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

A combined risk model shows viability for personalized breast cancer risk assessment in the Indonesian population: A case/control study

Breast cancer remains a significant concern worldwide, with a rising incidence in Indonesia. This study aims to evaluate the applicability of risk-based screening approaches in the Indonesian demographic through a case-control study involving 305 women. We developed a personalized breast cancer risk assessment workflow that integrates multiple risk factors, including clinical (Gail) and polygenic (Mavaddat) risk predictions, into a consolidated risk category. By evaluating the area under the receiver operating characteristic curve (AUC) of each single-factor risk model, we demonstrated that they retained their predictive accuracy in the Indonesian context (AUC for clinical risk: 0.67 [0.61,0.74]; AUC for genetic risk: 0.67 [0.61,0.73]). Notably, our combined risk approach enhanced the AUC to 0.70 [0.64,0.76], highlighting the advantages of a multifaceted model. Our findings demonstrate for the first time the applicability of the Mavaddat and Gail models to Indonesian populations, and show that within this demographic, combined risk models provide a superior predictive framework compared to single-factor approaches.

Do women with a history of breast cancer recommend risk-based breast cancer screening? An in-depth interview study

Objectives

Personalizing screening recommendations could enhance efficiency, support timely detection, and optimize resource use. This study explores women's perceptions of the facilitators and barriers to current screening guidelines and the implementation of risk-based screening (RBS) for breast cancer in Singapore.

Methods

Individual semi-structured interviews were conducted with 11 women aged 21 and above with a history of breast cancer. Data coding and thematic analysis were guided by the Health Belief Model (HBM).

Results

Five themes were identified and mapped to the Health Belief Model (HBM): (1) Knowledge and beliefs, (2) Access to mammography screening, (3) Social influences, (4) Healthcare delivery, and (5) Needs and preferences for RBS implementation. Key barriers to screening adherence included low perceived susceptibility, cost concerns, and accessibility issues. Factors that could improve adherence included social influences promoting breast health awareness, reminders from trusted healthcare professionals (HCP), and confidence in affording screening and treatment. Participants were generally receptive to RBS and valued personalized recommendations, but concerns were raised about risk prediction accuracy, insurance implications, and potential negative reactions to risk results.

Conclusion

This study identifies challenges and enablers for enhancing breast screening in Singapore, based on the experiences of breast cancer survivors. Participants supported RBS for routine screening. Successful RBS implementation requires improved health literacy, HCP engagement, and accessible healthcare. Women's acceptance will rely on research to refine prediction accuracy and communication of risk results.

Overlap of high-risk individuals across family history, genetic & non-genetic breast cancer risk models: Analysis of 180,398 women from European & Asian ancestries

Background

Breast cancer is multifactorial. Focusing on limited risk factors may miss high-risk individuals.

Methods

We assessed the performance and overlap of various risk factors in identifying high-risk individuals for invasive breast cancer (BrCa) and ductal carcinoma in situ (DCIS) in 161,849 European-ancestry and 18,549 Asian-ancestry women. Discriminatory ability was evaluated using the area under the receiver operating characteristic curve (AUC). High-risk criteria included: 5-year absolute risk ≥1·66% by the Gail model [GAILbinary]; first-degree family history of breast cancer [FHbinary]; 5-year absolute risk ≥1·66% by a 313-variants polygenic risk score [PRSbinary]; and carriers of pathogenic variants in breast cancer predisposition genes [PTVbinary].

Findings

The 5-year absolute risk by PRS outperformed the Gail model in predicting BrCa (Europeansvs controls: AUCPRS=0·635 [0·632-0·638] vs AUCGail=0·492 [0·489-0·495]; Asiansvs controls: AUCPRS=0·564 [0·556-0·573] vs AUCGail=0·506 [0·497-0·514]). PRSbinary and GAILbinary identified more high-risk European than Asia individuals. High-risk proportions were higher among BrCa (16-26%) and DCIS (20-33%) compared to controls (9-15%) among young Europeans and all Asians. Fewer than 7% of BrCa, 10% of DCIS, and 3% of controls were classified as high-risk by multiple risk classifiers. Overlap between PRSbinary and PTVbinary was minimal (<0·65% Europeans, <0·15% Asians) compared to the proportion at high risk using PTVbinary alone (Europeans: 4·6%, Asians: 4·4%) and PRSbinary alone (Europeans: 13·9%, Asians: 8·5%). PRSbinary and FHbinary uniquely identified 5-6% and 9-11% of young BrCa, respectively.

Interpretation

The incomplete overlap between high-risk individuals identified by PRSbinary, GAILbinary, FHbinary, and PTVbinary highlights the need for a comprehensive approach to breast cancer risk prediction.

Importance of circulating tumor DNA analysis at diagnosis in early triple-negative breast cancer patients

BACKGROUND

Circulating tumor DNA (ctDNA) enables non-invasive evaluation and is considered a promising tool for diagnosis, treatment selection, risk stratification, and disease monitoring. However, while the utility of ctDNA has been demonstrated in advanced-stage cancers, its detection in early breast cancer (EBC) remains limited. This study investigated the characteristics of EBC patients associated with higher ctDNA detectability.

METHODS

A total of 101 patients with EBC were enrolled. Formalin-fixed paraffin-embedded samples (FFPEs) were obtained from biopsy tissue, and plasma samples were collected before and after neoadjuvant chemotherapy (NAC). Forty-seven breast cancer-related genes were analyzed using next-generation sequencing. The diagnostic performance of ctDNA was evaluated, and logistic regression analyses were conducted to assess the impact of clinical and molecular factors on ctDNA status.

RESULTS

The most frequently identified gene was TP53 (FFPE, 66.7%; ctDNA, 46.4%), followed by PIK3CA (FFPE, 36.2%; ctDNA, 17.4%). The diagnostic performance of the three most common genes showed a sensitivity range of 11.1-58.7%, specificity of 78.3-100%, and diagnostic accuracy of 65.2-78.3%. The triple-negative breast cancer (TNBC) subtype exhibited the strongest association with ctDNA detection (odds ratio [OR] 209.50, p = 0.005) in multivariate analysis. Also, those who exhibited ctDNA clearance after NAC had a higher pathological complete response rate compared to those without clearance (38.5% vs. 11.1%, p = 0.238).

CONCLUSIONS

Our study highlights that ctDNA analysis can complement genetic testing from a single tissue biopsy in breast cancer patients. Furthermore, ctDNA analysis may be particularly important in patients with TNBC.

Women's preferences for testing to predict breast cancer risk - a discrete choice experiment

BACKGROUND

Risk-based breast cancer screening offers a more targeted and potentially cost-effective approach in cancer detection compared to age-based screening. This study aims to understand women's preferences and willingness for undergoing risk assessment tests.

METHODS

A discrete choice experiment (DCE) was conducted. Six attributes were selected to construct the DCE questionnaire: one-time cost of the test, methods for reducing late-stage breast cancer, annual breast cancer screening expenses, insurance coverage for early-stage breast cancer, family risk correlation, and risk communication methods. Women aged between 21 and 59 were recruited from Singapore. Latent class analysis was performed.

RESULTS

Three hundred twenty-eight women were included in the analysis and classified into two classes: test supporters and non-supporters. Both classes prioritised test costs and screening costs. Among non-cost attributes, the potential to reduce late-stage breast cancer diagnosis was the most influential factor. Insurance coverage increased willingness to undergo testing. Risk communication methods were not significant in influencing the decision of undergoing tests. Non-supporters were less inclined to take the test if family risk correlation was high. Younger women, married women, full-time employees, and those with a history of breast disease were more likely to be supporters. Women with a family history of breast cancer were more likely to be non-supporters.

CONCLUSIONS

Financial incentives play a notable role in increasing the uptake of risk-prediction tests. However, the programme's success depends on understanding and addressing the diverse preferences of women. While cost considerations ranked highly, additional strategies are needed to engage groups that are hesitant, particularly those with a high family risk correlation.

Associations between the life's essential 8, genetic risk and breast cancer incidence in premenopausal and postmenopausal women: a prospective study in UK Biobank

The combined effect of cardiovascular risk factors on breast cancer in women is unknown. The relationship between genetic risk combined with cardiovascular health (CVH) levels and breast cancer has not been confirmed. This study aims to explore the relationship between CVH level based on life's essential 8 (LE8) score and breast cancer risk in women with different menopausal statuses and to estimate further the effect of CVH level combined with genetic susceptibility on breast cancer risk. A total of 118,911 women from UK Biobank were included in the study, including 22,676 premenopausal women and 96,235 postmenopausal women. The association between the CVH level and the risk of breast cancer in women with different menopausal statuses was assessed using the Cox proportional hazards regression models, with the healthiest CVH group as the reference. In addition, risk ratios (HRs) and 95% confidence intervals (95% CIs) for the joint effect of the CVH level and polygenic risk score (PRS) were calculated using the PRS from the UK Biobank. During a mean follow-up period of 13.8 years, we observed 733 cases and 3,645 cases of breast cancer in premenopausal and postmenopausal women, respectively. In premenopausal women, the risk of breast cancer was significantly increased in the intermediate CVH group (HR, 1.28; 95%CI 1.08-1.52) and the low CVH group (HR, 1.44; 95%CI 1.13-1.85). In postmenopausal women, the risk of incidence was also significantly increased in the intermediate CVH group (HR, 1.20; 95%CI 1.07-1.32) and the low CVH group (HR, 1.34; 95%CI 1.17-1.54). In the joint effect analysis, the risk of breast cancer for women in the low CVH group and the high genetic risk group was highest in both premenopausal (HR, 8.26; 95%CI 4.44-15.35) and postmenopausal (HR, 8.10; 95%CI 5.50-11.93) women. Women with lower LE8 scores and higher genetic susceptibility have the higher risk of breast cancer. This suggests that women with lower levels of CVH and higher genetic susceptibility have an increased risk of breast cancer under different menopausal statuses.

What do women want to see in a personalized breast cancer risk report? A qualitative study of Asian women of two countries

A breast cancer risk assessment tool for Asian populations, incorporating Polygenic Risk Score and Gail Model algorithm, has been established and validated. However, effective methods for delivering personalized risk information remain underexplored. This study aims to identify and develop effective methods for conveying breast cancer risk information to Asian women. Through ten focus group discussions with 32 women in Indonesia and Singapore, we explored preferences for the presentation of risk information. Participants favored comprehensive reports featuring actionable steps, simplified language, non-intimidating visuals, and personalized risk reduction recommendations. Singaporean participants, more aware of breast cancer prevention, showed a lower likelihood of seeking follow-ups upon receiving low-risk results compared to Indonesians. Overall, participants found the reports useful and advocated for similar approaches in other disease assessments. Balancing content and complexity in reports is crucial, highlighting the need for improved patient understanding and engagement with healthcare providers. Future studies could explore physicians' roles in delivering personalized risk assessments for breast cancer prevention.

Polygenic Risk Score (PRS) Combined with NGS Panel Testing Increases Accuracy in Hereditary Breast Cancer Risk Estimation

Breast cancer (BC) is the most prominent tumor type among women, accounting for 32% of newly diagnosed cancer cases. BC risk factors include inherited germline pathogenic gene variants and family history of disease. However, the etiology of the disease remains occult in most cases. Therefore, in the absence of high-risk factors, a polygenic basis has been suggested to contribute to susceptibility. This information is utilized to calculate the Polygenic Risk Score (PRS) which is indicative of BC risk. This study aimed to evaluate retrospectively the clinical usefulness of PRS integration in BC risk calculation, utilizing a group of patients who have already been diagnosed with BC. The study comprised 105 breast cancer patients with hereditary genetic analysis results obtained by NGS. The selection included all testing results: high-risk gene-positive, intermediate/low-risk gene-positive, and negative. PRS results were obtained from an external laboratory (Allelica). PRS-based BC risk was computed both with and without considering additional risk factors, including gene status and family history. A significantly different PRS percentile distribution consistent with higher BC risk was observed in our cohort compared to the general population. Higher PRS-based BC risks were detected in younger patients and in those with FH of cancers. Among patients with a pathogenic germline variant detected, reduced PRS values were observed, while the BC risk was mainly determined by a monogenic etiology. Upon comprehensive analysis encompassing FH, gene status, and PRS, it was determined that 41.90% (44/105) of the patients demonstrated an elevated susceptibility for BC. Moreover, 63.63% of the patients with FH of BC and without an inherited pathogenic genetic variant detected showed increased BC risk by incorporating the PRS result. Our results indicate a major utility of PRS calculation in women with FH in the absence of a monogenic etiology detected by NGS. By combining high-risk strategies, such as inherited disease analysis, with low-risk screening strategies, such as FH and PRS, breast cancer risk stratification can be improved. This would facilitate the development of more effective preventive measures and optimize the allocation of healthcare resources.

Tumor initiation and early tumorigenesis: molecular mechanisms and interventional targets

Tumorigenesis is a multistep process, with oncogenic mutations in a normal cell conferring clonal advantage as the initial event. However, despite pervasive somatic mutations and clonal expansion in normal tissues, their transformation into cancer remains a rare event, indicating the presence of additional driver events for progression to an irreversible, highly heterogeneous, and invasive lesion. Recently, researchers are emphasizing the mechanisms of environmental tumor risk factors and epigenetic alterations that are profoundly influencing early clonal expansion and malignant evolution, independently of inducing mutations. Additionally, clonal evolution in tumorigenesis reflects a multifaceted interplay between cell-intrinsic identities and various cell-extrinsic factors that exert selective pressures to either restrain uncontrolled proliferation or allow specific clones to progress into tumors. However, the mechanisms by which driver events induce both intrinsic cellular competency and remodel environmental stress to facilitate malignant transformation are not fully understood. In this review, we summarize the genetic, epigenetic, and external driver events, and their effects on the co-evolution of the transformed cells and their ecosystem during tumor initiation and early malignant evolution. A deeper understanding of the earliest molecular events holds promise for translational applications, predicting individuals at high-risk of tumor and developing strategies to intercept malignant transformation.

Assessing the Value of Incorporating a Polygenic Risk Score with Nongenetic Factors for Predicting Breast Cancer Diagnosis in the UK Biobank

BACKGROUND

Previous studies have demonstrated that incorporating a polygenic risk score (PRS) to existing risk prediction models for breast cancer improves model fit, but to determine its clinical utility the impact on risk categorization needs to be established. We add a PRS to two well-established models and quantify the difference in classification using the net reclassification improvement (NRI).

METHODS

We analyzed data from 126,490 post-menopausal women of "White British" ancestry, aged 40 to 69 years at baseline from the UK Biobank prospective cohort. The breast cancer outcome was derived from linked registry data and hospital records. We combined a PRS for breast cancer with 10-year risk scores from the Tyrer-Cuzick and Gail models, and compared these to the risk scores from the models using phenotypic variables alone. We report metrics of discrimination and classification, and consider the importance of the risk threshold selected.

RESULTS

The Harrell's C statistic of the 10-year risk from the Tyrer-Cuzick and Gail models was 0.57 and 0.54, respectively, increasing to 0.67 when the PRS was included. Inclusion of the PRS gave a positive NRI for cases in both models [0.080 (95% confidence interval (CI), 0.053-0.104) and 0.051 (95% CI, 0.030-0.073), respectively], with negligible impact on controls.

CONCLUSIONS

The addition of a PRS for breast cancer to the well-established Tyrer-Cuzick and Gail models provides a substantial improvement in the prediction accuracy and risk stratification.

IMPACT

These findings could have important implications for the ongoing discussion about the value of PRS in risk prediction models and screening.

Surgical options for patients with early-stage breast cancer and pathogenic germline variants: an oncologist perspectives

Breast cancer continues to be the most common cancer diagnosed among women worldwide. Family history of breast cancer is frequently encountered, and 5-15% of patients may carry inherited pathogenic germline variants, identification of which can be helpful for both; patients themselves and their unaffected close relatives. The availability and affordability of molecular diagnostics, like next generation sequencing (NGS), had resulted in wider adoption of such technologies to detect pathogenic variants of cancer-predisposing genes. International guidelines had recently broadened the indications for germline genetic testing to include much more patients, and also expanded the testing to include multi-gene panels, while some professional societies are calling for universal testing of all newly diagnosed patients with breast cancer, regardless of their age, personal or family history. The risk of experiencing a contralateral breast cancer (CBC) or ipsilateral recurrence, is well known. Such risk is highest with variants like BRCA1 and BRCA2, but less well-studied with other less common variants. The optimal local therapy for women with BRCA-associated breast cancer remains controversial, but tends to be aggressive and may involve bilateral mastectomies, which may not have any survival advantage. Additionally, surgical management of unaffected women, known to carry a pathogenic cancer-predisposing gene, may vary from surveillance to bilateral mastectomies, too. The oncological safety, and the higher satisfaction of unaffected women and patients with new surgical techniques, like the skin-sparing (SSM) and nipple-sparing (NSM) mastectomies, eased up the process of counselling. In this review, we address the oncological safety of less aggressive surgical options for both; patients and unaffected carriers.