Pathology of breast and ovarian cancers among BRCA1 and BRCA2 mutation carriers: results from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA)

Inherited Breast Cancer in Nigerian Women

PURPOSE

Among Nigerian women, breast cancer is diagnosed at later stages, is more frequently triple-negative disease, and is far more frequently fatal than in Europe or the United States. We evaluated the contribution of an inherited predisposition to breast cancer in this population.

PATIENTS AND METHODS

Cases were 1,136 women with invasive breast cancer (mean age at diagnosis, 47.5 ± 11.5 years) ascertained in Ibadan, Nigeria. Patients were selected regardless of age at diagnosis, family history, or prior genetic testing. Controls were 997 women without cancer (mean age at interview, 47.0 ± 12.4 years) from the same communities. BROCA panel sequencing was used to identify loss-of-function mutations in known and candidate breast cancer genes.

RESULTS

Of 577 patients with information on tumor stage, 86.1% (497) were diagnosed at stage III (241) or IV (256). Of 290 patients with information on tumor hormone receptor status and human epidermal growth factor receptor 2, 45.9% (133) had triple-negative breast cancer. Among all cases, 14.7% (167 of 1,136) carried a loss-of-function mutation in a breast cancer gene: 7.0% in BRCA1, 4.1% in BRCA2, 1.0% in PALB2, 0.4% in TP53, and 2.1% in any of 10 other genes. Odds ratios were 23.4 (95% CI, 7.4 to 73.9) for BRCA1 and 10.3 (95% CI, 3.7 to 28.5) for BRCA2. Risks were also significantly associated with PALB2 (11 cases, zero controls; P = .002) and TP53 (five cases, zero controls; P = .036). Compared with other patients, BRCA1 mutation carriers were younger ( P < .001) and more likely to have triple-negative breast cancer ( P = .028).

CONCLUSION

Among Nigerian women, one in eight cases of invasive breast cancer is a result of inherited mutations in BRCA1, BRCA2, PALB2, or TP53, and breast cancer risks associated with these genes are extremely high. Given limited resources, prevention and early detection services should be especially focused on these highest-risk women.

Comprehensive Analysis of Germline Variants in Mexican Patients with Hereditary Breast and Ovarian Cancer Susceptibility

Hereditary breast and ovarian cancer syndrome (HBOC) represents 5⁻10% of all patients with breast cancer and is associated with high-risk pathogenic alleles in BRCA1/2 genes, but only for 25% of cases. We aimed to find new pathogenic alleles in a panel of 143 cancer-predisposing genes in 300 Mexican cancer patients with suspicion of HBOC and 27 high-risk patients with a severe family history of cancer, using massive parallel sequencing. We found pathogenic variants in 23 genes, including BRCA1/2. In the group of cancer patients 15% (46/300) had a pathogenic variant; 11% (33/300) harbored variants with unknown clinical significance (VUS) and 74% (221/300) were negative. The high-risk group had 22% (6/27) of patients with pathogenic variants, 4% (1/27) had VUS and 74% (20/27) were negative. The most recurrent mutations were the Mexican founder deletion of exons 9-12 and the variant p.G228fs in BRCA1, each found in 5 of 17 patients with alterations in this gene. Rare VUS with potential impact at the protein level were found in 21 genes. Our results show for the first time in the Mexican population a higher contribution of pathogenic alleles in other susceptibility cancer genes (54%) than in BRCA1/2 (46%), highlighting the high locus heterogeneity of HBOC and the necessity of expanding genetic tests for this disease to include broader gene panels.

Olaparib tablets for the treatment of germ line BRCA-mutated metastatic breast cancer

INTRODUCTION

Germ line BRCA mutations (gBRCAm) are diagnosed in approximately 5% of unselected breast cancer patients. Olaparib is a new treatment option for patients with a gBRCAm who have metastatic HER2-negative breast cancer. Areas covered: Olaparib is an oral poly (ADP-ribose) polymerase inhibitor that has been shown in phase I-III clinical trials to have single-agent efficacy in breast cancer patients with gBRCAm. The recent phase III OlympiAD study demonstrated a statistically significant progression-free survival benefit compared with the chemotherapy control arm, although an overall survival benefit has not been demonstrated. The most common adverse events seen with olaparib include nausea, anemia, and vomiting. The most common grade 3 adverse events are anemia and neutropenia. Expert commentary: The US FDA-approved olaparib tablets in January 2018 for the treatment of patients with a gBRCAm and metastatic HER2-negative breast cancer. This is a well-tolerated and effective treatment option for this patient population, particularly in patients with triple-negative breast cancer in which chemotherapy is the only alternative. More data are needed to understand the role of olaparib in combination with endocrine therapy, other targeted agents, and chemotherapy, as well as sequentially with platinum chemotherapy in the metastatic setting.

Male Breast Cancer in the Age of Genetic Testing: An Opportunity for Early Detection, Tailored Therapy, and Surveillance

In detection, treatment, and follow-up, male breast cancer has historically lagged behind female breast cancer. On the whole, breast cancer is less common among men than among women, limiting utility of screening, yet the incidence of male breast cancer is rising, and there are men at high risk for breast cancer. While women at high risk for breast cancer are well characterized, with clearly established guidelines for screening, supplemental screening, risk prevention, counseling, and advocacy, men at high risk for breast cancer are poorly identified and represent a blind spot in public health. Today, more standardized genetic counseling and wider availability of genetic testing are allowing identification of high-risk male relatives of women with breast cancer, as well as men with genetic mutations predisposing to breast cancer. This could provide a new opportunity to update our approach to male breast cancer. This article reviews male breast cancer demographics, risk factors, tumor biology, and oncogenetics; recognizes how male breast cancer differs from its female counterpart; highlights its diagnostic challenges; discusses the implications of the widening clinical use of multigene panel testing; outlines current National Comprehensive Cancer Network guidelines (version 1, 2018) for high-risk men; and explores the possible utility of targeted screening and surveillance. Understanding the current state of male breast cancer management and its challenges is important to shape future considerations for care. Shifting the paradigm of male breast cancer detection toward targeted precision medicine may be the answer to improving clinical outcomes of this uncommon disease. ^©RSNA, 2018.

BRCA1 founder mutations and beyond in the Polish population: A single-institution BRCA1/2 next-generation sequencing study

Hereditary mutations in BRCA1/2 genes increase the risk of breast cancer by 60–80% and ovarian cancer by about 20–40% in female carriers. Detection of inherited mutations in asymptomatic carriers allows for the implementation of appropriate preventive measures. BRCA1/2 genotyping is also important for poly(adenosine diphosphate)-ribose polymerase (PARP) inhibitor administration. This work addresses the need for next-generation sequencing (NGS) technology for the detection of BRCA1/2 mutations in Poland where until recently mostly founder mutations have been tested, and whether BRCA diagnostics should be extended beyond the panel of founder mutations in this population. The study comprises 2931 patients who were referred for genetic counseling and tested for founder and recurrent mutations in BRCA1 (5382insC (c.5266dupC; p.Gln1756Profs), c.5370C>T (c.5251C>T; p.R1751*), 300T>G (c.181T>G; p.Cys61Gly), 185delAG (c.68_69delAG; p.Glu23Valfs), and 4153delA (c.4035delA; p.Glu1346Lysfs)) by high-resolution melting/Sanger sequencing. A total of 103 (3.5%) mutations were detected, including 53 (51%) in healthy subjects and 50 (49%) in cancer patients. Then, based on more stringent clinical and pedigree criteria, sequencing of all BRCA1/2 exons was performed in 454 (16%) patients without founder mutations by NGS, which detected 58 mutations (12.8%), 40 (8.8%) of which were pathogenic. In 14 (3.1%) subjects, variants of uncertain significance (VUS) were detected, and in four (0.9%) subjects, the detected mutations were benign. In total, 161 mutations were detected using our two-step algorithm (founder test and NGS), of which 64% were founder mutations, 25% were NGS-detected pathogenic mutations, 9% were VUS, and 2% were benign. In addition, 38 mutations not yet reported in the Polish population were detected. In total, founder mutations accounted for only 64% of all detected mutations, and the remaining mutations (36%) were dispersed across the BRCA1/2 gene sequences. Thus, in Poland, testing for constitutional mutations in BRCA1/2 should be carried out in two stages, where NGS is performed in qualifying subjects if founder mutations are not identified.

Targeting ubiquitin-proteasome pathway by natural, in particular polyphenols, anticancer agents: Lessons learned from clinical trials

The ubiquitin-proteasome pathway (UPP) is the main non-lysosomal proteolytic system responsible for degradation of most intracellular proteins, specifically damaged and regulatory proteins. The UPP is implicated in all aspects of the cellular metabolic networks including physiological or pathological conditions. Alterations in the components of the UPP can lead to stabilization of oncoproteins or augmented degradation of tumour suppressor favouring cancer appearance and progression. Polyphenols are natural compounds that can modulate proteasome activity or the expression of proteasome subunits. All together and due to the pleiotropic functions of UPP, there is a great interest in this proteasome system as a promising therapeutic target for the development of novel anti-cancer drugs. In the present review, the main features of the UPP and its implication in cancer development and progression are described, highlighting the importance of bioactive polyphenols that target the UPP as potential anti-cancer agents.

The Preventive Intervention of Hereditary Breast Cancer

Approximately 5-10% of breast cancer is considered to be hereditary. Familial breast cancers exhibit a dominant hereditary pattern, which typically have an early age of onset and are accompanied by symptoms of ovarian cancer, bilateral breast cancer, or male breast cancer. BRCA gene mutation carriers should be regarded as high-risk groups for breast cancer, which necessitates early examination of breast cancer. Studies have built up kinds of predictive models and recommended that female BRCA mutation carriers should receive breast self-test training and take monthly breast self-examination. Familial or hereditary breast cancer family members are high-risk groups, and their risks of breast cancer can be reduced by chemoprevention, including dietary composition adjustment and application of endocrine drugs. In recent years, large-scale clinical trials have shown the important role of chemoprevention in reducing the occurrence of hereditary breast cancer. Prophylactic mastectomy is also suitable for healthy women with high breast cancer risk factors. It can reduce the incidence rate of breast cancer in high-risk women by 90% and decrease the breast cancer mortality rate in medium-risk and high-risk women by 100% and 81%, respectively.

Breast cancer in women with neurofibromatosis type 1 (NF1): a comprehensive case series with molecular insights into its aggressive phenotype

PURPOSE

The purpose of the study was to improve the understanding of NF1-associated breast cancer, given the increased risk of breast cancer in this tumour predisposition syndrome and the limited data.

METHODS

We identified 18 women with NF1 and breast cancer at our institution. Clinical and pathologic characteristics of NF1-associated breast cancers were compared with 7132 breast cancers in patients without NF1 from our institutional database. Next generation sequencing was performed on DNA from blood and breast cancer specimens available. Blood specimens negative for NF1 mutation were subjected to multiplex ligation-dependent probe amplification (MLPA) to identify complete/partial deletions or duplications. Expression of neurofibromin in the NF1-associated breast cancers was evaluated using immunohistochemistry.

RESULTS

There was a higher frequency of grade 3 (83.3% vs 45.4%, p = 0.005), oestrogen receptor (ER) negative (66.7% vs 26.3%, p < 0.001) and human epidermal growth factor receptor 2 (HER2)-positive (66.7% vs 23.4%, p < 0.001) tumours among NF1 patients compared to non-NF1 breast cancers. Overall survival was inferior in NF1 patients in multivariable analysis (hazard ratio 2.25, 95% CI 1.11-4.60; p = 0.025). Apart from germline NF1 mutations (11/16; 69%), somatic mutations in TP53 (8/10; 80%), second-hit NF1 (2/10; 20%), KMT2C (4/10; 40%), KMT2D (2/10; 20%), and PIK3CA (2/10; 20%) were observed. Immunohistochemical expression of neurofibromin was seen in the nuclei and/or cytoplasm of all specimens, but without any consistent pattern in the intensity or extent.

CONCLUSIONS

This comprehensive series of NF1-associated breast cancers suggests that their aggressive features are related to germline NF1 mutations in cooperation with somatic mutations in TP53, KMT2C and other genes.

Characteristics of Lynch syndrome associated ovarian cancer

OBJECTIVE

To describe clinical characteristics of Lynch syndrome associated ovarian cancer and the efficacy of surveillance in the early detection of these ovarian cancers.

METHODS

All Lynch syndrome associated ovarian cancer cases identified in either the Dutch Lynch syndrome registry (DLSR) between 1987 and 2016, and/or the cohort at the University Medical Center Groningen (UMCG) between 1993 and 2016 were included. Clinical data on age at diagnosis, mutation type, histological type, FIGO stage, treatment, follow-up and gynecological surveillance were collected.

RESULTS

A total of 46/798 (6%) women in the DLSR and 7/80 (9%) in the UMCG cohort were identified as LS associated ovarian cancer patients. The median age at ovarian cancer diagnosis was 46.0 years (range 20-75 years). The most frequently reported histological type was endometrioid adenocarcinoma (40%; n = 21) and serous carcinoma (36%; n = 19). Most tumors (87%; n = 46) were detected at an early stage (FIGO I/II). Forty-one of 53 (77%) patients were diagnosed with ovarian cancer before LS was diagnosed. In the other 12/53 (23%) women, ovarian cancer developed after starting annual gynecological surveillance for LS; three ovarian cancers were screen-detected in asymptomatic women. Overall survival was 83%.

CONCLUSION

Ovarian cancer in women with LS has a wide age-range of onset, is usually diagnosed at an early stage with predominantly endometrioid type histology and a good overall survival. The early stage at diagnosis could not be attributed to annual gynecological surveillance.

BRCA1/2 testing: therapeutic implications for breast cancer management

Testing for germline BRCA1/2 mutations has an established predictive role in breast cancer risk assessment. More recently, studies have also identified BRCA1/2 status as clinically relevant in the selection of therapy for patients already diagnosed with breast cancer. Emerging breast and ovarian cancer research indicate that BRCA status predicts responsiveness to platinum-based chemotherapy, as well as to inhibitors of poly(ADP-ribose) polymerase (PARP), owing to the ability of these interventions to inhibit DNA repair pathways. BRCA1/2 mutation testing thus has important and expanding roles in treatment planning for subsets of patients with breast cancer. Recent studies have demonstrated different activity of platinum salts in BRCA-mutated compared with non-BRCA-mutated breast cancer. Furthermore, phase II/III studies of single-agent PARP inhibitors (PARPi) have shown encouraging progression-free survival results in patients with BRCA1/2-mutated breast cancer, which led to the recent approval of olaparib, the first PARPi to be approved in breast cancer. Determining BRCA1/2 mutation status in this breast cancer subgroup could potentially expand treatment options beyond the current standard of taxane and anthracycline-based chemotherapy. Although attempts have been made to develop scoring systems that measure defects in homologous recombination repair pathways to predict response to platinum or PARPi, none have yet made it into clinical use. In this review, we summarise the recent and ongoing preclinical and clinical studies on the treatment of BRCA-associated breast cancer, and discuss efforts to identify other breast cancer patients who may be responsive to therapies effective in BRCA mutation carriers, including platinum-containing chemotherapy and PARPi.

BRCA mutations and their influence on pathological complete response and prognosis in a clinical cohort of neoadjuvantly treated breast cancer patients

PURPOSE

BRCA1/2 mutations influence the molecular characteristics and the effects of systemic treatment of breast cancer. This study investigates the impact of germline BRCA1/2 mutations on pathological complete response and prognosis in patients receiving neoadjuvant systemic chemotherapy.

METHODS

Breast cancer patients were tested for a BRCA1/2 mutation in clinical routine work and were treated with anthracycline-based or platinum-based neoadjuvant chemotherapy between 1997 and 2015. These patients were identified in the tumor registry of the Breast Center of the University of Erlangen (Germany). Logistic regression and Cox regression analyses were performed to investigate the associations between BRCA1/2 mutation status, pathological complete response, disease-free survival, and overall survival.

RESULTS

Among 355 patients, 59 had a mutation in BRCA1 or in BRCA2 (16.6%), 43 in BRCA1 (12.1%), and 16 in BRCA2 (4.5%). Pathological complete response defined as "ypT0; ypN0" was observed in 54.3% of BRCA1/2 mutation carriers, but only in 22.6% of non-carriers. The adjusted odds ratio was 2.48 (95% CI 1.26-4.91) for BRCA1/2 carriers versus non-carriers. Patients who achieved a pathological complete response had better disease-free survival and overall survival rates compared with those who did not achieve a pathological complete response, regardless of BRCA1/2 mutation status.

CONCLUSIONS

BRCA1/2 mutation status leads to better responses to neoadjuvant chemotherapy in breast cancer. Pathological complete response is the main predictor of disease-free survival and overall survival, independently of BRCA1/2 mutation status.

Morphology and genomic hallmarks of breast tumours developed by ATM deleterious variant carriers

Background

The ataxia telangiectasia mutated (ATM) gene is a moderate-risk breast cancer susceptibility gene; germline loss-of-function variants are found in up to 3% of hereditary breast and ovarian cancer (HBOC) families who undergo genetic testing. So far, no clear histopathological and molecular features of breast tumours occurring in ATM deleterious variant carriers have been described, but identification of an ATM-associated tumour signature may help in patient management.

Methods

To characterise hallmarks of ATM-associated tumours, we performed systematic pathology review of tumours from 21 participants from ataxia-telangiectasia families and 18 participants from HBOC families, as well as copy number profiling on a subset of 23 tumours. Morphology of ATM-associated tumours was compared with that of 599 patients with no BRCA1 and BRCA2 mutations from a hospital-based series, as well as with data from The Cancer Genome Atlas. Absolute copy number and loss of heterozygosity (LOH) profiles were obtained from the OncoScan SNP array. In addition, we performed whole-genome sequencing on four tumours from ATM loss-of-function variant carriers with available frozen material.

Results

We found that ATM-associated tumours belong mostly to the luminal B subtype, are tetraploid and show LOH at the ATM locus at 11q22–23. Unlike tumours in which BRCA1 or BRCA2 is inactivated, tumours arising in ATM deleterious variant carriers are not associated with increased large-scale genomic instability as measured by the large-scale state transitions signature. Losses at 13q14.11-q14.3, 17p13.2-p12, 21p11.2-p11.1 and 22q11.23 were observed. Somatic alterations at these loci may therefore represent biomarkers for ATM testing and harbour driver mutations in potentially ‘druggable’ genes that would allow patients to be directed towards tailored therapeutic strategies.

Conclusions

Although ATM is involved in the DNA damage response, ATM-associated tumours are distinct from BRCA1-associated tumours in terms of morphological characteristics and genomic alterations, and they are also distinguishable from sporadic breast tumours, thus opening up the possibility to identify ATM variant carriers outside the ataxia-telangiectasia disorder and direct them towards effective cancer risk management and therapeutic strategies.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0951-9) contains supplementary material, which is available to authorized users.

Update on PARP Inhibitors in Breast Cancer

OPINION STATEMENT

The single agent activity of PARP inhibitors (PARPi) in germline BRCA mutated (gBRCAm) breast and ovarian cancer suggests untapped potential for this new class of drug in breast cancer. The US Food and Drug Administration has approved three PARPi (olaparib, rucaparib, and niraparib) so far to treat certain ovarian cancers, including those with gBRCAm and olaparib for treatment of gBRCAm breast cancers. Several PARPi are now under clinical development for breast cancer in the various treatment settings. Recently, two phase III trials of olaparib (OlympiaD) and talazoparib (EMBRACA) demonstrated 3-month progression-free survival improvement with PARPi compared to physician's choice single agent chemotherapy in metastatic gBRCAm breast cancer. To date, PARPi seems less efficacious in metastatic breast cancer patients than those with BRCA mutated platinum-sensitive recurrent ovarian cancer, perhaps reflecting the biologic heterogeneity and low somatic BRCA mutation rate in breast cancer. The use of PARPi is gradually evolving, including combination strategies with chemotherapy, targeted agents, radiotherapy, or immunotherapy in women with and without gBRCAm. The role of predictive biomarkers, including molecular signatures and homologous recombination repair deficiency scores based on loss of heterozygosity and other structural genomic aberrations, will be crucial to identify a subgroup of patients who may have benefit from PARPi. An improved understanding of the mechanisms underlying PARPi clinical resistance will also be important to enable the development of new approaches to increase efficacy. This is a field rich in opportunity, and the coming years should see a better understanding of which breast cancer patients we should treat with PARPi and where these agents should come in over the course of treatment.

Full in-frame exon 3 skipping of BRCA2 confers high risk of breast and/or ovarian cancer

Germline pathogenic variants in the BRCA2 gene are associated with a cumulative high risk of breast/ovarian cancer. Several BRCA2 variants result in complete loss of the exon-3 at the transcript level. The pathogenicity of these variants and the functional impact of loss of exon 3 have yet to be established.

As a collaboration of the COVAR clinical trial group (France), and the ENIGMA consortium for investigating breast cancer gene variants, this study evaluated 8 BRCA2 variants resulting in complete deletion of exon 3. Clinical information for 39 families was gathered from Portugal, France, Denmark and Sweden. Multifactorial likelihood analyses were conducted using information from 293 patients, for 7 out of the 8 variants (including 6 intronic). For all variants combined the likelihood ratio in favor of causality was 4.39*10²⁵. These results provide convincing evidence for the pathogenicity of all examined variants that lead to a total exon 3 skipping, and suggest that other variants that result in complete loss of exon 3 at the molecular level could be associated with a high risk of cancer comparable to that associated with classical pathogenic variants in BRCA1 or BRCA2 gene. In addition, our functional study shows, for the first time, that deletion of exon 3 impairs the ability of cells to survive upon Mitomycin-C treatment, supporting lack of function for the altered BRCA2 protein in these cells.

Finally, this study demonstrates that any variant leading to expression of only BRCA2 delta-exon 3 will be associated with an increased risk of breast and ovarian cancer.

Oral Contraceptive Use and Breast Cancer Risk: Retrospective and Prospective Analyses From a BRCA1 and BRCA2 Mutation Carrier Cohort Study

BACKGROUND

For BRCA1 and BRCA2 mutation carriers, the association between oral contraceptive preparation (OCP) use and breast cancer (BC) risk is still unclear.

METHODS

Breast camcer risk associations were estimated from OCP data on 6030 BRCA1 and 3809 BRCA2 mutation carriers using age-dependent Cox regression, stratified by study and birth cohort. Prospective, left-truncated retrospective and full-cohort retrospective analyses were performed.

RESULTS

For BRCA1 mutation carriers, OCP use was not associated with BC risk in prospective analyses (hazard ratio [HR] = 1.08, 95% confidence interval [CI] = 0.75 to 1.56), but in the left-truncated and full-cohort retrospective analyses, risks were increased by 26% (95% CI = 6% to 51%) and 39% (95% CI = 23% to 58%), respectively. For BRCA2 mutation carriers, OCP use was associated with BC risk in prospective analyses (HR = 1.75, 95% CI = 1.03 to 2.97), but retrospective analyses were inconsistent (left-truncated: HR = 1.06, 95% CI = 0.85 to 1.33; full cohort: HR = 1.52, 95% CI = 1.28 to 1.81). There was evidence of increasing risk with duration of use, especially before the first full-term pregnancy (BRCA1: both retrospective analyses, P < .001 and P = .001, respectively; BRCA2: full retrospective analysis, P = .002).

CONCLUSIONS

Prospective analyses did not show that past use of OCP is associated with an increased BC risk for BRCA1 mutation carriers in young middle-aged women (40-50 years). For BRCA2 mutation carriers, a causal association is also not likely at those ages. Findings between retrospective and prospective analyses were inconsistent and could be due to survival bias or a true association for younger women who were underrepresented in the prospective cohort. Given the uncertain safety of long-term OCP use for BRCA1/2 mutation carriers, indications other than contraception should be avoided and nonhormonal contraceptive methods should be discussed.

Common Genetic Variation and Breast Cancer Risk-Past, Present, and Future

Breast cancer is the most common cancer among women in the United States, with up to 30% of those diagnosed displaying a family history of breast cancer. To date, 18% of the familial risk of breast cancer can be explained by SNPs. This review summarizes the discovery of risk-associated SNPs using candidate gene and genome-wide association studies (GWAS), including discovery and replication in large collaborative efforts such as The Collaborative Oncologic Gene-environment Study and OncoArray. We discuss the evolution of GWAS studies, efforts to discover additional SNPs, and methods for identifying causal variants. We summarize findings associated with overall breast cancer, pathologic subtypes, and mutation carriers (BRCA1, BRCA2, and CHEK2). In addition, we summarize the development of polygenic risk scores (PRS) using the risk-associated SNPs and show how PRS can contribute to estimation of individual risks for developing breast cancer. Cancer Epidemiol Biomarkers Prev; 27(4); 380-94. ©2018 AACRSee all articles in this CEBP Focus section, "Genome-Wide Association Studies in Cancer."

Breast Organotypic Cancer Models

Breast cancer is the most common cancer type diagnosed in women, it represents a critical public health problem worldwide, with 1,671,149 estimated new cases and nearly 571,000 related deaths. Research on breast cancer has mainly been conducted using two-dimensional (2D) cell cultures and animal models. The usefulness of these models is reflected in the vast knowledge accumulated over the past decades. However, considering that animal models are three-dimensional (3D) in nature, the validity of the studies using 2D cell cultures has recently been questioned. Although animal models are important in cancer research, ethical questions arise about their use and usefulness as there is no clear predictivity of human disease outcome and they are very expensive and take too much time to obtain results. The poor performance or failure of most cancer drugs suggests that preclinical research on cancer has been based on an over-dependence on inadequate animal models. For these reasons, in the last few years development of alternative models has been prioritized to study human breast cancer behavior, while maintaining a 3D microenvironment, and to reduce the number of experiments conducted in animals. One way to achieve this is using organotypic cultures, which are being more frequently explored in cancer research because they mimic tissue architecture in vivo. These characteristics make organotypic cultures a valuable tool in cancer research as an alternative to replace animal models and for predicting risk assessment in humans. This chapter describes the cultures of multicellular spheroids, organoids, 3D bioreactors, and tumor slices, which are the most widely used organotypic models in breast cancer research.

Clinical and pathologic characteristics of breast cancer patients carrying the c.3481_3491del11 mutation

Tumor characteristics are used today to evaluate the possibility of mutation and to target mutation screening in families with high risk of breast and/or ovarian cancer. We studied the breast tumor profile associated to the c.3481_3491del11 French founder effect mutation on the BRCA1 gene to an attempt to identify any particularity or difference when comparing it to that related to other BRCA1 mutations. Within the population who were referred to our oncogenetic clinic at the Lorraine Oncology Institute in France and who underwent genetic testing between 1994 and 2012, we identified 404 women carrying a BRCA1 mutation. Interestingly, 45% (180/404) women had the germline c.3481_3491del11 mutation. These included 91 patients affected by first breast cancer. Clinical and pathologic data were retrieved from medical files. Descriptive statistics were conducted using the SPSS software (version 20.0). For the entire cohort of 91 women, the mean age was 43.64 years (SD 10.04). Tumors were identified in 37.4% of cases aged < 40 years. Estrogen receptor status and progesterone receptor status were reported to 67 patients. Seventy-four percent were ER negative. Hormonal receptors status was negative in 68.6% of tumors. HER2 status was available for 32 tumors. The triple-negative subtype was found in 21 cases, which accounts for 65.6% of the patients. High tumor grade was found in 81% of triple negative breast cancer patients. Based on our results compared to those of previous international studies, we concluded that the breast cancer associated to the c.3481_3491del11 is not different from that associated to other BRCA1 mutations. A larger cohort with complete information on the breast cancer pathologic characteristics and including other BRCA1 mutations would allow us to statistically compare the breast tumor profile associated to the c.3481_3491del11 to that related to other BRCA1 mutations.

Hereditary Breast and Ovarian Cancer Syndrome: Moving Beyond BRCA1 and BRCA2

The recent implementation of next generation sequencing and multigene platforms has expanded the spectrum of hereditary breast and ovarian cancer syndrome, beyond the traditional genes BRCA1 and BRCA2. A large number of other moderate penetrance genes have now been uncovered, which also play critical roles in repairing double stranded DNA breaks through the homologous recombination pathway. This review discusses the landmark discoveries of BRCA1 and BRCA2, the homologous repair pathway and new genes discovered in hereditary breast and ovarian cancer syndrome, as well as their clinicopathologic significance and implications for genetic testing. It also highlights the new role of PARP inhibitors in the context of synthetic lethality and prophylactic surgical options.

Difference in Risk of Breast and Ovarian Cancer According to Putative Functional Domain Regions in Korean BRCA1/2 Mutation Carriers

INTRODUCTION

We investigated the relative risk of breast and ovarian cancers related to the putative functional domain regions, obesity, and parity among Korean BRCA1/2 mutation carriers.

PATIENTS AND METHODS

We analyzed the clinical characteristics, cancer history, and mutations according to the putative functional domain of BRCA proteins among 229 women with BRCA1/2 mutations who were treated at Yonsei Cancer Center, Severance Hospital between January 2009 and March 2017.

RESULTS

Twenty-two carriers (18.8% of 117 BRCA1 mutation carriers) with mutations located in the BRCT domain region had a higher risk of breast cancers (hazard ratio [HR], 2.851; 95% confidence interval [CI], 1.614-5.039; P < .001) than those with mutations outside of the putative functional domains of BRCA1. The risk of ovarian cancer was increased in 13 (11.6%) of 112 BRCA2 mutation carriers, with mutations located on BRC repeat regions (HR, 3.129; 95% CI, 1.123-8.720; P = .029). The term-pregnancies number was a significant risk-reducing factor for breast cancers in BRCA1 mutation carriers (HR per pregnancy, 0.640; 95% CI, 0.508-0.806; P < .001), for breast cancers in BRCA2 mutation carriers (HR per pregnancy, 0.534; 95% CI, 0.419-0.681; P < .001), and for ovarian cancers for BRCA1 mutation carriers (HR per pregnancy, 0.625; 95% CI, 0.474-0.824; P = .001).

CONCLUSION

Among Korean women with the BRCA1/2 mutation, the location of the mutations may influence the risk of breast and ovarian cancers according to the putative functional domain regions. Further investigations are required for risk prediction and preventive strategies in the BRCA1/2 mutation carriers.

Somatic BRCA1 mutations in clinically sporadic breast cancer with medullary histological features

BACKGROUND

The role of somatic BRCA1/2 gene mutations in breast cancer is getting increasing attention in view of hereditary disease. The medullary phenotype and triple negative intrinsic subtypes are often, but not exclusively encountered in BRCA1 germline mutated breast cancer, whilst for BRCA2, no association to specific histological features are known. In this study, we addressed the relationship between morphological medullary phenotype and BRCA1/2 somatic mutations in breast cancer without known positive family anamnesis.

METHODS

32 clinically sporadic breast cancers with medullary features were analyzed for somatic BRCA1/2 mutations (all coding exons) with next-generation sequencing technology. Paraffin-embedded formalin-fixed breast cancer samples from all patients were analyzed.

RESULTS

Three of 32 tumors (9%) had pathogenic (ARUP class-5) BRCA1 gene alterations. Two of these pathogenic variants exhibited deletions leading to frameshift mutations (p.Glu23fs, p.Val1234fs), and the remaining single-nucleotid-variant resulted in premature STOP codon (p.Glu60Ter). In one patient, the same pathogenic BRCA1 mutation was detected (p.Glu23fs) in normal breast tissue. Retrospective follow-up in two patients revealed a positive family history for breast cancer and consecutive germline mutation testing confirmed presence of BRCA1 mutations. No somatic pathogenic BRCA2 mutations were detected.

CONCLUSIONS

BRCA1 mutation testing may be useful in clinically sporadic breast cancer patients with medullary features to identify potential mutation carriers independently from intrinsic molecular subtype. Formalin-fixed paraffin-embedded cancer tissue can undergo testing within a routine molecular-diagnostic setting as a clinical BRCA1/2 mutation screening strategy.

Germline BRCA mutation and outcome in young-onset breast cancer (POSH): a prospective cohort study

BACKGROUND

Retrospective studies provide conflicting interpretations of the effect of inherited genetic factors on the prognosis of patients with breast cancer. The primary aim of this study was to determine the effect of a germline BRCA1 or BRCA2 mutation on breast cancer outcomes in patients with young-onset breast cancer.

METHODS

We did a prospective cohort study of female patients recruited from 127 hospitals in the UK aged 40 years or younger at first diagnosis (by histological confirmation) of invasive breast cancer. Patients with a previous invasive malignancy (except non-melanomatous skin cancer) were excluded. Patients were identified within 12 months of initial diagnosis. BRCA1 and BRCA2 mutations were identified using blood DNA collected at recruitment. Clinicopathological data, and data regarding treatment and long-term outcomes, including date and site of disease recurrence, were collected from routine medical records at 6 months, 12 months, and then annually until death or loss to follow-up. The primary outcome was overall survival for all BRCA1 or BRCA2 mutation carriers (BRCA-positive) versus all non-carriers (BRCA-negative) at 2 years, 5 years, and 10 years after diagnosis. A prespecified subgroup analysis of overall survival was done in patients with triple-negative breast cancer. Recruitment was completed in 2008, and long-term follow-up is continuing.

FINDINGS

Between Jan 24, 2000, and Jan 24, 2008, we recruited 2733 women. Genotyping detected a pathogenic BRCA mutation in 338 (12%) patients (201 with BRCA1, 137 with BRCA2). After a median follow-up of 8·2 years (IQR 6·0-9·9), 651 (96%) of 678 deaths were due to breast cancer. There was no significant difference in overall survival between BRCA-positive and BRCA-negative patients in multivariable analyses at any timepoint (at 2 years: 97·0% [95% CI 94·5-98·4] vs 96·6% [95·8-97·3]; at 5 years: 83·8% [79·3-87·5] vs 85·0% [83·5-86·4]; at 10 years: 73·4% [67·4-78·5] vs 70·1% [67·7-72·3]; hazard ratio [HR] 0·96 [95% CI 0·76-1·22]; p=0·76). Of 558 patients with triple-negative breast cancer, BRCA mutation carriers had better overall survival than non-carriers at 2 years (95% [95% CI 89-97] vs 91% [88-94]; HR 0·59 [95% CI 0·35-0·99]; p=0·047) but not 5 years (81% [73-87] vs 74% [70-78]; HR 1·13 [0·70-1·84]; p=0·62) or 10 years (72% [62-80] vs 69% [63-74]; HR 2·12 [0·82-5·49]; p= 0·12).

INTERPRETATION

Patients with young-onset breast cancer who carry a BRCA mutation have similar survival as non-carriers. However, BRCA mutation carriers with triple-negative breast cancer might have a survival advantage during the first few years after diagnosis compared with non-carriers. Decisions about timing of additional surgery aimed at reducing future second primary-cancer risks should take into account patient prognosis associated with the first malignancy and patient preferences.

FUNDING

Cancer Research UK, the UK National Cancer Research Network, the Wessex Cancer Trust, Breast Cancer Now, and the PPP Healthcare Medical Trust Grant.

Peritoneal carcinomatosis after risk-reducing surgery in BRCA1/2 mutation carriers

BACKGROUND

Risk-reducing salpingo-oophorectomy (RRSO) is recommended for BRCA1/2 mutation carriers because of their increased risk of ovarian carcinoma. Despite RRSO, metachronous peritoneal carcinomatosis occasionally is diagnosed.

METHODS

The literature was searched for BRCA1/2 mutation carriers with peritoneal carcinomatosis after risk-reducing surgery. The authors were asked for additional data. Clinical and histopathological data were descriptively analyzed. Cases were compared with a single-institution control cohort.

RESULTS

Of 36 cases, 86.1% concerned BRCA1 mutation carriers. The median age of the patients was 52 years (range, 30-71 years) at the time of risk-reducing surgery and 60 years (range, 37-75 years) at the time of diagnosis of peritoneal carcinomatosis. The median interval between the 2 events was 54.5 months (range, 11-292 months). Peritoneal carcinomatosis was mostly high-grade serous carcinoma. Histopathological details of the RRSO specimens were retrieved in 8 cases; 5 (62.5%) were found to have serous tubal intraepithelial carcinoma and 1 had epithelial atypia. Cases were older (P = .025) at the time of risk-reducing surgery and harbored more serous tubal intraepithelial carcinomas (P<.001) compared with women from the control cohort.

CONCLUSIONS

Metachronous peritoneal carcinomatosis after risk-reducing surgery occurs predominantly in BRCA1 mutation carriers, usually within 5 years. Data have suggested that surgery at a younger age lowers the rates of peritoneal carcinomatosis. These data can be used in the gynecologic counseling of BRCA1/2 mutation carriers. RRSO should include complete salpingectomy. Detailed histopathological examination of specimens removed during RRSO is essential. Cancer 2018;124:952-9. © 2018 American Cancer Society.

Multi-gene Panel Testing in Breast Cancer Management

Hereditary predisposition accounts for approximately 10% of all breast cancers and is mostly associated with germline mutations in high-penetrance genes encoding for proteins participating in DNA repair through homologous recombination (BRCA1 and BRCA2). With the advent of massive parallel next-generation DNA sequencing, simultaneous analysis of multiple genes with a short turnaround time and at a low cost has become possible. The clinical validity and utility of multi-gene panel testing is getting better characterized as more data on the significance of moderate-penetrance genes are collected from large, cancer genetic testing studies. In this chapter, we attempt to provide a general guide for interpretation of panel gene testing in breast cancer and use of the information obtained for clinical decision-making.

Clinical and molecular characterization of BRCA-associated breast cancer: results from the DBCG

BACKGROUND

In breast cancer (BC) patients a cancer predisposing BRCA1/2 mutation is associated with adverse tumor characteristics, risk assessment and treatment allocation. We aimed to estimate overall- (OS) and disease-free survival (DFS) according to tumor characteristics and treatment among women who within two years of definitive surgery for primary BC were shown to carry a mutation in BRCA1/2 .

MATERIAL AND METHODS

From the clinical database of the Danish Breast Cancer Group we included 141 BRCA1 and 96 BRCA2 BC patients. Estrogen receptor and HER2 status were centrally reviewed on paraffin-embedded tumor tissue. Information on risk reducing surgery was obtained from the Danish Pathology and Patient Registries and included as time-dependent variables in Cox proportional hazard models.

RESULTS

Ten-year OS and DFS for BRCA1 BC patients were 78% (95% CI 69-85) and 74% (95% CI 64-81). Ten-year OS and DFS for BRCA2 BC were 88% (95% CI 78-94) and 84% (95% CI 74-91). BRCA1 BC patients as compared to BRCA2 BC patients had a higher risk of BC relapse or non-breast cancer within ten years of follow-up, independent of ER status (adjusted HR 2.78 95% CI 1.28-6.05, p = .01), but BRCA mutation was not associated with OS (adjusted HR 1.98, 95% CI 0.87-4.52, p = .10). In multivariate analysis, including both BRCA1 and BRCA2 carriers, no chemotherapy was associated with a higher risk of death (adjusted OS HR 3.58, 95% CI 1.29-9.97, p = .01) and risk reducing contralateral mastectomy (RRCM) was associated with a significantly reduced risk of death (adjusted OS HR 0.42, 95% CI =0.21-0.84, p = .01).

CONCLUSION

Difference in OS between BRCA1 and BRCA2 BC patients could be ascribed to tumor-biology. BRCA1 BC patients may have a shorter ten-year DFS than BRCA2 BC patients. Chemotherapy and risk reducing contralateral mastectomy reduce mortality for both BRCA1 and BRCA2 BC patients.

Characterization of mutations in BRCA1/2 and the relationship with clinic-pathological features of breast cancer in a hereditarily high-risk sample of chinese population

The database of BRCA1/2 mutations in Chinese population remains incomplete at present. Therefore, the present study aimed to report specific harmful BRCA1/2 mutations in the Chinese population and discuss the clinicopathological features in mutation carriers. BRCA1/2 germline mutation tests for 71 patients with breast cancer from a hereditarily high-risk Chinese population were performed using next-generation sequencing for identification of deleterious mutations. Furthermore, the clinicopathological features between BRCA1/2 mutation carriers and non-carriers were compared. A total of 13/71 (18.3%) patients carried a BRCA1 or BRCA2 mutation (7 BRCA1 and 6 BRCA2). The incidence of BRCA1/2 mutation in patients with bilateral breast cancer and patients with family history were 25, and 32.2%, respectively. Eleven pathogenic or likely pathogenic mutations were identified in 13 patients, among the mutation sites 7 were never reported before in Asian populations. The age at diagnosis of BRCA1/2 mutation carriers was older compared with non-mutation carriers (44.73 vs. 35.39 years; P=0.001) in this cohort. BRCA1/2 deleterious mutation carriers had a significantly lower chance of human epidermal growth factor receptor-2 (Her-2) positive status (P=0.010), higher tumor grade at diagnosis (P=0.009), higher probability to have a family history (P=0.016) and older age at diagnosis. Estrogen receptor (ER) and progesterone receptor (PR) status were significantly different between BRCA1, and BRCA2 mutation carriers (P=0.007). The current interpretation of BRCA1/2 status can only explain a small part of hereditary high-risk breast cancer. However, BRCA1/2 gene testing should still be recommended for women with a family history of breast cancer, as well as patients with breast cancer with specific pathologic types, which may be useful to make appropriate clinical decisions for treatment and prevention.

Identification of ten variants associated with risk of estrogen-receptor-negative breast cancer

Most common breast cancer susceptibility variants have been identified through genome-wide association studies (GWAS) of predominantly estrogen receptor (ER)-positive disease. We conducted a GWAS using 21,468 ER-negative cases and 100,594 controls combined with 18,908 BRCA1 mutation carriers (9,414 with breast cancer), all of European origin. We identified independent associations at P < 5 × 10-8 with ten variants at nine new loci. At P < 0.05, we replicated associations with 10 of 11 variants previously reported in ER-negative disease or BRCA1 mutation carrier GWAS and observed consistent associations with ER-negative disease for 105 susceptibility variants identified by other studies. These 125 variants explain approximately 16% of the familial risk of this breast cancer subtype. There was high genetic correlation (0.72) between risk of ER-negative breast cancer and breast cancer risk for BRCA1 mutation carriers. These findings may lead to improved risk prediction and inform further fine-mapping and functional work to better understand the biological basis of ER-negative breast cancer.

Genetic and clinical characteristics in Japanese hereditary breast and ovarian cancer: first report after establishment of HBOC registration system in Japan

The hereditary breast and ovarian cancer (HBOC) registration system of Japan was established by the Japanese HBOC Consortium. The first trial was registered in 2015 in four institutions to which some registration committee members belonged. We analyzed the information of 830 Japanese pedigrees, who underwent BRCA1/2 genetic testing, including mutation carriers with BRCA1 (N = 127) and BRCA2 (N = 115), and their families. The mutation-positive rate was 19.7%. Variants of uncertain significance were found in 6.5% of all individuals subjected to genetic testing for BRCA1/2. Compared to the United States, Japan had a higher mutation-positive rate in most categories, except for the groups with male breast cancer. Among the intrinsic subtypes of BRCA1-associated breast cancers, 75.8% were triple-negative. The incidence rate of contralateral breast cancer in BRCA1/2 mutation carriers was 0.99%/year. Among 240 mutation carriers, 26 and 62 patients underwent risk-reducing mastectomy (RRM) and risk-reducing salpingo-oophorectomy (RRSO), respectively; the respective frequencies of occult cancer were 7.1 and 3.2%. Metachronous breast cancer after RRM or peritoneal cancer after RRSO was not observed during the follow-up period. The nationwide registration system began last year and the system enables follow-up analysis in Japan.

Cancer Risk-Reducing Opportunities in Gynecologic Surgery

This review article discusses cancer risk-reducing opportunities in gynecologic surgery. We cover strategies to reduce ovarian and uterine cancer risk by presenting general practice guidelines and expanding on the literature behind clinical decision points. We address populations of women at increased hereditary risk and those at population risk. We specifically discuss risk-reducing salpingo-oophorectomy, prophylactic salpingectomy with delayed oophorectomy, concomitant hysterectomy, opportunistic salpingectomy, bilateral tubal ligation, and hysterectomy. For clinical scenarios in which data are limited or conflicting, we detail the studies on which clinicians' decisions hinge to allow the reader to weigh the available evidence.

Breast Cancer in Latinas: A Focus on Intrinsic Subtypes Distribution

Breast cancer is the most frequent cancer in women worldwide. It is classified into intrinsic subtypes characterized by different molecular profiles and prognosis. The prevalence of the different intrinsic subtypes varies between population groups. IHC surrogates based on the expression of the estrogen receptor, progesterone receptor, and HER2 have been widely used to study the distribution of intrinsic subtypes in non-Hispanic whites and African Americans, but data are limited for Hispanic/Latina women. Similarly, most studies analyzing gene expression profiles only include women of European descent. This review focuses on studies that describe the distribution of breast cancer subtypes in Hispanic/Latina women and highlights the need for more research in this population. Cancer Epidemiol Biomarkers Prev; 27(1); 3-10. ©2017 AACR.

Imaging and Screening of Hereditary Cancer Syndromes

There is a wide spectrum of mendelian disorders that predispose patients to an increased risk of benign as well as malignant tumors. Hereditary cancer syndromes are characterized by the early onset of diverse, frequently advanced malignancies in specific organ systems in multiple family members, posing significant challenges to diagnosis and management. A better understanding of the genetic abnormalities and pathophysiology that underlie these disorders has led to contemporary paradigms to screen, allowing early diagnosis, and has improved targeted therapies to aid in management. This article reviews select hereditary cancer syndromes with an emphasis on imaging-based screening and surveillance strategies.

Risk-reducing salpingo-oophorectomy in BRCA1 and BRCA2 mutated patients: An evidence-based approach on what women should know

This review is focused on the ovarian cancer risk reduction management in BRCA mutation carriers and is intended to assist with clinical decision-making. Obviously, treatment decisions must be based on the available evidence. Despite risk-reducing salpingo-oophorectomy is firmly recommended, several separate questions can be raised to address the variety of intense controversy of this approach. A special emphasis lies in the effective preventive surgical measure against ovarian cancer risk, in an attempt to detect the optimal timing and mitigate the impact on patients. The long term implications of risk-reducing salpingo-oophorectomy as well as hormone replacement therapy are also actively debated. This is expected to represent an opportunity for improved management modelling of BRCA mutated patients.

No evidence of increased breast cancer risk for proven noncarriers from BRCA1 and BRCA2 families

In families screened for mutations in the BRCA1 or BRCA2 genes and found to have a segregating mutation the breast cancer risk for women shown not to carry the family-specific mutation might be at above "average" risk. We assessed the risk of breast cancer in a clinic based cohort of 725 female proven noncarriers in 239 BRCA1 and BRCA2 families compared with birth-matched controls from the Danish Civil Registration System. Prospective analysis showed no significantly increased risk for breast cancer in noncarriers with a hazard ratio of 0.67 [95 % confidence interval (CI) 0.32-1.42, p = 0.29] for all family members who tested negative and 0.87 (95 % CI 0.38-1.97, p = 0.73) for non-carries who were first-degree relatives of mutation carriers. Proven noncarriers from BRCA1 and BRCA2 families have no markedly increased risk for breast cancer compared to the general population, and our data do not suggest targeted breast cancer surveillance for noncarriers from BRCA1 and BRCA2 families.

Efficacy of anthracycline/taxane-based neo-adjuvant chemotherapy on triple-negative breast cancer in BRCA1/BRCA2 mutation carriers

This study aims to estimate the pathologic complete response (pCR) rate after neo-adjuvant chemotherapy and to compare disease-free survival (DFS) and overall survival (OS) between pCR and non-pCR groups of patients with triple-negative breast cancer (TNBC) and deleterious BRCA1 or BRCA2 mutation. We carried out a retrospective analysis of 53 patients including 46 BRCA1, 6 BRCA2, and 1 combined BRCA1 and BRCA2 mutation. All patients had been diagnosed with triple-negative breast cancer (TNBC) between 1997 and 2014. Neo-adjuvant therapy consisted of regimens that were based on anthracycline or an anthracycline-taxane doublet. DFS included any relapse or second cancer. The Kaplan-Meier method and the log-rank test were used to compare pCR and non-pCR groups. A pCR was observed in 23 (42.6% [95% CI, 29.2%-56.8%]) of the TNBC included. The pCR rate was 38.3% [95% CI, 26%-55%] among BRCA1 mutation carriers, and 66% among the 6 BRCA2 mutation carriers. Median follow-up was 4.4 years (range 0.62-16.2 years) and did not differ between the groups (P = .25). Fifteen relapses and six second cancers were recorded during the follow-up period. Eleven deaths occurred, all of which were in the non-pCR group. DFS (P < .01) and OS (P < .01) were significantly better in the pCR group than the non-pCR group. This study shows a high pCR rate after neo-adjuvant therapy in BRCA-mutated triple-negative breast cancer, and the survival results confirm the prognostic value of pCR in this group. These outcomes should be considered as a basis of comparison to be used by future studies about new therapies in this domain.

Olaparib for Metastatic Breast Cancer in Patients with a Germline BRCA Mutation

BACKGROUND

Olaparib is an oral poly(adenosine diphosphate-ribose) polymerase inhibitor that has promising antitumor activity in patients with metastatic breast cancer and a germline BRCA mutation.

METHODS

We conducted a randomized, open-label, phase 3 trial in which olaparib monotherapy was compared with standard therapy in patients with a germline BRCA mutation and human epidermal growth factor receptor type 2 (HER2)-negative metastatic breast cancer who had received no more than two previous chemotherapy regimens for metastatic disease. Patients were randomly assigned, in a 2:1 ratio, to receive olaparib tablets (300 mg twice daily) or standard therapy with single-agent chemotherapy of the physician's choice (capecitabine, eribulin, or vinorelbine in 21-day cycles). The primary end point was progression-free survival, which was assessed by blinded independent central review and was analyzed on an intention-to-treat basis.

RESULTS

Of the 302 patients who underwent randomization, 205 were assigned to receive olaparib and 97 were assigned to receive standard therapy. Median progression-free survival was significantly longer in the olaparib group than in the standard-therapy group (7.0 months vs. 4.2 months; hazard ratio for disease progression or death, 0.58; 95% confidence interval, 0.43 to 0.80; P<0.001). The response rate was 59.9% in the olaparib group and 28.8% in the standard-therapy group. The rate of grade 3 or higher adverse events was 36.6% in the olaparib group and 50.5% in the standard-therapy group, and the rate of treatment discontinuation due to toxic effects was 4.9% and 7.7%, respectively.

CONCLUSIONS

Among patients with HER2-negative metastatic breast cancer and a germline BRCA mutation, olaparib monotherapy provided a significant benefit over standard therapy; median progression-free survival was 2.8 months longer and the risk of disease progression or death was 42% lower with olaparib monotherapy than with standard therapy. (Funded by AstraZeneca; OlympiAD ClinicalTrials.gov number, NCT02000622 .).

Screening for familial cancer risk: Focus on breast cancer

A breast or an ovarian cancer occurring at a young age and/or in a family where other cases preexist suggests that those patients should be candidates for screening for mutations. Despite decades of medical research, less than 30% of cases with a suggestive personal and/or family history of hereditary breast cancer have an identified causative gene mutation. The vast majority of these cases are due to a mutation in one of the highly penetrant breast cancer genes (BRCA1, BRCA2, PTEN, TP53, CDH1, and STK11) and various guidelines direct the management of these patients. A minority of cases are due to mutations in moderate-penetrance genes (PALB2, ATM, BRIP1, and CHEK2). A small number of low-penetrance alleles have been identified using advanced genetic testing methods. While these may contribute to risk in a polygenic fashion, this is likely to be relevant to a minority of cases and their identification should not be considered routine practice. Mutation testing currently requires a high index of suspicion for a specific contributing etiology, but next-generation sequencing may improve the identification of such genes and the clinical management of these cases. Where no genetic susceptibility is identified, lifetime breast cancer risk can be calculated with standard tools. Breast cancer risk management then depends on the calculated lifetime risk. The psychological consequences of such screening for mutation carriers and non-carriers are discussed.

The role of BRCA status on prognosis in patients with triple-negative breast cancer

Studies have showed that dysfunction in the breast cancer susceptibility gene (BRCA) is associated with triple-negative breast cancer (TNBC); however, its effect on patient survival remains controversial. We investigated the distribution of BRCA1/2 mutations in unselected Chinese patients with TNBC and explored their roles in prognosis. Then a systematic review and meta-analysis were performed to evaluate the prognostic role of BRCA dysfunction, including BRCA1/2 germline/somatic mutations, BRCA1 promoter methylation, and low BRCA1 protein expression in TNBC patients. Pooled hazard ratios with 95% confidence intervals were estimated to determine the association between BRCA dysfunction and survival. Our results showed a high frequency of BRCA1/2 mutations, especially germline BRCA1 variants, were associated with bilateral breast cancer. Although no correlations were found between BRCA1/2 mutations and recurrence-free survival (RFS) or overall survival (OS). In the meta-analysis, patients with BRCA1 promoter methylation showed poor OS. However, there was a favorable impact on disease free survival (DFS) for TNBC patients with BRCA1 promoter methylation when received adjuvant-chemotherapy. In conclusion, BRCA1/2 mutations were associated with bilateral breast cancer and BRCA1 promoter methylation may have a prognostic effect on TNBC.

Niraparib in ovarian cancer: results to date and clinical potential

Ovarian cancer is the first cause of death from gynaecological malignancy. Germline mutation in BRCA1 and 2, two genes involved in the mechanisms of reparation of DNA damage, are showed to be related with the incidence of breast and ovarian cancer, both sporadic and familiar. PARP is a family of enzymes involved in the base excision repair (BER) system. The introduction of inhibitors of PARP in patients with BRCA-mutated ovarian cancer is correlated with the concept of synthetic lethality. Among the PARP inhibitors introduced in clinical practice, niraparib showed interesting results in a phase III trial in the setting of maintenance treatment in ovarian cancer, after platinum-based chemotherapy. Interestingly, was niraparib showed to be efficacious not only in BRCA-mutated patients, but also in patients with other alterations of the homologous recombination (HR) system and in patients with unknown alterations. These results position niraparib as the first PARP-inhibitor with clinically and statistically significant results also in patients with no alterations in BRCA 1/2 and other genes involved in the DNA repair system. Even if the results are potentially practice-changing, the action of niraparib must be further studied and deepened.

Evaluation of Polygenic Risk Scores for Breast and Ovarian Cancer Risk Prediction in BRCA1 and BRCA2 Mutation Carriers

Background

Genome-wide association studies (GWAS) have identified 94 common single-nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk and 18 associated with ovarian cancer (OC) risk. Several of these are also associated with risk of BC or OC for women who carry a pathogenic mutation in the high-risk BC and OC genes BRCA1 or BRCA2. The combined effects of these variants on BC or OC risk for BRCA1 and BRCA2 mutation carriers have not yet been assessed while their clinical management could benefit from improved personalized risk estimates.

Methods

We constructed polygenic risk scores (PRS) using BC and OC susceptibility SNPs identified through population-based GWAS: for BC (overall, estrogen receptor [ER]-positive, and ER-negative) and for OC. Using data from 15 252 female BRCA1 and 8211 BRCA2 carriers, the association of each PRS with BC or OC risk was evaluated using a weighted cohort approach, with time to diagnosis as the outcome and estimation of the hazard ratios (HRs) per standard deviation increase in the PRS.

Results

The PRS for ER-negative BC displayed the strongest association with BC risk in BRCA1 carriers (HR = 1.27, 95% confidence interval [CI] = 1.23 to 1.31, P =  8.2×10 -53 ). In BRCA2 carriers, the strongest association with BC risk was seen for the overall BC PRS (HR = 1.22, 95% CI = 1.17 to 1.28, P =  7.2×10 -20 ). The OC PRS was strongly associated with OC risk for both BRCA1 and BRCA2 carriers. These translate to differences in absolute risks (more than 10% in each case) between the top and bottom deciles of the PRS distribution; for example, the OC risk was 6% by age 80 years for BRCA2 carriers at the 10th percentile of the OC PRS compared with 19% risk for those at the 90th percentile of PRS.

Conclusions

BC and OC PRS are predictive of cancer risk in BRCA1 and BRCA2 carriers. Incorporation of the PRS into risk prediction models has promise to better inform decisions on cancer risk management.