Skip to main content

Homologous recombination deficiency (HRD) testing in ovarian cancer clinical practice: a review of the literature

Abstract

Until recently our knowledge of a genetic contribution to ovarian cancer focused almost exclusively on mutations in the BRCA1/2 genes. However, through germline and tumor sequencing an understanding of the larger phenomenon of homologous recombination deficiency (HRD) has emerged. HRD impairs normal DNA damage repair which results in loss or duplication of chromosomal regions, termed genomic loss of heterozygosity (LOH). The list of inherited mutations associated with ovarian cancer continues to grow with the literature currently suggesting that up to one in four cases will have germline mutations, the majority of which result in HRD. Furthermore, an additional 5–7% of ovarian cancer cases will have somatic HRD. In the near future, patients with germline or somatic HRD will likely be candidates for a growing list of targeted therapies in addition to poly (ADP-ribose) polymerase (PARP) inhibitors, and, as a result, establishing an infrastructure for widespread HRD testing is imperative. The objective of this review article is to focus on the current germline and somatic contributors to ovarian cancer and the state of both germline and somatic HRD testing. For now, germline and somatic tumor testing provide important and non-overlapping clinical information. We will explore a proposed testing strategy using somatic tumor testing as an initial triage whereby those patients found with somatic testing to have HRD gene mutations are referred to genetics to determine if the mutation is germline. This strategy allows for rapid access to genomic information that can guide targeted treatment decisions and reduce the burden on genetic counselors, an often limited resource, who will only see patients with a positive somatic triage test.

Background

Ovarian cancer is the fifth leading cause of death in women in the United States with an estimated 22,280 new cases and 14,240 deaths in 2016 [1]. The majority of women with epithelial ovarian cancer (EOC) are diagnosed with advanced disease. Standard therapy includes surgical debulking and platinum and taxane-based chemotherapy, resulting in complete clinical remission in up to 75% of patients, however only 30% of patients will be cured. Once recurrent, ovarian cancer generally does not exhibit the same level of chemo-sensitivity, highlighting the need for rational therapies directed toward specific molecular targets [2, 3]. The advent of next-generation sequencing (NGS) has allowed for the systematic investigation of the genomic and molecular alterations in EOC which can identify patients as candidates for individualized targeted therapy. EOC tumors with deficient homologous recombination (HR) repair represent such a group and have demonstrated sensitivity to poly(ADP-ribose)polymerase (PARP) inhibitors [46]. The majority of homologous recombination deficient (HRD) tumors will occur in patients with germline BRCA1 and BRCA2 mutations. However, there also are patients with germline mutations in other HR pathway genes and patients who do not carry an inherited germline mutation but have tumors with sporadic HRD mutations. Data from the Cancer Genome Atlas (TCGA) demonstrates that approximately fifty percent of high grade serous ovarian cancers have aberrations in HR repair [7]. Patients and physicians now have access to NGS analysis of both germline samples and somatic tumor tissue. The objective of this review article is to focus on the current germline and somatic contributors to ovarian cancer and the state of germline and somatic HRD testing.

Homologous recombination (HR)

DNA damage is a constantly occurring phenomenon that necessitates a complex network of molecular repair pathways in order to maintain genomic integrity and prevent cell death. HR is an important pathway that allows repair of double-stranded DNA breaks. HR operates during the S and G2 phases of the cell cycle and relies on many proteins including BRCA1 and BRCA2, proteins of the MNR complex (MRE11/RAD50/NBS1), CtIP, MRE11, RAD51, ATM, H2AX, PALB2, RPA, RAD52 and proteins of the Fanconi anemia pathway [8, 9]. When cells have non-functioning HR, for example due to BRCA1 or BRCA2 deficiency, they rely on other repair pathways like non-homologous end-joining (NHEJ), which is less precise and more error-prone [10]. NHEJ results in the accumulation of additional mutations and chromosomal instability, increasing the risk that a cell undergoes malignant transformation [10, 11].

Until recently, hereditary EOC was thought to be caused almost exclusively by mutations in BRCA1 and BRCA2, with a small contribution from mutations in the DNA mismatch repair (MMR) genes [12]. TCGA, however, has shown that about half of high grade serous ovarian cancers, the most common histologic subtype, have aberrations in HR repair. Further investigation of the HR pathway highlights multiple other protein co-factors that are necessary for successful HR repair including RAD51C, RAD51D, BRIP1, PALB2, BARD1 and the MMR genes [12, 13]. This group of genes is collectively referred to as the HRD genes [14].

Germline mutations in EOC

When considering the genetic contribution to carcinogenesis, an important distinction is whether a mutation is germline or somatic. Germline implies that the mutation was inherited and is therefore present in all of the individuals’ cells. Somatic mutations are those mutations that are acquired and therefore occur exclusively in the tumor cells. BRCA1 and BRCA2 are the most well-known ovarian cancer susceptibility genes, with germline genetic testing available since the 1990s [15]. BRCA mutation-associated ovarian cancers have multiple distinct clinical features including earlier age at diagnosis, visceral distribution of disease, improved survival, enhanced sensitivity to platinum-based chemotherapies and sensitivity to PARP inhibitors [1618]. The prevalence of BRCA1/2 germline mutations in patients with epithelial ovarian cancer is estimated to be about 11–15% [1921].

In June 2013 the Supreme Court ruled unanimously against Myriad Genetics, invalidating the exclusive license rights to BRCA1 and BRCA2 testing in the United States. Following this decision, many other clinical laboratories began offering BRCA1 and BRCA2 testing, both as single gene tests and in the form of comprehensive genetic panels [22]. Although used for many hereditary cancer syndromes, multigene panels have been particularly interesting in ovarian cancer. Recent literature suggests that up to 24% of ovarian cancers are associated with germline mutations, and of these, 29% have mutations in genes other than BRCA1 or BRCA2 [12, 13, 23, 24] (Table 1).

Table 1 Genes associated with hereditary ovarian cancer

Somatic mutations in EOC

Several publications have reported the presence of somatic BRCA1/2 mutations in ovarian cancer, highlighting that both germline and somatic mutations in HRD genes can result in ovarian cancer. TCGA sequenced 316 high grade serous EOCs and matched germline patient DNA. Germline BRCA1 mutations were discovered in 9% of patients and BRCA2 mutations in 8%. Evaluation of tumor tissue found additional somatic mutations in BRCA1/2 (3%), EMSY (8%), PTEN (7%), RAD51C (3%), ATM/ATR (2%) and Fanconi anemia genes (5%) [7]. Hennessy et al. [25] performed BRCA1 and BRCA2 sequencing of 235 unselected ovarian cancer tumors and found mutations in 19% of cases (31 mutations in BRCA1 and 13 in BRCA2). Germline DNA specimens were available for 28 of the patients harboring a BRCA1 or BRCA2 tumor mutation. Eleven (39.3%) of the mutations present in the EOC tumor were found to be somatic and 17 germline (60.7%) [25]. When evaluating 367 ovarian carcinomas, Pennington et al.[26] discovered that 24% patients carried a germline mutations in HRD genes and 9% of patients had a somatic tumor mutation. Finally, Cunningham et al. [27] evaluated 279 EOC patients and found that 3.5% of patients had somatic mutations in BRCA1 (2.1%) and BRCA2 (1.4%). (Table 2). The variable rates of somatic mutations reported in the literature likely reflect differences in patient selection (e.g., histologic subtype) and scope of testing (e.g., number of genes included on the NGS panel). Currently, the true prevalence of somatic mutations remains unknown, however it has been estimated as somewhere between 5 and 7% of cases. This implies that for every 4–5 ovarian cancer patients with a germline BRCA mutation there will be one patient with a somatic mutation [8].

Table 2 Germline and somatic HRD mutations in ovarian cancer

Genetic evaluation

Germline testing

Genetic testing for germline mutations is recommended for all women with non-mucinous epithelial ovarian cancer by multiple professional societies including the American College of Medical Genetics and Genomics (ACMG) [28], the American Society of Clinical Oncology (ASCO) [29], the National Cancer Comprehensive Network (NCCN) [30], the National Society of Genetic Counselors (NSGC) [28] and the Society of Gynecologic Oncology (SGO) [31]. Multigene panels can assess a virtually unlimited number of genes in a method that is both time- and cost-effective when compared to the prior standard of single gene Sanger sequencing. The availability of NGS technology combined with the Supreme Court ruling invalidating exclusive gene patent rights has resulted in rapid uptake of multigene panels [32]. The scope of available testing ranges from screening for founder mutations, to sequencing BRCA1 and BRCA2, to full panel testing of multiple cancer-associated genes.

Currently, the guidelines that recommend germline testing do not make specific recommendations regarding which of the many available platforms to utilize [14]. Cancer genetic counselors play an integral role both in helping patients choose the specific method of testing and analyzing the results, which are becoming increasingly complex. While adding additional genes to panels increases the chance of finding deleterious mutations it also increases the likelihood of finding variants of uncertain significance (VUS) and non-actionable mutations defined as mutations for which the clinical relevance is unclear and clinical management guidelines do not exist. Finding VUS and non-actionable mutations does not improve patient outcomes but can result in patient and physician anxiety and unindicated and inappropriate interventions [33]. Pre- and post-test cancer genetic counseling has been recognized to benefit the individual tested and relatives, associated with improved adherence to cancer risk management, better informed surgical decision making, increased cancer genetics knowledge, improved patient satisfaction and cost savings [3446].

Discovering a germline mutation in a patient with EOC has multiple significant clinical implications. As previously stated, BRCA1/2-associated ovarian cancer has multiple distinct features affecting age at diagnosis, disease distribution, chemosensitivity and survival. Patients with known mutations have access to targeted therapy, for example PARP inhibitors for BRCA1/2 mutation carriers. In December 2014, the U.S. Food and Drug Administration (FDA) granted olaparib accelerated approval for monotherapy in patients with germline BRCA1/2 mutations and recurrent ovarian cancer with three or more prior lines of chemotherapy, making olaparib the first of the PARP inhibitors to receive FDA approval. On December 19, 2016 the FDA granted accelerated approval to rucaparib in patients with recurrent ovarian cancer with two or more prior lines of chemotherapy and either germline BRCA1/2 mutations or somatic BRCA1/2 mutations in the tumor detected by a next-generation sequencing-based companion diagnostic test. The European Commission granted marketing authorization for the PARP inhibitor olaparib as monotherapy in the maintenance treatment of adult patients with platinum-sensitive, relapsed BRCA-mutated (germline and/or somatic) high-grade serous epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in complete response or partial response following platinum-based chemotherapy [47]. The recently published phase III data of Mirza et al. support the use of Niraparib in the maintenance setting for patients with platinum sensitive recurrent ovarian cancer. Patients with germline HRD mutations derived the greatest clinical benefit from this treatment [48].

In addition to treatment eligibility, many mutations are predictive of other cancers in addition to ovarian cancer, offering patients the opportunity for heightened awareness and screening. Finally, identifying a germline mutation can allow family members to undergo genetic counseling and testing, termed “cascade” testing. Informed relatives have the opportunity to pursue intensive cancer surveillance and risk-reducing options. Data from individuals with Lynch syndrome demonstrate that awareness of a mutation results in cancer prevention or early diagnosis of cancer, which can improve morbidity and prevent mortality [4951].

Tumor profiling

In addition to germline testing, multiple companies now offer tumor genetic profiling for somatic mutations. There are methods using NGS similar to that done for germline DNA. There are also independent DNA-based measures of genomic instability reflecting underlying tumor HRD on the basis of loss of heterozygosity (LOH), telomeric allelic imbalance (TAI) and large-scale state transitions (LST). Each individual metric and the combination is significantly associated with BRCA1/2 status and identifying HRD tumors [5254]. Somatic mutation testing is more laborious and less reproducible than germline testing for several reasons. First, unlike germline testing, somatic testing utilizes a heterogeneous collection of cells. Different tumor types and specimens will have varying quantities of normal cells and neoplastic cells in a sample. Multiple methods of DNA evaluation exist for tumor profiling. Obtaining high-quality tumor DNA extraction relies on an adequately sized specimen that has been well preserved. In contrast to germline testing which looks at DNA extracted from healthy cells to determine if a mutation was inherited, somatic testing evaluates the genetic composition of tumor cells. Once adequate high-quality DNA has been obtained the data analysis is also challenging. There is currently no standard method of interpreting results. Laboratories rely on databases such as COSMIC or in silico predictive software to attempt to predict pathogenicity of findings but neither is exhaustive [8]. Finally there is the issue of the stability of a somatic mutation. Data suggest that there is intra-tumor genetic heterogeneity resulting from clonal evolution and the emergence of subclonal tumor populations in high grade EOC, causing spatial and temporal heterogeneity [55]. While data from the ARIEL-2 trial has begun to address this issue, demonstrating a change in biomarker status over time, the phenomenon of tumor heterogeneity is not fully understood [56].

Early evidence suggests that a somatic BRCA1/2 mutation is a predictive biomarker of PARP inhibitor activity however the number of patients with somatic mutations that have been analyzed is low. In a phase II study of olaparib, Gelmon et al. found that 24% of BRCA-negative patients with high grade serous or undifferentiated ovarian cancer achieved a radiological objective response [57]. In the recent publication by Mirza et al. [48] niraparib maintenance therapy had activity in all patients with platinum sensitive recurrent ovarian cancer, however there was improved progression free survival in patients with germline BRCA1/2 mutations and without germline BRCA1/2 mutations but with HRD. Swisher et al. [59] found that for patients with platinum sensitive recurrent ovarian cancer, rucaparib had activity in patients with germline BRCA1/2 mutations and patients who were BRCA1/2 wild-type but were found to be LOH high. LOH status was determined by next-generation sequencing using a cutoff of 14% or more of genomic LOH in pretreatment biopsy specimens to be considered LOH high. Studies that are currently ongoing or recently completed, and future planned studies will likely clarify this question, including SOLO-2 (NCT01874353) and ARIEL-3 (NCT01968213) [5, 60]. See Table 3 for a review of phase II/III trials of PARP inhibitors in ovarian cancer.

Table 3 Phase II/III studies of PARP inhibitors in ovarian cancer

Somatic tumor testing has two important implications: 1) identifying patients for targeted therapies like PARP inihibitors, 2) identifying patients who should be referred for genetic counseling and offered genetic testing. Mutations that are purely somatic and not found in the germline DNA are not inherited, cannot be passed to offspring, and therefore do not warrant cascade genetic counseling and testing. If a patient is found to have a mutation on tumor profiling, the only way to definitively classify it as a germline versus somatic mutation is through germline testing. As described previously, Hennessy et al. [25] found that among 28 tumors with BRCA1/2 mutations, 61% were the result of germline inherited mutations. This presents an important ethical consideration regarding patient counseling and informed consent. Thorough genetic counseling and informed consent are required prior to germline genetic testing however this is not the case with tumor profiling. This is important given that almost two-thirds of patients with a mutation found on tumor profiling will have a germline mutation which carries significant clinical implications for the patient and her family members.

Tumor profiling vs. germline testing?

It has become clear that both somatic and germline mutation testing provide important information for patients with EOC. The question is whether or not both are necessary and if so what is the ideal chronology of testing. Table 4 outlines the advantages of each testing method. Germline testing is more well established with more robust data linking results to valuable prognostic and predictive information. Germline testing can also identify other cancers for which a patient is at risk and can initiate cascade testing of family members. Somatic testing will capture a larger number of patients with HRD who can potentially receive targeted therapy and does not require access to a genetic counselor, which is limited in many clinical settings.

Table 4 Advantages of germline versus somatic tumor testing of HRD genes

This issue of genetic counseling as a limited resource is an important one. The exponential growth in diagnostic and treatment options that utilize genetic and genomic sequencing information coupled with public coverage of celebrity BRCA mutation status has led to an increasing demand for genetic counselors [61, 62]. A study of 3765 patients in the U.S. with epithelial ovarian cancer found that only 50% of patients meeting substantial-risk criteria for BRCA1/2 mutations were referred to genetics [63]. Another study of 416 patients in Ontario with epithelial ovarian cancer found that only 19% of patients had undergone clinical genetic testing for BRCA1/2 [64]. There currently are not enough genetic counselors and geneticists to meet this demand and alternative service delivery models are being evaluating including telephone counseling, videoconferencing, group counseling and direct-to-consumer testing [65]. Video-assisted genetic counseling has been found to significantly increase the percentage of patients undergoing testing compared to traditional referral to genetic counseling (31% vs. 55%) however this method has not yet been tested in a prospective manor [66].

The recent approval of rucaparib for BRCA positive (germline or somatic) patients with recurrent ovarian cancer who have had two or more lines of therapy would argue for tumor testing to screen for therapeutic options and as a triage for germline testing. However, the success of niraparib in significantly extending the duration of progression-free survival in all platinum-sensitive recurrent ovarian cancer patienrs, (those with and without BRCA1/2 mutations) indicates a great expansion of the population who can benefit from PARP inhibitors. Interestingly Mirza et al. even found efficacy in the non-germline BRCA mutation and HRD-negative group (HR 0.58, P = 0.02). In an exploratory analysis of ARIEL2 Part 1, Swisher et al. [59] found that among BRCA wild-type tumors, genomic LOH was a more sensitive predictor of response than was mutation of other HR genes and gene methylation. In the near future PARP inhibitors may be available to all patients with ovarian cancer regardless of their genetic profile for treatment and maintenance therapy. With this expanded information about germline mutations, somatic mutations and LOH status may serve a new role, no longer as an indicator of who is eligible for treatment with this class of drugs but instead as a biomarker for treatment efficacy. This information would allow individualized patient counseling where the provider can offer information about the magnitude of benefit given the patient’s genetic profile in the context of risk of side effects.

In summary both somatic and germline testing offer clinically important and not entirely overlapping information. One strategy is to start with somatic tumor testing and use this to triage additional testing. Those patients found to have HRD gene mutations on somatic testing can be referred to genetics to establish whether the mutation is somatic or germline. This strategy would allow for rapid access to genomic information that can guide targeted treatment decisions especially with the recent approval of rucaparib for BRCA mutation carriers, and reduce the burden on genetic counselors who would then only see patients with positive somatic testing. Whether this proposed strategy is feasible based on availability of testing resources and cost is unknown and must be examined in future studies. Furthermore, given recent niraparib data this strategy may not be needed as therapeutic benefit was noted in the maintenance setting in all patients with ovarian cancer regardless of BRCA or HRD status.

Future directions, can somatic testing replace germline testing?

Currently, as stated above, somatic tumor testing can provide information only about genetic aberrations in the tumor, however as NGS continues to become increasing widespread its applications will likely broaden. Stadler et al. [67] recently published their experience with tumor genomic profiling via NGS panels in 224 patients with colorectal cancer. Previously in colorectal cancer NGS panels were used to identify KRAS, NRAS and BRAF somatic mutations and parallel MMR protein assessment via ether immunohistochemistry (IHC) or microsatellite instability (MSI) analysis was used for initial screening of Lynch syndrome. Mismatch repair deficiency (MMR-D) occurs in 15–20% of colorectal tumors with one-quarter resulting from Lynch syndrome [68]. Stadley and colleagues discovered that by utilizing an expanded NGS panel with 341-genes, a specific mutational load cutoff could reliably identify tumors with DNA MMR-D. This was not surprising given that a deficiency in the DNA MMR apparatus would be expected to result in more uncorrected mismatched bases and thus a greater rate of mutations. The authors concluded that the use of multigene tumor panels may obviate the need for parallel MMR protein assessment and thus make the molecular work-up patients with colorectal cancer more efficient and cost-effective. Identifying MMR-D is becoming particularly important as it may serve as a biomarker for response to immunotherapy with checkpoint inhibitors in colorectal and endometrial cancer [69, 70].

If somatic tumor profiling can replace MMR assessment, the next question is whether or not somatic tumor profiling can replace germline testing altogether. Currently none of the tumor profiling platforms offer information on germline mutational status however this may change. The feasibility of this question was evaluated with a study comparing deep, uniform NGS sequencing of tumor tissue compared to Clinical Laboratory Improvement Amendments (CLIA)-certified, NGS-based germline exon sequencing of 236-cancer related genes. A computational method could predict the somatic status of mutations from tumor tissue without the need for a matched normal control with an accuracy of greater than 95%. As tumor profiling for this indication is permitted under investigational use only and is not CLIA-certified, the authors concluded that NGS tumor sequencing can indicate which patients require additional work-up for germline testing [71]. However, with further analysis and certification, clinicians will likely be able to use somatic testing to definitively predict germline status. While this approach to testing may not make sense for cancers with a low prevalence of hereditary causation, it is very applicable and exciting in ovarian cancer where up to a quarter of patients carry a germline mutation. The FDA accelerated approvals of olaparib and rucaparib came with specified companion diagnostic tests however there are multiple available next-generation sequencing assays and algorithms for defining LOH. Whether or not approval for specific targeted therapies will mandate a specific companion test and how physicians choose the most appropriate diagnostic test remains unclear. Methods to combine assays and validate data across the various PARP inhibitors, so one cost-effective test can be utilized makes logical sense.

Finally, an important remaining area of uncertainty is the role of epigenetic alterations in EOC. HRD can result from genomic processes that are distinct from germline and somatic mutations in HR genes. For example BRCA1/2 silencing can occur via indirect mechanisms including promoter methylation and interactions with other proteins involved in DNA repair. The clinical implications of epigenetic changes remain unclear with conflicting data in the literature. Chiang et al. [72] found that BRCA1 promoter hypermethylation resulted in significantly shorter survival when compared to BRCA1 germline mutations and BRCA1 wild-type without promoter hypermethylation. In contrast, TCGA found no survival difference with BRCA1 hypermethylation [7] and Cunningham et al. [27] observed that BRCA1 methylated cases had a survival benefit compared to germline wild-type and similar to that of the germline mutation cases. Prospective studies are necessary to better address the clinical significance of epigenetic alterations in the HR pathway.

Conclusions

It is clear that the knowledge of both germline and somatic mutation status is becoming increasingly important in the management of patients with ovarian cancer. The experience with PARP inhibitors in ovarian cancer clinical trials demonstrates that the targeted therapeutic effect is beyond just BRCA germline mutations and more widely applicable to HRD. Whether epigenetic modifications to HRD genes confer the same therapeutic sensitivity remains unclear however future studies will likely allow for a better understanding of their underlying mechanisms and clinical significance. The list of ovarian cancer-associated genes continues to grow and the literature currently suggests that up to one in four women with ovarian cancer will have a germline HR deficiency and an additional 5–7% will have a somatic HR deficiency. Currently, these patients with recurrent disease are candidates for approved therapy with PARP inhibitors, however in the near future there will likely be a growing list of targeted therapies available for ovarian cancer patients. As a result, infrastructure for widespread somatic HRD testing in routine clinical practice, as is the case for HER2 in breast cancer and epidermal growth factor receptor in lung cancer, should be supported [8]. Furthermore, in the maintenance setting where PARP inhibitors may be useful in all patients as noted the NOVA trial, HRD testing maybe useful for counseling to understand the magnitude of the benefit in context with the risks of side effects. Both germline and somatic tumor testing provide important and non-overlapping clinical information. Further research is necessary to address whether somatic testing can completely replace germline testing or if the practice of universal somatic tumor testing followed by directed germline confirmation should be implemented.

Abbreviations

ACMG:

American College of Medical Genetics and Genomics

ASCO:

American Society of Clinical Oncology

CLIA:

Clinical Laboratory Improvement Amendments

EOC:

Epithelial ovarian cancer

HRD:

Homologous recombination deficiency

IHC:

Immunohistochemistry

LOH:

Loss of heterozygosity

LST:

Large scale transitions

MMR:

Mismatch repair

MMR-D:

Mismatch repair deficiency

MSI:

Microsatellite instability

NCCN:

National Comprehensive Cancer Network

NGS:

Next generation sequencing

NHEJ:

Non-homologous end-joining

NSGC:

National Society of Genetic Counselors

PARP:

Poly(ADP-ribose)polymerase

SGO:

Society of Gynecologic Oncology

TCGA:

The Cancer Genome Atlas

VUS:

Variants of uncertain significance

References

  1. American Cancer Society: Cancer Statistics Center. 2016. p. https://cancerstatisticscenter.cancer.org/.

  2. Covens A, Carey M, Bryson P, Verma S, Fung Kee Fung M, Johnston M. Systematic review of first-line chemotherapy for newly diagnosed postoperative patients with stage II, III, or IV epithelial ovarian cancer. Gynecol Oncol. 2002;85:71–80.

    Article  CAS  PubMed  Google Scholar 

  3. Gadducci A, Sartori E, Maggino T, Zola P, Landoni F, Fanucchi A, et al. Analysis of failures after negative second-look in patients with advanced ovarian cancer: an Italian multicenter study. Gynecol Oncol. 1998;68:150–5.

    Article  CAS  PubMed  Google Scholar 

  4. Audeh MW, Carmichael J, Penson RT, Friedlander M, Powell B, Bell-McGuinn KM, et al. Oral poly(ADP-ribose) polymerase inhibitor olaparib in patients with BRCA1 or BRCA2 mutations and recurrent ovarian cancer: a proof-of-concept trial. Lancet. 2010;376:245–51.

    Article  CAS  PubMed  Google Scholar 

  5. Ledermann J, Harter P, Gourley C, Friedlander M, Vergote I, Rustin G, et al. Olaparib maintenance therapy in patients with platinum-sensitive relapsed serous ovarian cancer: a preplanned retrospective analysis of outcomes by BRCA status in a randomised phase 2 trial. Lancet Oncol. 2014;15:852–61.

    Article  CAS  PubMed  Google Scholar 

  6. Fong PC, Yap TA, Boss DS, Carden CP, Mergui-Roelvink M, Gourley C, et al. Poly(ADP)-ribose polymerase inhibition: frequent durable responses in BRCA carrier ovarian cancer correlating with platinum-free interval. J Clin Oncol. 2010;28:2512–9.

    Article  CAS  PubMed  Google Scholar 

  7. Cancer Genome Atlas Research N. Integrated genomic analyses of ovarian carcinoma. Nature. 2011;474:609–15.

    Article  Google Scholar 

  8. Moschetta M, George A, Kaye SB, Banerjee S. BRCA somatic mutations and epigenetic BRCA modifications in serous ovarian cancer. Ann Oncol. 2016;27:1449–55.

  9. Lupo B, Trusolino L. Inhibition of poly(ADP-ribosyl)ation in cancer: old and new paradigms revisited. Biochim Biophys Acta. 1846;2014:201–15.

    Google Scholar 

  10. Wang M, Wu W, Wu W, Rosidi B, Zhang L, Wang H, et al. PARP-1 and Ku compete for repair of DNA double strand breaks by distinct NHEJ pathways. Nucleic Acids Res. 2006;34:6170–82.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Hoeijmakers JH. Genome maintenance mechanisms for preventing cancer. Nature. 2001;411:366–74.

    Article  CAS  PubMed  Google Scholar 

  12. Pennington KP, Swisher EM. Hereditary ovarian cancer: beyond the usual suspects. Gynecol Oncol. 2012;124:347–53.

    Article  CAS  PubMed  Google Scholar 

  13. Norquist BM, Harrell MI, Brady MF, Walsh T, Lee MK, Gulsuner S, et al. Inherited mutations in women with ovarian carcinoma. JAMA Oncol. 2015:1–9.

  14. Randall LM, Pothuri B. The genetic prediction of risk for gynecologic cancers. Gynecol Oncol. 2016;141:10–6.

    Article  CAS  PubMed  Google Scholar 

  15. Hall JM, Lee MK, Newman B, Morrow JE, Anderson LA, Huey B, et al. Linkage of early-onset familial breast cancer to chromosome 17q21. Science. 1990;250:1684–9.

    Article  CAS  PubMed  Google Scholar 

  16. Alsop K, Fereday S, Meldrum C, DeFazio A, Emmanuel C, George J, et al. 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. J Clin Oncol. 2012;30:2654–63.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Gourley C, Michie CO, Roxburgh P, Yap TA, Harden S, Paul J, et al. Increased incidence of visceral metastases in scottish patients with BRCA1/2-defective ovarian cancer: an extension of the ovarian BRCAness phenotype. J Clin Oncol. 2010;28:2505–11.

    Article  PubMed  Google Scholar 

  18. Tan DS, Yap TA, Hutka M, Roxburgh P, Ang J, Banerjee S, et al. Implications of BRCA1 and BRCA2 mutations for the efficacy of paclitaxel monotherapy in advanced ovarian cancer. Eur J Cancer. 2013;49:1246–53.

    Article  CAS  PubMed  Google Scholar 

  19. Risch HA, McLaughlin JR, Cole DE, Rosen B, Bradley L, Fan I, et al. Population BRCA1 and BRCA2 mutation frequencies and cancer penetrances: a kin-cohort study in Ontario, Canada. J Natl Cancer Inst. 2006;98:1694–706.

    Article  CAS  PubMed  Google Scholar 

  20. Risch HA, McLaughlin JR, Cole DE, Rosen B, Bradley L, Kwan E, et al. Prevalence and penetrance of germline BRCA1 and BRCA2 mutations in a population series of 649 women with ovarian cancer. Am J Hum Genet. 2001;68:700–10.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Pal T, Permuth-Wey J, Betts JA, Krischer JP, Fiorica J, Arango H, et al. BRCA1 and BRCA2 mutations account for a large proportion of ovarian carcinoma cases. Cancer. 2005;104:2807–16.

    Article  CAS  PubMed  Google Scholar 

  22. Walsh CS. Two decades beyond BRCA1/2: Homologous recombination, hereditary cancer risk and a target for ovarian cancer therapy. Gynecol Oncol. 2015;137:343–50.

  23. Walsh T, Casadei S, Lee MK, Pennil CC, Nord AS, Thornton AM, et al. Mutations in 12 genes for inherited ovarian, fallopian tube, and peritoneal carcinoma identified by massively parallel sequencing. Proc Natl Acad Sci U S A. 2011;108:18032–7.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Song H, Dicks E, Ramus SJ, Tyrer JP, Intermaggio MP, Hayward J, et al. Contribution of Germline Mutations in the RAD51B, RAD51C, and RAD51D Genes to Ovarian Cancer in the Population. J Clin Oncol. 2015;33:2901–7.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Hennessy BT, Timms KM, Carey MS, Gutin A, Meyer LA, Flake 2nd DD, et al. Somatic mutations in BRCA1 and BRCA2 could expand the number of patients that benefit from poly (ADP ribose) polymerase inhibitors in ovarian cancer. J Clin Oncol. 2010;28:3570–6.

    Article  PubMed  PubMed Central  Google Scholar 

  26. Pennington KP, Walsh T, Harrell MI, Lee MK, Pennil CC, Rendi MH, et al. Germline and somatic mutations in homologous recombination genes predict platinum response and survival in ovarian, fallopian tube, and peritoneal carcinomas. Clin Cancer Res. 2014;20:764–75.

    Article  CAS  PubMed  Google Scholar 

  27. Cunningham JM, Cicek MS, Larson NB, Davila J, Wang C, Larson MC, et al. Clinical characteristics of ovarian cancer classified by BRCA1, BRCA2, and RAD51C status. Sci Rep. 2014;4:4026.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Hampel H, Bennett RL, Buchanan A, Pearlman R, Wiesner GL. Guideline Development Group ACoMG, et al. A practice guideline from the American College of Medical Genetics and Genomics and the National Society of Genetic Counselors: referral indications for cancer predisposition assessment. Genet Med. 2015;17:70–87.

    Article  PubMed  Google Scholar 

  29. Lu KH, Wood ME, Daniels M, Burke C, Ford J, Kauff ND, et al. American Society of Clinical Oncology Expert Statement: collection and use of a cancer family history for oncology providers. J Clin Oncol. 2014;32:833–40.

    Article  PubMed  PubMed Central  Google Scholar 

  30. Daly MB, Pilarski R, Axilbund JE, Berry M, Buys SS, Crawford B, et al. Genetic/familial high-risk assessment: breast and ovarian, version 2.2015. J Natl Compr Canc Netw. 2016;14:153–62.

    PubMed  Google Scholar 

  31. Lancaster JM, Powell CB, Chen LM, Richardson DL, Committee SGOCP. Society of Gynecologic Oncology statement on risk assessment for inherited gynecologic cancer predispositions. Gynecol Oncol. 2015;136:3–7.

    Article  PubMed  Google Scholar 

  32. Blackburn HL, Schroeder B, Turner C, Shriver CD, Ellsworth DL, Ellsworth RE. Management of incidental findings in the era of next-generation sequencing. Curr Genomics. 2015;16:159–74.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Norquist BM, Swisher EM. More genes, more problems? Benefits and risks of multiplex genetic testing. Gynecol Oncol. 2015;139:209–10.

    Article  PubMed  Google Scholar 

  34. Collins VR, Meiser B, Ukoumunne OC, Gaff C, St John DJ, Halliday JL. The impact of predictive genetic testing for hereditary nonpolyposis colorectal cancer: three years after testing. Genet Med. 2007;9:290–7.

    Article  PubMed  Google Scholar 

  35. Watson M, Kash KM, Homewood J, Ebbs S, Murday V, Eeles R. Does genetic counseling have any impact on management of breast cancer risk? Genet Test. 2005;9:167–74.

    Article  CAS  PubMed  Google Scholar 

  36. Pal T, Lee JH, Besharat A, Thompson Z, Monteiro AN, Phelan C, et al. Modes of delivery of genetic testing services and the uptake of cancer risk management strategies in BRCA1 and BRCA2 carriers. Clin Genet. 2014;85:49–53.

    Article  CAS  PubMed  Google Scholar 

  37. Hadley DW, Jenkins JF, Dimond E, de Carvalho M, Kirsch I, Palmer CG. Colon cancer screening practices after genetic counseling and testing for hereditary nonpolyposis colorectal cancer. J Clin Oncol. 2004;22:39–44.

    Article  PubMed  Google Scholar 

  38. Schwartz MD, Lerman C, Brogan B, Peshkin BN, Halbert CH, DeMarco T, et al. Impact of BRCA1/BRCA2 counseling and testing on newly diagnosed breast cancer patients. J Clin Oncol. 2004;22:1823–9.

    Article  PubMed  Google Scholar 

  39. Calzone KA, Prindiville SA, Jourkiv O, Jenkins J, DeCarvalho M, Wallerstedt DB, et al. Randomized comparison of group versus individual genetic education and counseling for familial breast and/or ovarian cancer. J Clin Oncol. 2005;23:3455–64.

    Article  PubMed  Google Scholar 

  40. Armstrong J, Toscano M, Kotchko N, Friedman S, Schwartz MD, Virgo KS, et al. Utilization and outcomes of BRCA genetic testing and counseling in a national commercially insured population: the ABOUT study. JAMA Oncol. 2015;1:1251–60.

    Article  PubMed  Google Scholar 

  41. Hilgart JS, Coles B, Iredale R. Cancer genetic risk assessment for individuals at risk of familial breast cancer. Cochrane Database Syst Rev. 2012;15.

  42. Braithwaite D, Emery J, Walter F, Prevost AT, Sutton S. Psychological impact of genetic counseling for familial cancer: a systematic review and meta-analysis. J Natl Cancer Inst. 2004;96:122–33.

    Article  PubMed  Google Scholar 

  43. DeMarco TA, Peshkin BN, Mars BD, Tercyak KP. Patient satisfaction with cancer genetic counseling: a psychometric analysis of the Genetic Counseling Satisfaction Scale. J Genet Couns. 2004;13:293–304.

    Article  PubMed  PubMed Central  Google Scholar 

  44. Miller CE, Krautscheid P, Baldwin EE, Tvrdik T, Openshaw AS, Hart K, et al. Genetic counselor review of genetic test orders in a reference laboratory reduces unnecessary testing. Am J Med Genet A. 2014;164A:1094–101.

    Article  PubMed  Google Scholar 

  45. Cragun D, Camperlengo L, Robinson E, Caldwell M, Kim J, Phelan C, et al. Differences in BRCA counseling and testing practices based on ordering provider type. Genet Med. 2015;17:51–7.

    Article  CAS  PubMed  Google Scholar 

  46. Weitzel JN, McCaffrey SM, Nedelcu R, MacDonald DJ, Blazer KR, Cullinane CA. Effect of genetic cancer risk assessment on surgical decisions at breast cancer diagnosis. Arch Surg. 2003;138:1323–8. discussion 9.

    Article  PubMed  Google Scholar 

  47. Lynparza prescribing information. Lynparza [package insert]. Wilmington, DE: AstraZeneca Pharmaceuticals LP. 2014. Available at http://www.azpicentral.com/Lynparza/pi_lynparza.pdf#page=1.

  48. Mirza MR, Monk BJ, Herrstedt J, Oza AM, Mahner S, Redondo A, et al. Niraparib maintenance therapy in platinum-sensitive, recurrent ovarian cancer. N Engl J Med. 2016;375:2154-2164.

  49. Vasen HF, Abdirahman M, Brohet R, Langers AM, Kleibeuker JH, van Kouwen M, et al. One to 2-year surveillance intervals reduce risk of colorectal cancer in families with Lynch syndrome. Gastroenterology. 2010;138:2300–6.

    Article  PubMed  Google Scholar 

  50. Schmeler KM, Lynch HT, Chen LM, Munsell MF, Soliman PT, Clark MB, et al. Prophylactic surgery to reduce the risk of gynecologic cancers in the Lynch syndrome. N Engl J Med. 2006;354:261–9.

    Article  CAS  PubMed  Google Scholar 

  51. Engel C, Rahner N, Schulmann K, Holinski-Feder E, Goecke TO, Schackert HK, et al. Efficacy of annual colonoscopic surveillance in individuals with hereditary nonpolyposis colorectal cancer. Clin Gastroenterol Hepatol. 2010;8:174–82.

    Article  PubMed  Google Scholar 

  52. Abkevich V, Timms KM, Hennessy BT, Potter J, Carey MS, Meyer LA, et al. Patterns of genomic loss of heterozygosity predict homologous recombination repair defects in epithelial ovarian cancer. Br J Cancer. 2012;107:1776–82.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  53. Birkbak NJ, Wang ZC, Kim JY, Eklund AC, Li Q, Tian R, et al. Telomeric allelic imbalance indicates defective DNA repair and sensitivity to DNA-damaging agents. Cancer Discov. 2012;2:366–75.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Popova T, Manie E, Rieunier G, Caux-Moncoutier V, Tirapo C, Dubois T, et al. Ploidy and large-scale genomic instability consistently identify basal-like breast carcinomas with BRCA1/2 inactivation. Cancer Res. 2012;72:5454–62.

    Article  CAS  PubMed  Google Scholar 

  55. Schwarz RF, Ng CK, Cooke SL, Newman S, Temple J, Piskorz AM, et al. Spatial and temporal heterogeneity in high-grade serous ovarian cancer: a phylogenetic analysis. PLoS Med. 2015;12:e1001789.

    Article  PubMed  PubMed Central  Google Scholar 

  56. Lin K, Sun J, Maloney L, Goble S, Oza A, Coleman R, Scott C, Robillard L, Mann E, Isaacson J, Harding T. 2710 Quantification of genomic loss of heterozygosity enables prospective selection of ovarian cancer patients who may derive benefit from the PARP inhibitor rucaparib. Eur J Cancer. 2015;51:S531–2.

    Article  Google Scholar 

  57. Gelmon KA, Tischkowitz M, Mackay H, Swenerton K, Robidoux A, Tonkin K, et al. Olaparib in patients with recurrent high-grade serous or poorly differentiated ovarian carcinoma or triple-negative breast cancer: a phase 2, multicentre, open-label, non-randomised study. Lancet Oncol. 2011;12:852–61.

    Article  CAS  PubMed  Google Scholar 

  58. Kummar S, Oza AM, Fleming GF, Sullivan DM, Gandara DR, Naughton MJ, et al. Randomized Trial of Oral Cyclophosphamide and Veliparib in High-Grade Serous Ovarian, Primary Peritoneal, or Fallopian Tube Cancers, or BRCA-Mutant Ovarian Cancer. Clin Cancer Res. 2015;21:1574–82.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Swisher EM, Lin KK, Oza AM, Scott CL, Giordano H, Sun J, et al. Rucaparib in relapsed, platinum-sensitive high-grade ovarian carcinoma (ARIEL2 Part 1): an international, multicentre, open-label, phase 2 trial. Lancet Oncol. 2017;18:75–87.

    Article  CAS  PubMed  Google Scholar 

  60. Ledermann J, Harter P, Gourley C, Friedlander M, Vergote I, Rustin G, et al. Olaparib maintenance therapy in platinum-sensitive relapsed ovarian cancer. N Engl J Med. 2012;366:1382–92.

    Article  CAS  PubMed  Google Scholar 

  61. Collins FS, Varmus H. A new initiative on precision medicine. N Engl J Med. 2015;372:793–5.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. Borzekowski DL, Guan Y, Smith KC, Erby LH, Roter DL. The Angelina effect: immediate reach, grasp, and impact of going public. Genetics Med. 2014;16:516–21.

    Article  Google Scholar 

  63. Meyer LA, Anderson ME, Lacour RA, Suri A, Daniels MS, Urbauer DL, et al. Evaluating women with ovarian cancer for BRCA1 and BRCA2 mutations: missed opportunities. Obstet Gynecol. 2010;115:945–52.

    Article  PubMed  PubMed Central  Google Scholar 

  64. Metcalfe KA, Fan I, McLaughlin J, Risch HA, Rosen B, Murphy J, et al. Uptake of clinical genetic testing for ovarian cancer in Ontario: a population-based study. Gynecol Oncol. 2009;112:68–72.

    Article  PubMed  Google Scholar 

  65. Buchanan AH, Rahm AK, Williams JL. Alternate service delivery models in cancer genetic counseling: a mini-review. Front Oncol. 2016;6:120.

    Article  PubMed  PubMed Central  Google Scholar 

  66. Watson MU CH, Tillmanns T, Reed ME, Smiley L, Covington R. The implementation of video-assisted genetic counseling for ovarian, fallopian, and peritoneal cancer patients Society of Gynecologic Oncology Annual Meeting on Women’s Cancer San Diego. 2016.

    Google Scholar 

  67. Stadler ZK, Battaglin F, Middha S, Hechtman JF, Tran C, Cercek A, et al. Reliable detection of mismatch repair deficiency in colorectal cancers using mutational load in next-generation sequencing panels. J Clin Oncol. 2016;34:2141–7.

    Article  CAS  PubMed  Google Scholar 

  68. Hampel H, Frankel WL, Martin E, Arnold M, Khanduja K, Kuebler P, et al. Screening for the Lynch syndrome (hereditary nonpolyposis colorectal cancer). N Engl J Med. 2005;352:1851–60.

    Article  CAS  PubMed  Google Scholar 

  69. Le DT, Uram JN, Wang H, Bartlett BR, Kemberling H, Eyring AD, et al. PD-1 blockade in tumors with mismatch-repair deficiency. N Engl J Med. 2015;372:2509–20.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  70. A.N. Fader LAD, D.K. Armstrong, E.J. Tanner III, J. Uram, A. Eyring, H. Wang, G. Fisher, T. Greten and D. Le. Preliminary results of a phase II study: PD-1 blockade in mismatch repair–deficient, recurrent or persistent endometrial cancer. Society of Gynecologic Oncology Annual Meeting on Women’s Cancer: Late-breaking abstract sessions 3; 2016.

  71. James X. Sun GF, Kai Wang, Jeffrey S. Ross, Vincent A. Miller, Philip J. Stephens, Doron Lipson, Roman Yelensky. Abstract 1893: A computational method for somatic versus germline variant status determination from targeted next-generation sequencing of clinical cancer specimens without a matched normal control. Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5–9. San Diego, CA 2014.

  72. Chiang JW, Karlan BY, Cass L, Baldwin RL. BRCA1 promoter methylation predicts adverse ovarian cancer prognosis. Gynecol Oncol. 2006;101:403–10.

    Article  CAS  PubMed  Google Scholar 

  73. Kaye SB, Lubinski J, Matulonis U, Ang JE, Gourley C, Karlan BY, et al. Phase II, open-label, randomized, multicenter studycomparing the efficacy and safety of olaparib, a poly (ADP-ribose) polymerase inhibitor, and pegylated liposomal doxorubicin in patients with BRCA1 or BRCA2mutations and recurrent ovarian cancer. J Clin Oncol. 2012;30:372–9.

  74. Oza AM, Cibula D, Benzaquen AO, Poole C, Mathijssen RH, Sonke GS, et al. Olaparib combined with chemotherapy for recurrent platinum-sensitive ovarian cancer: a randomised phase 2 trial. Lancet Oncol. 2015;16:87–97.

  75. Coleman RL, Sill MW, Bell-McGuinn K, Aghajanian C, Gray HJ, Tewari KS, et al. A phase II evaluation of the potent, highly selective PARP inhibitor veliparib in the treatment of persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer in patients who carry a germline BRCA1 or BRCA2 mutation - An NRG Oncology/Gynecologic Oncology Group study. Gynecol Oncol. 2015;137:386–91.

  76. Kaufman B, Shapira-Frommer R, Schmutzler RK, Audeh MW, Friedlander M, Balmaña J, et al. Olaparib monotherapy in patients with advanced cancer and a germline BRCA1/2 mutation. J Clin Oncol. 2015; 33:244–50.

Download references

Acknowledgements

Not applicable.

Funding

Not applicable.

Availability of data and materials

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.

Authors’ contributions

All authors worked together to research and draft the manuscript. All authors read and approved the final manuscript.

Competing interests

The authors declare that they have no competing interests.

Consent for publication

Not applicable.

Ethics approval and consent to participate

Not applicable.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Bhavana Pothuri.

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Frey, M.K., Pothuri, B. Homologous recombination deficiency (HRD) testing in ovarian cancer clinical practice: a review of the literature. gynaecol oncol res pract 4, 4 (2017). https://doi.org/10.1186/s40661-017-0039-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s40661-017-0039-8

Keywords