Clinical utility of hereditary cancer panel testing: Impact of PALB2, ATM, CHEK2, NBN, BRIP1, RAD51C, and RAD51D results on patient management and adherence to provider recommendations.

BACKGROUND: Although management guidelines exist for several genes associated with a 2-fold to 5-fold increase in the relative risk for certain cancers, the value of testing for them remains controversial. METHODS: De-identified personal and family history data for 654 individuals with pathogenic variants (PVs) in PALB2, ATM, CHEK2, NBN, BRIP1, RAD51C, and/or RAD51D were analyzed for pretest and post-test candidacy for guideline-recommended management of cancer risk. These individuals were invited to complete a survey about provider recommendations and their adherence. RESULTS: Twenty-four percent of CHEK2, ATM, PALB2, or NBN PV carriers were appropriate for consideration of annual breast magnetic resonance imaging screening before genetic testing, with the remaining 76% appropriate only after testing. No BRIP1, RAD51C, or RAD51D PV carriers were appropriate for consideration of risk-reducing salpingo-oophorectomy before genetic testing; 100% were appropriate only after testing. Seventeen percent of CHEK2 PV carriers were appropriate for earlier and more frequent colonoscopy before genetic testing, with the remaining 83% appropriate only after testing. Provider recommendations for annual breast magnetic resonance imaging, consideration of risk-reducing salpingo-oophorectomy, and earlier and more frequent colonoscopy were reported by 42%, 26%, and 66% of breast, ovarian, and colorectal cancer risk PV carriers, respectively, before genetic testing, versus 82%, 79%, and 81%, respectively, after testing. Nearly all respondents had planned or undertaken provider-recommended management. CONCLUSIONS: Testing for PALB2, ATM, CHEK2, NBN, BRIP1, RAD51C, and RAD51D changed management for those carrying PVs. Provider recommendations were aligned with guidelines, and patients adhered to recommendations, both of which are critical for reducing both long-term cancer morbidity and mortality.

Validation of a digital identification tool for individuals at risk for hereditary cancer syndromes.

BACKGROUND: The number of individuals meeting criteria for genetic counseling and testing for hereditary cancer syndromes (HCS) is far less than the number that actually receive it. To facilitate identification of patients at risk for HCS, Counsyl developed a digital identification tool (digital ID tool) to match personal and family cancer history to National Comprehensive Cancer Network (NCCN) BRCA-related Hereditary Breast and Ovarian Cancer (HBOC), Lynch syndrome, and polyposis testing criteria in one-to-one, automated fashion. The purpose of this study was to validate the ability of the digital ID tool to accurately identify histories that do and do not meet NCCN testing criteria. METHODS: Third-party recorded three-generation pedigrees were retrospectively reviewed by a certified genetic counselor (CGC) to determine if independent events included in pedigree histories met NCCN guidelines, and were then sorted into groups: high risk events (meets criteria) and low risk events (does not meet criteria). Events were entered into the digital ID tool to determine the extent of its concordance with events sorted by CGC review. Statistical tests of accuracy were calculated at a 95% confidence interval (CI). RESULTS: One hundred ninety-seven pedigrees were reviewed consecutively representing 765 independent events for analysis across groups. 382/382 (100%) high risk events identified by the digital ID tool and 381/383 (99.47%) low risk events identified by the digital ID tool were concordant with CGC sorting. The digital ID tool had a sensitivity of 100% (99.04-100% CI) and specificity of 99.48% (98.13-99.94% CI). The overall accuracy of the digital ID tool was estimated to be 99.74% (99.06-99.97% CI), reflecting the rate at which the digital ID tool reached the same conclusion as that of CGC review of pedigree events for the recommendation of genetic testing for individuals at risk for HCS. CONCLUSIONS: The digital ID tool accurately matches NCCN criteria in one-to-one fashion to identify at-risk individuals for HCS and may be useful in clinical practice, specifically for BRCA-related HBOC and Lynch Syndrome.

Genotype in BRCA-associated breast cancers.

Women with BRCA1 or 2 mutations are at high risk for breast cancer. For BRCA1, a trend of increasing risk has been associated with increasing downstream (3') location for mutations compared to the upstream (5') mutations in the gene. For BRCA2, an increased risk of breast cancer has been associated with mutations outside of the ovarian cancer cluster region (OCCR). We sought to determine the mutation position in BRCA-associated breast cancers and whether or not there was a genotype-phenotype correlation. Breast cancer patients with BRCA1/2 mutations were identified by a search of a prospectively maintained data base. Mutation site, patient, and tumor characteristics were determined through retrospective review. One hundred and sixty-four patients with BRCA1-associated breast cancer and 109 patients with BRCA2-associated breast cancer were identified. Among patients with BRCA1-associated cancers, 86 (52%) had mutations in the 5' half of the gene. Among patients with BRCA2-associated breast cancers, 40 (37%) had OCCR mutations. Although BRCA1-associated tumors were more likely to be ER/PR- than BRCA2-associated cancers (p < 0.0001), there was no difference in the tumor characteristics among BRCA1 or BRCA2-associated cancers based on mutation location. In this single-institution study, over half of BRCA1-associated and over a third of BRCA2-associated breast cancers were associated with putative lower risk mutations. Although we cannot exclude the possibility that mutations in these regions confer a lower relative risk for breast cancer, vigilance in cancer screening and prevention remains necessary. Further studies in genotype/phenotype correlation are needed to individualize prevention strategies.

Early onset HER2-positive breast cancer is associated with germline TP53 mutations.

BACKGROUND: Germline TP53 mutations predispose to early onset breast cancer in women and are associated with Li-Fraumeni syndrome. Published data on the pathological characteristics of breast cancer among women with TP53 mutations is limited. METHODS: We retrospectively reviewed the clinical records of women who underwent genetic testing for suspected germline TP53 mutations and who were diagnosed with breast cancer between 2000 and 2011. The pathological characteristics of the breast tumors from patients testing positive for a mutation (cases) were compared with those testing negative (controls). RESULTS: Patients who tested positive for germlineTP53 mutations (n = 30) were compared with controls (n = 79). Human epidermal growth factor receptor 2 (HER2) amplification and/or overexpression was found in 67% of the tumors from the cases, compared with 25% for the controls (P = .0001). Among patients with a mutation, 70% had estrogen receptor- and/or progesterone receptor-positive tumors, compared with 68% in the control group (P = .87). After adjusting for age at breast cancer diagnosis, having a HER2-positive tumor increased the odds of testing positive for a germline TP53 mutation (odds ratio, 6.9; 95% confidence interval, 2.6-18.2). For each yearly increment in age at breast cancer diagnosis, there was decreased likelihood of having a TP53 mutation of 5% (odds ratio, 0.95; 95% confidence interval0.91-0.99). CONCLUSIONS: This study suggests an association between germline TP53 mutations and early onset HER2-positive breast cancer. If confirmed in a larger cohort, these results could guide genetic testing strategies, lead to chemoprevention trials incorporating HER2-targeted therapies, and elucidate some of the molecular pathways involved in breast cancer.

Earlier age of onset of BRCA mutation-related cancers in subsequent generations.

BACKGROUND: Women who are diagnosed with a deleterious mutation in either breast cancer (BRCA) gene have a high risk of developing breast and ovarian cancers at young ages. In this study, the authors assessed age at diagnosis in 2 generations of families with known mutations to investigate for earlier onset in subsequent generations. METHODS: Of the 132 BRCA-positive women with breast cancer who participated in a high-risk protocol at The University of Texas MD Anderson Cancer Center (Gen 2), 106 women could be paired with a family member in the previous generation (Gen 1) who was diagnosed with a BRCA-related cancer (either breast cancer or ovarian cancer). Age at diagnosis, location of the mutation, and year of birth were recorded. A previously published parametric anticipation model was applied in these genetically predisposed families. RESULTS: The median age of cancer diagnosis was 42 years (range, 28-55 years) in Gen 2 and 48 years (range, 30-72 years) in Gen 1 (P < .001). [corrected]. In the parametric model, the estimated change in the expected age at onset for the entire cohort was 7.9 years (P < .0001). Statistically significant earlier ages at diagnosis also were observed within subgroups of BRCA1 and BRCA2 mutations, maternal inheritance, paternal inheritance, breast cancer only, and breast cancer-identified and ovarian cancer-identified families. CONCLUSIONS: Breast and ovarian cancers in BRCA mutation carriers appeared to be diagnosed at an earlier age in later generations. The authors concluded that patients who are younger at the onset of BRCA-related cancers should continue to be tracked to offer appropriate screening modalities at appropriate ages.

Predictive factors for BRCA1/BRCA2 mutations in women with ductal carcinoma in situ.

BACKGROUND: It is unclear whether women with ductal carcinoma in situ (DCIS), like their counterparts with invasive breast cancer, warrant genetic risk assessment and testing on the basis of high-risk variables. The authors of this report identified predictive factors for mutations in the breast cancer-susceptibility genes BRCA1 and BRCA2 in women who were diagnosed with DCIS. METHODS: One hundred eighteen women with DCIS who were referred for genetic counseling and underwent genetic testing for BRCA1/BRCA2 mutations between 2003 and 2010 were included in the study. Logistic regression models were fit to determine the associations between potential predictive factors and BRCA status. RESULTS: Of 118 high-risk women with DCIS, 27% (n = 32) tested positive for BRCA1/BRCA2 mutations. Of those, 10% (n = 12) and 17% (n = 20) had BRCA1 and BRCA2 mutations, respectively. Age, race, and tumor characteristics did not differ between BRCA noncarriers and carriers. In a multivariate logistic model, ≥2 relatives with ovarian cancer (OC) (odds ratio [OR], 8.81; 95% confidence interval [CI], 1.38-56.29; P = .034), and a score ≥10% according to the BRCAPRO mathematical model for calculating the probability that a particular family member carries a germline BRCA mutation (OR, 6.37; 95% CI, 2.23-18.22; P = .0005) remained as independent significant predictors for a BRCA mutation. Fifty-seven percent of mutation carriers but only 25% of noncarriers underwent prophylactic mastectomy(P = .0037). This difference remained significant for patients aged ≤40 years (P = .025). CONCLUSIONS: Women who had DCIS and a family history of OC or who had BRCAPRO scores ≥10% had a high rate of BRCA positivity regardless of age at diagnosis. These findings suggest that high-risk patients with DCIS are appropriate candidates for genetic testing for BRCA mutations in the presence of predictive factors even if they do not have invasive breast cancer.

Assessing the added value of breast tumor markers in genetic risk prediction model BRCAPRO.

The BRCAPRO model estimates carrier probabilities for the BRCA1 and BRCA2 genes, and was recently enhanced to use estrogen receptor (ER) and progesterone receptor (PR) status of breast cancer. No independent assessment of the added value of these markers exists. Moreover, earlier versions of BRCAPRO did not use human epidermal growth factor receptor 2 (Her-2/neu) status of breast cancer. Here, we incorporate Her-2/neu in BRCAPRO and validate all the markers. We trained the enhanced model on 406 germline tested individuals, and validated on a separate clinical cohort of 796 individuals for whom test results and family history are available. For model-building, we estimated joint probabilities of ER, PR, and Her-2/neu status for carriers and non-carriers of BRCA1/2 mutations. For validation, we obtained BRCAPRO predictions with and without markers. We calculated area under the receiver operating characteristic curve (AUC), sensitivity, specificity, predictive values, and correct reclassification rates. The AUC for predicting BRCA1 status among individuals who are carriers of at least one mutation improved when ER and PR were used. The AUC for predicting the presence of either mutation improved when Her-2/neu was added. Use of markers also produced highly significant correct reclassification improvements in both cases. Breast tumor markers are useful for prediction of BRCA1/2 mutation status. ER and PR improve discrimination between BRCA1 and BRCA2 mutation carriers while Her-2/neu helps discriminate between carriers and non-carriers, particularly among women who are ER positive and Her-2/neu negative. These results support the use of the enhanced version of BRCAPRO in clinical settings.

Clinical application of breast cancer risk assessment models.

With the evolving availability of testing for genetic cancer syndromes, oncologists now are increasingly expected to review family histories and to give a genetic risk assessment as part of their care for breast cancer. The most important of these breast cancer genetic syndromes identified to date have been those associated with the BRCA1 and BRCA2 genes. Therefore, the proper identification of potentially affected families and providing risk assessment estimates will be ever more essential. This review outlines several different available breast cancer risk assessment models. Risk models for the development of breast cancer as well as risk models that estimate the chance of having a genetic cancer syndrome are discussed. Their clinical applications are also outlined and clinical situations appropriate for each model are reviewed.

Obstetrics/gynecology residents' knowledge of hereditary breast and ovarian cancer and Lynch syndrome.

Although there have been many studies regarding physicians' knowledge of hereditary cancer syndromes, very little information exists regarding medical residents' knowledge of hereditary cancer syndromes. Obstetrics/gynecology residents completed a test which evaluated their knowledge of hereditary breast and ovarian cancer and Lynch syndrome. Areas of relative deficit were identified. Residents indicated a desire and need for more education regarding this topic. Cancer genetics education programs should place more emphasis on the areas in which residents' appeared to be deficient in order to aid future physicians in the identification of high-risk individuals.

Software-Assisted Manual Review of Clinical Next-Generation Sequencing Data: An Alternative to Routine Sanger Sequencing Confirmation with Equivalent Results in >15,000 Germline DNA Screens.

Clinical genomic tests increasingly use a next-generation sequencing (NGS) platform due in part to the high fidelity of variant calls, yet rare errors are still possible. In germline DNA screening, failure to correct such errors could have serious consequences for patients, who may follow an unwarranted screening or surgical management path. It has been suggested that routine orthogonal confirmation by Sanger sequencing is required to verify NGS results, especially low-confidence positives with depressed allele fraction (<30% of alternate allele). We evaluated whether an alternative method of confirmation-software-assisted manual call review-performed comparably with Sanger confirmation in >15,000 samples. Licensed reviewers manually inspected both raw and processed data at the batch, sample, and variant levels, including raw NGS read pileups. Of ambiguous variant calls with <30% allele fraction (1707 total calls at 38 unique sites), manual call review classified >99% (n = 1701) as true positives (enriched for long insertions or deletions and homopolymers) or true negatives (often conspicuous NGS artifacts), with the remaining <1% (n = 6) being mosaic. Critically, results from software-assisted manual review and retrospective Sanger sequencing were concordant for samples selected from all ambiguous sites. We conclude that the confirmation required for high confidence in NGS-based germline testing can manifest in different ways; a trained NGS expert operating platform-tailored review software achieves quality comparable with routine Sanger confirmation.

Inherited Cancer in the Age of Next-Generation Sequencing.

Next-generation sequencing (NGS) technology has led to the ability to test for multiple cancer susceptibility genes simultaneously without significantly increasing cost or turnaround time. With growing usage of multigene testing for inherited cancer, ongoing education for nurses and other health-care providers about hereditary cancer screening is imperative to ensure appropriate testing candidate identification, test selection, and posttest management. The purpose of this review article is to (1) provide an overview of how NGS works to detect germline mutations, (2) summarize the benefits and limitations of multigene panel testing, (3) describe risk categories of cancer susceptibility genes, and (4) highlight the counseling considerations for patients pursuing multigene testing.

Development and validation of a 36-gene sequencing assay for hereditary cancer risk assessment.

The past two decades have brought many important advances in our understanding of the hereditary susceptibility to cancer. Numerous studies have provided convincing evidence that identification of germline mutations associated with hereditary cancer syndromes can lead to reductions in morbidity and mortality through targeted risk management options. Additionally, advances in gene sequencing technology now permit the development of multigene hereditary cancer testing panels. Here, we describe the 2016 revision of the Counsyl Inherited Cancer Screen for detecting single-nucleotide variants (SNVs), short insertions and deletions (indels), and copy number variants (CNVs) in 36 genes associated with an elevated risk for breast, ovarian, colorectal, gastric, endometrial, pancreatic, thyroid, prostate, melanoma, and neuroendocrine cancers. To determine test accuracy and reproducibility, we performed a rigorous analytical validation across 341 samples, including 118 cell lines and 223 patient samples. The screen achieved 100% test sensitivity across different mutation types, with high specificity and 100% concordance with conventional Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). We also demonstrated the screen's high intra-run and inter-run reproducibility and robust performance on blood and saliva specimens. Furthermore, we showed that pathogenic Alu element insertions can be accurately detected by our test. Overall, the validation in our clinical laboratory demonstrated the analytical performance required for collecting and reporting genetic information related to risk of developing hereditary cancers.

Susceptibility to breast cancer: hereditary syndromes and low penetrance genes.

Several genes are associated with hereditary susceptibility to breast cancer. Most notably these include BRCA1 and BRCA2; however, other less common gene mutations which confer elevated breast cancer risk are associated with Cowden syndrome, Li-Fraumeni syndrome, Peutz-Jeghers syndrome, ataxia-telangiectasia heterozygosity and hereditary diffuse gastric cancer. In this article we highlight the genetic epidemiology, gene function, genotype-phenotype correlations, cancer risks and clinicopathologic findings for the cancer susceptibility genes related to these syndromes. We also examine genes, such as CHEK2, which confer a lower penetrance for breast cancer in comparison to these highly penetrant genes.

Design and validation of a next generation sequencing assay for hereditary BRCA1 and BRCA2 mutation testing.

Hereditary breast and ovarian cancer syndrome, caused by a germline pathogenic variant in the BRCA1 or BRCA2 (BRCA1/2) genes, is characterized by an increased risk for breast, ovarian, pancreatic and other cancers. Identification of those who have a BRCA1/2 mutation is important so that they can take advantage of genetic counseling, screening, and potentially life-saving prevention strategies. We describe the design and analytic validation of the Counsyl Inherited Cancer Screen, a next-generation-sequencing-based test to detect pathogenic variation in the BRCA1 and BRCA2 genes. We demonstrate that the test is capable of detecting single-nucleotide variants (SNVs), short insertions and deletions (indels), and copy-number variants (CNVs, also known as large rearrangements) with zero errors over a 114-sample validation set consisting of samples from cell lines and deidentified patient samples, including 36 samples with BRCA1/2pathogenic germline mutations.

Clinicopathologic characteristics of breast cancer in BRCA-carriers and non-carriers in women 35 years of age or less.

PURPOSE: Breast cancer diagnosed in women 35 years of age or less accounts for <2% of all breast cancer cases. Clinical and pathologic characteristics of early onset breast cancer are not well defined in BRCA mutation carriers and non-carriers. METHODS: 194 women diagnosed with breast cancer at 35 years of age or less who had BRCA1/2 mutation testing were included in the study. Logistic regression models were fit to determine the associations between clinical variables and BRCA status. RESULTS: Thirty-two (17%) and 12 (6%) patients had BRCA1 and BRCA2 mutations, respectively. BRCA1-carriers had a higher likelihood of a positive family history (FH) of breast and/or ovarian cancer (P = 0.001), or first-degree relatives diagnosed with breast cancer at <50 years old (P = 0.001) compared to non-carriers. BRCA2-carriers were more likely to have a FH of male breast cancer compared to noncarriers (P = 0.02). Among BRCA2-carriers, the age at first full-term pregnancy was younger in ER-negative cases compared with ERpositive cases (19.5 vs. 28.5 years old; P = 0.01). BRCA1-carriers with a later age at menarche were more likely to have a later stage at diagnosis (P = 0.04). Non-carriers with a lower BMI were more likely to have lymph node involvement (P = 0.03). CONCLUSIONS: Several associations were identified between reproductive risk factors or BMI and disease characteristics. Further characterization may result in a better understanding of the trends in young onset breast cancer in BRCA-carriers and non-carriers.

Comparison of attitudes regarding preimplantation genetic diagnosis among patients with hereditary cancer syndromes.

Preimplantation genetic diagnosis (PGD) allows couples to avoid having a child with an inherited condition, potentially reducing cancer burden in families with a hereditary cancer predisposition. This study investigated and compared awareness and acceptance of PGD among patients with different hereditary cancer syndromes. Questionnaires were mailed to 984 adults with hereditary breast and ovarian cancer, Lynch syndrome, familial adenomatous polyposis, or multiple endocrine neoplasia type 1 or 2. Associations between clinical, demographic, and psychosocial factors and awareness and acceptance of PGD were examined. Of 370 respondents (38 % return rate), 28 % felt their syndrome impacted family planning, 24 % were aware of PGD, 72 % felt that PGD should be offered, 43 % would consider using PGD, and 29 % were uncertain. Family experience and syndrome-specific characteristics, such as disease severity, quality of life and availability of medical interventions as well as gender, family planning stage, and religiosity impact perceptions of the acceptability of PGD, though a high level of uncertainty exists. Hereditary cancer patients lack awareness of PGD despite feeling that PGD should be offered, highlighting the need for education on this topic. While we found attitudes about the acceptability of PGD to be generally similar to those reported in the literature and of genetics and ethics experts, we observed similarities and differences between syndromes that provide insight into why some hereditary cancer patients may find PGD more acceptable than others.

Knowledge and attitudes regarding expanded genetic carrier screening among women's healthcare providers.

OBJECTIVE: To determine women's healthcare providers' knowledge and attitudes regarding genetic disorders and expanded genetic screening. DESIGN: Survey of American Society for Reproductive Medicine 2010 and American College of Obstetricians and Gynecologists 2011 Annual Meeting attendees. The survey included 60 items (12 demographic, 10 knowledge, and 38 attitude). Attitudes were assessed with a 5-point Likert scale. Chi-square or t tests determined significance. SETTING: American Society for Reproductive Medicine 2010 and American College of Obstetricians and Gynecologists 2011 Annual Meeting. PATIENT(S): A total of 203 participants completed the survey. Of these, 48% were male, 61% were physicians, 73% were Caucasian, and 42% were aged 35-50 years. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): None. RESULT(S): Physicians had better knowledge scores than other participants (87% vs. 79%). Knowledge was not influenced by prior personal/family experience with genetic screening. Fewer correct answers were observed for the probability of a positive test (65.2%), the risk of transmitting a gene mutation (62.2%), and the risk of having an affected child (56.2%). Very few participants (18.3%) disagreed with the notion of carrier screening as socially responsible behavior. Some had concerns about test result confidentiality (40.1%) and resulting insurance rate increases (37.0%). Assuming equal costs, most participants preferred to be tested for a larger number of diseases (77.7%) and believed posttest counseling to be helpful (83.7%). CONCLUSION(S): Women's healthcare providers generally had good knowledge and positive attitudes about genetic disorders and expanded genetic screening. Specific misperceptions, both medical and legal, require education.

Clinical assessment of breast cancer risk based on family history.

Family history is a key component of breast cancer risk assessment. Family history provides clues as to the likelihood of a hereditary breast cancer syndrome and the need for a cancer genetics referral and can be used in the setting of a breast cancer risk assessment model to estimate a woman's risk. Appropriate breast cancer screening and risk reduction management plans rely on an accurate assessment of a patient's family history. This article reviews the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer Risk Reduction and provides insight into the application of the guidelines in clinical practice.