Cancer risk management among female BRCA1/2, PALB2, CHEK2, and ATM carriers

Effects of breast size on breast reconstruction in BRCA mutation carriers and genetic high-risk patients after bilateral mastectomy

BACKGROUND

Women with genetic susceptibility to breast cancer and indication for bilateral mastectomy are more likely to undergo implant-based breast reconstruction (IBR) than autologous breast reconstruction (ABR), while the impact of breast size in this context is insufficiently studied. Ultimately, comparative data on IBR and different types of ABR beyond abdominal-based flaps in genetic susceptible women remain scarce. This study aimed to evaluate factors associated with ABR and the effects of breast size for bilateral reconstruction in high-risk patients.

METHODS

A 2.5-year retrospective study was conducted at a single institution including all genetic high-risk patients who underwent bilateral mastectomy and breast reconstruction. Patients were stratified into two groups based on the weight of the mastectomy specimen. Small breast sizes were defined by mastectomy weights below 400 g, and medium-to-large breasts by specimen weights above 400 g. Binary logistic regression was performed to assess variables predictive of ABR, followed by an analysis of the breast size-dependent reconstructive algorithm and its complication rates.

RESULTS

We included 71 patients with BRCA1/2 (97.2%), CHEK2 (1.4%), and PALB2 (1.4%) mutations in the study. Among those, 68 IBRs and 74 ABRs were performed. Increasing age, immediate reconstruction, and medium-to-large breast size were predictive of ABR compared to IBR (p < 0.05). In the IBR-group, the majority of preoperative small breasts received subpectoral implant placements (81.0%, p = 0.003), while prepectoral implants (53.9%, p = 0.003) were preferred in medium-to-large breasts. In the ABR-group, the deep inferior epigastric artery (DIEP) flap was the choice in the vast majority of cases with larger breasts (86.4%, p < 0.001), whereas the transverse myocutaneous gracilis (TMG) flap (46.7%, p < 0.001) and superior gluteal artery perforator (SGAP) flap (20.0%, p = 0.002) were only considered in small-breasted patients. No elevated incidence of overall complications with increasing breast size was found. However, patients with larger breasts were more likely to undergo elective revisions after IBR (p < 0.001) as well as ABR (p = 0.013). With regard to two-stage tissue expander reconstructions, high-risk patients with larger breast size revealed increased explantations (p = 0.043) and expander-related revisions requiring additional surgery (p = 0.003). The latter was significantly reduced by reduction mammoplasty prior to expander placement (p = 0.036).

CONCLUSIONS

The preoperative breast size of gene mutation carriers influences the postmastectomy reconstructive choice. TMG and SGAP flaps are suitable options for bilateral reconstruction of genetic susceptible patients with small breasts, while DIEP flaps are preferred in larger breast sizes. With increasing breast size an elevated risk for elective revisions after either IBR or ABR need to be considered. Women with medium-to-large breasts exhibit increased morbidity related to expansion and genetic high-risk patients may benefit from prior reduction mammoplasty.

Chemotherapy receipt in affected BRCA1/2 and PALB2 carriers with operable breast cancer: the impact of early detection and pre-diagnostic awareness on clinical outcomes and treatment

PURPOSE

While enhanced breast screening of germline pathogenic variant (GPV) carriers results in earlier stage at diagnosis, the impact of tumour biology and GPV on chemotherapy receipt in early-stage disease remains understudied.

METHODS

We retrospectively reviewed treatment administered following a first diagnosis of BRCA1/2- and PALB2-associated breast cancer between 2002 and 2022. Chemotherapy receipt was compared according to tumor size, biologic subtype, and GPV. Subgroup analyses were performed in women with T1N0 disease and in those with pre-diagnostic awareness of their GPV.

RESULTS

Overall, 309 affected BRCA1/2 and PALB2 carriers with a median age of 43 years at breast cancer diagnosis (range, 19-80 years) were included; 160 (51.8%) BRCA1, 130 (42.1%) BRCA2, and 19 (6.1%) PALB2 carriers. Chemotherapy was administered in 70.9% of index breast cancer cases and was significantly associated with younger age, tumor size, histologic grade, nodal status, and biologic subtype (all p < 0.05). Chemotherapy receipt was 80.6% in BRCA1-associated breast cancers compared to 56.9% in BRCA2 and 84.2% in PALB2 associated breast cancers (p < 0.001). In subgroup analysis of early stage, T1N0 disease, chemotherapy was administered in 78.9% BRCA1 and 59.5% BRCA2/PALB2 patients (p = 0.04). Pre-diagnostic awareness of a GPV in BRCA1/2 or PALB2 was associated with smaller invasive tumors (%T1, 50% vs. 32.9%; p = 0.002) and node-negative invasive disease (87.1% vs. 72.2%), as well as a reduced likelihood of chemotherapy (59.7% vs. 74.3%, p = 0.02).

CONCLUSION

Chemotherapy receipt is high in BRCA1/2 and PALB2-associated breast cancers including in early stage, node-negative disease. Pre-diagnostic awareness is associated with a lower likelihood of requiring chemotherapy for a breast cancer diagnosis.

Causative Genes of Homologous Recombination Deficiency (HRD)-Related Breast Cancer and Specific Strategies at Present

Recently, homologous recombination deficiency (HRD) has become a new target for hereditary cancers. Molecular-based approaches for hereditary cancers in the clinical setting have been reviewed. In particular, the efficacy of the PARP inhibitor has been considered by several clinical trials for various kinds of hereditary cancers. This indicates that the PARP inhibitor can be effective for any kind of BRCA mutated cancers, regardless of the organ-specific cancer. Homologous recombination deficiency (HRD) has become a new target for hereditary cancers, indicating the necessity to confirm the status of HRD-related genes. ARID1A, ATM, ATRX, PALB2, BARD1, RAD51C and CHEK2 are known as HRD-related genes for which simultaneous examination as part of panel testing is more suitable. Both surgical and medical oncologists should learn the basis of genetics including HRD. An understanding of the basic mechanism of homologous repair recombination (HRR) in BRCA-related breast cancer is mandatory for all surgical or medical oncologists because PARP inhibitors may be effective for these cancers and a specific strategy of screening for non-cancers exists. The clinical behavior of each gene should be clarified based on a large-scale database in the future, or, in other words, on real-world data. Firstly, HRD-related genes should be examined when the hereditary nature of a cancer is placed in doubt after an examination of the relevant family history. Alternatively, HRD score examination is a solution by which to identify HRD-related genes at the first step. If lifetime risk is estimated at over 20%, an annual breast MRI is necessary for high-risk screening. However, there are limited data to show its benefit compared with BRCA. Therefore, a large-scale database, including clinical information and a long-term follow-up should be established, after which a periodical assessment is mandatory. The clinical behavior of each gene should be clarified based on a large-scale database, or, in other words, real-world data.

The Impact of a Breast Cancer Risk Assessment on the Decision for Gender-Affirming Chest Masculinization Surgery in Transgender and Gender-Diverse Individuals: A Pilot Single-Arm Educational Intervention Trial

BACKGROUND

Persons assigned female or intersex at birth and identify as transgender and/or gender-diverse (TGD) may undergo gender-affirming chest masculinization surgery (GACMS); however, GACMS is not considered equivalent to risk-reducing mastectomies (RRM). This study aimed to estimate the prevalence of elevated breast cancer (BC) risk in TGD persons, compare self-perceived versus calculated risk, and determine how risk impacts the decision for GACMS versus RRM.

METHODS

A prospective single-arm pilot educational intervention trial was conducted in individuals assigned female or intersex at birth, age ≥ 18 years, considering GACMS, without a BC history or a known pathogenic variant. BC risk was calculated using the Tyrer-Cuzik (all) and Gail models (age ≥ 35 years). Elevated risk was defined as ≥ 17%.

RESULTS

Twenty-five (N = 25) participants were enrolled with a median age of 24.0 years (interquartile range, IQR 20.0-30.0 years). All were assigned female sex at birth, most (84%) were Non-Hispanic (NH)-White, 48% identified as transgender and 40% as nonbinary, and 52% had a first- and/or second-degree family member with BC. Thirteen (52%) had elevated risk (prevalence 95% confidence interval (CI) 31.3-72.2%). Median self-perceived risk was 12% versus 17.5% calculated risk (p = 0.60). Of the 13 with elevated risk, 5 (38.5%) underwent/are scheduled to undergo GACMS, 3 (23%) of whom underwent/are undergoing RRM.

CONCLUSIONS

Over half of the cohort had elevated risk, and most of those who moved forward with surgery chose to undergo RRM. A BC risk assessment should be performed for TGD persons considering GACMS. Future work is needed to examine BC incidence and collect patient-reported outcomes. Trial Registration Number ClinicalTrials.gov (No. NCT06239766).

Comparing Cancer Risk Management between Females with Truncating CHEK2 1100delC versus Missense CHEK2 I157T Variants

Breast cancer (BC) risks imparted by CHEK2 c.1100delC ("1100delC") germline pathogenic/likely pathogenic variant (GPV) are 20-30%, compared to CHEK2 c.470T>C ("I157T") GPV with <20%, leading to different breast screening recommendations through MRI. We compared cancer risk management (CRM) across these two GPVs. Study participants were adult females with an 1100delC or I157T GPV drawn from the Inherited Cancer Registry (ICARE) across the United States. Cancer history, clinical characteristics, and CRM were compared using chi-squared tests, t-tests, and logistic regression. Of 150 CHEK2 carriers, 40.7% had BC, with a mean age of 50. Comparing 1100delC and I157T GPVs, there were no differences in rates of (1) breast MRI among those with (65.2% versus 55.6% of 23 and 9; p = 0.612) and without (44.0% versus 44.8% of 50 and 29; p = 0.943) BC; (2) risk-reducing mastectomy among those with (50% versus 38.9% of 46 and 15; p = 0.501) and without (13.8% versus 6.5% of 58 and 31; p = 0.296) BC; and (3) risk-reducing salpingo-oophorectomy among those with (24.2% versus 22.2% of 45 and 18; p = 0.852) and without (17.5% versus 16.7% of 57 and 30; p = 0.918) BC. The results suggest over-screening with breast MRI among CHEK2 I157T GPV carriers and possible overuse of risk-reducing surgeries among CHEK2 carriers.

Uptake of screening and risk-reducing recommendations among women with hereditary breast and ovarian cancer syndrome due to pathogenic BRCA1/2 variants evaluated at a large urban comprehensive cancer center

PURPOSE

Carriers of pathogenic variants in BRCA1/2 have an elevated lifetime cancer risk warranting high-risk screening and risk-reducing procedures for early detection and prevention. We report on prevention practices among women with pathogenic BRCA variants in order to document follow through with NCCN recommendations and to identify barriers to guideline-recommended care.

METHODS

Our cohort included women who had genetic testing through a cancer genetic clinic and completed a 54-item questionnaire to measure socio-demographics, medical history, rates of cancer screening and risk-reducing surgery, disclosure of test results, and cancer worry. Outcomes included rates of completion of risk-reducing salpingo-oophorectomy (RRSO), risk-reducing mastectomy (RRM), and NCCN risk-reducing and age-dependent screening guidelines (version 3.2019). Multivariable logistic regression analyses were used to evaluate potential predictors of these outcomes.

RESULTS

Of 129 evaluable women with pathogenic BRCA1/2 variants, 95 (74%) underwent RRSO and 77 (60%) had RRM, respectively, and 107 (83%) were considered adherent to NCCN guidelines. Women with a history of breast or ovarian cancer were more likely to have RRM (OR = 4.38; 95% CI 1.80-11.51; p = 0.002). Increasing age was associated with an increased likelihood of RRSO (OR = 1.05; 95% CI 1.01-1.09; p = 0.019) and decreased likelihood for RRM (OR = 0.95; 95% CI 0.92-0.99; p = 0.013). Women who had RRM were 3 times more likely to undergo RRSO (OR = 2.81; 95% CI 1.10-7.44; p = 0.025). Women who had genetic testing after June 2013 were less likely to have RRM than those tested before June 2013 (OR = 0.42; 95% CI 0.18-0.95; p = 0.040. None of the other measured factors were associated with rates of RRSO, RRM or follow through with NCCN recommendations. There was near universal (127/129) reported disclosure of genetic test results to family members, resulting in the discovery of a median of 1 relative with a pathogenic variant (range = 0-8).

CONCLUSION

An evaluation of follow up practice in a cohort of women with pathogenic variants in BRCA1/2 revealed high rates of reported completion of screening and surgical risk-reducing recommendations. Educational efforts should continue to reinforce the importance of follow-through with guideline recommended care among this high-risk group.

Evaluating the utility of multi-gene, multi-disease population-based panel testing accounting for uncertainty in penetrance estimates

Panel germline testing allows for the efficient detection of deleterious variants for multiple conditions, but the benefits and harms of identifying these variants are not always well understood. We present a multi-gene, multi-disease aggregate utility formula that allows the user to consider adding or removing each gene in a panel based on variant frequency, estimated penetrances, and subjective disutilities for testing positive but not developing the disease and testing negative but developing the disease. We provide credible intervals for utility that reflect uncertainty in penetrance estimates. Rare, highly penetrant deleterious variants tend to contribute positive net utilities for a wide variety of user-specified disutilities, even when accounting for parameter estimation uncertainty. However, the clinical utility of deleterious variants with moderate, uncertain penetrance depends more on assumed disutilities. The decision to include a gene on a panel depends on variant frequency, penetrance, and subjective utilities and should account for uncertainties around these factors.

Implementation Mapping for Managing Patients at High Risk for Hereditary Cancer

INTRODUCTION

Currently, no standard workflow exists for managing patients with pathogenic variants that put them at higher risk for hereditary cancers. Therefore, follow-up care for individuals with pathogenic variants is logistically challenging and results in poor guideline adherence. To address this challenge, authors created clinical management strategies for individuals identified at high risk for hereditary cancers.

METHODS

An implementation mapping approach was used to develop and evaluate the establishment of a Hereditary Cancer Clinic at the Medical University of South Carolina throughout in 2022. This approach consisted of 5 steps: conduct a needs assessment, identify objectives, select implementation strategies, produce implementation protocols, and develop an evaluation plan. The needs assessment consisted of qualitative interviews with patients (n=11), specialists (n=9), and members of the implementation team (n=4). Interviews were coded using the Consolidated Framework for Implementation Research to identify barriers and facilitators to establishment of the Hereditary Cancer Clinic. Objectives were identified, and then the team selected implementation strategies and produced implementation protocols to address concerns identified during the needs assessment. Authors conducted a second round of patient interviews to assess patient education materials.

RESULTS

The research team developed a long-term evaluation plan to guide future assessment of implementation, service, and clinical/patient outcomes.

CONCLUSIONS

This approach provides the opportunity for real-time enhancements and impact, with strategies for care specialists, patients, and implementation teams. Findings support ongoing efforts to improve patient management and outcomes while providing an opportunity for long-term evaluation of implementation strategies and guidelines for patients at high risk for hereditary cancers.

Risk-management decision-making data from a community-based sample of racially diverse women at high risk of breast cancer: rationale, methods, and sample characteristics of the Daughter Sister Mother Project survey

BACKGROUND

To understand the dynamics that limit use of risk-management options by women at high risk of breast cancer, there is a critical need for research that focuses on patient perspectives. Prior research has left important gaps: exclusion of high-risk women not in risk-related clinical care, exclusion of non-white populations, and lack of attention to the decision-making processes that underlie risk-management choices. Our objective was to create a more inclusive dataset to facilitate research to address disparities related to decision making for breast cancer risk management.

METHODS

The Daughter Sister Mother Project survey collects comprehensive information about the experiences of women at high risk of breast cancer. We collected novel measures of feelings about and reactions to cancer screenings; knowledge, barriers, and facilitators of risk-management options; beliefs related to cancer risk and risk management; and involvement with loved ones who had cancer. Eligible individuals were non-Hispanic white and non-Hispanic Black adult women who self-identified as having high risk of breast cancer and had no personal history of cancer. Between October 2018 and August 2019, 1053 respondents completed the online survey. Of these, 717 were confirmed through risk prediction modeling to have a lifetime breast cancer risk of ≥ 20%. Sociodemographic characteristics of this sample were compared to those of nationally representative samples of the US population: the 2019 Health Information National Trends Survey and the Pew Research Center report: Jewish Americans in 2020.

RESULTS

The sample of 717 women at objectively high risk of breast cancer was largely (95%) recruited from non-clinical sources. Of these respondents, only 31% had seen a genetic counselor, 34% had had genetic testing specific to breast cancer risk, and 35% had seen at least one breast or cancer care specialist. The sample includes 35% Black respondents and 8% with Ashkenazi Jewish ancestry. Although encompassing a substantial range of ages, incomes, and education levels, respondents are overall somewhat younger, higher-income, and more educated than the US population as a whole.

CONCLUSIONS

The DSM dataset offers comprehensive data from a community-based, diverse sample of women at high risk of breast cancer. The dataset includes substantial proportions of Black and Ashkenazi Jewish women and women who are not already in clinical care related to their breast cancer risk. This sample will facilitate future studies of risk-management behaviors among women who are and are not receiving high-risk care, and of variations in risk-management experiences across race and ethnicity.

Racial Disparities in Accessing Care along the Continuum of Cancer Genetic Service Delivery

BACKGROUND

Public health calls to ensure equity in genomics and precision medicine necessitate a closer examination of how these efforts might differentially affect access to genetic services across demographic subgroups. This study set out to examine racial/ethnic disparities along the cancer genetic service delivery continuum.

METHODS

Retrospective data are drawn from 15 clinical sites across 6 U.S. States. Individuals who screened at-risk for hereditary cancer were: (i) referred/scheduled to see a genetic counselor (referral workflow), or (ii) offered genetic testing at the point-of-care (POC testing workflow). Logistic regression analyses evaluated the associations between race/ethnicity and several outcomes including appointment scheduling, genetic counseling, and genetic testing, controlling for demographics, clinical factors, and county-level covariates.

RESULTS

A total of 14,527 patients were identified at-risk. Genetic testing uptake was significantly higher at POC sites than referral sites (34% POC vs. 11% referral, P < 0.001). Race/ethnicity was significantly associated with testing uptake among all sites, with non-Hispanic Blacks having lower odds of testing compared with non-Hispanic Whites [aOR = 0.84; 95% confidence interval (CI), 0.71-1.00; P = 0.049]. Moreover, this disparity was observed at referral sites, but not POC sites. Among patients scheduled, non-Hispanic Blacks had lower odds of counseling (aOR = 0.28; 95% CI, 0.17-0.47; P < 0.001).

CONCLUSIONS

Findings suggest that factors influencing genetic counseling show rates may be driving disparities in genetic testing.

IMPACT

Strategies to reduce barriers to seeing a genetic counselor, including modifications to clinical workflow, may help mitigate racial/ethnic disparities in genetic testing.

Calibrating variant curation by clinical context based on factors that influence patients' tolerance of uncertainty

PURPOSE

Shared decision making manages genomic uncertainty by integrating molecular and clinical uncertainties with patient values to craft a person-centered management plan. Laboratories seek genomic report consistency, agnostic to clinical context. Molecular reports often mask laboratory-managed uncertainties from clinical decision making. Better integration of these uncertainty management strategies requires a nuanced understanding of patients' perceptions and reactions to test uncertainties. We explored patients' tolerance to variant uncertainty in 3 parameters: (1) relative causal significance, (2) risk accuracy, and (3) classification validity.

METHOD

Deliberative forums were undertaken with 18 patients with predictive testing experience. Uncertainty deliberations were elicited for each parameter. A thematic framework was first developed, and then mapped to whether they justified tolerance to more or less parameter-specific uncertainty.

RESULTS

Six identified themes mapped to clinical and personal domains. These domains generated opposing forces when calibrating uncertainty. Personal themes justified tolerance of higher uncertainty and clinical themes lower uncertainty. Decision making in uncertainty focused on reducing management regret. Open communication increased tolerance of classification validity and risk accuracy uncertainty. Using these data, we have developed a nascent clinical algorithm integrating molecular uncertainty with clinical context through a targeted communication framework.

CONCLUSION

Maximizing test utility necessitates context-specific recalibration of uncertainty management and communication.

Applying the framework for developing and evaluating complex interventions to increase family communication about hereditary cancer

Objective

Evaluate an intervention to increase family communication (FC) of positive hereditary cancer test results using the Framework for Developing and Evaluating Complex Interventions (FDECI).

Methods

We developed 'programme theory' during the FDECI development phase by aligning intervention components with behavior change techniques (BCTs) and theoretical factors expected to improve FC. During the feasibility phase, we obtained feedback from 12 stakeholder interviews.

Results

Intervention components aligned with a total of 14 unique BCTs for which prior evidence links the BCT to theoretical factors that influence behavior change. Constructive stakeholder feedback included: more information desired, rewording to support autonomy by highlighting options, and improvements to navigation, visuals, and audio. Positive comments included: comprehensiveness of materials, modeling of conversations, and usefulness of the materials for helping a person prepare to share positive test results.

Conclusion

The first FDECI phases were helpful for improving the intervention and planning our ongoing effectiveness and future implementation phases.

Innovation

Our application of the FDECI is novel, including plans to test our 'programme theory' using coincidence analysis (CNA) to determine who accesses which intervention materials, how utilizing certain materials impact the aligned theoretical factors, and whether these in turn make a difference in the behavioral outcome.

Association of Moderate-Risk Breast Cancer Genes with Contralateral Prophylactic Mastectomy and Bilateral Disease

BACKGROUND

The impact of ATM, CHEK2, and PALB2, the three most prevalent moderate-risk breast cancer genes, on surgical decision making is not well known.

METHODS

Our retrospective study included patients with resectable non-metastatic breast cancer who underwent multigene panel testing between July 2014 and January 2020 with at least one genetic alteration (pathogenic or variant of uncertain significance [VUS] in ATM [n = 49], CHEK [n = 57], or PALB2 [n = 27]). Our objectives were to determine the rate of contralateral prophylactic mastectomy (CPM) and the rate of bilateral breast cancer. Univariable analyses (UVA) and multivariable analyses (MVA) were performed to identify factors associated with CPM and bilateral breast cancer.

RESULTS

The rate of CPM was 39% (n = 49/127), with 54% (n = 25/46) of patients with a pathogenic mutation and 30% (n = 24/81) of patients with a VUS choosing CPM. On MVA, premenopausal status (odds ratio [OR] 3.46) and a pathogenic alteration (OR 3.01) were associated with increased use of CPM. Bilateral disease was noted in 16% (n = 22/138). Patients with pathogenic mutations had a 22% (n = 11/51) incidence of bilateral breast cancer, while patients with VUS had a 13% (n = 11/87) incidence, although this was not statistically significant on UVA or MVA. On MVA, premenopausal status was associated with a decreased risk of bilateral disease (OR 0.33, p = 0.022). During follow-up, a breast cancer event occurred in 16% (n = 22/138).

CONCLUSIONS

Our study identified a high rate of CPM among those with ATM, CHEK2, and PALB2 alterations, including VUS. Further studies are needed to clarify reasons for CPM among patients with moderate-risk alterations.

Screening Practices for Breast and Nonbreast Cancers in High-Risk Mutation Carriers

INTRODUCTION

Women with breast cancer often undergo genetic testing and may have a pathogenic variant associated with multiple cancers. This study examines the current screening practices for breast and nonbreast cancers in mutation carriers.

METHODS

An institutional retrospective chart review of patients with BRCA1, BRCA2, ATM, CHEK2, BARD1, BRIP1, PALB2, and TP53 mutations were identified. Adherence to recommended screening based on National Comprehensive Cancer Network guidelines was analyzed.

RESULTS

Six hundred sixty-two patients met inclusion criteria: 220 patients with BRCA1, 256 patients with BRCA2, 58 patients with PALB2, 51 patients with ATM, 48 patients with CHEK2, 14 patients with BRIP1, 10 patients with BARD1, and 5 patients with TP53. Overall, 214 (46%) of eligible patients completed recommended breast imaging. Of 106 patients eligible for pancreatic cancer screening, 20 (19%) received a magnetic resonance cholangiopancreatography and 16 (15%) received an endoscopic ultrasound. On multivariable analysis, age was associated with improved breast imaging adherence: patients in age groups 40-55 (adjusted odds ratio 2.05, 95% confidence interval 1.18-3.55) and age 56-70 (adjusted odds ratio 2.16, 95% confidence interval 1.18-3.95, P = 0.012) had better adherence than younger patients.

CONCLUSIONS

Increases in genetic testing and updates to National Comprehensive Cancer Network guidelines provide an opportunity for improved cancer screening. While recommended breast cancer screenings are being completed at higher rates, there is a need for clear protocols in this high-risk population.

Factors that differentiate cancer risk management decisions among females with pathogenic/likely pathogenic variants in PALB2, CHEK2, and ATM

PURPOSE

Following disclosure of pathogenic or likely pathogenic variants in hereditary cancer genes, patients face cancer risk management decisions. Through this mixed-methods study, we investigated cancer risk management decisions among females with pathogenic or likely pathogenic variants in PALB2, CHEK2, and ATM to understand why some patients follow National Comprehensive Cancer Network guidelines, whereas others do not.

METHODS

Survey and interview data were cross-analyzed using a 3-stage approach. Identified factors were used to conduct coincidence analysis and differentiate between combinations of factors that result in following or not following guidelines.

RESULTS

Of the 13 participants who underwent guideline inconsistent prophylactic surgery, 12 fit 1 of 3 unique patterns: (1) cancer-related anxiety in the absence of trust in care, (2) provider recommending surgery inconsistent with National Comprehensive Cancer Network guidelines, or (3) surgery occurring before genetic testing. Two unique patterns were found among 18 of 20 participants who followed guidelines: (1) anxiety along with trust in care or (2) lack of anxiety and no prophylactic surgery before testing.

CONCLUSION

Health care provider recommendations and trust in care may influence whether individuals receive care that is congruent with risk levels conferred by specific genes. Interventions are needed to improve provider knowledge, patient trust in non-surgical care, and patient anxiety.

Management of individuals with germline pathogenic/likely pathogenic variants in CHEK2: A clinical practice resource of the American College of Medical Genetics and Genomics (ACMG)

PURPOSE

Although the role of CHEK2 germline pathogenic variants in cancer predisposition is well known, resources for managing CHEK2 heterozygotes in clinical practice are limited.

METHODS

An international workgroup developed guidance on clinical management of CHEK2 heterozygotes informed by peer-reviewed publications from PubMed.

RESULTS

Although CHEK2 is considered a moderate penetrance gene, cancer risks may be considered as a continuous variable, which are influenced by family history and other modifiers. Consequently, early cancer detection and prevention for CHEK2 heterozygotes should be guided by personalized risk estimates. Such estimates may result in both downgrading lifetime breast cancer risks to those similar to the general population or upgrading lifetime risk to a level at which CHEK2 heterozygotes are offered high-risk breast surveillance according to country-specific guidelines. Risk-reducing mastectomy should be guided by personalized risk estimates and shared decision making. Colorectal and prostate cancer surveillance should be considered based on assessment of family history. For CHEK2 heterozygotes who develop cancer, no specific targeted medical treatment is recommended at this time.

CONCLUSION

Systematic prospective data collection is needed to establish the spectrum of CHEK2-associated cancer risks and to determine yet-unanswered questions, such as the outcomes of surveillance, response to cancer treatment, and survival after cancer diagnosis.

A study of clinical and molecular characteristics in bilateral primary breast cancer

BACKGROUND

Bilateral primary breast cancer (BPBC) is a rare type of breast cancer. Studies on the clinicopathologic and molecular characteristics of BPBC in a metastatic context are very limited.

METHODS

A total of 574 unselected metastatic breast cancer patients with clinical information were enrolled in our next-generation sequencing (NGS) database. Patients with BPBC from our NGS database were regarded as the study cohort. In addition, 1467 patients with BPBC and 2874 patients with unilateral breast cancer (UBC) from the Surveillance, Epidemiology, and End Results (SEER) public database were also analyzed to determine the characteristics of BPBC.

RESULTS

Among the 574 patients enrolled in our NGS database, 20 (3.5%) patients had bilateral disease, comprising 15 (75%) patients with synchronous bilateral disease and 5 (25%) patients with metachronous bilateral disease. Eight patients had bilateral hormone receptor-positive (HR+)/human epidermal growth factor receptor-negative (HER2-) tumors, and three had unilateral HR+/HER2- tumors. More HR+/HER2- tumors and lobular components were found in BPBC patients than in UBC patients. The molecular subtype of the metastatic lesions in three patients was inconsistent with either side of the primary lesions, which suggested the importance of rebiopsy. Strong correlations in clinicopathologic features between the left and right tumors in BPBC were exhibited in the SEER database. In our NGS database, only one BPBC patient was found with a pathogenic germline mutation in BRCA2. The top mutated somatic genes in BPBC patients were similar to those in UBC patients, including TP53 (58.8% in BPBC and 60.6% in UBC) and PI3KCA (47.1% in BPBC and 35.9% in UBC).

CONCLUSIONS

Our study suggested that BPBC may tend to be lobular carcinoma and have the HR+/HER2- subtype. Although our study did not find specific germline and somatic mutations in BPBC, more research is needed for verification.

Non-coding RNAs in radiotherapy resistance: Roles and therapeutic implications in gastrointestinal cancer

Radiotherapy has become an indispensable and conventional means for patients with advanced solid tumors including gastrointestinal cancer. However, innate or acquired radiotherapy resistance remains a significant challenge and greatly limits the therapeutic effect, which results in cancer relapse and poor prognosis. Therefore, it is an urgent need to identify novel biomarkers and therapeutic targets for clarify the biological characteristics and mechanism of radiotherapy resistance. Recently, lots of studies have revealed that non-coding RNAs (ncRNAs) are the potential indicators and regulators of radiotherapy resistance via the mediation of various targets/pathways in different cancers. These findings may serve as a potential therapeutic strategy to overcome radiotherapy resistance. In this review, we will shed light on the recent findings regarding the functions and regulatory mechanisms of ncRNAs following radiotherapy, and comprehensively discuss their potential as biomarkers and therapeutic targets in radiotherapy resistance of gastrointestinal cancer.

Pathogenic variant profile in DNA damage response genes correlates with metastatic breast cancer progression-free survival in a Mexican-mestizo population

INTRODUCTION

Metastatic breast cancer causes the most breast cancer-related deaths around the world, especially in countries where breast cancer is detected late into its development. Genetic testing for cancer susceptibility started with the BRCA 1 and 2 genes. Still, recent research has shown that variations in other members of the DNA damage response (DDR) are also associated with elevated cancer risk, opening new opportunities for enhanced genetic testing strategies.

METHODS

We sequenced BRCA1/2 and twelve other DDR genes from a Mexican-mestizo population of 40 metastatic breast cancer patients through semiconductor sequencing.

RESULTS

Overall, we found 22 variants -9 of them reported for the first time- and a strikingly high proportion of variations in ARID1A. The presence of at least one variant in the ARID1A, BRCA1, BRCA2, or FANCA genes was associated with worse progression-free survival and overall survival in our patient cohort.

DISCUSSION

Our results reflected the unique characteristics of the Mexican-mestizo population as the proportion of variants we found differed from that of other global populations. Based on these findings, we suggest routine screening for variants in ARID1A along with BRCA1/2 in breast cancer patients from the Mexican-mestizo population.

MRI phenotypes associated with breast cancer predisposing genetic variants, a multisite review

PURPOSE

Examine MRI phenotypes of breast cancers arising in patients with various pathogenic variants, to assess for imaging trends and associations.

METHOD

Multisite retrospective review evaluated 410 patients from 2001 to 2020 with breast cancer and a predisposing pathogenic variant who underwent breast MRI at time of cancer diagnosis. Dominant malignant lesion features were reported, including lesion type (mass versus non-mass enhancement), size, shape, margin, internal enhancement pattern, plus other features. Kruskal-Wallis test, Fisher's exact test, and pairwise comparisons performed comparing imaging manifestations for the most frequent genetic results.

RESULTS

BRCA1 (29.5 %) and BRCA2 (25.9 %) variants were most common, followed by CHEK2 (16.6 %), ATM (8.0 %), and PALB2 (6.3 %), with significant associated differences in race/ethnicity (p = 0.040), age at cancer diagnosis (p = 0.005), tumor shapes (p = 0.001), margins (p < 0.001), grade (p < 0.001), internal enhancement pattern (rim enhancement) (p < 0.001), kinetics (washout) (p < 0.001), and presence of necrosis (p < 0.001). CHEK2 and ATM tumors were often lower grade with spiculated margins (CHEK2: 47.1 %, ATM: 45.5 %), rarely exhibiting washout or tumor necrosis (p < 0.001), and were mostly comprised of luminal molecular subtypes (CHEK2: 88.2 %, ATM: 90.9 %). BRCA1 tumors had the highest proportions with round shape (31.4 %), circumscribed margins (24.0 %), rim enhancement (24.0 %), washout (58.7 %), and necrosis (19.8 %), with 47.9 % comprised of triple negative subtype. Bilateral mastectomy was performed in higher proportions of patients with BRCA1 (84.3 %) and BRCA2 (75.5 %) variants compared to others.

CONCLUSIONS

Genetic and molecular profiles of breast cancers demonstrate reproducible MRI phenotypes.

Risk‐reducing mastectomy decisions among women with mutations in high‐ and moderate‐ penetrance breast cancer susceptibility genes

Background

Women harboring mutations in breast cancer susceptibility genes are at increased lifetime risk of developing breast cancer and are faced with decisions about risk management, including whether to undergo high‐risk screening or risk‐reducing mastectomy (RRM). National guidelines recommend BRCA1 or BRCA2 mutation carriers consider RRM, but that carriers of moderate penetrance mutations (e.g., ATM or CHEK2) should be managed based on family history. We aimed to investigate determinants of decision for RRM, and hypothesized that mutation status, age, family history, partner status, and breast cancer would impact RRM decision making.

Methods

We performed a retrospective study assessing RRM decisions for 279 women.

Results

Women with BRCA and moderate penetrance gene mutations, a personal history of breast cancer, or a first degree relative with a history of breast cancer were more likely to undergo RRM. Breast cancer status and age showed an interaction effect such that women with breast cancer were less likely to undergo RRM with increasing age.

Conclusion

Although national guidelines do not recommend RRM for moderate penetrance carriers, the rates of RRM for this population approached those for BRCA mutation carriers. Further insights are needed to better support RRM decision‐making in this population.

Timely cancer genetic counseling and testing for young women with breast cancer: impact on surgical decision-making for contralateral risk-reducing mastectomy

PURPOSE

Genetic testing (GT) can identify individuals with pathogenic/likely pathogenic variants (PV/LPVs) in breast cancer (BC) predisposition genes, who may consider contralateral risk-reducing mastectomy (CRRM). We report on CRRM rates in young women newly diagnosed with BC who received GT through a multidisciplinary clinic.

METHODS

Clinical data were reviewed for patients seen between November 2014 and June 2019. Patients with non-metastatic, unilateral BC diagnosed at age ≤ 45 and completed GT prior to surgery were included. Associations between surgical intervention and age, BC stage, family history, and GT results were evaluated.

RESULTS

Of the 194 patients, 30 (15.5%) had a PV/LPV in a BC predisposition gene (ATM, BRCA1, BRCA2, CHEK2, NBN, NF1), with 66.7% in BRCA1 or BRCA2. Of 164 (84.5%) uninformative results, 132 (68%) were negative and 32 (16.5%) were variants of uncertain significance (VUS). Overall, 67 (34.5%) had CRRM, including 25/30 (83.3%) PV/LPV carriers and 42/164 (25.6%) non-carriers. A positive test result (p < 0.01) and significant family history were associated with CRRM (p = 0.02). For the 164 with uninformative results, multivariate analysis showed that CRRM was not associated with age (p = 0.23), a VUS, (p = 0.08), family history (p = 0.10), or BC stage (p = 0.11).

CONCLUSION

In this cohort of young women with BC, the identification of a PV/LPV in a BC predisposition gene and a significant family history were associated with the decision to pursue CRRM. Thus, incorporation of genetic services in the initial evaluation of young patients with a new BC could contribute to the surgical decision-making process.

An overview of genetic services delivery for hereditary breast cancer

Breast cancer is the most common cancer diagnosed in women worldwide, with approximately 5-10% of cases attributed to high penetrance hereditary breast cancer (HBC) genes. The tremendous advances in precision oncology have broadened indications for germline genetic testing to guide both systemic and surgical treatment, with increasing demand for cancer genetic services. The HBC continuum of care includes (1) identification, access, and uptake of genetic counseling and testing; (2) the delivery of genetic counseling and testing services; and (3) initiation of guideline-adherent follow-up care and family communication of results. Challenges to delivering care on the HBC care continuum include factors such as access to services, cost, discrimination and bias, and lack of education and awareness, which can be mitigated through implementing a multi-level approach. This includes strategies such as increasing awareness and utilization of genetic counseling and testing, developing new methods to meet the growing demand for genetic services, and improving the uptake of follow-up care by increasing patient and provider awareness of the management recommendations.

IMProving care After inherited Cancer Testing (IMPACT) study: protocol of a randomized trial evaluating the efficacy of two interventions designed to improve cancer risk management and family communication of genetic test results

BACKGROUND

Implementing genetic testing for inherited cancer predisposition into routine clinical care offers a tremendous opportunity for cancer prevention and early detection. However, genetic testing itself does not improve outcomes; rather, outcomes depend on implemented follow-up care. The IMPACT study is a hybrid type I randomized effectiveness-implementation trial to simultaneously evaluate the effectiveness of two interventions for individuals with inherited cancer predisposition focused on: 1) increasing family communication (FC) of genetic test results; and 2) improving engagement with guideline-based cancer risk management (CRM).

METHODS

This prospective study will recruit a racially, geographically, and socioeconomically diverse population of individuals with a documented pathogenic/likely pathogenic (P/LP) variant in an inherited cancer gene. Eligible participants will be asked to complete an initial trial survey and randomly assigned to one of three arms: A) GeneSHARE, a website designed to increase FC of genetic test results; B) My Gene Counsel's Living Lab Report, a digital tool designed to improve understanding of genetic test results and next steps, including CRM guidelines; or C) a control arm in which participants continue receiving standard care. Follow-up surveys will be conducted at 1, 3, and 12 months following randomization. These surveys include single-item measures, scales, and indices related to: 1) FC and CRM behaviors and behavioral factors following the COM-B theoretical framework (i.e., capability, opportunity, and motivation); 2) implementation outcomes (i.e., acceptability, appropriateness, exposure, and reach); and 3) other contextual factors (i.e., sociodemographic and clinical factors, and uncertainty, distress, and positive aspects of genetic test results). The primary outcomes are an increase in FC of genetic test results (Arm A) and improved engagement with guideline-based CRM without overtreatment or undertreatment (Arm B) by the 12-month follow-up survey.

DISCUSSION

Our interventions are designed to shift the paradigm by which individuals with P/LP variants in inherited cancer genes are provided with information to enhance FC of genetic test results and engagement with guideline-based CRM. The information gathered through evaluating the effectiveness and implementation of these real-world approaches is needed to modify and scale up adaptive, stepped interventions that have the potential to maximize FC and CRM.

TRIAL REGISTRATION

This study is registered at Clinicaltrials.gov (NCT04763915, date registered: February 21, 2021).

PROTOCOL VERSION

September 17th, 2021 Amendment Number 04.

CHEK2 Pathogenic Variants in Greek Breast Cancer Patients: Evidence for Strong Associations with Estrogen Receptor Positivity, Overuse of Risk-Reducing Procedures and Population Founder Effects

Simple Summary

CHEK2 germline pathogenic variants are identified at a relatively high frequency among hereditary breast cancer cases and are known to be associated with intermediate breast cancer risk i.e., 2–2.5-fold increase, compared to the general population. Histopathological characteristics and clinical outcomes of breast cancer patients who are CHEK2 carriers have not been thoroughly investigated. We have therefore sought to determine the CHEK2 variant spectrum and identify variants with possible founder effect, while investigating the clinicopathological features and outcomes of Greek patients who were CHEK2 carriers. Three variants have been identified as Greek founders. The vast majority of CHEK2-associated breast tumors were hormone receptor positive, underlying a possible benefit from chemoprophylaxis with tamoxifen. A trend for longer survival was observed in patients that underwent mastectomy and received hormone-therapy. Nearly half of patients underwent a risk-reducing surgery, which was not mandated according to current guidelines or relevant risks associated with CHEK2.

Abstract

CHEK2 germline pathogenic variants predispose to breast cancer and possibly to other malignancies, with their spectrum and frequency being variable among populations. Τhe majority of CHEK2-associated breast tumors are hormone receptor positive; however, relevant clinical outcomes are not well defined. Herein, we illustrate the histopathological characteristics and clinical outcomes of 52 Greek breast cancer patients who are CHEK2 carriers. Genetic analysis was performed by Sanger/massively parallel sequencing, followed by MLPA. Subsequent haplotype analysis investigated possible founder effects. Blood relatives were offered cascade testing. CHEK2 variant spectrum was characterized by variability, while influenced by founder effects. The majority of carriers, i.e., 60.8%, were diagnosed with breast cancer before the age of 45. Notably, 91.5% of breast tumors were hormone receptor positive. Hormone therapy and mastectomy at diagnosis seem to have a positive trend on overall survival, after a median follow-up of 9.5 years. Remarkably, 41.9% of patients underwent risk-reducing surgery, one third of which involved salpingo-oophorectomy. Nearly half of families responded to cascade testing. Our data highlight the need for guideline-adherent choices, based on the evidence that CHEK2 carriers are at moderate risk for breast cancer and no risk for ovarian cancer, while underscore the possible role of chemoprevention with tamoxifen.

Germline genetic testing in breast cancer: Rationale for the testing of all women diagnosed by the age of 60 years and for risk-based testing of those older than 60 years

Approximately 5% to 10% of women diagnosed with breast cancer will have a pathogenic variant (PV) in a hereditary cancer susceptibility gene, and this has significant implications for the management of these patients and their relatives. Despite the benefits of genetic testing, many eligible patients with breast cancer never undergo testing because of various barriers, including complicated testing criteria such as those from the National Comprehensive Cancer Network (NCCN). In 2019, the American Society of Breast Surgeons (ASBrS) proposed germline genetic testing for all patients with breast cancer to increase the identification of PV carriers. In 2020, a Mayo Clinic study highlighted the limitations of these 2 genetic testing guidelines (NCCN and ASBrS) and proposed a hybrid approach of testing all women diagnosed with breast cancer by the age of 65 years and using NCCN criteria for older patients. This commentary presents an updated analysis of the Mayo Clinic data and discusses the rationale for using the age of 60 years rather than 65 years as the cutoff for this hybrid approach. Using an age at diagnosis of ≤60 or ≤65 years for the universal testing of patients with breast cancer detected more PVs (11.9% [16 of 134] and 15.7% [21 of 134], respectively) in comparison with using the NCCN criteria. Lowering the age for universal testing from 65 to 60 years maintained the sensitivity of detecting a PV at >90% while sparing testing for an additional 10% of women. Compared with the testing of all patients, the hybrid approach would allow 31% of all women with breast cancer to forgo testing and result in fewer variants of uncertain significance identified and, therefore, would decrease the chance of harm from misinterpretation of these variants.