionnaire. Groups were built in respect to neoadjuvant chemotherapy (FT) and before/after AJE.

Results

The 917 (88.5%) counselees (FT: 8.2%) were on average female (97.3%), with a mean age of 44.6, had children (71.9%), higher education (88%), personal (46.4%) or at least one first-degree relative (74.6%) with BC/OC or known BRCA1/2 mutation (11.8%), were in a relationship (76.1%), and living in a village (40.7%). The AJE is associated with significantly fewer cancelations (p = 0.005), more attendance among men (4.2% vs. 0.8%, p = 0.002), and people with familial BRCA1/2 (14.8% vs. 7.5%, p = 0.003). The majority seek information regarding their cancer risk (83%) or relatives’ risk (74.8%), HBOC (69.1%), and surveillance programs for themselves (66.6%) or relatives (60.6%).

Conclusion

Enhanced media awareness of genetic cancer motivates patients, including other patient groups. A higher number of participants, including more men, are attending GC due to the AJE. In terms of the rising complexity of genetic testing, the analysis of patients’ expectations and initiators for GC suggests that there is an urgent need to develop to participate motivation analysis. The factors revealed as impediments to accessing GC-HBOC guide recommendations to optimize access to genetic counseling. Medical educational programs for primary gynecologists and families at risk might be options to reach more participants.

Adherence to the breast cancer surveillance program for women at risk for familial breast and ovarian cancer versus overscreening: a monocenter study in Germany

Breast cancer (BC) is the leading cancer among women worldwide and in 5-10 % of cases is of hereditary origin, mainly due to BRCA1/2 mutations. Therefore, the German Consortium for Familial Breast and Ovarian Cancer (HBOC) with its 15 specialized academic centers offers families at high risk for familial/hereditary cancer a multimodal breast cancer surveillance program (MBCS) with regular breast MRI, mammography, ultrasound, and palpation. So far, we know a lot about the psychological effects of genetic testing, but we know little about risk-correlated adherence to MBCS or prophylactic surgery over time. The aim of this study was to investigate counselees' adherence to recommendations for MBCS in order to adjust the care supply and define predictors for incompliance. All counselees, who attended HBOC consultation at the University Hospital Heidelberg between July 01, 2009 and July 01, 2011 were eligible to participate. A tripartite questionnaire containing sociodemographic information, psychological parameters, behavioral questions, and medical data collection from the German consortium were used. A high participation rate was achieved among the study population, with 72 % returning the questionnaire. This study showed a rate of 59 % of full-adherers to the MBCS. Significant predictors for partial or full adherence were having children (p = 0.0221), younger daughters (p = 0.01795), a higher awareness of the topic HBOC (p = 0.01795, p < 0.0001), a higher perceived breast cancer risk (p < 0.0001), and worries (p = 0.0008)/impairment (p = 0.0257) by it. Although the current data suggest a good adherence of MBCS, prospective studies are needed to understand counselees' needs to further improve surveillance programs and adherence to them. Adherence to the breast cancer surveillance program for women at risk for familial breast and ovarian cancer versus overscreening-a monocenter study in Germany.

Fanconi anemia pathway defects in inherited and sporadic cancers

Fanconi anemia (FA) is a recessive chromosomal instability syndrome. It is a hereditary disorder with defects in DNA repair characterized by progressive bone marrow failure, variable congenital malformations and predisposition to develop hematological or solid tumors. Bi-allelic gene mutations in FA cause not only the FA phenotype but also genome instability and additional mutations in their somatic cells resulting in a high predisposition to many different types of cancers. Mono-allelic mutation in FA genes increases the susceptibility to several types of cancers in a sporadic manner in non-FA patients. The strong link between cancer from bi-allelic and mono-allelic FA gene mutations has been well established. Studies have demonstrated a link between FA and cancer due to gene defects which cause the disruption of the FA pathways in a proportion of familial and sporadic cancers. The convincing evidence is that one of the FA genes, FANCD1 is identical to the well-known breast cancer susceptibility gene, BRCA2. Another three FA genes were found to be associated with genes mutated from breast cancer and other types of cancers such as prostate cancer as well. Studies on FA's biological function in genome instability maintenance, DNA damage/repair and its complex regulation pathways have become the main focus within the genetic cancer research field because of many unique features of FA. The lessons learnt from FA studies provided invaluable information towards the understanding of cancer pathogenesis to be translated into targeting cancer therapies. Studies also demonstrated that FA is a paradigm of cancer-prone inherited monogenic disease, offering insights into the pathogenesis of many types of human diseases, particularly in bone marrow failure, cancer and aging. In this review, brief FA clinical characteristics, identification of FA genes and their protein pathways, the pathogenic linking between cancers from bi-allelic and mono-allelic mutated FA genes will be discussed.

Extent of primary breast cancer surgery: standards and individualized concepts

Surgery is still a main therapeutic option in breast cancer treatment. Nowadays, methods of resection and reconstruction vary according to different tumors and patients. This review presents and discusses standards of care and arising questions on how radical primary breast cancer surgery should be according to different clinical situations. In most early breast cancer patients, breast conservation is the method of choice. The discussion on resection margins is still controversial as different studies show conflicting results. Modified radical mastectomy is the standard in locally advanced breast cancer patients, although there are different promising approaches to spare skin or even the nipple-areola complex. A sentinel node biopsy is the standard of care in clinically node-negative invasive breast cancer patients, whereas the significance of axillary lymphonodectomy seems to be questioned through a number of different findings. Although there are interesting findings to modify surgical approaches in very young or elderly breast cancer patients, it will always be an individualized approach if we do not adhere to current guidelines. Up to date, there are no special surgical procedures in BRCA mutation carriers or patients of high-risk families.

Identification of a novel in-frame deletion in BRCA2 and analysis of variants of BRCA1/2 in Italian patients affected with hereditary breast and ovarian cancer

BACKGROUND

An estimated 5 % – 10 % of all breast cancers are due to an inherited predisposition and, out of these, about 30 % are caused by germline mutations of the BRCA1 and BRCA2 genes. The prevalence of germline mutations in theBRCA1 and BRCA2 genes varies among ethnic groups. The aims of this study are to evaluate deleterious mutations and genomic rearrangements in BRCA1/2 genes and the CHEK21100delC mutation in a cohort of Italian women affected with hereditary breast and/or ovarian cancer. In addition we clarify the effect of the novel variants identified in BRCA2 gene bymRNA analysis and prediction software.

METHODS

We enrolled 103 consecutive Italian patients affected with hereditary breast and/or ovarian cancer, aged23 – 69 years.

RESULTS

We found BRCA1/2 mutations in 15/103 probands(14.6 % ). Among these, a BRCA2 gene mutation has not been described previously. In addition, we identified five novel BRCA2 variants (S1341, IVS1-59t > c, IVS11-74insA, IVS12 + 74c > g and I1167V). No genomic BRCA1/2re arrangements or CHEK2 1100delC mutation was found in our patients. The novel BRCA2 mutation NS1742del(p.N1742_S1743del) was an in-frame 6 bp deletion that results in loss of two amino acids.

CONCLUSIONS

In silico analysis conducted for S1341, IVS1-59t > c, IVS11-74insA and IVS12 + 74c > g of BRCA2 predicted the variants as neutral and benign, whereas the results for I1167V was inconclusive. mRNA analysis for the novel BRCA2 intronic variant IVS11-74insA and the already published BRCA1 variant C197 shows that they have no effect on the splicing. These results are in agreement with in silico analysis.

Cancer syndromes and therapy by stop-codon readthrough

Several hereditary cancer syndromes are associated with nonsense mutations that create premature termination codons (PTC). Therapeutic strategies involving readthrough induction partially restore expression of proteins with normal function from nonsense-mutated genes, and small molecules such as aminoglycosides and PTC124 have exhibited promising results for treating patients with cystic fibrosis and Duchenne muscular dystrophy. Transgenic expression of suppressor-tRNAs and depleting translation termination factors are, among others, potential strategies for treating PTC-associated diseases. In this review, the potential of using readthrough strategies as a therapy for cancer syndromes is discussed, and we consider the effect of nonsense-mediated decay and other factors on readthrough efficiency.

Development of breast cancer in a 21-year-old childhood Wilms' tumor survivor with a BRCA1 2634delC mutation

Breast cancer at age 21 is rare, even in individuals who have a genetic predisposition. These early diagnoses are usually the result of a hereditary cancer syndrome. Other contributing factors, such as chemotherapy and radiation for previous malignancies, can also increase the risk of secondary malignancies, including breast cancer. Here we present one of the youngest cases of breast cancer reported in the literature: a 21-year-old Wilms' tumor survivor (diagnosed at age 6), who was found to have a familial BRCA1 mutation and was diagnosed with ductal carcinoma in situ at age 21.

Risk-reducing strategies for women carrying BRCA1/2 mutations with a focus on prophylactic surgery

Background

Women who have inherited mutations in the BRCA1 or BRCA2 genes have substantially elevated risks of breast and ovarian cancer. Mutation carriers have various options, including extensive and regular surveillance, chemoprevention and risk-reducing surgery. The aim of this review is to provide an up-to-date analysis and to subsequently summarise the available literature in relation to risk-reducing strategies, with a keen focus on prophylactic surgery.

Methods

The literature review is facilitated by Medline and PubMed databases. The cross-referencing of the obtained articles was used to identify other relevant studies.

Results

Prophylactic surgery (bilateral mastectomy, bilateral salpingo-oophorectomy or a combination of both procedures) has proved to be the most effective risk-reducing strategy. There are no randomised controlled trials able to demonstrate the potential benefits or harms of prophylactic surgery; therefore, the evidence has been derived from retrospective and short follow-up prospective studies, in addition to hypothetical mathematical models.

Based on the current knowledge, it is reasonable to recommend prophylactic oophorectomy for BRCA1 or BRCA2 mutation carriers when childbearing is completed in order to reduce the risk of developing breast and ovarian cancer. In addition, women should be offered the options of rigorous breast surveillance, chemoprevention with anti-oestrogens--especially for carriers of BRCA2--or bilateral prophylactic mastectomy.

Conclusion

The selection of the most appropriate risk-reducing strategy is not a straightforward task. The impact of risk-reducing strategies on cancer risk, survival, and overall quality of life are the key criteria considered for decision-making. Notably, various other factors should be taken into consideration when evaluating individual mutation carriers' individual circumstances, namely woman's age, morbidity, type of mutation, and individual preferences and expectations.

Although prospective randomised controlled trials concerned with examining the various interventions in relation to the woman's age and type of mutation are needed, randomisation is extremely difficult and rather deemed unethical given the current available evidence from retrospective studies.

Genomic alterations in histopathologically normal breast tissue from BRCA1 mutation carriers may be caused by BRCA1 haploinsufficiency

Multiple biopsies of normal breast tissue from 10 BRCA1 mutation carriers have been analyzed using array-based comparative genomic hybridization. Normal breast tissue from five age-matched control subjects without a family history of breast cancer was included for reference purposes. We repeatedly found multiple low copy number aberrations at a significantly higher frequency in histopathologically normal tissue from BRCA1 mutation carriers than in normal control tissue. Some of these aberrations were similar across samples from different patients and linked to biological functions such as transcriptional regulation and DNA binding. We also observed a high degree of genomic heterogeneity between samples from the same patient, suggestive of tissue heterogeneity and etiological clonality in the breast epithelium. We show that neither loss of heterozygosity nor promoter methylation of the wild-type BRCA1 allele is the predominant mechanistic origin of the observed genomic instability. Instead, we propose that haploinsufficiency of BRCA1 might be the underlying cause responsible for initiation of breast cancer in these predisposed women, making cells vulnerable to mitotic recombination. We also propose that loss of ERalpha expression is preceded by genetic instability in the initiation of BRCA1-dependent tumorigenesis, indicating that the breast epithelium of BRCA1 mutation carriers may initially be estrogen-responsive. Our results imply that genomic instability instigated by BRCA1 haploinsufficiency may be required for breast cancer initiation in BRCA1 mutation carriers. Finding molecular markers of tumor initiation and progression, for the potential use in early disease detection, may be of great clinical importance for the improved management of at-risk women.

BRCA1/2 genetic background-based therapeutic tailoring of human ovarian cancer: hope or reality?

Ovarian epithelial tumors are an hallmark of hereditary cancer syndromes which are related to the germ-line inheritance of cancer predisposing mutations in BRCA1 and BRCA2 genes. Although these genes have been associated with multiple different physiologic functions, they share an important role in DNA repair mechanisms and therefore in the whole genomic integrity control. These findings have risen a variety of issues in terms of treatment and prevention of breast and ovarian tumors arising in this context. Enhanced sensitivity to platinum-based anticancer drugs has been related to BRCA1/2 functional loss. Retrospective studies disclosed differential chemosensitivity profiles of BRCA1/2-related as compared to "sporadic" ovarian cancer and led to the identification of a "BRCA-ness" phenotype of ovarian cancer, which includes inherited BRCA1/2 germ-line mutations, a serous high grade histology highly sensitive to platinum derivatives. Molecularly-based tailored treatments of human tumors are an emerging issue in the "era" of molecular targeted drugs and molecular profiling technologies. We will critically discuss if the genetic background of ovarian cancer can indeed represent a determinant issue for decision making in the treatment selection and how the provocative preclinical findings might be translated in the therapeutic scenario. The presently available preclinical and clinical evidence clearly indicates that genetic background has an emerging role in treatment individualization for ovarian cancer patients.

Stem cells and genetic disease

Stem cell research is now a very broad field encompassing cells derived from all stages of life from the embryonic stem cells of the early blastocyst through to the adult stem cells of many tissues of the body. Adult stem cells from a variety of tissues are proving to be pluripotent and can differentiate into cell types different from the tissues from which they derive. Pre-clinical animal models indicate that adult stem cells do not cause tumours, not even, teratomas when transplanted. These properties, combined with the possibility of autologous transplantation, indicate significant advantages over embryonic stem cells in many proposed clinical applications.

Utility of family history reports of major birth defects as a public health strategy

A major birth defect is an abnormality that can affect the structure or function of an organ. In the United States, major birth defects are the leading cause of infant mortality and contribute substantially to childhood disability and morbidity. Globally, these conditions lead to the death of millions of infants and children annually. Patients with 1 or more affected family members may be at increased risk for having a child with a major birth defect; thus, accurate knowledge of these conditions among family members of their patients gives the clinician the ability to provide improved risk assessment and reproductive planning. Such knowledge can also serve as motivation for patients to adhere to healthy behaviors such as folic acid use or smoking cessation. To evaluate the utility of collecting family history reports of major birth defects as a public health strategy, 6 key criteria were examined by reviewing the relevant published literature. Overall, the review showed that major birth defects satisfied several of the criteria. Additional research is needed, however, regarding the awareness of parent reports of the occurrence of these conditions among relatives and how knowledge of birth defect diagnoses and related risk factors are transmitted among relatives. Such research needs to encompass not only immediate family members but also other first-degree and second-degree relatives. In summary, routine collection of family history reports of birth defects in pediatric practice holds promise as a public health strategy to reduce the burden of morbidity, mortality, and disability associated with major birth defects.

Risk-based and diagnostics-linked personalized medicine for cancer

Personalized medicine is gaining momentum in healthcare by allowing physicians to determine an individual’s predisposition to different diseases and to better diagnose and treat those diseases. Personalized medicine is frequently described as the right drug for the right patient at the right time; that is, a physician will prescribe treatment based on the individual characteristics of each patient such that the patient is likely to respond to a particular treatment with minimal adverse events. The heterogeneity of cancer makes the implementation of personalized medicine a necessity.

Differences in the frequency and distribution of BRCA1 and BRCA2 mutations in breast/ovarian cancer cases from the Basque country with respect to the Spanish population: implications for genetic counselling

The prevalence of unique and recurrent BRCA1 and BRCA2 pathogenic mutations and unclassified variants varies among different populations. Two hundred and thirty-six breast and/or ovarian cancer patients were analysed to clarify the role of these genes in the Basque Country. We also studied 130 healthy women from the general population from the same region. Fifteen different pathological mutations were found in 16 index cases: 10 truncating mutations, 4 missense mutations and 1 splicing mutation. c.3002_3003insT and c.5788_5789delGT, both in exon 11 of BRCA2 have not previously been described. No pathological mutations were found in cases of sporadic juvenile breast cancer. There are no recurrent mutations in our population; apart from the mutation c.9254_9258del5, which appears in only two index cases. We have also found a lot of variants whose effect is unknown. From these variants, 17 have not previously been described: 6 missenses, 6 synonymous and 5 alterations in intronic regions. We would like to highlight the fact that 14.3% of patients with 3 or more cases of breast cancer in the family, and 16.7% of patients with family history of breast and ovarian cancer, present a pathological mutation in BRCA1 or BRCA2. This manuscript demonstrates that each population can have different mutations and due to this, Genetic Counselling and selection criteria must be different for each population. Furthermore, this article describes for the first time some new mutations and unclassified variants found in our population.