Use of the BOADICEA Web Application in clinical practice: appraisals by clinicians from various countries

Genetic clinicians' confidence in BOADICEA comprehensive breast cancer risk estimates and counselees' psychosocial outcomes: a prospective study

Counseling for familial breast cancer focuses on communicating the gene test result (GENE) to counselees, but risk prediction models have become more complex by including non‐genetic risk factors (NGRF) and polygenic risk scores (PRS). We examined genetic clinicians' confidence in counseling and counselees' psychosocial outcomes, using the BOADICEA risk prediction tool with different categories of risk factors as input. A prospective observational study in Dutch, French and German genetic clinics was performed including 22 clinicians, and 406 of 460 (88.3%) eligible cancer‐unaffected women at high breast cancer risk assessed at pre‐test and 350 (76.1%) at post‐test. We performed multilevel analyses accounting for the clinician, and counselees' characteristics. Overall, risk estimates category by GENE versus GENE+ NGRF, or GENE+NGRF+PRS differed in 11% and 25% of counselees, respectively. In multilevel analyses, clinicians felt less confident in counseling when the full model provided lower breast cancer risks than GENE (i.e., in 8% of cases). Older counselees expressed higher breast cancer risk perception and worries about the hereditary predisposition when the full model provided higher breast cancer risks than GENE only. Genetic clinicians appear confident with breast cancer risk comprehensive models, which seem only to affect perceptions of older counselees.

Survey on Physicians' Knowledge and Training Needs in Genetic Counseling in Germany

Background

In recent years, germline testing of women with a risk of developing breast and ovarian cancer has increased rapidly. This is due to lower costs for new high-throughput sequencing technologies and the manifold preventive and therapeutic options for germline mutation carriers. The growing demand for genetic counseling meets a shortfall of counselors and illustrates the need to involve the treating clinicians in the genetic testing process. This survey was undertaken to assess their state of knowledge and training needs in the field of genetic counseling and testing.

Methods

A cross-sectional survey within the European Bridges Study (Breast Cancer Risk after Diagnostic Gene Sequencing) was conducted among physician members (n = 111) of the German Cancer Society who were primarily gynecologists. It was designed to examine their experience in genetic counseling and testing.

Results

Overall, the study revealed a need for training in risk communication and clinical recommendations for persons at risk. One-third of respondents communicated only relative disease risks (31.5%) instead of absolute disease risks in manageable time spans. Moreover, almost one-third of the respondents (31.2%) communicated bilateral and contralateral risk-reducing mastectomy as an option for healthy women and unilateral-diseased breast cancer patients without mutations in high-risk genes (e.g. BRCA1 or BRCA2). Most respondents expressed training needs in the field of risk assessment models, the clinical interpretation of genetic test results, and the decision-making process.

Conclusion

The survey demonstrates a gap of genetic and risk literacy in a relevant proportion of physicians and the need for appropriate training concepts.

Utilization of breast cancer risk prediction models by cancer genetic counselors in clinical practice predominantly in the United States

Risk assessment in cancer genetic counseling is essential in identifying individuals at high risk for developing breast cancer to recommend appropriate screening and management options. Historically, many breast cancer risk prediction models were developed to calculate an individual's risk to develop breast cancer or to carry a pathogenic variant in the BRCA1 or BRCA2 genes. However, how or when genetic counselors use these models in clinical settings is currently unknown. We explored genetic counselors' breast cancer risk model usage patterns including frequency of use, reasons for using or not using models, and change in usage since the adoption of multi-gene panel testing. An online survey was developed and sent to members of the National Society of Genetic Counselors; board-certified genetic counselors whose practice included cancer genetic counseling were eligible to participate in the study. The response rate was estimated at 23% (243/1,058), and respondents were predominantly working in the United States. The results showed that 93% of all respondents use at least one breast cancer risk prediction model in their clinical practice. Among the six risk models selected for the study, the Tyrer-Cuzick (IBIS) model was used most frequently (95%), and the BOADICEA model was used least (40%). Determining increased or decreased surveillance and breast MRI eligibility were the two most common reasons for most model usage, while time consumption and difficulty in navigation were the two most common reasons for not using models. This study provides insight into perceived benefits and limitations of risk models in clinical use in the United States, which may be useful information for software developers, genetic counseling program curriculum developers, and currently practicing cancer genetic counselors.

Population frequencies of pathogenic alleles of BRCA1 and BRCA2: analysis of 173 Danish breast cancer pedigrees using the BOADICEA model

The Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) calculates the probability that a woman carries a pathogenic variant in BRCA1 or BRCA2 based on her pedigree and the population frequencies of pathogenic alleles of BRCA1 (0.0006394) and BRCA2 (0.00102) in the United Kingdom (UK). BOADICEA allows the clinician to define the population frequencies of pathogenic alleles of BRCA1 and BRCA2 for other populations but only includes preset values for the Ashkenazy Jewish and Icelandic populations. Among 173 early-onset breast cancer pedigrees in Denmark, BOADICEA discriminated well between carriers and non-carriers of pathogenic variants (area under the receiver operating characteristics curve: 0.81; 95% CI 0.74-0.86) but underestimated the frequency of carriers of pathogenic variants in BRCA1 or BRCA2 as measured by the observed-to-expected ratio (O/E 1.83; 95% CI 1.18-2.84). This reflects findings from older studies of BOADICEA in UK, German, Italian, and Chinese populations, all accounting for the different calibration for different carrier probabilities. To improve the performance of BOADICEA for non-UK populations, we developed a method to derive population frequencies of pathogenic alleles of BRCA1 and BRCA2. Compared to the UK population frequencies, we estimated the Danish population frequencies of pathogenic alleles to be higher for BRCA1 (0.0015; 95% CI 0.00064-0.0034) and lower for BRCA2 (0.00052; 95% CI 0.00018-0.0017) after adjusting for the different calibration of BOADICEA for different carrier probabilities. Incorporating additional population frequencies into BOADICEA could improve its performance for non-UK populations.

[What attitude to women at high risk of breast cancer?]

In France, breast cancer is the most common cancer among women and the leading cause of cancer deaths. Identifying women with a "high" or "very high" breast cancer risk, according the terminology of the Haute Autorité de Santé 2014 guidelines, is essential to offer them special cares in term of screening and prevention. Women genetically predisposed have a very high risk of breast cancer. During the oncogenetic specialist consultation, familial and personal history of cancer is taken into account to evaluate the risk of hereditary Breast/Ovarian syndrome and thus the need of a genetic screening. In 2017, a list of 13 genes involved in hereditary ovarian or breast cancer has been established in France (Genetic and Cancer Group - Unicancer). Women carrying a BRCA1, BRCA2, PALB2, TP53, CDH1, PTEN mutation have a higher risk of breast cancer and are considered as "high risk". Therefore, medical breast surveillance similar to carriers of BRCA1/BRCA2 mutation is recommended for these patients (INCa guidelines 2017). However a mutation in one of those genes is only identified in approximatively 10 % of the screened families. The oncogenetic specialist's assessment distinguishes families in which women remain at a "high" risk of breast cancer (HAS 2014 for screening) from those where women have a "very high" risk (INCa guidelines 2017 for screening and prevention).

Clinicians' use of breast cancer risk assessment tools according to their perceived importance of breast cancer risk factors: an international survey

The BOADICEA breast cancer (BC) risk assessment model and its associated Web Application v3 (BWA) tool are being extended to incorporate additional genetic and non-genetic BC risk factors. From an online survey through the BOADICEA website and UK, Dutch, French and Swedish national genetic societies, we explored the relationships between the usage frequencies of the BWA and six other common BC risk assessment tools and respondents' perceived importance of BC risk factors. Respondents (N = 443) varied in age, country and clinical seniority but comprised mainly genetics health professionals (82%) and BWA users (93%). Oncology professionals perceived reproductive, hormonal (exogenous) and lifestyle BC risk factors as more important in BC risk assessment compared to genetics professionals (p values < 0.05 to 0.0001). BWA was used more frequently by respondents who gave high weight to breast tumour pathology and low weight to personal BC history as BC risk factors. BWA use was positively related to the weight given to hormonal BC risk factors. The importance attributed to lifestyle and BMI BC risk factors was not associated with the use of BWA or any of the other tools. Next version of the BWA encompassing additional BC risk factors will facilitate more comprehensive BC risk assessment in genetics and oncology practice.