Selected medical interventions in women with a deleterious BRCA mutation: a population-based study in British Columbia

"There should be one spot that you can go:" BRCA mutation carriers' perspectives on cancer risk management and a hereditary cancer registry

Individuals who carry BRCA1 or BRCA2 pathogenic variants are recommended to have extensive cancer prevention screening and risk-reducing surgeries. Uptake of these recommendations is variable, and there remains room for improvement in the risk management of BRCA carriers. This paper explores female BRCA carriers' experiences with the current model of care and their perspectives on (and interest in) an inherited cancer registry. Findings can inform the development of a dedicated high-risk screening and management program for these patients. Quantitative and qualitative data were gathered through a provincial descriptive survey and semi-structured qualitative interviews to assess BRCA carriers' opinions toward risk management services in the province of Newfoundland and Labrador (NL), Canada. Survey (n = 69) and interview data (n = 15) revealed continuity and coordination challenges with the current system of care of high-risk individuals. Respondents suggested an inherited cancer registry would help identify high-risk individuals and provide a centralized system of risk management for identified carriers. Respondents identified concerns about the privacy of their registry data, including who could access it. Findings suggest BRCA carriers see great value in an inherited cancer registry. Specifically, participants noted it could provide a centralized system to help improve the coordination of burdensome, life-long risk management. Important patient concerns about protecting their privacy and their health data confidentiality must be addressed in patient and public information and informed consent documents about a registry.

The Risk Function of Breast and Ovarian Cancers in the Avrami-Dobrzyński Cellular Phase-Transition Model

Specifying the role of genetic mutations in cancer development is crucial for effective screening or targeted treatments for people with hereditary cancer predispositions. Our goal here is to find the relationship between a number of cancerogenic mutations and the probability of cancer induction over the lifetime of cancer patients. We believe that the Avrami-Dobrzyński biophysical model can be used to describe this mechanism. Therefore, clinical data from breast and ovarian cancer patients were used to validate this model of cancer induction, which is based on a purely physical concept of the phase-transition process with an analogy to the neoplastic transformation. The obtained values of model parameters established using clinical data confirm the hypothesis that the carcinogenic process strongly follows fractal dynamics. We found that the model's theoretical prediction and population clinical data slightly differed for patients with the age below 30 years old, and that might point to the existence of an ancillary protection mechanism against cancer development. Additionally, we reveal that the existing clinical data predict breast or ovarian cancers onset two years earlier for patients with BRCA1/2 mutations.

Ovarian Cancer: From Precursor Lesion Identification to Population-Based Prevention Programs

Epithelial ovarian cancer (EOC) is a heterogeneous group of malignancies, including high-grade serous ovarian cancer (HGSC). HGSC is often diagnosed at advanced stages and is linked to TP53 variants. While BRCA variants elevate risk, most HGSC cases occur in individuals without known genetic variants, necessitating prevention strategies for people without known high-risk genetic variants. Effective prevention programs are also needed due to the lack of traditional screening options. An emerging primary prevention strategy is opportunistic salpingectomy, which involves removing fallopian tubes during another planned pelvic surgery. Opportunistic salpingectomy offers a safe and cost-effective preventative option that is gaining global adoption. With the publication of the first cohort study of patients who underwent salpingectomy, specifically for cancer prevention, attention has turned to broadening opportunities for salpingectomy in addition to more targeted approaches. Prevention opportunities are promising with increasing adoption of salpingectomy and the increased understanding of the etiology of the distinct histotypes of ovarian cancer. Yet, further research on targeted risk-reducing salpingectomy with thoughtful consideration of equity is necessary to reduce death and suffering from ovarian cancer.

Specialty Care and Counselling about Hereditary Cancer Risk Improves Adherence to Cancer Screening and Prevention in Newfoundland and Labrador Patients with BRCA1/2 Pathogenic Variants: A Population-Based Retrospective Cohort Study

Pathogenic variants (PVs) in BRCA1 and BRCA2 increase the lifetime risks of breast and ovarian cancer. Guidelines recommend breast screening (magnetic resonance imaging (MRI) and mammogram) or risk-reducing mastectomy (RRM) and salpingo-oophorectomy (RRSO). We sought to (1) characterize the population of BRCA1/2 PV carriers in Newfoundland and Labrador (NL), (2) evaluate risk-reducing interventions, and (3) identify factors influencing screening and prevention adherence. We conducted a retrospective study from a population-based provincial cohort of BRCA1/2 PV carriers. The eligibility criteria for risk-reducing interventions were defined for each case and patients were categorized based on their level of adherence with recommendations. Chi-squared and regression analyses were used to determine which factors influenced uptake and level of adherence. A total of 276 BRCA1/2 PV carriers were identified; 156 living NL biological females composed the study population. Unaffected females were younger at testing than those with a cancer diagnosis (44.4 years versus 51.7 years; p = 0.002). Categorized by eligibility, 61.0%, 61.6%, 39.0%, and 75.7% of patients underwent MRI, mammogram, RRM, and RRSO, respectively. Individuals with breast cancer were more likely to have RRM (64.7% versus 35.3%; p < 0.001), and those who attended a specialty hereditary cancer clinic were more likely to be adherent to recommendations (73.2% versus 13.4%; p < 0.001) and to undergo RRSO (84.1% versus 15.9%; p < 0.001). Nearly 40% of the female BRCA1/2 PV carriers were not receiving breast surveillance according to evidence-based recommendations. Cancer risk reduction and uptake of breast imaging and prophylactic surgeries are significantly higher in patients who receive dedicated specialty care. Organized hereditary cancer prevention programs will be a valuable component of Canadian healthcare systems and have the potential to reduce the burden of disease countrywide.

Treatment of women with BRCA mutation

The cumulative risk for breast and ovarian cancer is high in BRCA1 or BRCA2 mutation carriers. The lifetime risk of breast cancer by the age of 80 years is respectively up to 72% and 69% in BRCA1 and BRCA2 mutation carriers. The risk of ovarian cancer is higher (44%) in BRCA1 than in BRCA2 (17%) mutation carriers. Breast and ovarian cancers tend to arise earlier in BRCA1 mutation carriers. Breast cancers in BRCA1 mutation carriers are more frequently (up to 70%) triple negative while the majority (up to 80%) of breast cancers in BRCA2 mutation carriers are hormone sensitive. Many issues remain to be resolved. In daily practice we are often confronted with patients having BRCA mutations classified as variants of unknown significance, who do have breast cancer personally or have a strong family history of breast cancer. On the other hand, 30-40% of mutation carriers will not develop breast cancer. Moreover, it is very difficult to predict the age at which cancer will arise. In a multidisciplinary setting we need to offer BRCA and other mutation carriers a wide range of information, advice and support.

Cancer prevention in cancer predisposition syndromes: A protocol for testing the feasibility of building a hereditary cancer research registry and nurse navigator follow up model

Monogenic, high penetrance syndromes, conferring an increased risk of malignancies in multiple organs, are important contributors to the hereditary burden of cancer. Early detection and risk reduction strategies in patients with a cancer predisposition syndrome can save their lives. However, despite evidence supporting the benefits of early detection and risk reduction strategies, most Canadian jurisdictions have not implemented programmatic follow up of these patients. In our study site in the province of Newfoundland and Labrador (NL), Canada, there is no centralized, provincial registry of high-risk individuals. There is no continuity or coordination of care providing cancer genetics expertise and no process to ensure that patients are referred to the appropriate specialists or risk management interventions. This paper describes a study protocol to test the feasibility of obtaining and analyzing patient risk management data, specifically patients affected by hereditary breast ovarian cancer syndrome (HBOC; BRCA 1 and BRCA 2 genes) and Lynch syndrome (LS; MLH1, MSH2, MSH6, and PMS2 genes). Through a retrospective cohort study, we will describe these patients' adherence to risk management guidelines and test its relationship to health outcomes, including cancer incidence and stage. Through a qualitative interviews, we will determine the priorities and preferences of patients with any inherited cancer mutation for a follow up navigation model of risk management. Study data will inform a subsequent funding application focused on creating and evaluating a research registry and follow up nurse navigation model. It is not currently known what proportion of cancer mutation carriers are receiving care according to guidelines. Data collected in this study will provide clinical uptake and health outcome information so gaps in care can be identified. Data will also provide patient preference information to inform ongoing and planned research with cancer mutation carriers.

Examining interprofessional collaboration in oncogenetic service delivery models for hereditary cancers: a scoping review protocol

INTRODUCTION

In a context of limited genetic specialists, collaborative models have been proposed to ensure timely access to high quality oncogenetic services for individuals with inherited cancer susceptibility. Yet, extensive variability in the terminology used and lack of a clear understanding of how interprofessional collaboration is operationalised and evaluated currently constrains the development of a robust evidence base on the value of different approaches used to optimise access to these services. To fill in this knowledge gap, this scoping review aims to systematically unpack the nature and extent of collaboration proposed by these interventions, and synthesise the evidence available on their implementation, effectiveness and economic impact.

METHODS AND ANALYSIS

Following the Joanna Briggs Institute guidelines for scoping reviews, a comprehensive literature search will be conducted to identify peer-reviewed and grey literature on collaborative models used for adult patients with, or at increased risk of, hereditary breast, ovarian, colorectal and prostate cancers. An initial search was developed for Medline, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane and Web of Science on 13 June 2022 and will be complemented by searches in Google and relevant websites. Documents describing either the theory of change, planning, implementation and/or evaluation of these interventions will be considered for inclusion. Results will be summarised descriptively and used to compare relevant model characteristics and synthesise evidence available on their implementation, effectiveness and economic impact. This process is expected to guide the development of a definition and typology of collaborative models in oncogenetics that could help strengthen the knowledge base on these interventions. Moreover, because we will be mapping the existing evidence on collaborative models in oncogenetics, the proposed review will help us identify areas where additional research might be needed.

ETHICS AND DISSEMINATION

This research does not require ethics approval. Results from this review will be disseminated through peer-reviewed articles and conferences.

Bone health after RRBSO among BRCA1/2 mutation carriers: a population-based study

Objective

Examine the risks of fractures and osteoporosis after risk-reducing bilateral salpingo-oophorectomy (RRBSO) among women with BRCA1/2 mutations.

Methods

In this retrospective population-based study in British Columbia, Canada, between 1996 to 2017, we compared risks of osteoporosis and fractures among women with BRCA1/2 mutations who underwent RRBSO before the age of 50 (n=329) with two age-matched groups without known mutations: 1) women who underwent bilateral oophorectomy (BO) (n=3,290); 2) women with intact ovaries who had hysterectomy or salpingectomy (n=3,290). Secondary outcomes were: having dual-energy X-ray absorptiometry (DEXA) scan, and bisphosphonates use.

Results

The mean age at RRBSO was 42.4 years (range, 26–49) and the median follow-up for women with BRCA1/2 mutations was 6.9 years (range, 1.1–19.9). There was no increased hazard of fractures for women with BRCA1/2 mutations (adjusted hazard ratio [aHR]=0.80; 95% confidence interval [CI]=0.56–1.14 compared to women who had BO; aHR=1.02; 95% CI=0.65–1.61 compared to women with intact ovaries). Among women who had DEXA-scan, those with BRCA1/2 mutations had higher risk of osteoporosis (aHR=1.60; 95% CI=1.00–2.54 compared to women who had BO; aHR=2.49; 95% CI=1.44–4.28 compared to women with intact ovaries). Women with BRCA1/2 mutations were more likely to get DEXA-scan than either control groups, but only 46% of them were screened. Of the women with BRCA1/2 mutations diagnosed with osteoporosis, 36% received bisphosphonates.

Conclusion

Women with BRCA1/2 mutations had higher risk of osteoporosis after RRBSO, but were not at increased risk of fractures during our follow-up. Low rates of DEXA-scan and bisphosphonates use indicate we can improve prevention of bone loss.

BRCA mutations carriers had higher osteoporosis risk after risk-reducing bilateral salpingo-oophorectomy (RRBSO) than the groups without mutations. However, they were not at increased risk of fractures during the study period. Only 46% of BRCA mutations carriers were screened for bone loss after RRBSO. The rate of bisphosphonates use was also low.

Uptake of bilateral-risk-reducing-mastectomy: Prospective analysis of 7195 women at high-risk of breast cancer

Background

Bilateral-Risk-Reducing-Mastectomy-(BRRM) is well described in BRCA1/2 pathogenic variant carriers. However, little is known about the relative uptake, time trends or factors influencing uptake in those at increased breast cancer risk not known to be carriers. The aim of this study is to assess these factors in both groups.

Methods

BRRM uptake was assessed from entry to the Manchester Family History Clinic or from date of personal BRCA1/2 test. Follow up was censored at BRRM, breast cancer diagnosis, death or January 01, 2020. Cumulative incidence and cause specific and competing risk regression analyses were used to assess the significance of factors associated with BRRM.

Results

Of 7195 women at ≥25% lifetime breast cancer risk followed for up to 32 years, 451 (6.2%) underwent pre-symptomatic BRRM. Of those eligible in different risk groups the 20-year uptake of BRRM was 47.7%-(95%CI = 42.4–53.2%) in 479 BRCA1/2 carriers; 9.0% (95%CI = 7.26–11.24%) in 1261 women at ≥40% lifetime risk (non-BRCA), 4.8%-(95%CI = 3.98–5.73%) in 3561 women at 30–39% risk and 2.9%-(95%CI = 2.09–4.09%) in 1783 women at 25–29% lifetime risk. In cause-specific Cox regression analysis death of a sister with breast cancer<50 (OR = 2.4; 95%CI = 1.7–3.4), mother<60 (OR = 1.9; 95%CI = 1.5–2.3), having children (OR = 1.4; 95%CI = 1.1–1.8), breast biopsy (OR = 1.4; 95%CI = 1.0–1.8) were all independently associated with BRRM uptake, while being older at assessment was less likely to be associated with BRRM (>50; OR = 0.26,95%CI = 0.17–0.41). Uptake continued to rise to 20 years from initial risk assessment.

Conclusion

We have identified several additional factors that correlate with BRRM uptake and demonstrate continued increases over time. These factors will help to tailor counselling and support for women.

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BRRM continues even 20 years post original breast cancer risk assessment.

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Potential triggers include death of mother/sister, children and a breast biopsy.

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Uptake is clearly informed by lifetime risk of BC and higher in younger the women.

Risk of cardiovascular disease among women carrying BRCA mutations after risk-reducing bilateral salpingo-oophorectomy: A population-based study

OBJECTIVE

Examine the risk of cardiovascular disease (CVD) following risk reducing bilateral salpingo-oophorectomy (RRBSO) among women with BRCA mutations.

METHODS

In this retrospective population-based study in British Columbia, Canada, between 1996 and 2017, we compared the risk of CVD among women with known BRCA mutations who underwent RRBSO before the age of 50 (n = 360) with two groups of age-matched women without known BRCA mutations: 1) women who underwent bilateral oophorectomy (BO) for benign conditions (n = 3600); and, 2) women with intact ovaries who had hysterectomy or salpingectomy (n = 3600). Our primary outcome was CVD (a composite (any of) myocardial infarction, heart failure, and/or cerebrovascular disease). Secondary outcomes included a diagnostic code for predisposing conditions (hypertension, dyslipidemia, and/or diabetes mellitus), and use of cardioprotective medications (statins and/or beta-blockers).

RESULTS

We report no significant increased risk for CVD between women with BRCA mutations and women who underwent BO (aHR = 1.08, 95%CI: 0.72-1.62), but women with BRCA mutations were less likely to be diagnosed with predisposing conditions (aHR = 0.69, 95%CI: 0.55-0.85). Compared to women without BRCA mutations with intact ovaries who underwent hysterectomy or salpingectomy, women with BRCA mutations had significantly increased risk for CVD (aHR = 1.82, 95%CI: 1.18-2.79) and were less likely to be diagnosed with predisposing conditions (aHR = 0.78, 95%CI: 0.62-0.97) and to fill cardioprotective medications (aHR = 0.88, 95%CI: 0.64-1.22).

CONCLUSION

Our results suggest an opportunity for improved prevention of CVD in women with BRCA mutations after prophylactic oophorectomy. Despite the observed lower prevalence of predisposing conditions for CVD and lesser use of cardioprotective medications, this population did not have a lower rate of CVD.

A Collaborative Model to Implement Flexible, Accessible and Efficient Oncogenetic Services for Hereditary Breast and Ovarian Cancer: The C-MOnGene Study

Simple Summary

We recently developed an oncogenetic model to overcome the unprecedented demand for genetic counseling and testing for hereditary breast and ovarian cancer. Quality and performance indicators showed that the implementation of this model improved access to genetic counseling and minimized delays for genetic tests for patients, who reported to be overwhelmingly satisfied with the process. However, it remains unknown whether this model is robust and sustainable or requires adjustments. In addition, whether the model could be deployed elsewhere remains also to be elucidated. The C-MOnGene study was therefore designed to gain an in-depth understanding of the context in which the model was developed and implemented, and document the lessons that can be learned to optimize oncogenetic services delivery in other settings.

Abstract

Medical genetic services are facing an unprecedented demand for counseling and testing for hereditary breast and ovarian cancer (HBOC) in a context of limited resources. To help resolve this issue, a collaborative oncogenetic model was recently developed and implemented at the CHU de Québec-Université Laval; Quebec; Canada. Here, we present the protocol of the C-MOnGene (Collaborative Model in OncoGenetics) study, funded to examine the context in which the model was implemented and document the lessons that can be learned to optimize the delivery of oncogenetic services. Within three years of implementation, the model allowed researchers to double the annual number of patients seen in genetic counseling. The average number of days between genetic counseling and disclosure of test results significantly decreased. Group counseling sessions improved participants’ understanding of breast cancer risk and increased knowledge of breast cancer and genetics and a large majority of them reported to be overwhelmingly satisfied with the process. These quality and performance indicators suggest this oncogenetic model offers a flexible, patient-centered and efficient genetic counseling and testing for HBOC. By identifying the critical facilitating factors and barriers, our study will provide an evidence base for organizations interested in transitioning to an oncogenetic model integrated into oncology care; including teams that are not specialized but are trained in genetics.