Assessing BRCA Carrier Probabilities in Extended Families

Validating Risk Prediction Models for Multiple Primaries and Competing Cancer Outcomes in Families With Li-Fraumeni Syndrome Using Clinically Ascertained Data

PURPOSE

There exists a barrier between developing and disseminating risk prediction models in clinical settings. We hypothesize that this barrier may be lifted by demonstrating the utility of these models using incomplete data that are collected in real clinical sessions, as compared with the commonly used research cohorts that are meticulously collected.

MATERIALS AND METHODS

Genetic counselors (GCs) collect family history when patients (ie, probands) come to MD Anderson Cancer Center for risk assessment of Li-Fraumeni syndrome, a genetic disorder characterized by deleterious germline mutations in the TP53 gene. Our clinical counseling-based (CCB) cohort consists of 3,297 individuals across 124 families (522 cases of single primary cancer and 125 cases of multiple primary cancers). We applied our software suite LFSPRO to make risk predictions and assessed performance in discrimination using AUC and in calibration using observed/expected (O/E) ratio.

RESULTS

For prediction of deleterious TP53 mutations, we achieved an AUC of 0.78 (95% CI, 0.71 to 0.85) and an O/E ratio of 1.66 (95% CI, 1.53 to 1.80). Using the LFSPRO.MPC model to predict the onset of the second cancer, we obtained an AUC of 0.70 (95% CI, 0.58 to 0.82). Using the LFSPRO.CS model to predict the onset of different cancer types as the first primary, we achieved AUCs between 0.70 and 0.83 for sarcoma, breast cancer, or other cancers combined.

CONCLUSION

We describe a study that fills in the critical gap in knowledge for the utility of risk prediction models. Using a CCB cohort, our previously validated models have demonstrated good performance and outperformed the standard clinical criteria. Our study suggests that better risk counseling may be achieved by GCs using these already-developed mathematical models.

Breast cancer risk stratification using genetic and non-genetic risk assessment tools for 246,142 women in the UK Biobank

PURPOSE

The benefit of using individual risk prediction tools to identify high-risk individuals for breast cancer (BC) screening is uncertain, despite the personalized approach of risk-based screening.

METHODS

We studied the overlap of predicted high-risk individuals among 246,142 women enrolled in the UK Biobank. Risk predictors assessed include the Gail model (Gail), BC family history (FH, binary), BC polygenic risk score (PRS), and presence of loss-of-function (LoF) variants in BC predisposition genes. Youden J-index was used to select optimal thresholds for defining high-risk.

RESULTS

In total, 147,399 were considered at high risk for developing BC within the next 2 years by at least 1 of the 4 risk prediction tools examined (Gail2-year > 0.5%: 47%, PRS2-yea r > 0.7%: 30%, FH: 6%, and LoF: 1%); 92,851 (38%) were flagged by only 1 risk predictor. The overlap between individuals flagged as high-risk because of genetic (PRS) and Gail model risk factors was 30%. The best-performing combinatorial model comprises a union of high-risk women identified by PRS, FH, and, LoF (AUC2-year [95% CI]: 62.2 [60.8 to 63.6]). Assigning individual weights to each risk prediction tool increased discriminatory ability.

CONCLUSION

Risk-based BC screening may require a multipronged approach that includes PRS, predisposition genes, FH, and other recognized risk factors.

Validating risk prediction models for multiple primaries and competing cancer outcomes in families with Li-Fraumeni syndrome using clinically ascertained data at a single institute

Purpose

There exists a barrier between developing and disseminating risk prediction models in clinical settings. We hypothesize this barrier may be lifted by demonstrating the utility of these models using incomplete data that are collected in real clinical sessions, as compared to the commonly used research cohorts that are meticulously collected.

Patients and methods

Genetic counselors (GCs) collect family history when patients (i.e., probands) come to MD Anderson Cancer Center for risk assessment of Li-Fraumeni syndrome, a genetic disorder characterized by deleterious germline mutations in the TP53 gene. Our clinical counseling-based (CCB) cohort consists of 3,297 individuals across 124 families (522 cases of single primary cancer and 125 cases of multiple primary cancers). We applied our software suite LFSPRO to make risk predictions and assessed performance in discrimination using area under the curve (AUC), and in calibration using observed/expected (O/E) ratio.

Results

For prediction of deleterious TP53 mutations, we achieved an AUC of 0.81 (95% CI, 0.70 - 0.91) and an O/E ratio of 0.96 (95% CI, 0.70 - 1.21). Using the LFSPRO.MPC model to predict the onset of the second cancer, we obtained an AUC of 0.70 (95% CI, 0.58 - 0.82). Using the LFSPRO.CS model to predict the onset of different cancer types as the first primary, we achieved AUCs between 0.70 and 0.83 for sarcoma, breast cancer, or other cancers combined.

Conclusion

We describe a study that fills in the critical gap in knowledge for the utility of risk prediction models. Using a CCB cohort, our previously validated models have demonstrated good performance and outperformed the standard clinical criteria. Our study suggests better risk counseling may be achieved by GCs using these already-developed mathematical models.

DrABC: deep learning accurately predicts germline pathogenic mutation status in breast cancer patients based on phenotype data

Background

Identifying breast cancer patients with DNA repair pathway-related germline pathogenic variants (GPVs) is important for effectively employing systemic treatment strategies and risk-reducing interventions. However, current criteria and risk prediction models for prioritizing genetic testing among breast cancer patients do not meet the demands of clinical practice due to insufficient accuracy.

Methods

The study population comprised 3041 breast cancer patients enrolled from seven hospitals between October 2017 and 11 August 2019, who underwent germline genetic testing of 50 cancer predisposition genes (CPGs). Associations among GPVs in different CPGs and endophenotypes were evaluated using a case-control analysis. A phenotype-based GPV risk prediction model named DNA-repair Associated Breast Cancer (DrABC) was developed based on hierarchical neural network architecture and validated in an independent multicenter cohort. The predictive performance of DrABC was compared with currently used models including BRCAPRO, BOADICEA, Myriad, PENN II, and the NCCN criteria.

Results

In total, 332 (11.3%) patients harbored GPVs in CPGs, including 134 (4.6%) in BRCA2, 131 (4.5%) in BRCA1, 33 (1.1%) in PALB2, and 37 (1.3%) in other CPGs. GPVs in CPGs were associated with distinct endophenotypes including the age at diagnosis, cancer history, family cancer history, and pathological characteristics. We developed a DrABC model to predict the risk of GPV carrier status in BRCA1/2 and other important CPGs. In predicting GPVs in BRCA1/2, the performance of DrABC (AUC = 0.79 [95% CI, 0.74–0.85], sensitivity = 82.1%, specificity = 63.1% in the independent validation cohort) was better than that of previous models (AUC range = 0.57–0.70). In predicting GPVs in any CPG, DrABC (AUC = 0.74 [95% CI, 0.69–0.79], sensitivity = 83.8%, specificity = 51.3% in the independent validation cohort) was also superior to previous models in their current versions (AUC range = 0.55–0.65). After training these previous models with the Chinese-specific dataset, DrABC still outperformed all other methods except for BOADICEA, which was the only previous model with the inclusion of pathological features. The DrABC model also showed higher sensitivity and specificity than the NCCN criteria in the multi-center validation cohort (83.8% and 51.3% vs. 78.8% and 31.2%, respectively, in predicting GPVs in any CPG). The DrABC model implementation is available online at http://gifts.bio-data.cn/.

Conclusions

By considering the distinct endophenotypes associated with different CPGs in breast cancer patients, a phenotype-driven prediction model based on hierarchical neural network architecture was created for identification of hereditary breast cancer. The model achieved superior performance in identifying GPV carriers among Chinese breast cancer patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01027-9.

Preventive population genomics: The model of BRCA related cancers

Preventive population genomics offers the prospect of population stratification for targeting screening and prevention and tailoring care to those at greatest risk. Within cancer, this approach is now within reach, given our expanding knowledge of its heritable components, improved ability to predict risk, and increasing availability of effective preventive strategies. Advances in technology and bioinformatics has made population-testing technically feasible. The BRCA model provides 30 years of insight and experience of how to conceive of and construct care and serves as an initial model for preventive population genomics. Population-based BRCA-testing in the Jewish population is feasible, acceptable, reduces anxiety, does not detrimentally affect psychological well-being or quality of life, is cost-effective and is now beginning to be implemented. Population-based BRCA-testing and multigene panel testing in the wider general population is cost-effective for numerous health systems and can save thousands more lives than the current clinical strategy. There is huge potential for using both genetic and non-genetic information in complex risk prediction algorithms to stratify populations for risk adapted screening and prevention. While numerous strides have been made in the last decade several issues need resolving for population genomics to fulfil its promise and potential for maximizing precision prevention. Healthcare systems need to overcome significant challenges associated with developing delivery pathways, infrastructure expansion including laboratory services, clinical workforce training, scaling of management pathways for screening and prevention. Large-scale real world population studies are needed to evaluate context specific population-testing implementation models for cancer risk prediction, screening and prevention.

Prevalence of BRCA1 and BRCA2 Mutations in Patients with Primary Ovarian Cancer - Does the German Checklist for Detecting the Risk of Hereditary Breast and Ovarian Cancer Adequately Depict the Need for Consultation?

BackgroundBRCA1/2 mutations are the leading cause of hereditary epithelial ovarian cancer (EOC). The German Consortium for Hereditary Breast and Ovarian Cancer has defined inclusion criteria, which are retrievable as a checklist and facilitate genetic counselling/testing for affected persons with a mutation probability of ≥ 10%. Our objective was to evaluate the prevalence of the BRCA1/2 mutation(s) based on the checklist score (CLS).

Methods A retrospective data analysis was performed on EOC patients with a primary diagnosis treated between 1/2011 – 5/2019 at the Central Essen Clinics, where a BRCA1/2 genetic analysis result and a CLS was available. Out of 545 cases with a BRCA1/2 result (cohort A), 453 cases additionally had an extended gene panel result (cohort B).

Results A BRCA1/2 mutation was identified in 23.3% (127/545) in cohort A, pathogenic mutations in non- BRCA1/2 genes were revealed in a further 6.2% in cohort B. In cohort A, 23.3% (127/545) of patients had a BRCA1 (n = 92) or BRCA2 (n = 35) mutation. Singular EOC (CLS 2) was present in 40.9%. The prevalence for a BRCA1/2 mutation in cohort A was 10.8%, 17.2%, 25.0%, 35.1%, 51.4% and 66.7% for patients with CLS 2, 3, 4, 5, 6 and ≥ 7 respectively. The mutation prevalence in cohort B was 15.9%, 16.4%, 28.2%, 40.4%, 44.8% and 62.5% for patients with CLS 2, 3, 4, 5, 6 and ≥ 7 respectively.

Conclusions The BRCA1/2 mutation prevalence in EOC patients positively correlates with a rising checklist score. Already with singular EOC, the prevalence of a BRCA1/2 mutation exceeds the required 10% threshold. Our data support the recommendation of the S3 guidelines Ovarian Cancer of offering genetic testing to all patients with EOC. Optimisation of the checklist with clear identification of the testing indication in this population should therefore be aimed for.

Comparative Analysis between the Gail, Tyrer-Cuzick and BRCAPRO Models for Breast Cancer Screening in Brazilian Population

OBJECTIVE

To analyze the diagnostic accuracy of predictive models of breast cancer risk for the Brazilian population.

METHOD

A cross-sectional, study was conducted in a sample of 382 women aged 35-69 years who were users of the Unified Health System (SUS) residing in a municipality in southern Brazil.

RESULTS

The results showed that the Tyrer-Cuzick model had the highest mean risk values and estimates (proportion) for predicting the 5-year risk of breast cancer, reaching a maximum risk of ±1.63% in the 60-64 year age group. For the 90-year risk, a maximum risk of ±12.8% was predicted for the 50-54 year age group using this model. The 5-year risk calculated by the three tools increased progressively with increasing age, where the mean risk was ±0.8% in women aged 35-39 and reached ±1.50% in women aged 65-69. The 90-year risk declined with increasing age only in the Tyrer-Cuzick model, from ±10.8% to ±9%. The BRCAPRO model presented a greater sensitivity compared to the Gail and Tyrer-Cuzick models. And, the model that presented greater specificity was Gail.

CONCLUSION

The Tyrer-Cuzick model presented the highest risk estimates for 5 years and 90 years in the studied population, however, this data is not enough to validate this tool, since when analyzing the sensitivity and specificity the BRCAPRO and Gail have the highest values respectively.

Risk Assessment, Genetic Counseling, and Genetic Testing for BRCA-Related Cancer: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

Potentially harmful mutations of the breast cancer susceptibility 1 and 2 genes (BRCA1/2) are associated with increased risk for breast, ovarian, fallopian tube, and peritoneal cancer. For women in the United States, breast cancer is the most common cancer after nonmelanoma skin cancer and the second leading cause of cancer death. In the general population, BRCA1/2 mutations occur in an estimated 1 in 300 to 500 women and account for 5% to 10% of breast cancer cases and 15% of ovarian cancer cases.

OBJECTIVE

To update the 2013 US Preventive Services Task Force (USPSTF) recommendation on risk assessment, genetic counseling, and genetic testing for BRCA-related cancer.

EVIDENCE REVIEW

The USPSTF reviewed the evidence on risk assessment, genetic counseling, and genetic testing for potentially harmful BRCA1/2 mutations in asymptomatic women who have never been diagnosed with BRCA-related cancer, as well as those with a previous diagnosis of breast, ovarian, tubal, or peritoneal cancer who have completed treatment and are considered cancer free. In addition, the USPSTF reviewed interventions to reduce the risk for breast, ovarian, tubal, or peritoneal cancer in women with potentially harmful BRCA1/2 mutations, including intensive cancer screening, medications, and risk-reducing surgery.

FINDINGS

For women whose family or personal history is associated with an increased risk for harmful mutations in the BRCA1/2 genes, or who have an ancestry associated with BRCA1/2 gene mutations, there is adequate evidence that the benefits of risk assessment, genetic counseling, genetic testing, and interventions are moderate. For women whose personal or family history or ancestry is not associated with an increased risk for harmful mutations in the BRCA1/2 genes, there is adequate evidence that the benefits of risk assessment, genetic counseling, genetic testing, and interventions are small to none. Regardless of family or personal history, the USPSTF found adequate evidence that the overall harms of risk assessment, genetic counseling, genetic testing, and interventions are small to moderate.

CONCLUSIONS AND RECOMMENDATION

The USPSTF recommends that primary care clinicians assess women with a personal or family history of breast, ovarian, tubal, or peritoneal cancer or who have an ancestry associated with BRCA1/2 gene mutations with an appropriate brief familial risk assessment tool. Women with a positive result on the risk assessment tool should receive genetic counseling and, if indicated after counseling, genetic testing. (B recommendation) The USPSTF recommends against routine risk assessment, genetic counseling, or genetic testing for women whose personal or family history or ancestry is not associated with potentially harmful BRCA1/2 gene mutations. (D recommendation).

Risk Assessment, Genetic Counseling, and Genetic Testing for BRCA-Related Cancer in Women: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Pathogenic mutations in breast cancer susceptibility genes BRCA1 and BRCA2 increase risks for breast, ovarian, fallopian tube, and peritoneal cancer in women; interventions reduce risk in mutation carriers.

OBJECTIVE

To update the 2013 US Preventive Services Task Force review on benefits and harms of risk assessment, genetic counseling, and genetic testing for BRCA1/2-related cancer in women.

DATA SOURCES

Cochrane libraries; MEDLINE, PsycINFO, EMBASE (January 1, 2013, to March 6, 2019, for updates; January 1, 1994, to March 6, 2019, for new key questions and populations); reference lists.

STUDY SELECTION

Discriminatory accuracy studies, randomized clinical trials (RCTs), and observational studies of women without recently diagnosed BRCA1/2-related cancer.

DATA EXTRACTION AND SYNTHESIS

Data on study methods, setting, population characteristics, eligibility criteria, interventions, numbers enrolled and lost to follow-up, outcome ascertainment, and results were abstracted. Two reviewers independently assessed study quality.

MAIN OUTCOMES AND MEASURES

Cancer incidence and mortality; discriminatory accuracy of risk assessment tools for BRCA1/2 mutations; benefits and harms of risk assessment, genetic counseling, genetic testing, and risk-reducing interventions.

RESULTS

For this review, 103 studies (110 articles; N = 92 712) were included. No studies evaluated the effectiveness of risk assessment, genetic counseling, and genetic testing in reducing incidence and mortality of BRCA1/2-related cancer. Fourteen studies (n = 43 813) of 8 risk assessment tools to guide referrals to genetic counseling demonstrated moderate to high accuracy (area under the receiver operating characteristic curve, 0.68-0.96). Twenty-eight studies (n = 8060) indicated that genetic counseling was associated with reduced breast cancer worry, anxiety, and depression; increased understanding of risk; and decreased intention for testing. Twenty studies (n = 4322) showed that breast cancer worry and anxiety were higher after testing for women with positive results and lower for others; understanding of risk was higher after testing. In 8 RCTs (n = 54 651), tamoxifen (relative risk [RR], 0.69 [95% CI, 0.59-0.84]; 4 trials), raloxifene (RR, 0.44 [95% CI, 0.24-0.80]; 2 trials), and aromatase inhibitors (RR, 0.45 [95% CI, 0.26-0.70]; 2 trials) were associated with lower risks of invasive breast cancer compared with placebo; results were not specific to mutation carriers. Mastectomy was associated with 90% to 100% reduction in breast cancer incidence (6 studies; n = 2546) and 81% to 100% reduction in breast cancer mortality (1 study; n = 639); oophorectomy was associated with 69% to 100% reduction in ovarian cancer (2 studies; n = 2108); complications were common with mastectomy.

CONCLUSIONS AND RELEVANCE

Among women without recently diagnosed BRCA1/2-related cancer, the benefits and harms of risk assessment, genetic counseling, and genetic testing to reduce cancer incidence and mortality have not been directly evaluated by current research.

Hereditary gynaecologic cancers in Nepal: a proposed model of care to serve high risk populations in developing countries

Background

Endometrial, ovarian and breast cancers are paradigms for global health disparity. Women living in the developing world continue to present in later stages of disease and have fewer options for treatment than those in developed countries. Risk reducing surgery is of proven benefit for women at high risk of gynaecological cancer. There is no specific model for identification and management of such women in the developing world.

Methods

We have integrated data from our published audit of a major gynaecological oncology centre at Royal Hospital for Women in Australia, with data from our survey and a focus group discussion of Nepalese gynaecological health care professionals regarding genetic testing, and findings from the literature. These data have been used to identify current barriers to multidisciplinary gynaecological oncology care in developing nations, and to develop a model to integrate hereditary cancer services into cancer care in Nepal, as a paradigm for other developing nations.

Results

The ability to identify women with hereditary gynaecological cancer in developing nations is influenced by their late presentation (if active management is declined or not appropriate), limited access to specialised services and cultural and financial barriers. In order to include genetic assessment in multidisciplinary gynaecological cancer care, education needs to be provided to all levels of health care providers to enable reporting of family history, and appropriate ordering of investigations. Training of genetic counsellors is needed to assist in the interpretation of results and extending care to unaffected at-risk relatives. Novel approaches will be required to overcome geographic and financial barriers, including mainstreaming of genetic testing, telephone counselling, use of mouth swabs and utilisation of international laboratories.

Conclusion

Women in Nepal have yet to receive benefits from the advances in early cancer diagnosis and management. There is a potential of extending the benefits of hereditary cancer diagnosis in Nepal due to the rapid fall in the cost of genetic testing and the ability to collect DNA from a buccal swab through appropriate training of the gynaecological carers.

Evaluating the performance of National Comprehensive Cancer Network (NCCN) breast and ovarian genetic/familial high risk assessment referral criteria for breast cancer women in an Asian surgical breast clinic

BACKGROUND

Globally, resources for genomic services vary. Current National Comprehensive Cancer Network (NCCN) breast and ovarian genetic/familial high risk assessment criteria for further genetic risk evaluation are useful, but lack specificity for reliably excluding patients with low a priori risk. This may result in patient overload in lesser-equipped genetics clinics. Since we use Manchester and the Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) risk assessment models in our genetics clinic to determine whether genetic testing is warranted, we chose Manchester and BOADICEA as the reference standard to compare how the NCCN breast and ovarian genetic/familial high risk assessment criteria for further genetic risk evaluation performs against these two risk assessment models in referring breast cancer patients for genetic evaluation.

METHODS

Breast cancer patients diagnosed from 2009-2011 were assessed using the NCCN criteria, Manchester and BOADICEA. Logistic regression and receiver operating characteristic (ROC) analysis were used to compare the NCCN criteria versus the Manchester and BOADICEA scoring systems in identifying high-risk patients.

RESULTS

A total of 666 patients were included in the study. Percentages of high-risk patients resulting from Manchester and BOADICEA were 1.80% and 2.55%, respectively. Among the NCCN criteria, breast cancer and ≥1 close relatives with breast cancer at ≤50 years of age correlated best with Manchester and/or BOADICEA (c-statistic =0.831) with a false negative rate of 1.0%.

CONCLUSIONS

Breast cancer at any age and ≥1 close relative with breast cancer at ≤50 years of age exhibited the highest correlation with Manchester and/or BOADICEA, promising greater specificity compared to the other NCCN criteria for segregating high risk, Asian breast cancer patients for referral to a genetics clinic, nevertheless recognizing the inherent limitations of the scoring systems.

Comparison between CaGene 5.1 and 6.0 for BRCA1/2 mutation prediction: a retrospective study of 150 BRCA1/2 genetic tests in 517 families with breast/ovarian cancer

During the past years, several empirical and statistical models have been developed to discriminate between carriers and non-carriers of germline BRCA1/BRCA2 (breast cancer 1, early onset/breast cancer 2, early onset) mutations in families with hereditary breast or ovarian cancer. Among these, the BRCAPRO or CaGene model is commonly used during genetic counseling, and plays a central role in the identification of potential carriers of BRCA1/2 mutations. We compared performance and clinical applicability of BRCAPRO version 5.1 vs version 6.0 in order to assess diagnostic accuracy of updated version. The study was carried out on 517 pedigrees of patients with familial history of breast or ovarian cancer, 150 of which were submitted to BRCA1/2 mutation screening, according to BRCAPRO evaluation or to criteria based on familial history. In our study, CaGene 5.1 was more sensitive than CaGene 6.0, although the latter showed a higher specificity. Both BRCAPRO versions better discriminate BRCA1 than BRCA2 mutations. This study evidenced similar performances in the two BRCAPRO versions even if the CaGene 6.0 has underestimated the genetic risk prediction in some BRCA mutation-positive families. Genetic counselors should recognize this limitation and during genetic counseling would be advisable to use a set of criteria in order to improve mutation carrier prediction.

KOHBRA BRCA risk calculator (KOHCal): a model for predicting BRCA1 and BRCA2 mutations in Korean breast cancer patients

The widely used Western BRCA mutation prediction models underestimated the risk of having a BRCA mutation in Korean breast cancer patients. This study aimed to identify predictive factors for BRCA1/2 mutations and to develop a Korean BRCA risk calculator. The model was constructed by logistic regression model, and it was based on the Korean Hereditary Breast Cancer study, in which 1669 female patients were enrolled between May 2007 and December 2010. A separate data set of 402 patients, who were enrolled from Jan 2011 to August 2012, was used to test the performance of our model. In total, 264 (15.8%) and 67 (16.7%) BRCA mutation carriers were identified in the model and validation set, respectively. Multivariate analysis showed that age at breast cancer diagnosis, bilateral breast cancer, triple-negative breast cancer (TNBC) and the number of relatives with breast or ovarian cancer within third-degree relatives were independent predictors of the BRCA mutation among familial breast cancer patients. An age <35 years at diagnosis, bilateral breast cancer, both breast and ovarian cancer and TNBC remained significant predictors in non-familial breast cancer cases. Our model was developed based on logistic regression models. The validation results showed no differences between the observed and expected carrier probabilities. This model will be a useful tool for providing genetic risk assessments in Korean populations.

Skin cancer risk in BRCA1/2 mutation carriers

Women with BRCA1/2 mutations have an elevated risk of breast and ovarian cancer. These patients and their clinicians are often concerned about their risk for other cancers, including skin cancer. Research evaluating the association between BRCA1/2 mutations and skin cancer is limited and has produced inconsistent results. Herein, we review the current literature on the risk of melanoma and nonmelanoma skin cancers in BRCA1/2 mutation carriers. No studies have shown a statistically significant risk of melanoma in BRCA1 families. BRCA2 mutations have been linked to melanoma in large breast and ovarian cancer families, though a statistically significant elevated risk was reported in only one study. Five additional studies have shown some association between BRCA2 mutations and melanoma, while four studies did not find any association. With respect to nonmelanoma skin cancers, studies have produced conflicting results. Given the current state of medical knowledge, there is insufficient evidence to warrant increased skin cancer surveillance of patients with a confirmed BRCA1/2 mutation or a family history of a BRCA1/2 mutation, in the absence of standard risk factors. Nonetheless, suspected BRCA1/2 mutation carriers should be counselled about skin cancer risks and may benefit from yearly full skin examinations.

Population testing for cancer predisposing BRCA1/BRCA2 mutations in the Ashkenazi-Jewish community: a randomized controlled trial

BACKGROUND

Technological advances raise the possibility of systematic population-based genetic testing for cancer-predisposing mutations, but it is uncertain whether benefits outweigh disadvantages. We directly compared the psychological/quality-of-life consequences of such an approach to family history (FH)-based testing.

METHODS

In a randomized controlled trial of BRCA1/2 gene-mutation testing in the Ashkenazi Jewish (AJ) population, we compared testing all participants in the population screening (PS) arm with testing those fulfilling standard FH-based clinical criteria (FH arm). Following a targeted community campaign, AJ participants older than 18 years were recruited by self-referral after pretest genetic counseling. The effects of BRCA1/2 genetic testing on acceptability, psychological impact, and quality-of-life measures were assessed by random effects regression analysis. All statistical tests were two-sided.

RESULTS

One thousand, one hundred sixty-eight AJ individuals were counseled, 1042 consented, 1034 were randomly assigned (691 women, 343 men), and 1017 were eligible for analysis. Mean age was 54.3 (SD = 14.66) years. Thirteen BRCA1/2 carriers were identified in the PS arm, nine in the FH arm. Five more carriers were detected among FH-negative FH-arm participants following study completion. There were no statistically significant differences between the FH and PS arms at seven days or three months on measures of anxiety, depression, health anxiety, distress, uncertainty, and quality-of-life. Contrast tests indicated that overall anxiety (P = .0001) and uncertainty (P = .005) associated with genetic testing decreased; positive experience scores increased (P = .0001); quality-of-life and health anxiety did not change with time. Overall, 56% of carriers did not fulfill clinical criteria for genetic testing, and the BRCA1/2 prevalence was 2.45%.

CONCLUSION

Compared with FH-based testing, population-based genetic testing in Ashkenazi Jews doesn't adversely affect short-term psychological/quality-of-life outcomes and may detect 56% additional BRCA carriers.

Completeness of pedigree and family cancer history for ovarian cancer patients

OBJECTIVE

To investigate the completeness of pedigree and of number of pedigree analysis to know the acceptable familial history in Korean women with ovarian cancer.

METHODS

Interview was conducted in 50 ovarian cancer patients for obtaining familial history three times over the 6 weeks. The completeness of pedigree is estimated in terms of familial history of disease (cancer), health status (health living, disease and death), and onset age of disease and death.

RESULTS

The completion of pedigree was 79.3, 85.1, and 85.6% at the 1st, 2nd, and 3rd time of interview and the time for pedigree analysis was 34.3, 10.8, and 3.1 minutes, respectively. The factors limiting pedigree analysis were as follows: out of contact with their relatives (38%), no living ancestors who know the family history (34%), dispersed family member because of the Korean War (16%), unknown cause of death (12%), reluctance to ask medical history of relatives (10%), and concealing their ovarian cancer (10%). The percentage of cancers revealed in 1st (2%) and 2nd degree (8%) relatives were increasing through surveys, especially colorectal cancer related with Lynch syndrome (4%).

CONCLUSION

Analysis of pedigree at least two times is acceptable in Korean woman with ovarian cancer from the first study. The completion of pedigree is increasing, while time to take family history is decreasing during three time survey.

Assessment of individuals with BRCA1 and BRCA2 large rearrangements in high-risk breast and ovarian cancer families

BRCA1/2 large rearrangement (LR) testing has been available to patients since 2006. Three existing models commonly used in cancer genetics clinical and research settings (BRCAPRO, Penn II and Myriad II) have not been assessed for their performance in predicting the presence of BRCA1/2 large genomic rearrangements in patients who do not have mutations detectable by the traditional Sanger sequencing approach. This study sought to determine if there is an optimal pre-test probability "cut off" value, calculated using these models, to optimize detection of large rearrangements (LRs). Our cohort consisted of 3,301 probands seen for genetic counseling and BRCA1/2 clinical testing from September 2006 to September 2011. A detailed personal and three-generation family history, including self-reported ethnicity, was taken as part of our standard clinical practice. We applied the BRCAPRO, Penn II, and Myriad II models to the probands with LRs. In our cohort of 3,301 probands, 150 carried a non-Ashkenazi mutation in BRCA1 or BRCA2. Seventeen unrelated probands carried a private BRCA1/2 LR (17/150, 11.3 % of all detectable non-AJ mutations). At a pre-test probability cutoff of 10 %, all three empiric risk models would have failed to identify almost 30 % of probands with LRs. Our study shows that BRCA1/2 LR testing should be offered to all women who meet criteria for BRCA1/2 sequence analysis.

Frailty Models for Familial Risk with Application to Breast Cancer

In evaluating familial risk for disease we have two main statistical tasks: assessing the probability of carrying an inherited genetic mutation conferring higher risk; and predicting the absolute risk of developing diseases over time, for those individuals whose mutation status is known. Despite substantial progress, much remains unknown about the role of genetic and environmental risk factors, about the sources of variation in risk among families that carry high-risk mutations, and about the sources of familial aggregation beyond major Mendelian effects. These sources of heterogeneity contribute substantial variation in risk across families. In this paper we present simple and efficient methods for accounting for this variation in familial risk assessment. Our methods are based on frailty models. We implemented them in the context of generalizing Mendelian models of cancer risk, and compared our approaches to others that do not consider heterogeneity across families. Our extensive simulation study demonstrates that when predicting the risk of developing a disease over time conditional on carrier status, accounting for heterogeneity results in a substantial improvement in the area under the curve of the receiver operating characteristic. On the other hand, the improvement for carriership probability estimation is more limited. We illustrate the utility of the proposed approach through the analysis of BRCA1 and BRCA2 mutation carriers in the Washington Ashkenazi Kin-Cohort Study of Breast Cancer.

Performance of BOADICEA and BRCAPRO genetic models and of empirical criteria based on cancer family history for predicting BRCA mutation carrier probabilities: a retrospective study in a sample of Italian cancer genetics clinics

PURPOSE

To evaluate in current practice the performance of BOADICEA and BRCAPRO risk models and empirical criteria based on cancer family history for the selection of individuals for BRCA genetic testing.

PATIENTS AND METHODS

The probability of BRCA mutation according to the three tools was retrospectively estimated in 918 index cases consecutively undergone BRCA testing at 15 Italian cancer genetics clinics between 2006 and 2008.

RESULTS

179 of 918 cases (19.5%) carried BRCA mutations. With the strict use of the criteria based on cancer family history 173 BRCA (21.9%) mutations would have been detected in 789 individuals. At the commonly used 10% threshold of BRCA mutation carrier probability, the genetic models showed a similar performance [PPV (38% and 37%), sensitivity (76% and 77%) and specificity (70% and 69%)]. Their strict use would have avoided around 60% of the tests but would have missed approximately 1 every 4 carriers.

CONCLUSION

Our data highlight the complexity of BRCA testing referral in routine practice and question the strict use of genetic models for BRCA risk assessment.

Establishing a program for individuals at high risk for breast cancer

Our need to create a program for individuals at high risk for breast cancer development led us to research the available data on such programs. In this paper, we summarize our findings and our thinking process as we developed our own program. Breast cancer incidence is increasing worldwide. Even though there are known risk factors for breast cancer development, approximately 60% of patients with breast cancer have no known risk factor, although this situation will probably change with further research, especially in genetics. For patients with risk factors based on personal or family history, different models are available for assessing and quantifying risk. Assignment of risk levels permits tailored screening and risk reduction strategies. Potential benefits of specialized programs for women with high breast cancer risk include more cost -effective interventions as a result of patient stratification on the basis of risk; generation of valuable data to advance science; and differentiation of breast programs from other breast cancer units, which can result in increased revenue that can be directed to further improvements in patient care. Guidelines for care of patients at high risk for breast cancer are available from various groups. However, running a high-risk breast program involves much more than applying a guideline. Each high-risk program needs to be designed by its institution with consideration of local resources and country legislation, especially related to genetic issues. Development of a successful high-risk program includes identifying strengths, weaknesses, opportunities, and threats; developing a promotion plan; choosing a risk assessment tool; defining "high risk"; and planning screening and risk reduction strategies for the specific population served by the program. The information in this article may be useful for other institutions considering creation of programs for patients with high breast cancer risk.

Practical aspects of genetic counseling in breast cancer: lights and shadows

In unselected populations, less than 10% of breast cancers are associated with germline mutations in predisposing genes. Breast cancer type 1 and 2 (BRCA1 and BRCA2) susceptibility genes are the most common involved genes and confer a 10-30 times higher risk of developing the disease compared to the general population. A personal or family history suggestive of inherited breast cancer syndrome may be further evaluated to assess the risk of genetic predisposition and the presence of a genetic mutation. Breast cancer genetic counseling should include a careful risk assessment with associated psychosocial evaluation and support, possible molecular testing, personalized discussion of results. Knowledge of BRCA status can influence individualized cancer risk-reduction strategies. i.e. active surveillance, prophylactic surgery and/or pharmacoprevention.

Evaluation of the BOADICEA risk assessment model in women with a family history of breast cancer

The ability of the Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) model to predict BRCA1 and BRCA2 mutations and breast cancer incidence in women with a family history of breast cancer was evaluated. Observed mutations in 263 screened families were compared to retrospective predictions. Similarly, observed breast cancers in 640 women were compared to retrospective predictions of breast cancer incidence. The ratios of observed to expected number of BRCA1- , BRCA2- and BRCA(1 or 2) mutations were 1.43 (95% CI 1.05–1.90), 0.63 (95% CI 0.34–1.08), and 1.12 (95% CI 0.86–1.44), showing a significant underestimation of BRCA1 mutations. Discrimination between carriers and non-carriers as measured by area under the receiver operating characteristic (ROC) curve was 0.83 (95% CI 0.76–0.88). The ratio of observed to expected number of invasive breast cancers was 1.41 (0.91–2.08). The corresponding area under the ROC curve for prediction of invasive breast cancer at individual level was 0.62 (95% CI 0.52–0.73). In conclusion, the BOADICEA model can predict the total prevalence of BRCA(1 or 2) mutations and the incidence of invasive breast cancers. The mutation probability as generated by BOADICEA can be used clinically as a guideline for screening, and thus decrease the proportion of negative mutation analyses. Likewise, individual breast cancer risks can be used for selecting women whose risk of breast cancer indicates follow-up. Application of local mutation frequencies of BRCA1 and BRCA2 could improve the ability to distinguish between the two genes.

Cancer genetic risk assessment for individuals at risk of familial breast cancer

BACKGROUND

The recognition of an inherited component to breast cancer has led to an increase in demand for information, reassurance, and genetic testing, which has resulted in the creation of genetic clinics for familial cancer. The first step for patients referred to a cancer genetic clinic is a risk assessment.

OBJECTIVES

To evaluate the impact of cancer genetic risk-assessment services on patients at risk of familial breast cancer.

SEARCH METHODS

The specialised register maintained by the Cochrane Breast Cancer Group was searched on 16th February 2005. We also searched MEDLINE, EMBASE, CINAHL, PsycLIT, CENTRAL, DARE, ASSIA, Web of Science, SIGLE and LILACS. The original searches covered the period 1985 to February 2005. We also handsearched relevant journals. For this review update the search was repeated through to April 2011.

SELECTION CRITERIA

We considered trials looking at interventions for cancer genetic risk-assessment services for familial breast cancer for inclusion. Trials assessed outcomes such as understanding of risk, satisfaction and psychological well-being. We excluded studies if they concerned cancers other than breast cancer or if participants were not at risk of inherited breast cancer. We also excluded trials concerning the provision of general cancer genetic information or education as this review was concerned with the delivery of genetic risk assessment. Participants could be individuals of any age or gender, with or without a known BRCA mutation, but without a previous history of breast cancer or any other serious illness.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Additional information was sought from investigators as necessary. Due to the heterogeneity of both the interventions and outcomes, we reported data descriptively.

MAIN RESULTS

In this review update, we included five new trials, bringing the total number of included studies to eight. The included trials (pertaining to 10 papers), provided data on 1973 participants and assessed the impact of cancer genetic risk assessment on outcomes including perceived risk of inherited cancer, and psychological distress. This review suggests that cancer genetic risk-assessment services help to reduce distress, improve the accuracy of the perceived risk of breast cancer, and increase knowledge about breast cancer and genetics. The health professional delivering the risk assessment does not appear to have a significant impact on these outcomes.

AUTHORS' CONCLUSIONS

This review found favourable outcomes for patients after risk assessment for familial breast cancer. However, there were too few papers to make any significant conclusions about how best to deliver cancer genetic risk-assessment services. Further research is needed assessing the best means of delivering cancer risk assessment, by different health professionals, in different ways and in alternative locations.

Prevalence of BRCA1 and BRCA2 mutations in Ashkenazi Jewish families with breast and pancreatic cancer

BACKGROUND

Germline mutations in the BRCA2 cancer susceptibility gene are associated with an increased risk of pancreatic cancer (PC). Breast-pancreas cancer families with BRCA1 mutations have also been observed. The influence of a family history (FH) of PC on BRCA mutation prevalence in patients with breast cancer (BC) is unknown.

METHODS

A clinical database review (2000-2009) identified 211 Ashkenazi Jewish (AJ) BC probands who 1) underwent BRCA1/2 mutation analysis by full gene sequencing or directed testing for Ashkenazi founder mutations (BRCA1: 185delAG and 5382insC; BRCA2: 6174delT) and 2) had a FH of PC in a first-, second-, or third-degree relative. For each proband, the pretest probability of identifying a BRCA1/2 mutation was estimated using the Myriad II model. The observed-to-expected (O:E) mutation prevalence was calculated for the entire group.

RESULTS

Of the 211 AJ BC probands with a FH of PC, 30 (14.2%) harbored a BRCA mutation. Fourteen (47%) of the mutations were in BRCA1 and 16 (53%) were in BRCA2. Patients diagnosed with BC at age ≤ 50 years were found to have a higher BRCA1/2 mutation prevalence than probands with BC who were diagnosed at age > 50 years (21.1% vs 6.9%; P = .003). In patients with a first-, second-, or third-degree relative with PC, mutation prevalences were 15.4%, 15.3%, and 8.6%, respectively (P = .58). In the overall group, the observed BRCA1/2 mutation prevalence was 14.2% versus an expected prevalence of 11.8% (O:E ratio, 1.21; P = .15).

CONCLUSIONS

BRCA1 and BRCA2 mutations are observed with nearly equal distribution in AJ breast-pancreas cancer families, suggesting that both genes are associated with PC risk. In this population, a FH of PC was found to have a limited effect on mutation prevalence.

Conditions and consequences of a BRCA mutation in young, single women of childbearing age

PURPOSE/OBJECTIVES

To explore the experiences of young, single women who are at increased risk for hereditary breast and ovarian cancer (HBOC) because of a BRCA mutation.

RESEARCH APPROACH

Qualitative.

SETTING

Seven states and Canada.

PARTICIPANTS

11 single women aged 18-35 years who tested positive for a BRCA mutation.

METHODOLOGIC APPROACH

Grounded theory with in-depth individual interviews conducted via e-mail or telephone.

FINDINGS

Analysis resulted in three conditions and three consequences. Conditions were dating or not dating, time in a relationship, and physical impact of surgery or breast cancer treatment. Consequences were explaining their choices, experiencing a sense of urgency, and experiencing a sense of loss.

CONCLUSIONS

Young women who are at risk for HBOC face a complex array of decisions after finding out that they carry a BRCA mutation. Being single and childless adds to this complexity.

INTERPRETATION

Nurses can listen to young women with HBOC risk, help them clarify their fears and understanding of their risk, and provide nonthreatening support that goes beyond simply providing more information and includes a nonjudgmental understanding of the young women's experience.

Assessing women at high risk of breast cancer: a review of risk assessment models

Women who are at high risk of breast cancer can be offered more intensive surveillance or prophylactic measures, such as surgery or chemoprevention. Central to decisions regarding the level of prevention is accurate and individualized risk assessment. This review aims to distill the diverse literature and provide practicing clinicians with an overview of the available risk assessment methods. Risk assessments fall into two groups: the risk of carrying a mutation in a high-risk gene such as BRCA1 or BRCA2 and the risk of developing breast cancer with or without such a mutation. Knowledge of breast cancer risks, taken together with the risks and benefits of the intervention, is needed to choose an appropriate disease management strategy. A number of models have been developed for assessing these risks, but independent validation of such models has produced variable results. Some models are able to predict both mutation carriage risks and breast cancer risk; however, to date, all are limited by only moderate discriminatory accuracy. Further improvements in the knowledge of how to best integrate both new risk factors and newly discovered genetic variants into these models will allow clinicians to more accurately determine which women are most likely to develop breast cancer. These steady and incremental improvements in models will need to undergo revalidation.

BRCA1 and BRCA2 mutations across race and ethnicity: distribution and clinical implications

PURPOSE OF REVIEW

To summarize evidence on the prevalence and spectrum of BRCA1 and BRCA2 BRCA1/2 mutations across racial and ethnic groups and discuss implications for clinical practice.

RECENT FINDINGS

The prevalence of BRCA1/2 mutations is comparable among breast cancer patients of African, Asian, white, and Hispanic descent: approximately 1-4% per gene. Among ovarian cancer patients in North America, BRCA1/2 mutations are present in 13-15%. Between racial/ethnic groups, there are important differences in the spectrum of BRCA1 compared with BRCA2 mutations, in BRCA1/2 variants of uncertain significance, and in the accuracy of clinical models that predict BRCA1/2 mutation carriage.

SUMMARY

Given the significant prevalence of BRCA1/2 mutations across race/ethnicity, there is a need to expand and customize genetic counseling, genetic testing, and follow-up care for members of all racial/ethnic groups.

The BRCAPRO 5.0 model is a useful tool in genetic counseling and clinical management of male breast cancer cases

No study has evaluated the performance of BRCA1/2 mutations prediction models in male breast cancer (MBC) series. Although rare, MBC deserves attention because male and female breast cancers share many characteristics, including the involvement of genetic predisposition factors such as BRCA1/BRCA2 mutations. Indeed, the occurrence of MBC is a commonly used criterion to select families for BRCA mutation testing. We evaluated the performance and clinical effectiveness of four different predictive models in a population-based series of 102 Italian MBC patients characterized for BRCA1/2 mutations. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were calculated for each risk model at the 10% threshold. The area under the ROC (AUC) curves and its corresponding asymptotic 95% CIs were calculated as a measure of the accuracy. In our study, the BRCAPRO version 5.0 had the highest combination of sensitivity, specificity, NPV and PPV for the combined probability and for the discrimination of BRCA2 mutations. In individuals with negative breast-ovarian cancer family history, BRCAPRO 5.0 reached a high discriminatory capacity (AUC=0.92) in predicting BRCA2 mutations and showed values of sensitivity, specificity, NPV and PPV of 0.5, 0.98, 0.97 and 0.67, respectively, for the combined probability. BRCAPRO version 5.0 can be particularly useful in dealing with non-familial MBC, a circumstance that often represents a challenging situation in genetic counseling.

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.

Hereditary breast and ovarian cancer: referral source for genetic assessment and communication regarding assessment with nongenetic clinicians in the community setting

PURPOSE

To examine referral source to cancer genetic services; communication of results of genetic evaluation to clinicians; role of clinicians in postcounseling management; and use of alternative information sources after cancer genetic risk assessment/counseling in the community setting.

METHODS

Retrospective telephone survey.

SETTING

A community/private hospital-based cancer genetic counseling service.

PATIENTS

Women, at least 21 years of age, who had undergone cancer genetic counseling with (1) at least a 10% predicted likelihood of carrying a BRCA1/2 mutation or (2) a documented BRCA1/2 mutation.

INTERVENTION

A 121-item telephone survey.

MAIN OUTCOME MEASURE

(1) initial referral source to cancer genetic services; (2) women's communication of results of cancer genetic assessment to primary and (nongenetic) specialist clinician(s); (3) education and support role played by subjects' physician(s); and (4) use of other hereditary breast and ovarian cancer (HBOC) information resources.

RESULTS

Of 225 women eligible for study, 69 (31%) completed the survey. Sixty-two percent were referred by their medical oncologist; 13% by their primary care physician, and fewer by their surgeon (6%) or gynecologist (4%). Results of the cancer genetic assessment were not shared with 19% of primary care clinicians, 26% of primary gynecologists, 12% of oncologists, and 36% of surgeons. Twenty-six percent of participants noted that their primary care clinician had not been involved in their HBOC-related, cancer prevention decisions, 16% had not included their gynecologist, 2% had not involved their oncologist, and 20% replied that their surgeon had not been involved in these decisions. Overall, clinicians were perceived as supportive when it came to a participants' information and decision support needs. One exception was that 21% of respondents reported the use by clinicians of medical terms, without definition. Over two-thirds had sought alternative "self-help" HBOC-related materials, most Internet based.

CONCLUSIONS

These results have implications for interdisciplinary communication and decision support for those with or at risk for HBOC, cared for in the community setting.

Development of a scoring system to screen for BRCA1/2 mutations

Selection for genetic testing for pathogenic mutations in BRCA1 and BRCA2 is an important area of healthcare. While testing costs for mutational analysis are falling, costs of tests in North America remain in excess of $3,000. Most countries state that there should be at least a 10-20% likelihood of detecting a mutation in BRCA1 or BRCA2 within a family before mutational analysis is performed. A number of computer-based models have been developed to assess this likelihood, and these continue to be improved to incorporate mutation frequencies, breast cancer incidence and tumour histology. However, these can be time-consuming and difficult to use in a busy clinic. The Manchester scoring system was developed in 2003, and we have continued to validate its use in Western populations. The scoring system discriminates well at both the 10 and 20% threshold for testing and compares very well with more complex computer-based models. However, it should not be used in its current form in founder populations or populations with low incidence of breast cancer, although a lower points threshold could be used to determine an appropriate cut off. The development of the Manchester score and its comparison with other models will be described in this chapter.

Perceptions of high-risk care and barriers to care among women at risk for hereditary breast and ovarian cancer following genetic counseling in the community setting

Data are limited regarding barriers to care among women, with or at risk for hereditary breast and ovarian cancer (HBOC), following genetic counseling in the community setting. Using a telephone survey, we retrospectively addressed perceptions of post-genetic counseling medical care and barriers to care among 69 at-risk women from the non-academic setting. Of these, all agreed that following cancer screening recommendations was better than not following them; none felt recommendations were too difficult to follow; all believed screening would help keep them healthy; 57% believed screening would prevent cancer. Twenty-five percent noted discomfort with breast imaging; 29% found ovarian cancer screening uncomfortable. Close to a quarter of participants reported difficulty deciding whether or not to undergo risk-reducing mastectomy while 10% noted difficulty deciding for or against bilateral salpingo-oophorectomy. There were no perceived major barriers to care, although 38% felt that screening reminders would be helpful, and 10% needed more help in following through with care. Overall, participants believed that they were benefiting from their post-genetic counseling medical care. This work identified HBOC-related support needs to include: informational resources that promote improved understanding of cancer risk and high-risk management; screening reminder systems; and decision support tools.

Hereditary breast cancer: from bench to bedside

PURPOSE OF REVIEW

The proportion of breast cancers directly attributable to determinant hereditary factors is estimated to be 5-10%. A number of recent findings with regard to hereditary breast cancer should affect the criteria and scope of routine genetic testing and, soon, breast cancer therapy.

RECENT FINDINGS

The number of genes causing genetic cancer has expanded, mostly with genes that encode proteins that function in the BRCA1/2 pathways. The risk level associated with some genes is still under investigation, but is high for specific mutations. Some mutant alleles occur frequently, some are rare. High-throughput technologies will progressively allow investigating all genes involved in genetic (breast) cancer risks in all individuals for whom this information could be relevant. This and the emerging novel treatment options specific for cancers in mutation carriers will oblige us to progressively drop all currently used selection criteria such as familial phenotype for genomic testing. A major challenge remains the effective penetration of this knowledge in the professional and lay community, the broad application and financing of this high-throughput technology, and the identification of as yet unknown breast cancer predisposition genes.

SUMMARY

The assessment of breast cancer predisposition genes, previously only an optional predictive genetic test, is growing in importance as it also becomes a therapeutic predictive test.

Cancer prevention and screening practices among women at risk for hereditary breast and ovarian cancer after genetic counseling in the community setting

The context is that there are limited data regarding the management of women at risk for hereditary breast and ovarian cancer (HBOC) after genetic counseling in the community setting. The objective of the study is to examine the cancer screening and prevention behaviors among women with diverse risk factors for HBOC, counseled through a non-academic genetic counseling service. This study was designed as a retrospective telephone survey. A community/private-hospital based cancer genetic counseling service was setting. The patients studied were women, at least 21 years of age, who had undergone cancer genetic counseling with: (1) a >or=10% predicted likelihood of carrying a BRCA1/2 mutation; (2) a documented BRCA1/2 mutation. A 121-item telephone survey was intervened. Main outcome measures are (1) reason for referral, (2) genetic testing/results, and (3) screening and prevention behaviors. Sixty-nine women participated (31% response rate). Forty-nine (71%) respondents had a history of breast cancer. Forty-three women (62%) reported undergoing BRCA1/2 testing, of these, seven (16%) had a deleterious mutation; 32 (74%) received negative results and four (9%) had "inconclusive" findings. Among the seven with documented mutations; five had a personal history of breast cancer; none had a history of ovarian cancer; all had undergone bilateral salpingo-oophorectomy (BSO), while five (71%) had undergone bilateral mastectomy. Among those 62 respondents without a documented mutation, pretest likelihood of a BRCA1/2 mutation (based on established models) was as follows: 10-29% likelihood in 38 (61%); 30-59% likelihood in 16 (26%); and >or=60% likelihood in eight (13%). Of these, 16 (26%) had undergone bilateral mastectomy for treatment and/or risk-reduction while 20 (32%) had undergone BSO for risk-reduction or for "other reasons". Almost all who had not undergone bilateral mastectomy were presenting for regular mammograms; fewer were undergoing regular breast MRI imaging. For those who had not undergone risk-reducing BSO; few were having CA-125 levels or transvaginal ultrasounds. Among those studied, the majority underwent genetic testing. A significant percentage elected to undergo risk-reducing mastectomy and BSO. Although prophylactic surgical decisions appeared to be largely influenced by BRCA mutation status, a number of women in the lower risk categories had undergone these procedures.

Life trajectories, genetic testing, and risk reduction decisions in 18-39 year old women at risk for hereditary breast and ovarian cancer

This qualitative study identified four life trajectories that influenced the decision in young women to have genetic testing for mutations in BRCA1/2 and subsequent risk reduction decisions after receiving a positive mutation result. Fifty nine women between the ages of 18-39 years were interviewed in this grounded theory study, 44 of those tested were found to have a mutation in either BRCA1 or BRCA2. Of those with a mutation, 23 had no history of cancer and 21 had a breast cancer diagnosis. Analysis of the 44 participants tested found that risk reducing decisions were related to the life trajectories that preceded genetic testing. These life trajectories included: 1) Long-standing awareness of breast cancer in the family, 2) Loss of one's mother to breast cancer at a young age, 3) Expression of concern by a health care provider, and 4) Personal diagnosis of breast cancer. Understanding possible influences behind decision making for genetic testing and risk reduction in young women may assist health care providers in offering age appropriate guidance and support.

Performance of prediction models for BRCA mutation carriage in three racial/ethnic groups: findings from the Northern California Breast Cancer Family Registry

PURPOSE

Patients with early-onset breast and/or ovarian cancer frequently wish to know if they inherited a mutation in one of the cancer susceptibility genes, BRCA1 or BRCA2. Accurate carrier prediction models are needed to target costly testing. Two widely used models, BRCAPRO and BOADICEA, were developed using data from non-Hispanic Whites (NHW), but their accuracies have not been evaluated in other racial/ethnic populations.

METHODS

We evaluated the BRCAPRO and BOADICEA models in a population-based series of African American, Hispanic, and NHW breast cancer patients tested for BRCA1 and BRCA2 mutations. We assessed model calibration by evaluating observed versus predicted mutations and attribute diagrams, and model discrimination using areas under the receiver operating characteristic curves.

RESULTS

Both models were well-calibrated within each racial/ethnic group, with some exceptions. BOADICEA overpredicted mutations in African Americans and older NHWs, and BRCAPRO underpredicted in Hispanics. In all racial/ethnic groups, the models overpredicted in cases whose personal and family histories indicated >80% probability of carriage. The two models showed similar discrimination in each racial/ethnic group, discriminating least well in Hispanics. For example, BRCAPRO's areas under the receiver operating characteristic curves were 83% (95% confidence interval, 63-93%) for NHWs, compared with 74% (59-85%) for African Americans and 58% (45-70%) for Hispanics.

CONCLUSIONS

The poor performance of the model for Hispanics may be due to model misspecification in this racial/ethnic group. However, it may also reflect racial/ethnic differences in the distributions of personal and family histories among breast cancer cases in the Northern California population.

Prediction of BRCA Mutations Using the BRCAPRO Model in Clinic-Based African American, Hispanic, and Other Minority Families in the United States

PURPOSE

BRCAPRO, a BRCA mutation carrier prediction model, was developed on the basis of studies in individuals of Ashkenazi Jewish and European ancestry. We evaluated the performance of the BRCAPRO model among clinic-based minority families. We also assessed the clinical utility of mutation status of probands (the first individual tested in a family) in the recommendation of BRCA mutation testing for other at-risk family members.

PATIENTS AND METHODS

A total of 292 minority families with at least one member who was tested for BRCA mutations were identified through the Breast Cancer Family Registry and the University of Chicago. Using the BRCAPRO model, the predicted likelihood of carrying BRCA mutations was generated. Area under the receiver operating characteristic curves (AUCs) were calculated.

RESULTS

There were 104 African American, 130 Hispanic, 37 Asian-American, and 21 other minority families. The AUC was 0.748 (95% CI, 0.672 to 0.823) for all minorities combined. There was a statistically nonsignificant trend for BRCAPRO to perform better in Hispanic families than in other minority families. After taking into account the mutation status of probands, BRCAPRO performance in additional tested family members was improved: the AUC increased from 0.760 to 0.902.

CONCLUSION

The findings support the use of BRCAPRO in pretest BRCA mutation prediction among minority families in clinical settings, but there is room for improvement in ethnic groups other than Hispanics. Knowledge of the mutation status of the proband provides additional predictive value, which may guide genetic counselors in recommending BRCA testing of additional relatives when a proband has tested negative.

Breast cancer susceptibility: current knowledge and implications for genetic counselling

Breast cancer is the most common malignancy in women in the Western world. Except for the high breast cancer risk in BRCA1 and BRCA2 mutation carriers as well as the risk for breast cancer in certain rare syndromes caused by mutations in TP53, STK11, PTEN, CDH1, NF1 or NBN, familial clustering of breast cancer remains largely unexplained. Despite significant efforts, BRCA3 could not be identified, but several reports have recently been published on genes involved in DNA repair and single nucleotide polymorphisms (SNPs) associated with an increased breast cancer risk. Although candidate gene approaches demonstrated moderately increased breast cancer risks for rare mutations in genes involved in DNA repair (ATM, CHEK2, BRIP1, PALB2 and RAD50), genome-wide association studies identified several SNPs as low-penetrance breast cancer susceptibility polymorphisms within genes as well as in chromosomal loci with no known genes (FGFR2, TOX3, LSP1, MAP3K1, TGFB1, 2q35 and 8q). Some of these low-penetrance breast cancer susceptibility polymorphisms also act as modifier genes in BRCA1/BRCA2 mutation carriers. This review not only outlines the recent key developments and potential clinical benefit for preventive management and therapy but also discusses the current limitations of genetic testing of variants associated with intermediate and low breast cancer risk.

Genetic testing for cancer susceptibility

Genetic testing for mutations in genes associated with an inherited predisposition to cancer is rapidly moving outside specialty genetic services and into mainstream health care. Surgeons, as front-line providers of cancer care, are uniquely positioned to identify those who may benefit from genetic testing and institute changes to their health care management based on those results. This article provides an overview of the critical elements of the process of genetic testing for cancer susceptibility.

Evaluating the performance of models for predicting the BRCA germline mutations in Han Chinese familial breast cancer patients

PURPOSE

Established models (Penn, Myraid and BRCApro) are useful of estimating the probability that a person has a BRCA mutation. But the value of these models in Chinese population is unclear. The aim of the study is to evaluate the performance of three models on the assisting in pre-test genetic risk counseling.

METHODS

Three risk assessment models, Penn II, Myriad and BRCApro, were applied to 212 familial breast cancer patients who had undergone BRCA1/2 mutation analysis. Sensitivity, specificity, positive and negative predictive values, likelihood ratios and area under the receiver operator characteristic (ROC) curve were calculated for each model.

RESULTS

Myriad showed a better ROC curve than BRCApro either for BRCA1 or BRCA1/2 combination mutation prediction, but BRCApro had a higher positive likelihood ratio when using 10% as the probability threshold. The performance of three models improved when they were evaluated in 66 patients from high risk families, presenting increased ROC and positive likelihood ratio. Especially that of BRCApro for BRCA2, the ROC was increased to 0.716 and its positive likelihood was 5.6.

CONCLUSION

Three models had the similar impact on the pre-test probability of BRCA mutation. But at a 10% cutoff point, BRCApro had the best BRCA mutation carrier prediction value. The performance of BRCApro for BRCA2 mutation prediction was improved when it was restricted in patients from high risk families.

Performance of BRCA1/2 mutation prediction models in Asian Americans

PURPOSE

There are established differences in breast cancer epidemiology between Asian and white individuals, but little is known about hereditary breast cancer in Asian populations. Although increasing numbers of Asian individuals are clinically tested for BRCA1/2 mutations, it is not known whether computer models that predict mutations work accurately in Asian individuals. We compared the performance in Asian and white individuals of two widely used BRCA1/2 mutation prediction models, BRCAPRO and Myriad II.

PATIENTS AND METHODS

We evaluated BRCAPRO and Myriad II in 200 Asian individuals and a matched control group of 200 white individuals who were tested for BRCA1/2 mutations at four cancer genetics clinics, by comparing numbers of observed versus predicted mutation carriers and by evaluating area under the receiver operating characteristic curve (AUC) for each model.

RESULTS

BRCAPRO and Myriad II accurately predicted the number of white BRCA1/2 mutation carriers (25 observed v 24 predicted by BRCAPRO; 25 predicted by Myriad II, P > or = .69), but underpredicted Asian carriers by two-fold (49 observed v 25 predicted by BRCAPRO; 26 predicted by Myriad II; P < or = 3 x 10(-7)). For BRCAPRO, this racial difference reflects substantial underprediction of Asian BRCA2 mutation carriers (26 observed v 4 predicted; P = 1 x 10(-30)); for Myriad II, separate mutation predictions were not available. For both models, AUCs were nonsignificantly lower in Asian than white individuals, suggesting less accurate discrimination between Asian carriers and noncarriers.

CONCLUSION

Both BRCAPRO and Myriad II underestimated the proportion of BRCA1/2 mutation carriers, and discriminated carriers from noncarriers less well, in Asian compared with white individuals.

The relative contribution of point mutations and genomic rearrangements in BRCA1 and BRCA2 in high-risk breast cancer families

The demand for BRCA1 and BRCA2 mutation screening is increasing as their identification will affect medical management. However, both the contribution of different mutation types in BRCA1 and BRCA2 and whom should be offered testing for large genomic rearrangements have not been well established in the U.S. high-risk population. We define the prevalence and spectrum of point mutations and genomic rearrangements in BRCA genes in a large U.S. high-risk clinic population of both non-Ashkenazi and Ashkenazi Jewish descent, using a sample set representative of the U.S. genetic testing population. Two hundred fifty-one probands ascertained through the University of Pennsylvania high-risk clinic, all with commercial testing for BRCA1 and BRCA2, with an estimated prevalence of BRCA mutation >or=10% using the Myriad II model and a DNA sample available, were studied. Individuals without deleterious point mutations were screened for genomic rearrangements in BRCA1 and BRCA2. In the 136 non-Ashkenazi Jewish probands, 36 (26%) BRCA point mutations and 8 (6%) genomic rearrangements (7 in BRCA1 and 1 in BRCA2) were identified. Forty-seven of the 115 (40%) Ashkenazi Jewish probands had point mutations; no genomic rearrangements were identified in the group without mutations. In the non-Ashkenazi Jewish probands, genomic rearrangements constituted 18% of all identified BRCA mutations; estimated mutation prevalence (Myriad II model) was not predictive of their presence. Whereas these findings should be confirmed in larger sample sets, our data suggest that genomic rearrangement testing be considered in all non-Ashkenazi Jewish women with an estimated mutation prevalence >or=10%.

Genetic counseling and testing for common hereditary breast cancer syndromes: a paper from the 2007 William Beaumont hospital symposium on molecular pathology

Throughout the past 15 years, the identification of several genes associated with hereditary breast cancer has fueled the growth of clinical genetic counseling and testing services. In addition, increased knowledge of the genetic and molecular pathways of the known hereditary breast cancer genes, as well as an increased understanding of the impact of testing on individuals has added to the ability to identify, manage, and provide psychosocial support for mutation carriers. This review provides an overview of the clinical features, cancer risks, causative genes, and management for hereditary breast and ovarian cancer syndrome, Cowden syndrome, and Li-Fraumeni syndrome. This article summarizes the genetic counseling process and genetic test result interpretation, including a review of the key elements involved in the provision of risk assessment and informed consent, as well as a review of the risks, benefits, and limitations of cancer susceptibility genetic testing.