Clinical and pathological features of ovarian cancer in women with germ-line mutations of BRCA1

Clinical implications of using molecular diagnostics for ovarian cancers

In the era of morphologic diagnostics, any epithelial tumor on or involving the ovaries was presumed to come from and be strictly of ovarian origin, apart from the rare but clearly metastatic tumors. Thus, many women who might have had small fallopian tube primary cancers that rapidly extended on to or into the ovary were deemed to have ovarian cancer. Now, as we begin to better understand that there are different types of cancers of nonuterine Muellerian origin, we expand upon the morphologic to add the molecular characteristics. Morphomolecular characteristics are being applied to drive clinical advances including development and optimization of predictive and prognostic biomarkers, redefinition of historical controls, and consideration of novel clinical trial designs. Ovarian cancer, not a common cancer to start with, is now subdivided into types, making ever smaller clinical cohorts. The first studies evaluating tubo-ovarian Muellerian cancers of morphomolecular types have begun. Deleterious mutations in BRCA1 or 2 have been validated as the first new predictive and prognostic biomarker of the high-grade serous ovarian cancer type and polyADPribose polymerase inhibitors, the first targeted agents for this morphomolecular entity. Similar progress is developing in other tubo-ovarian cancer types. This new knowledge is driving the building of a structure-function-type relationship that is generating novel clinically applicable hypotheses for testing.

The role of BRCA status on the prognosis of patients with epithelial ovarian cancer: a systematic review of the literature with a meta-analysis

Objective

The role of BRCA dysfunction on the prognosis of patients with epithelial ovarian cancer (EOCs) remains controversial. This systematic review tried to assess the role of BRCA dysfunction, including BRCA1/2 germline, somatic mutations, low BRCA1 protein/mRNA expression or BRCA1 promoter methylation, as prognostic factor in EOCs.

Methods

Studies were selected for analysis if they provided an independent assessment of BRCA status and prognosis in EOC. To make it possible to aggregate survival results of the published studies, their methodology was assessed using a modified quality scale.

Results

Of 35 evaluable studies, 23 identified BRCA dysfucntion status as a favourable prognostic factor. No significant differences were detected in the global score of quality assessment. The aggregated hazard ratio (HR) of overall survival (OS) of 34 evaluable studies suggested that BRCA dysfunction status had a favourable impact on OS (HR = 0.69, 95% CI 0.61–0.79), and when these studies were categorised into BRCA1/2 mutation and low protein/mRNA expression of BRCA1 subgroups, all of them demonstrated positive results (HR = 0.67, 95% CI: 0.57–0.78; HR = 0.62, 95% CI: 0.51–0.75; and HR = 0.51, 95% CI: 0.33–0.78, respectively), except for the subgroup of BRCA1 promoter methylation (HR = 1.59, 95% CI: 0.72–3.50). The meta-analysis of progression-free survival (PFS), which included 18 evaluable studies, demonstrated that BRCA dysfunction status was associated with a longer PFS in EOC (HR = 0.69, 95% CI: 0.63–0.76).

Conclusions

Patients with BRCA dysfunction status tend to have a better outcome, but further prospective clinical studies comparing the different BRCA statuses in EOC is urgently needed to specifically define the most effective treatment for the separate patient groups.

Pathway-specific engineered mouse allograft models functionally recapitulate human serous epithelial ovarian cancer

The high mortality rate from ovarian cancers can be attributed to late-stage diagnosis and lack of effective treatment. Despite enormous effort to develop better targeted therapies, platinum-based chemotherapy still remains the standard of care for ovarian cancer patients, and resistance occurs at a high rate. One of the rate limiting factors for translation of new drug discoveries into clinical treatments has been the lack of suitable preclinical cancer models with high predictive value. We previously generated genetically engineered mouse (GEM) models based on perturbation of Tp53 and Rb with or without Brca1 or Brca2 that develop serous epithelial ovarian cancer (SEOC) closely resembling the human disease on histologic and molecular levels. Here, we describe an adaptation of these GEM models to orthotopic allografts that uniformly develop tumors with short latency and are ideally suited for routine preclinical studies. Ovarian tumors deficient in Brca1 respond to treatment with cisplatin and olaparib, a PARP inhibitor, whereas Brca1-wild type tumors are non-responsive to treatment, recapitulating the relative sensitivities observed in patients. These mouse models provide the opportunity for evaluation of effective therapeutics, including prediction of differential responses in Brca1-wild type and Brca1-deficient tumors and development of relevant biomarkers.

BRCA 1/2-Mutation Related and Sporadic Breast and Ovarian Cancers: More Alike than Different

No longer is histology solely predictive of cancer treatment and outcome. There is an increasing influence of tumor genomic characteristics on therapeutic options. Both breast and ovarian cancers are at higher risk of development in patients with BRCA 1/2-germline mutations. Recent data from The Cancer Genome Atlas and others have shown a number of genomic similarities between triple negative breast cancers (TNBCs) and ovarian cancers. Recently, poly (ADP-ribose) polymerase (PARP) inhibitors have shown promising activity in hereditary BRCA 1/2-mutated and sporadic breast and ovarian cancers. In this review, we will summarize the current literature regarding the genomic and phenotypic similarities between BRCA 1/2-mutation related cancers, sporadic TNBCs, and sporadic ovarian cancers. We will also review Phase I, II, and III data using PARP inhibitors for these malignancies and compare and contrast the results with respect to histology.

Molecular profiling and commercial predication assays in ovarian cancer: still not ready for prime time?

Short of early detection to allow curative primary intervention, the other major barrier to further success in treatment of ovarian cancers is matching the best treatment to the proper ovarian cancer type and to the individual patient. There are several decades of experience applying in vitro chemoresponse testing for solid tumors including ovarian cancer. This concept, first described in 1979, has yet to receive level one evidence supporting its application, despite the testing of numerous assays commercially as well as in academic centers and its use for tens of thousands of patients at a significant cost. The approach-rather than undergoing rigorous scientific examination-is now being muddied by the development of commercial molecular profiling assays from which treatment suggestions are provided. Molecular profiling as a research tool has added value to our understanding and treatment of patients with ovarian cancer. Morphologic and histochemical characterizations coupled now with increasing knowledge of ovarian cancer type-specific molecular patterns is improving our ability to properly diagnosis ovarian cancer type and thus guide therapy. With the exception of the role of germ-line and possibly somatic BRCA1 and BRCA2 mutations and their true predictiveness for probable response to poly(ADP-ribose) polymerase inhibition, molecular typing and profiling has yet to identify druggable molecular targets in ovarian cancer. Its use should be continued as a research and learning tool, and its results should be subjected to clinical trial validation. For very different reasons, neither chemoresponse assays nor molecular profiling are ready for prime time, yet.

The Role of PARP Inhibitors in the Treatment of Gynecologic Malignancies

Gynecologic malignancies annually account for over 91,000 new cancer cases and approximately 28,000 deaths in the United States. Although there have been advancements in cytotoxic chemotherapies, there has not been significant improvement in overall survival in these patients. While targeted therapies have shown some benefit in many solid tumors, further development of these agents is needed for the treatment of gynecologic malignancies. Poly(ADP-ribose) polymerase (PARP) catalyzes the polyADP-ribosylation of proteins involved in DNA repair. Inhibitors of PARP were originally developed for cancers with homologous recombination deficiencies, such as those harboring mutations in BRCA1 or BRCA2 genes. However, pre-clinical research and clinical trials have suggested that the activity of PARP inhibitors is not limited to those with BRCA mutations. PARP inhibitors may have activity in cancers deficient in other DNA repair genes, signaling pathways that mitigate DNA repair, or in combination with DNA-damaging agents independent of DNA repair dysfunction. Currently there are seven different PARP inhibitors in clinical development for cancer. While there has been promising clinical activity for some of these agents, there are still significant unanswered questions regarding their use. Going forward, specific questions that must be answered include timing of therapy, use in combination with cytotoxic agents or as single-agent maintenance therapy, and whether there is a predictive biomarker that can be used with PARP inhibition. Even with large strides in the treatment of many gynecologic malignancies in recent years, it is imperative that we develop newer agents and methods to identify patients that may benefit from these compounds. The focus of this review will be on pre-clinical data, current clinical trials, and the future of PARP inhibitors in the treatment of ovarian, endometrial, and cervical cancer.

Comparison of whole genome amplification and nested-PCR methods for preimplantation genetic diagnosis for BRCA1 gene mutation on unfertilized oocytes-a pilot study

Background

Preimplantation genetic diagnosis (PGD) remains nowadays a valid alternative for couples at high-risk of having a child with a genetic disease and for women older than 37–40 years with the high risk of chromosomal aneuploidies in the embryos. However the use of PGD for high penetrance recessive, dominant and X-liked disorders occurring in early life is documented, debate exists regarding its appropriateness in lower penetrance and late-onset cancer susceptibility syndromes. The data regarding the efficacy of different molecular techniques used in PGD are still lacking. We therefore sought to assess the different molecular techniques used in PGD for detecting three most frequent BRCA1 gene mutations: 5382insC, 185delAG and C61G.

Methods

Anonymous donors of the oocytes and control healthy blood samples were extracted and analyzed in the Fertility and Reproductive Center Invicta in Gdansk. Preimplantation genetic diagnosis for the most frequent mutations: 185delAG, 5382insC, C61G in BRCA 1 gene was carried out on single, unfertilized oocytes, in metaphase of second meiotic division, not qualified to IVF. Positive mutation controls were represented by cell lines from the Coriell Institute for Medical Research: GM14090 (185delAG), GM14097 (C61G), GM13715 (5382insC).

Results

Repeatability of the results acquired from the WGA analysis for the mutation 5382insC was 38%. The repeatability of the nested-PCR analysis in the second round of the amplification was labile for the mutation 5382insC and 185delAG and was ranged from 47% to 57%. However, the repeatability for the mutation C61G was 100%.

Conclusions

Our results suggest that the nested-PCR technique remains more sensitive and specific method as compared to WGA. WGA performed on the single cells did not reflect expected results. The repeatability of the WGA methodology remains questionable, and any analysis attempt does not guarantee reliable results.

Further evaluation is strongly needed to propose the most accurate molecular technique used in PGD for detecting three most frequent BRCA1 gene mutations: 5382insC, 185delAG and C61G.

Differing clinical impact of BRCA1 and BRCA2 mutations in serous ovarian cancer

A key function of BRCA1 and BRCA2 is the participation in dsDNAbreak repair via homologous recombination. BRCA1 and BRCA2 mutations, which occur in most hereditary ovarian cancers (OCs) and approximately 10% of all OC cases, are associated with defects in homologous recombination and genomic instability, a phenotype termed 'BRCAness'. The clinical effects of BRCA1 and BRCA2 mutations have commonly been analyzed together; however, it is becoming increasingly apparent that these mutations do not have the same effects in OC. Recently, three major reports highlighted the unequal clinical characteristics of OCs with BRCA1 and BRCA2 mutations. All studies demonstrated that BRCA2-mutated patients are associated with better survival and therapeutic response than BRCA1-mutated and wild-type patients with serous OC. The differing prognostic effects of the BRCA2 and BRCA1 mutations is likely due to differing roles of BRCA1 and BRCA2 in homologous recombination repair and a stronger association between the BRCA2 mutation and a hypermutator phenotype. These new findings have potentially important implications for clinical management of patients with serous OC.

Prevalence of BRCA1 mutations in familial and sporadic greek ovarian cancer cases

Germline mutations in the BRCA1 and BRCA2 genes contribute to approximately 18% of hereditary ovarian cancers conferring an estimated lifetime risk from 15% to 50%. A variable incidence of mutations has been reported for these genes in ovarian cancer cases from different populations. In Greece, six mutations in BRCA1 account for 63% of all mutations detected in both BRCA1 and BRCA2 genes. This study aimed to determine the prevalence of BRCA1 mutations in a Greek cohort of 106 familial ovarian cancer patients that had strong family history or metachronous breast cancer and 592 sporadic ovarian cancer cases. All 698 patients were screened for the six recurrent Greek mutations (including founder mutations c.5266dupC, p.G1738R and the three large deletions of exon 20, exons 23-24 and exon 24). In familial cases, the BRCA1 gene was consequently screened for exons 5, 11, 12, 20, 21, 22, 23, 24. A deleterious BRCA1 mutation was found in 43/106 (40.6%) of familial cancer cases and in 27/592 (4.6%) of sporadic cases. The variant of unknown clinical significance p.V1833M was identified in 9/698 patients (1.3%). The majority of BRCA1 carriers (71.2%) presented a high-grade serous phenotype. Identifying a mutation in the BRCA1 gene among breast and/or ovarian cancer families is important, as it enables carriers to take preventive measures. All ovarian cancer patients with a serous phenotype should be considered for genetic testing. Further studies are warranted to determine the prevalence of mutations in the rest of the BRCA1 gene, in the BRCA2 gene, and other novel predisposing genes for breast and ovarian cancer.

Does the Diagnosis of Breast or Ovarian Cancer Trigger Referral to Genetic Counseling?

Objective

Kaiser Permanente Northern California is a large integrated health care delivery system in the United States that has guidelines for referring women with newly diagnosed BRCA1-and BRCA2-associated cancers for genetic counseling. This study assesses adherence to genetic counseling referral guidelines within this health system.

Methods

Chart review was performed to identify patients with cancer who met the following pathology-based Kaiser Permanente Northern California guidelines for referral for genetic counseling: invasive breast cancer, younger than age 40; nonmucinous epithelial ovarian, fallopian tube, or peritoneal cancer, younger than age 60; women with synchronous or metachronous primary cancers of the breast and ovaries; and male breast cancer. We assessed compliance with referral guidelines. An electronic notice was sent to the managing physician of patients with newly diagnosed cancer to assess the feasibility of this intervention.

Results

A total of 340 patients were identified with breast cancer at younger than age 40 or with ovarian, peritoneal, or tubal cancer between January and June, 2008. Upon chart review, 105 of these patients met pathology-based criteria for referral to genetic counseling, of whom 47 (45%) were referred within the 2-year study period. Of the 67 subjects with breast cancer, 40 subjects (60%) were referred. In contrast, only 7 (21%) of 33 patients with ovarian cancer were referred (P < 0.001). A pilot study was performed to test the feasibility of notifying managing oncologists with an electronic letter alerting them of eligibility for genetic referral of patients with new diagnosis (n = 21). In the 3 to 6 months after this notification, 12 of these 21 patients were referred for counseling including 5 of 7 patients with a diagnosis of ovarian cancer.

Conclusion

There is a missed opportunity for referring patients to genetic counseling, especially among patients with ovarian cancer. A pilot study suggests that alerting treating physicians is a feasible strategy to increase appropriate referral.

Determination of molecular markers for BRCA1 and BRCA2 heterozygosity using gene expression profiling

Approximately 5% of all breast cancers can be attributed to an inherited mutation in one of two cancer susceptibility genes, BRCA1 and BRCA2. We searched for genes that have the potential to distinguish healthy BRCA1 and BRCA2 mutation carriers from noncarriers based on differences in expression profiling. Using expression microarrays, we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control noncarriers. We identified 137 probe sets in BRCA1 carriers and 1,345 in BRCA2 carriers with differential gene expression. Gene Ontology analysis revealed that most of these genes relate to regulation pathways of DNA repair processes, cell-cycle regulation, and apoptosis. Real-time PCR was conducted on the 36 genes, which were most prominently differentially expressed in the microarray assay; 21 genes were shown to be significantly differentially expressed in BRCA1 and/or BRCA2 mutation carriers as compared with controls (P < 0.05). On the basis of a validation study with 40 mutation carriers and 17 noncarriers, a multiplex model that included six or more coincidental genes of 18 selected genes was constructed to predict the risk of carrying a mutation. The results using this model showed sensitivity 95% and specificity 88%. In summary, our study provides insight into the biologic effect of heterozygous mutations in BRCA1 and BRCA2 genes in response to ionizing irradiation-induced DNA damage. We also suggest a set of 18 genes that can serve as a prediction and screening tool for BRCA1 or BRCA2 mutational carriers by using easily obtained lymphocytes.

Characteristics of women with ovarian carcinoma who have BRCA1 and BRCA2 mutations not identified by clinical testing

OBJECTIVES

Few studies have comprehensively tested all ovarian cancer patients for BRCA1 and BRCA2 (BRCA1/2) mutations. We sought to determine if clinically identified mutation carriers differed in clinical characteristics and outcomes from mutation carriers not identified during routine clinical care.

METHODS

We included women with ovarian, tubal or peritoneal carcinoma. BROCA, an assay using targeted capture and massively parallel sequencing was used to identify mutations in BRCA1/2 and 19 other tumor suppressor genes. We identified subjects with BRCA1/2 mutations using BROCA that had not previously received standard genetic testing (BROCA, n=37) and compared them to subjects with BRCA1/2 mutations identified during routine clinical care (known, n=70), and to those wildtype for 21 genes using BROCA (wildtype, n=291).

RESULTS

BROCA mutation carriers were older than known carriers, median age of 58 (range 41-77), vs. 51 (range 33-76, p=0.003, Mann-Whitney). 58/70 (82.9%) of known carriers had a strong family history, compared with 15/37 (40.5%) of BROCA carriers, p<0.0001, (Fisher's Exact). Median overall survival was significantly worse for BROCA mutation carriers compared to known mutation carriers, (45 vs. 93months, p<0.0001, HR 3.47 (1.79-6.72), Log-rank test). The improved survival for BRCA1/2 mutation carriers (known and BROCA) compared with wildtype cases (69 vs. 44months, p=0.0001, HR 0.58 (0.43-0.77), Log-rank test) was driven by known mutation carriers.

CONCLUSIONS

Older age, absence of a strong family history, and poor survival are all associated with decreased clinical identification of inherited BRCA1/2 mutations in women with ovarian cancer. Using age and family history to direct genetic testing will miss a significant percentage of mutation carriers. Testing should be initiated at the time of diagnosis to maximize identification of mutations and minimize survival bias.

HO-3867, a STAT3 inhibitor induces apoptosis by inactivation of STAT3 activity in BRCA1-mutated ovarian cancer cells

BRCA1 plays an important role in DNA damage and repair, homologous recombination, cell-cycle regulation and apoptosis. BRCA-mutated ovarian cancer often presents at an advanced stage, however, tend to have better response to platinum-based chemotherapy as compared with sporadic cases of epithelial ovarian cancer (EOC). In spite of this, most patients will develop a recurrence and eventually succumb to the disease. Preclinical studies are currently investigating natural compounds and their analogs for tumor-directed targets in ovarian cancer. The aim of this study is to investigate whether the STAT3 inhibitor HO-3867, a novel curcumin analog, has a therapeutic effect on BRCA1-mutated ovarian cancer. Our novel agent, HO-3867 and a commercial STAT3 inhibitor, STATTIC, significantly inhibited BRCA-mutated ovarian cancer cells in vitro in a dose- and time-dependent manner. BRCA-mutated ovarian cancer cells treated with HO-3867 exhibited a significant degree of apoptosis with elevated levels of cleaved caspase-3, caspase-7 and PARP. HO-3867 treatment induced more reactive oxygen species (ROS) in BRCA-mutated cells compared with wild-type cells, however, there was no increased ROS when benign ovarian surface epithelial cells were treated with HO-3867. BRCA1-mutated cancer cells had higher expression of Tyrosine-phosphorylated STAT3 (pTyr705) as compared with other STAT proteins. Furthermore, treatment of these cells with HO-3867 resulted in decreased expression of pTyr705 and its downstream targets cyclin D1, Bcl-2 and survivin. In addition, overexpression of STAT3 cDNA provided resistance to HO-3867-induced apoptosis. Our results show that HO-3867, a potent STAT3 inhibitor, may have a role as a biologically targeted agent for BRCA1-mutated cancers either as an adjunct to cytotoxic chemotherapy or as a single agent.

Hereditary ovarian cancer and two-compartment tumor metabolism: epithelial loss of BRCA1 induces hydrogen peroxide production, driving oxidative stress and NFκB activation in the tumor stroma

Mutations in the BRCA1 tumor suppressor gene are commonly found in hereditary ovarian cancers. Here, we used a co-culture approach to study the metabolic effects of BRCA1-null ovarian cancer cells on adjacent tumor-associated stromal fibroblasts. Our results directly show that BRCA1-null ovarian cancer cells produce large amounts of hydrogen peroxide, which can be abolished either by administration of simple antioxidants (N-acetyl-cysteine; NAC) or by replacement of the BRCA1 gene. Thus, the BRCA1 gene normally suppresses tumor growth by functioning as an antioxidant. Importantly, hydrogen peroxide produced by BRCA1-null ovarian cancer cells induces oxidative stress and catabolic processes in adjacent stromal fibroblasts, such as autophagy, mitophagy and glycolysis, via stromal NFκB activation. Catabolism in stromal fibroblasts was also accompanied by the upregulation of MCT4 and a loss of Cav-1 expression, which are established markers of a lethal tumor microenvironment. In summary, loss of the BRCA1 tumor suppressor gene induces hydrogen peroxide production, which then leads to metabolic reprogramming of the tumor stroma, driving stromal-epithelial metabolic coupling. Our results suggest that new cancer prevention trials with antioxidants are clearly warranted in patients that harbor hereditary/familial BRCA1 mutations.

Identifying and exploiting defects in the Fanconi anemia/BRCA pathway in oncology

Defects in components of DNA repair pathways are responsible for numerous hereditary cancer syndromes and are also common in many sporadic malignancies. Inherited mutations in the breast cancer susceptibility genes BRCA1 and BRCA2 or components of the Fanconi anemia (FA) complex incite genomic instability and predispose to malignancy. The products of the BRCA and FA genes participate in a conserved DNA damage repair pathway that is responsible for repairing interstrand crosslinks and double-strand DNA breaks by homologous recombination. While the genetic instability resulting from FA/BRCA dysfunction contributes to cancer pathogenesis, deficiency of these genes also lends to therapeutic exploitation. Crosslinking agents and ionizing radiation induce damage in cancer cells that requires the FA/BRCA pathway to be resolved; thus cancers that are deficient in BRCA1, BRCA2, or any other component of the FA/BRCA pathway are hypersensitive to these agents. Moreover, emerging synthetic lethal strategies offer opportunities to selectively target cancer cells with defects in homologous recombination. Conversely, enhanced activity of the FA/BRCA pathway is responsible for acquired resistance to specific therapeutic agents, suggesting that both dysfunction and hyperfunction of the FA/BRCA repair machinery are rational targets for cancer therapy. Selection of specific cytotoxic agents based on repair capacity may improve responses and enable personalized cytotoxic chemotherapy. This article reviews the FA/BRCA pathway and current approaches to identify deficiencies within it, discusses synthetic lethality and enhanced repair capacity as causes of therapeutic hypersensitivity and resistance, respectively, and highlights recent studies that have linked FA/BRCA pathway function with therapeutic efficacy.

Prognostic biomarkers in ovarian cancer

Epithelial ovarian cancer (EOC) remains the most lethal gynecological malignancy despite several decades of progress in diagnosis and treatment. Taking advantage of the robust development of discovery and utility of prognostic biomarkers, clinicians and researchers are developing personalized and targeted treatment strategies. This review encompasses recently discovered biomarkers of ovarian cancer, the utility of published prognostic biomarkers for EOC (especially biomarkers related to angiogenesis and key signaling pathways), and their integration into clinical practice.

BRCA mutation frequency and patterns of treatment response in BRCA mutation-positive women with ovarian cancer: a report from the Australian Ovarian Cancer Study Group

PURPOSE

The frequency of BRCA1 and BRCA2 germ-line mutations in women with ovarian cancer is unclear; reports vary from 3% to 27%. The impact of germ-line mutation on response requires further investigation to understand its impact on treatment planning and clinical trial design.

PATIENTS AND METHODS

Women with nonmucinous ovarian carcinoma (n = 1,001) enrolled onto a population-based, case-control study were screened for point mutations and large deletions in both genes. Survival outcomes and responses to multiple lines of chemotherapy were assessed.

RESULTS

Germ-line mutations were found in 14.1% of patients overall, including 16.6% of serous cancer patients (high-gradeserous, 17.1%); [corrected] 44% had no reported family history of breast orovarian cancer.Patients carrying germ-line mutations had improved rates of progression-free and overall survival. In the relapse setting, patients carrying mutations more frequently responded to both platin- and nonplatin-based regimens than mutation-negative patients, even in patients with early relapse after primary treatment. Mutation-negative patients who responded to multiple cycles of platin-based treatment were more likely to carry somatic BRCA1/2 mutations.

CONCLUSION

BRCA mutation status has a major influence on survival in ovarian cancer patients and should be an additional stratification factor in clinical trials. Treatment outcomes in BRCA1/2 carriers challenge conventional definitions of platin resistance, and mutation status may be able to contribute to decision making and systemic therapy selection in the relapse setting. Our data, together with the advent of poly(ADP-ribose) polymerase inhibitor trials, supports the recommendation that germ-line BRCA1/2 testing should be offered to all women diagnosed with nonmucinous, ovarian carcinoma, regardless of family history.

BRCAness: finding the Achilles heel in ovarian cancer

Ovarian cancer is the leading cause of death among gynecological cancers. It exhibits great heterogeneity in tumor biology and treatment response. Germline mutations of DNA repair genes BRCA1/2 are the fundamental defects in hereditary ovarian cancer that expresses a distinct phenotype of high response rates to platinum agents, improved disease-free intervals and survival rates, and high-grade serous histology. The term "BRCAness" describes the phenotypic traits that some sporadic ovarian tumors share with tumors in BRCA1/2 germline mutation carriers and reflects similar causative molecular abnormalities. BRCA pathway studies and molecular profiling reveal BRCA-related defects in almost half of the cases of ovarian cancer. BRCA-like tumors are particularly sensitive to DNA-damaging agents (e.g., platinum agents) because of inadequate BRCA-mediated DNA repair mechanisms, such as nucleotide-excision repair and homologous recombination (HR). Additional inhibition of other DNA repair pathways leads to synthetic lethality in HR-deficient cells; this has been employed in the treatment of BRCA-like ovarian tumors with poly(ADP-ribose) polymerase inhibitors with promising results. This article presents a comprehensive review of the relevant literature on the role of BRCAness in ovarian cancer with respect to BRCA function, methods of BRCA epigenetic defect detection and molecular profiling, and the implications of BRCA dysfunction in the treatment of ovarian cancer.

Clinical characteristics and outcomes of BRCA-associated ovarian cancer: genotype and survival

Previous studies have suggested that BRCA-related epithelial ovarian cancer (EOC) conveys improved survival compared with that of sporadic EOC, but few studies have evaluated differences between BRCA genotypes. We compared characteristics and outcome by genotype in BRCA-associated EOC. Patients with BRCA-associated EOC who were diagnosed between January 30,1981, and December 30, 2008, were retrospectively identified through institutional review board-approved registry studies. We examined clinical characteristics, including event-free survival (EFS) and overall survival (OS), for BRCA1 versus BRCA2 patients. We identified 197 cases (148 BRCA1 cases; 49 BRCA2 cases); the median follow-up period was 63 months. BRCA2 patients were older (55.4 vs. 51.1 y; P < 0.01) and had fewer poorly differentiated tumors (67% vs. 82%; P < 0.05). No difference in EFS was observed. OS at 5 years was 75% in BRCA2 patients versus 61% in BRCA1 patients; this was not statistically significant. A non-significant trend toward improved OS was observed in BRCA2 patients with advanced-stage disease (hazard ratio = 0.59; 95% confidence interval 0.32-1.08). Age and grade differed significantly between BRCA1 and BRCA2 carriers in our study population. Whereas no overall differences in EFS or OS were observed, there was a trend toward improved OS in BRCA2 carriers with advanced-stage disease. This may reflect important differences between BRCA genotypes and should be validated in larger studies.

BRCA1 and BRCA2 mutations correlate with TP53 abnormalities and presence of immune cell infiltrates in ovarian high-grade serous carcinoma

We characterized BRCA1 and BRCA2 status (mutation/methylation) in a consecutive series of cases of ovarian carcinoma in order to identify differences in clinicopathological features, molecular characteristics, and outcome between the pelvic high-grade serous cancers with (i) germline or somatic mutations in BRCA1 or BRCA2, (ii) methylation of BRCA1, and (iii) normal BRCA1 or BRCA2. In all, 131 women were identified prospectively, who were undergoing surgical staging and agreed to germline testing for BRCA1 and BRCA2 mutations. Histopathology, germline and somatic BRCA1 or BRCA2 mutations, BRCA1 methylation, and BRCA1 and BRCA2 mRNA expression levels distinguished four subgroups. In all, 103 cases were high-grade serous carcinoma and of these 31 (30%) had germline or somatic BRCA1 or BRCA2 mutations (20% BRCA1 and 10% BRCA2) (group 1), 21 (20%) had methylation of BRCA1 (group 2), and in 51 (50%) there was no BRCA loss (group 3). Group 4 consisted of 28 cases of non-high-grade serous, none of which had BRCA loss. BRCA1 and BRCA2 mRNA expression levels correlated with designated group (P=0.0008). Among high-grade serous carcinomas, there were no differences between groups 1-3 with respect to stage, ascites, CA125 level, platinum sensitivity, cytoreduction rate, neoadjuvant chemotherapy, or survival. Tumors with BRCA1 or BRCA2 mutations had increased immune infiltrates (CD20 and TIA-1) compared with high-grade serous without mutations (P=0.034, 0.027). TP53 expression differed between groups (P<0.0001), with abnormal TP53 expression in 49/50 tumors from groups 1 and 2. Wild-type TP53 expression was associated with worse outcome in high-grade serous (P<0.001). BRCA loss (mutation/methylation) is a common event in the pelvic high-grade serous (50%). TP53 abnormalities and increased immune cell infiltrates are significantly more common in high-grade serous with germline and somatic mutations in BRCA1 or BRCA2, compared with tumors lacking BRCA abnormalities.

Morphologic patterns associated with BRCA1 and BRCA2 genotype in ovarian carcinoma

This study was undertaken with the hypothesis that certain common morphologic features of ovarian carcinomas are predictably associated with BRCA1 and BRCA2 deficiencies. We selected 43 high-grade serous carcinomas diagnosed at Memorial Sloan-Kettering Cancer Center that were studied as part of The Cancer Genome Atlas pilot project. In addition to 12 randomly selected nonfamilial BRCA-unassociated cases, all 31 Memorial Sloan-Kettering Cancer Center cases with BRCA1 or BRCA2 abnormality were included (n=43). Slides were examined to assess tumor architecture, mitotic index, tumor-infiltrating lymphocytes (TILs), nuclear pleomorphism, necrosis, and involvement of fallopian tube epithelium. Comparing BRCA1-associated cases (BRCA1 germline mutation, n=4, BRCA1 somatic mutation, n=6, BRCA1 promoter methylation, n=13) with unassociated cases (n=12) identified statistically significant differences in morphology. BRCA1-associated high-grade serous carcinomas had more frequent Solid, pseudoEndometrioid, and Transitional cell carcinoma-like morphology (SET features) (P=0.0045), higher mitotic indexes (P=0.012), more TILs (P=0.034), and either geographic or comedo necrosis (P=0.034). BRCA2-associated cases (germline mutation, n=4 and somatic mutation, n=4) tended to show SET features, but they were relatively deficient in TILs and necrosis. Two algorithms incorporating tumor architecture, necrosis, and either mitotic indexes or TILs separated cases that showed 2 of 3 features (BRCA1 associated) from those with 0 of 3 features (BRCA unassociated; P=0.0016 and P=0.0033). A test set comprising 9 BRCA1 germline mutants and 14 high-grade serous carcinoma controls lacking BRCA1 and BRCA2 germline mutation was used to validate the algorithms, with specific emphasis on the ability to detect cases with BRCA1 germline mutation. Best results were obtained with the algorithm that incorporated SET features, necrosis, and mitotic index (P=0.0072; sensitivity of 1.0 (95% CI, 0.66-1.0); specificity of 0.57 (95% CI, 0.29-0.82); positive predictive value of 0.60 (95% CI, 0.32-0.84) and a negative predictive value of 1.0 (95% CI, 0.63-1.0)). These preliminary data indicate potential strong associations between morphology and genotype in high-grade serous carcinomas.

Structure-Function Of The Tumor Suppressor BRCA1

BRCA1, a multi-domain protein, is mutated in a large percentage of hereditary breast and ovarian cancers. BRCA1 is most often mutated in three domains or regions: the N-terminal RING domain, exons 11-13, and the BRCT domain. The BRCA1 RING domain is responsible for the E3 ubiquitin ligase activity of BRCA1 and mediates interactions between BRCA1 and other proteins. BRCA1 ubiquitinates several proteins with various functions. The BRCA1 BRCT domain binds to phosphoproteins with specific sequences recognized by both BRCA1 and ATM/ATR kinases. Structural studies of the RING and BRCT domains have revealed the molecular basis by which cancer causing mutations impact the functions of BRCA1. While no structural data is available for the amino acids encoded by exons 11-13, multiple binding sites and functional domains exist in this region. Many mutations in exons 11-13 have deleterious effects on the function of these domains. In this mini-review, we examine the structure-function relationships of the BRCA1 protein and the relevance to cancer progression.

Genetic risk and gynecologic cancers

Although most gynecologic malignancies are sporadic, hereditary cancer syndromes cause a substantial portion of these cancers. Given that the diagnosis of these syndromes has prognostic and therapeutic implications for the patient, as well as preventive implications for her family members, genetic testing is now an accepted part of the management of the patient who has gynecologic cancer.

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

BACKGROUND

Previously, small studies have found that BRCA1 and BRCA2 breast tumors differ in their pathology. Analysis of larger datasets of mutation carriers should allow further tumor characterization.

METHODS

We used data from 4,325 BRCA1 and 2,568 BRCA2 mutation carriers to analyze the pathology of invasive breast, ovarian, and contralateral breast cancers.

RESULTS

There was strong evidence that the proportion of estrogen receptor (ER)-negative breast tumors decreased with age at diagnosis among BRCA1 (P-trend = 1.2 × 10(-5)), but increased with age at diagnosis among BRCA2, carriers (P-trend = 6.8 × 10(-6)). The proportion of triple-negative tumors decreased with age at diagnosis in BRCA1 carriers but increased with age at diagnosis of BRCA2 carriers. In both BRCA1 and BRCA2 carriers, ER-negative tumors were of higher histologic grade than ER-positive tumors (grade 3 vs. grade 1; P = 1.2 × 10(-13) for BRCA1 and P = 0.001 for BRCA2). ER and progesterone receptor (PR) expression were independently associated with mutation carrier status [ER-positive odds ratio (OR) for BRCA2 = 9.4, 95% CI: 7.0-12.6 and PR-positive OR = 1.7, 95% CI: 1.3-2.3, under joint analysis]. Lobular tumors were more likely to be BRCA2-related (OR for BRCA2 = 3.3, 95% CI: 2.4-4.4; P = 4.4 × 10(-14)), and medullary tumors BRCA1-related (OR for BRCA2 = 0.25, 95% CI: 0.18-0.35; P = 2.3 × 10(-15)). ER-status of the first breast cancer was predictive of ER-status of asynchronous contralateral breast cancer (P = 0.0004 for BRCA1; P = 0.002 for BRCA2). There were no significant differences in ovarian cancer morphology between BRCA1 and BRCA2 carriers (serous: 67%; mucinous: 1%; endometrioid: 12%; clear-cell: 2%). CONCLUSIONS/IMPACT: Pathologic characteristics of BRCA1 and BRCA2 tumors may be useful for improving risk-prediction algorithms and informing clinical strategies for screening and prophylaxis.

Improved survival for BRCA2-associated serous ovarian cancer compared with both BRCA-negative and BRCA1-associated serous ovarian cancer

BACKGROUND

Multiple observational studies have suggested that breast cancer gene (BRCA)-associated ovarian cancers have improved survival compared with BRCA-negative ovarian cancers. However, most of those studies combined BRCA1 and BRCA2 patients or evaluated only BRCA1 patients. The objective of the current study was to examine whether BRCA1-associated and BRCA2-associated ovarian cancers were associated with different outcomes.

METHODS

This was a single-institution, retrospective analysis of patients who had a new diagnosis of histologically confirmed stage III or IV serous ovarian, fallopian tube, or primary peritoneal cancer between January 1, 1996 and February 1, 2011 and who underwent BRCA mutation testing on 1 of 2 institutional review board-approved follow-up studies. Patients who had been tested for BRCA mutations beyond 24 months of diagnosis were excluded from analysis to minimize selection bias from including patients who were referred for genetic testing because of long survival.

RESULTS

Data from 190 patients (143 BRCA-negative patients, 30 BRCA1-positive patients, and 17 BRCA2-positive patients) were analyzed. During the study period, 73 deaths were observed (60 BRCA-negative patients, 10 BRCA1-positive patients, 3 BRCA2-positive patients). The median follow-up for the remaining 117 survivors was 2.5 years. At 3 years, 69.4%, 90.7%, and 100% of BRCA-negative patients, BRCA1-positive patients, and BRCA2-positive patients were alive, respectively. On univariate analysis, age, BRCA2 mutations, debulking status, and type of first-line therapy (intravenous or intraperitoneal) were significant predictors of overall survival. On multivariate analysis, BRCA2 mutations (hazard ratio, 0.20; 95% confidence interval, 0.06-0.65; P = .007), but not BRCA1 mutations (hazard ratio, 0.70; 95% confidence interval, 0.36-1.38; P = .31), predicted for improved overall survival compared with BRCA-negative patients. When carriers of BRCA2 mutations were directly compared with carriers of BRCA1 mutations, BRCA2 mutations appeared to confer improved overall survival (hazard ratio, 0.29; 95% confidence interval, 0.08-1.05; P = .060), although this finding did not reach significance.

CONCLUSIONS

The current data suggests that BRCA2 mutations confer an overall survival advantage compared with either being BRCA-negative or having a BRCA1 mutation in high-grade serous ovarian cancer. This finding may have important implications for clinical trial design.

Association of BRCA1 and BRCA2 mutations with survival, chemotherapy sensitivity, and gene mutator phenotype in patients with ovarian cancer

CONTEXT

Attempts to determine the clinical significance of BRCA1/2 mutations in ovarian cancer have produced conflicting results.

OBJECTIVE

To determine the relationships between BRCA1/2 deficiency (ie, mutation and promoter hypermethylation) and overall survival (OS), progression-free survival (PFS), chemotherapy response, and whole-exome mutation rate in ovarian cancer.

DESIGN, SETTING, AND PATIENTS

Observational study of multidimensional genomics and clinical data on 316 high-grade serous ovarian cancer cases that were made public between 2009 and 2010 via The Cancer Genome Atlas project.

MAIN OUTCOME MEASURES

OS and PFS rates (primary outcomes) and chemotherapy response (secondary outcome).

RESULTS

BRCA2 mutations (29 cases) were associated with significantly better OS (adjusted hazard ratio [HR], 0.33; 95% CI, 0.16-0.69; P = .003 and 5-year OS, 61% for BRCA2-mutated vs 25% for BRCA wild-type cases) and PFS (adjusted HR, 0.40; 95% CI, 0.22-0.74; P = .004 and 3-year PFS, 44% for BRCA2-mutated vs 16% for BRCA wild-type cases), whereas neither BRCA1 mutations (37 cases) nor BRCA1 methylation (33 cases) was associated with prognosis. Moreover, BRCA2 mutations were associated with a significantly higher primary chemotherapy sensitivity rate (100% for BRCA2-mutated vs 82% [P = .02] and 80% [P = .05] for BRCA wild-type and BRCA1-mutated cases, respectively) and longer platinum-free duration (median platinum-free duration, 18.0 months for BRCA2-mutated vs 11.7 [P = .02] and 12.5 [P = .04] months for BRCA wild-type and BRCA1-mutated cases, respectively). BRCA2-mutated, but not BRCA1-mutated cases, exhibited a "mutator phenotype" by containing significantly more mutations than BRCA wild-type cases across the whole exome (median mutation number per sample, 84 for BRCA2-mutated vs 52 for BRCA wild-type cases, false discovery rate <0.1).

CONCLUSION

Among women with high-grade serous ovarian cancer, BRCA2 mutation, but not BRCA1 deficiency, was associated with improved survival, improved chemotherapy response, and genome instability compared with BRCA wild-type.

Management of hereditary ovarian cancer

Mutations in BRCA1 and BRCA2 genes account for the majority of hereditary breast and ovarian cancers. Approximately 10% of cases of ovarian cancer are due to germline mutations in BRCA1 and BRCA2. Ovarian cancer associated with BRCA1 and BRCA2 mutations has a distinct histological phenotype. This type of cancer is predominantly of serous or endometrioid histology and is high grade. Patients with BRCA1 or BRCA2 mutations should be offered risk-reducing salpingo-oophorectomy by age 40 years, or when childbearing is complete. Nowadays there are no differences between the treatments provided for sporadic and hereditary ovarian cancer, although there are indications that targeted therapy is effective in women with BRCA1/BRCA2-associated tumors. Retrospective studies reveal a high level of sensitivity to platinum agents in BRCA-associated tumors and initial trials show good efficacy and tolerability for polyADP-ribose polymerase inhibitors in mutation carriers with advanced ovarian cancers. These agents might also potentially be used in chemoprevention. Authors review the current management of hereditary ovarian cancer. Orv. Hetil., 2011, 152, 1596–1608.

BRCA1 is both a prognostic and predictive biomarker of response to chemotherapy in sporadic epithelial ovarian cancer

OBJECTIVES

We investigated the relationship between BRCA1 protein expression by immunohistochemistry (IHC) and clinical outcome following platinum and platinum/taxane chemotherapy in sporadic epithelial ovarian cancer (EOC).

METHODS

BRCA1 IHC was performed on a cohort of 292 ovarian tumours from two UK oncology centres. BRCA1 protein expression levels were correlated with overall survival (OS), progression free survival (PFS) and clinical response to chemotherapy by multivariate analysis.

RESULTS

EOC patients with absent/low BRCA1 protein expression (41%) had a better chance of clinical response following chemotherapy as compared to patients with high BRCA1 expression (odds ratio 2.47: 95%CI 1.10-5.55, p=0.029). Patients with absent/low BRCA1 had a higher probability of clinical response following single agent platinum compared to high BRCA1 expressing patients (68.5% vs. 46.8%), while addition of a taxane increased response rates independent of BRCA1. Overall, patients with absent/low BRCA1 had a better clinical outcome compared to patients with high BRCA1 protein expression in terms of both OS (HR=0.65: 95%CI 0.48-0.88, p=0.006) and PFS (HR=0.74, 95%CI 0.55-0.98, p=0.040).

CONCLUSIONS

We confirm that absent/low BRCA1 protein expression is a favourable prognostic marker. However, we also provide the first evidence that absent/low BRCA1 protein expression in sporadic EOC patients predicts for an improved clinical response to chemotherapy.

Improved survival in non-Ashkenazi Jewish ovarian cancer patients with BRCA1 and BRCA2 gene mutations

OBJECTIVES

Previous studies report a survival advantage in ovarian cancer patients with Ashkenazi Jewish (AJ) breast cancer gene (BRCA) founder mutations. The purpose of this study was to determine if this association exists in patients with non-Ashkenazi Jewish (non-AJ) BRCA mutations. We also sought to account for "survival bias" by minimizing lead time that may exist between diagnosis and genetic testing.

METHODS

Patients with stage III/IV ovarian cancer and a non-AJ BRCA mutation, seen between January 1996 and July 2007, were identified from eight institutions. Patients with sporadic ovarian cancer were compared to similar cases, matched by age, stage, year of diagnosis, and vital status at time interval to BRCA testing. Progression-free (PFS) and overall survival (OS) were calculated by the Kaplan-Meier method. Multivariate Cox proportional hazards models were calculated for variables of interest. Fisher's exact test and chi-square were also used for analysis.

RESULTS

Ninety-five advanced stage ovarian cancer patients with non-AJ BRCA mutations and 183 sporadic controls were analyzed. Compared to sporadic ovarian cancer patients, non-AJ BRCA patients had longer PFS (27.9 months vs. 17.9 months, HR 0.61 [95% CI 0.43-0.86]) and OS (101.7 months vs. 54.3 months, HR 0.43 [95% CI 0.27-0.68]). BRCA status was an independent predictor of PFS and OS.

CONCLUSIONS

This multicenter study demonstrates a significant survival advantage in advanced stage ovarian cancer patients with non-AJ BRCA mutations, confirming the previous studies in the Jewish population. This improved survival was evident when accounting for the "survival bias" that coincides with genetic testing.

Chemosensitivity and outcome of BRCA1- and BRCA2-associated ovarian cancer patients after first-line chemotherapy compared with sporadic ovarian cancer patients

BACKGROUND

Because it is insufficiently clear whether BRCA-associated epithelial ovarian cancer (EOC) is more chemosensitive than sporadic EOC, we examined response to chemotherapy, progression-free survival (PFS) and overall survival (OS) in BRCA1- and BRCA2-associated versus sporadic EOC patients.

METHODS

Data about patient characteristics, response to and outcome after primary therapy, including chemotherapy, were collected from 99 BRCA1, 13 BRCA2 and 222 sporadic patients. Analyses were carried out using a chi-square test and Kaplan-Meier and Cox regression methods.

RESULTS

Complete response (CR) or no evidence of disease (NED) was observed in 87% of the BRCA1 patients, progressive disease (PD) in 2%, being 71% and 15%, respectively, in sporadic EOC patients (P = 0.002). In BRCA2 patients, 92% had CR/NED, and none PD (P = 0.27). Median PFS in BRCA1, BRCA2 and sporadic patients was 2.1 [95% confidence interval (CI) 1.9-2.5] years (P = 0.006), 5.6 (95% CI 0.0-11.5) years (P = 0.008) and 1.3 (95% CI 1.1-1.5) years, respectively. Median OS in the three groups was 5.9 (95% CI 4.7-7.0) years (P < 0.001), >10 years (P = 0.008), and 2.9 (95% CI 2.2-3.5) years, respectively. A trend for a longer PFS and OS in BRCA2 compared with BRCA1 patients was observed.

CONCLUSION

Compared with sporadic EOC patients, both BRCA1- and BRCA2-associated patients have improved outcomes after primary therapy, including chemotherapy.

Survival in epithelial ovarian cancer: a multivariate analysis incorporating BRCA mutation status and platinum sensitivity

BACKGROUND

Patients with BRCA-associated ovarian cancer (OC) have a survival advantage over those with sporadic OC. To further explore this, we examined the impact of prognostic factors on disease-free survival (DFS) and overall survival (OS) in patients with known BRCA mutation status.

PATIENTS AND METHODS

We reviewed stage III-IV OC patients treated at our institution between 1 December 1996 and 30 September 2006 and also tested on protocol for BRCA mutations. Impact on DFS and OS was determined by Kaplan-Meier analysis and a Cox proportional hazards model.

RESULTS

Of the 110 patients, 36 had deleterious BRCA mutations [BRCA (+)] and 74 were BRCA wild type [BRCA(-)]. Thirty-one of 36 (86%) BRCA (+) and 60 of 74 (81%) BRCA (-) patients were platinum sensitive (P = 0.60). Median OS was longer for BRCA (+) patients (not reached versus 67.8 months; P = 0.02), but DFS was similar (26.9 versus 24.0, P = 0.3). On multivariate analysis, OS correlated with primary platinum sensitivity [HR = 0.15; 95% CI (confidence interval) 0.06-0.34] and BRCA (+) mutation status (HR = 0.33; 95% CI 0.12-0.86).

CONCLUSIONS

BRCA mutation status predicted OS independent of primary platinum sensitivity, suggesting that underlying tumor biology contributes to disease outcome and may be worthy of consideration in future clinical trial design.

Hereditary ovarian cancer: biology, response to chemotherapy and prognosis

Recent evidence has indicated that the prognosis of women with epithelial ovarian cancer who are BRCA-mutation carriers may be better than for noncarriers. Part of the explanation is a higher sensitivity to platinum and other chemotherapies, as was demonstrated in in vitro studies, as well as a possible different biology. BRCA genes are important in double-strand DNA break repair and in other important processes of the cell cycle. Mutation or reduced activity of BRCA genes leads to a higher vulnerability to DNA damage (caused by chemotherapy and radiotherapy) compared with malignant tumors of noncarriers. New targeted drugs, such as poly (ADP-ribose) polymerase-1 and -2 inhibitors, are currently under investigation, as are new biomarkers that will hopefully lead the way to better treatment and longer survival. Testing for the BRCA mutation should be carried out and used as a guide for therapy in most patients with epithelial ovarian cancer.

[Hereditary breast and ovarian cancers]

Hereditary factors are responsible for 5-10% of all breast cancers and 10% of all ovarian cancer cases and are predominantly caused by mutations in the high risk genes BRCA1 and BRCA2 (BRCA: breast cancer). Additional moderate and low penetrance gene variants are currently being analyzed via whole genome association studies. Interdisciplinary counseling, quality managed genetic testing and intensified prevention efforts in specialized medical centres are essential for members of high risk families considering the high prevalence of malignant tumors and the early age of onset. Furthermore, the identification of BRCA-deficient carcinomas is of particular clinical interest, especially regarding new specific therapeutic options, e.g. treatment with poly (ADP-ribose) polymerase (PARP) inhibitors. There are presently no valid surrogate markers verifying the association of BRCA1/BRC2 in tumors. However, breast cancers harboring pathogenic BRCA1 mutations in particular display specific histopathological features.

Expanding the criteria for BRCA mutation testing in breast cancer survivors

PURPOSE

Every year approximately 25% of women diagnosed with breast cancer are younger than 50 years of age, and almost 10% of them have a BRCA mutation. Not all potential carriers are identified by existing criteria for BRCA testing. We estimated the costs and benefits of different BRCA testing criteria for women with breast cancer younger than 50 years.

METHODS

We developed a Markov Monte Carlo simulation to compare six criteria for BRCA mutation testing: (1) no testing (reference); (2) medullary breast cancer in patients younger than 50 years; (3) any breast cancer in patients younger than 40 years; (4) triple negative (TN) breast cancer in patients younger than 40 years; (5) TN breast cancer in patients younger than 50 years; (6) any breast cancer in patients younger than 50 years. Net health benefits were life expectancy and quality-adjusted life expectancy, and primary outcome was the incremental cost-effectiveness ratio (ICER). The model estimated the number of new breast and ovarian cancer cases.

RESULTS

BRCA mutation testing for all women with breast cancer who were younger than 50 years could prevent the highest number of breast and ovarian cancer cases, but with unfavorable ICERs. Testing women with TN breast cancers who were younger than 50 years was cost-effective with an ICER of $8,027 per year of life gained ($9,084 per quality-adjusted life-year), and could reduce subsequent breast and ovarian cancer risks by 23% and 41%, respectively, compared with the reference strategy.

CONCLUSION

Testing women with TN breast cancers who were younger than 50 years for BRCA mutations is a cost-effective strategy and should be adopted into current guidelines for genetic testing.

Making the best of PARP inhibitors in ovarian cancer

Drugs that inhibit the enzyme poly(ADP-ribose)polymerase (PARP) are showing considerable promise for the treatment of cancers that have mutations in the BRCA1 or BRCA2 tumor suppressors. This therapeutic approach exploits a synthetic lethal strategy to target the specific DNA repair pathway in these tumors. High-grade ovarian cancers have a generally poor prognosis, and accumulating evidence suggests that mutations in BRCA1 or BRCA2, or silencing of BRCA1 by promoter methylation, may be common in this disease. Here, we consider how the potential benefit of PARP inhibitors might be maximized in ovarian cancer. We suggest that it will be crucial to explore novel therapeutic trial strategies and drug combinations, and incorporate robust biomarkers predictive of response if these drugs are to reach their full potential.

Hereditary breast and ovarian cancer due to mutations in BRCA1 and BRCA2

Hereditary breast and ovarian cancer due to mutations in the BRCA1 and BRCA2 genes is the most common cause of hereditary forms of both breast and ovarian cancer. The overall prevalence of BRCA1/2 mutations is estimated to be from 1 in 400 to 1 in 800 with a higher prevalence in the Ashkenazi Jewish population (1 in 40). Estimates of penetrance (cancer risk) vary considerably depending on the context in which they were derived and have been shown to vary within families with the same BRCA1/2 mutation. This suggests there is no exact risk estimate that can be applied to all individuals with a BRCA1/2 mutation. The likelihood of harboring a BRCA1 or BRCA2 mutation is dependent on one's personal and/or family history of cancer and can be estimated using various mutation probability models. For those individuals who have a BRCA1 or BRCA2 mutation, several screening and primary prevention options have been suggested, including prophylactic surgery and chemoprevention. Once a BRCA1 or BRCA2 mutation has been identified in a family, testing of at-risk relatives can identify those family members who also have the familial mutation and thus need increased surveillance and early intervention when a cancer is diagnosed.

Germline genetic variation, cancer outcome, and pharmacogenetics

Studies of the role of germline or inherited genetic variation on cancer outcome can fall into three distinct categories. First, the impact of highly penetrant but lowly prevalent mutations of germline DNA on cancer prognosis has been studied extensively for BRCA1 and BRCA2 mutations as well as mutations related to hereditary nonpolyposis colorectal cancer syndrome. These mainly modest-sized analyses have produced conflicting results. Although some associations have been observed, they may not be independent of other known clinical or molecular prognostic factors. Second, the impact of germline polymorphisms on cancer prognosis is a burgeoning field of research. However, a deeper understanding of potentially confounding somatic changes and larger multi-institutional, multistage studies may be needed before consistent results are seen. Third, research examining the impact of germline genetic variation on differential treatment response or toxicity (pharmacogenetics) has produced some proof-of-principle results. Putative germline pharmacogenetic predictors of outcome include DPYD polymorphisms and fluorouracil toxicity, UGT1A1 variation and irinotecan toxicity, and CYP2D6 polymorphisms and tamoxifen efficacy, with emerging data on predictors of molecularly targeted or biologic drugs. Here we review data pertaining to these germline outcome and germline toxicity relationships.

Somatic mutations in BRCA1 and BRCA2 could expand the number of patients that benefit from poly (ADP ribose) polymerase inhibitors in ovarian cancer

PURPOSE

The prevalence of BRCA(1/2) mutations in germline DNA from unselected ovarian cancer patients is 11% to 15.3%. It is important to determine the frequency of somatic BRCA(1/2) changes, given the sensitivity of BRCA-mutated cancers to poly (ADP ribose) polymerase-1 (PARP1) inhibitors and platinum analogs.

PATIENTS AND METHODS

In 235 unselected ovarian cancers, BRCA(1/2) was sequenced in 235, assessed by copy number analysis in 95, and tiling arrays in 65. 113 tumors were sequenced for TP53. BRCA(1/2) transcript levels were assessed by quantitative polymerase chain reaction in 220. When available for tumors with BRCA(1/2) mutations, germline DNA was sequenced.

RESULTS

Forty-four mutations (19%) in BRCA1 (n = 31)/BRCA2 (n = 13) were detected, including one homozygous BRCA1 intragenic deletion. BRCA(1/2) mutations were particularly common (23%) in high-grade serous cancers. In 28 patients with available germline DNA, nine (42.9%) of 21 and two (28.6%) of seven BRCA1 and BRCA2 mutations were demonstrated to be somatic, respectively. Five mutations not previously identified in germline DNA were more commonly somatic than germline (four of 11 v one of 17; P = .062). There was a positive association between BRCA1 and TP53 mutations (P = .012). BRCA(1/2) mutations were associated with improved progression-free survival (PFS) after platinum-based chemotherapy in univariate (P = .032; hazard ratio [HR] = 0.65; 95% CI, 0.43 to 0.98) and multivariate (P = .019) analyses. BRCA(1/2) deficiency, defined as BRCA(1/2) mutations or expression loss (in 24 [13.3%] BRCA(1/2)-wild-type cancers), was present in 67 ovarian cancers (30%) and was also significantly associated with PFS in univariate (P = .026; HR = 0.67; 95% CI, 0.47 to 0.96) and multivariate (P = .008) analyses.

CONCLUSION

BRCA(1/2) somatic and germline mutations and expression loss are sufficiently common in ovarian cancer to warrant assessment for prediction of benefit in clinical trials of PARP1 inhibitors.

Fine tuning chemotherapy to match BRCA1 status

Targeted cancer therapies have been primarily directed at inhibiting oncogenes that are overexpressed or constitutively active in tumors. It is thought that as the cell's circuitry gets re-wired by the constitutive activation of some pathways it becomes exquisitely dependent on this activity. Tumor cell death normally results from inhibiting constitutively active pathways. The dependence of tumor cells on the activity of these pathways has been called oncogene addiction. Approaches that aim to exploit loss of function, rather than gain of function changes have also become a powerful addition to our arsenal of cancer therapies. In particular, when tumors acquire mutations that disrupt pathways in the DNA damage response they rely on alternative pathways that can be targeted pharmacologically. Here we review the use of BRCA1 as a marker of response to therapy with a particular focus on the use of Cisplatin and PARP inhibitors. We also explore the use of BRCA1 as a marker of response to microtubule inhibitors and how all these approaches will bring us closer to the goal of personalized medicine in cancer treatment.

Increased Incidence of Visceral Metastases in Scottish Patients With BRCA1/2-Defective Ovarian Cancer: An Extension of the Ovarian BRCAness Phenotype

Purpose

To compare the frequency of visceral relapse of BRCA1/2-deficient ovarian cancer to that of nonhereditary controls.

Patients and Methods

All patients diagnosed in Scotland with epithelial ovarian cancer (EOC) or primary peritoneal cancer (PPC) and a germline BRCA1/2 mutation were identified. Those with previous malignancy were excluded. Each remaining patient who experienced relapse was matched with two nonhereditary controls.

Results

Seventy-nine patients with EOC/PPC and germline BRCA1/2 mutations were identified. Fifteen had inadequate clinical data, two had carcinosarcoma, 27 had previous breast cancer, and 16 were in remission. Of the remaining 19 patients who were BRCA1/2 deficient, 14 patients (74%) developed visceral metastases compared with six (16%) of 38 patients in the control group. The percentages of liver, lung, and splenic metastases were 53%, 32%, and 32%, respectively, in the patients compared with 5%, 3%, and 5%, respectively, in the controls. When events occurring outside the matched follow-up period were omitted, the percentages of visceral, liver, lung, and splenic metastases were 58%, 42%, 16%, and 32% in the patients compared with 5%, 0%, 0%, and 3% in controls (P < .001, P < .001, P = .066, and P = .011, respectively). In an independent validation set, the corresponding percentages of visceral, liver, lung, and splenic metastases were 63%, 46%, 13%, and 17% in the patients compared with 11%, 4%, 2%, and 2% in controls (P < .001, P < .001, P = .153, and P = .052, respectively).

Conclusion

Although sporadic EOC commonly remains confined to the peritoneum, BRCA1/2-deficient ovarian cancer frequently metastasizes to viscera. These data extend the ovarian BRCAness phenotype, imply BRCA1/2-deficient ovarian cancer is biologically distinct, and suggest that patients with visceral metastases should be considered for BRCA1/2 sequencing.

Evaluating women with ovarian cancer for BRCA1 and BRCA2 mutations: missed opportunities

OBJECTIVE

To estimate the incidence of genetic counseling referral for ovarian cancer patients who are at substantial risk for a BRCA1 or BRCA2 mutation.

METHODS

An analysis was performed of new ovarian cancer patients who were seen at a comprehensive cancer center from January 1, 1999, through December 31, 2007. Patients at substantial (more than 20-25%) risk for a BRCA1 or BRCA2 mutation were identified and records reviewed for referral to genetic counseling. Time to referral was estimated using the Kaplan-Meier method.

RESULTS

A total of 3,765 epithelial ovarian cancer patients were seen during the 9-year period. On average, 23.8% of patients met substantial-risk criteria for BRCA mutations. In 1999, only 12% of patients at substantial-risk were referred. Referral improved over time with 48% referred in 2007 (P<.001). Newly diagnosed patients were more often referred for genetic counseling than new patients with recurrent disease or those seen as second opinions. African-American women meeting substantial-risk criteria were less likely to be referred than were white or Hispanic women (P=.009).

CONCLUSION

Although dictated family history was accurate, interpretation of risk for BRCA1 or BRCA2 mutations and subsequent referral to genetic counseling was poor. Although there was significant improvement over time, 50% of substantial-risk patients still were missed. Systematic efforts to identify those ovarian cancer patients at substantial risk for a BRCA1 or BRCA2 are necessary.

The inherited genetics of ovarian and endometrial cancer

Endometrial and epithelial ovarian cancers are the fourth and fifth most common cancers in women in developed countries, after breast, lung, and colorectal cancer. In the United States alone, in 2008 there were about 40,000 new diagnoses of endometrial cancer and 7500 disease-related deaths. For ovarian cancer, there were about 22,000 new diagnoses and 15,000 deaths over the same period. The purpose of this article is to review the recent developments in the inherited genetics of ovarian and endometrial cancer, with particular attention to recent progress in identifying common low-penetrance susceptibility genes and their clinical implications.