Polygenic risk, susceptibility genes, and breast cancer over the life course

ABSTRACTPolygenic risk scores (PRS) for breast cancer have potential to improve risk prediction, but there is limited information on their clinical applicability. We set out to study how PRS could help in clinical decision making. Among 99,969 women in the FinnGen study with 6,879 breast cancer cases, the PRS was associated not only with breast cancer incidence but also with a range of breast cancer-related endpoints. Women with a breast cancer PRS above the 90th percentile had both higher breast cancer mortality (HR 2.40, 95%CI 1.82-3.17) and higher risk for non-localized disease at diagnosis (HR 2.94, 95%CI 2.63-3.28), compared to those with PRS <80th percentile. The PRS modified the breast cancer risk of two high-impact frameshift risk variants. Women with the c.1592delT variant in PALB2 (242-fold enrichment in Finland, 263 carriers) and an average PRS (20-80th percentile) had a lifetime risk of breast cancer at 58% (95%CI 50-66%), which increased to 85% (70-100%) with a high PRS (>90th percentile), and decreased to 27% (15-39%) with a low PRS (<20th percentile). Similarly, for c.1100delC in CHEK2 (3.7-fold enrichment; 1,543 carriers), the respective lifetime risks were 27% (95%CI 25-30%), 59% (52-67%), and 18% (13-22%). Among breast cancer cases, a PRS >90th percentile was associated with risk of contralateral breast cancer with HR 1.66 (95%CI 1.24-2.22). Finally, the PRS significantly refined the risk assessment of women with first-degree relatives diagnosed with breast cancer, i.e. the combination of high PRS (>90th percentile) and a positive family-history was associated with a 2.33-fold elevated risk (95%CI 1.57-3.46) compared to a positive family history alone. These findings demonstrate opportunities for a comprehensive way of assessing genetic risk in the general population, in breast cancer patients, and in unaffected family members.

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The role of polygenic risk and susceptibility genes in breast cancer over the course of life

Nature Communications ◽

10.1038/s41467-020-19966-5 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Nina Mars ◽

◽

Elisabeth Widén ◽

Sini Kerminen ◽

Tuomo Meretoja ◽

...

Keyword(s):

Breast Cancer ◽

Risk Assessment ◽

Positive Family History ◽

Breast Cancer Diagnosis ◽

Risk Scores ◽

Limited Information ◽

Breast Cancer Patients ◽

Polygenic Risk ◽

First Degree Relatives ◽

Fold Enrichment

AbstractPolygenic risk scores (PRS) for breast cancer have potential to improve risk prediction, but there is limited information on their utility in various clinical situations. Here we show that among 122,978 women in the FinnGen study with 8401 breast cancer cases, the PRS modifies the breast cancer risk of two high-impact frameshift risk variants. Similarly, we show that after the breast cancer diagnosis, individuals with elevated PRS have an elevated risk of developing contralateral breast cancer, and that the PRS can considerably improve risk assessment among their female first-degree relatives. In more detail, women with the c.1592delT variant in PALB2 (242-fold enrichment in Finland, 336 carriers) and an average PRS (10–90th percentile) have a lifetime risk of breast cancer at 55% (95% CI 49–61%), which increases to 84% (71–97%) with a high PRS ( > 90th percentile), and decreases to 49% (30–68%) with a low PRS ( < 10th percentile). Similarly, for c.1100delC in CHEK2 (3.7–fold enrichment; 1648 carriers), the respective lifetime risks are 29% (27–32%), 59% (52–66%), and 9% (5–14%). The PRS also refines the risk assessment of women with first-degree relatives diagnosed with breast cancer, particularly among women with positive family history of early-onset breast cancer. Here we demonstrate the opportunities for a comprehensive way of assessing genetic risk in the general population, in breast cancer patients, and in unaffected family members.

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Potential of polygenic risk scores for improving population estimates of women’s breast cancer genetic risks

Genetics in Medicine ◽

10.1038/s41436-021-01258-y ◽

2021 ◽

Author(s):

Michael Wolfson ◽

Steve Gribble ◽

Nora Pashayan ◽

Douglas F. Easton ◽

Antonis C. Antoniou ◽

...

Keyword(s):

Breast Cancer ◽

Family History ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Risk Stratification ◽

Breast Cancer Incidence ◽

Population Level ◽

Risk Scores ◽

Polygenic Risk ◽

Risk Algorithm

Abstract Purpose Breast cancer risk has conventionally been assessed using family history (FH) and rare high/moderate penetrance pathogenic variants (PVs), notably in BRCA1/2, and more recently PALB2, CHEK2, and ATM. In addition to these PVs, it is now possible to use increasingly predictive polygenic risk scores (PRS) as well. The comparative population-level predictive capability of these three different indicators of genetic risk for risk stratification is, however, unknown. Methods The Canadian heritable breast cancer risk distribution was estimated using a novel genetic mixing model (GMM). A realistically representative sample of women was synthesized based on empirically observed demographic patterns for appropriately correlated family history, inheritance of rare PVs, PRS, and residual risk from an unknown polygenotype. Risk assessment was simulated using the BOADICEA risk algorithm for 10-year absolute breast cancer incidence, and compared to heritable risks as if the overall polygene, including its measured PRS component, and PV risks were fully known. Results Generally, the PRS was most predictive for identifying women at high risk, while family history was the weakest. Only the PRS identified any women at low risk of breast cancer. Conclusion PRS information would be the most important advance in enabling effective risk stratification for population-wide breast cancer screening.

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Evaluating the prognostic performance of a polygenic risk score for breast cancer risk stratification

BMC Cancer ◽

10.1186/s12885-021-08937-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Maria Olsen ◽

Krista Fischer ◽

Patrick M. Bossuyt ◽

Els Goetghebeur

Keyword(s):

Breast Cancer ◽

Cancer Incidence ◽

Cox Regression ◽

Breast Cancer Incidence ◽

Independent Study ◽

Risk Scores ◽

Polygenic Risk Score ◽

Polygenic Risk ◽

Prognostic Performance

Abstract Background Polygenic risk scores (PRS) could potentially improve breast cancer screening recommendations. Before a PRS can be considered for implementation, it needs rigorous evaluation, using performance measures that can inform about its future clinical value. Objectives To evaluate the prognostic performance of a regression model with a previously developed, prevalence-based PRS and age as predictors for breast cancer incidence in women from the Estonian biobank (EstBB) cohort; to compare it to the performance of a model including age only. Methods We analyzed data on 30,312 women from the EstBB cohort. They entered the cohort between 2002 and 2011, were between 20 and 89 years, without a history of breast cancer, and with full 5-year follow-up by 2015. We examined PRS and other potential risk factors as possible predictors in Cox regression models for breast cancer incidence. With 10-fold cross-validation we estimated 3- and 5-year breast cancer incidence predicted by age alone and by PRS plus age, fitting models on 90% of the data. Calibration, discrimination, and reclassification were calculated on the left-out folds to express prognostic performance. Results A total of 101 (3.33‰) and 185 (6.1‰) incident breast cancers were observed within 3 and 5 years, respectively. For women in a defined screening age of 50–62 years, the ratio of observed vs PRS-age modelled 3-year incidence was 0.86 for women in the 75–85% PRS-group, 1.34 for the 85–95% PRS-group, and 1.41 for the top 5% PRS-group. For 5-year incidence, this was respectively 0.94, 1.15, and 1.08. Yet the number of breast cancer events was relatively low in each PRS-subgroup. For all women, the model’s AUC was 0.720 (95% CI: 0.675–0.765) for 3-year and 0.704 (95% CI: 0.670–0.737) for 5-year follow-up, respectively, just 0.022 and 0.023 higher than for the model with age alone. Using a 1% risk prediction threshold, the 3-year NRI for the PRS-age model was 0.09, and 0.05 for 5 years. Conclusion The model including PRS had modest incremental performance over one based on age only. A larger, independent study is needed to assess whether and how the PRS can meaningfully contribute to age, for developing more efficient screening strategies.

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Evaluating the Prognostic Performance of a Polygenic Risk Score for Breast Cancer Risk Stratification

10.21203/rs.3.rs-121122/v1 ◽

2020 ◽

Author(s):

Maria Olsen ◽

Krista Fischer ◽

Patrick M. Bossuyt ◽

Els Goetghebeur

Keyword(s):

Breast Cancer ◽

Cancer Incidence ◽

Cox Regression ◽

Breast Cancer Incidence ◽

Independent Study ◽

Risk Scores ◽

Polygenic Risk Score ◽

Breast Cancers ◽

Polygenic Risk ◽

Prognostic Performance

Abstract Background: Polygenic risk scores (PRS) could potentially improve breast cancer screening recommendations. We analyzed how well a recently developed prevalence-based breast cancer PRS (Läll et al., 2009) performs in expressing women’s future risk of incident breast cancer. Objectives: To evaluate the prognostic performance of models using PRS and age as predictors, vs age alone, for breast cancer incidence in women from the Estonian biobank (EstBB) cohort. Methods: We analyzed data on 30,312 women from the EstBB cohort. They entered the cohort between 2002 and 2011, were between 20-89 years, without history of breast cancer, and with full 5-year follow-up by 2015. We examined PRS and other potential risk factors as possible predictors in Cox regression models for breast cancer incidence. With 10-fold cross validation we estimated 3- and 5-year breast cancer incidence from age alone and PRS plus age, fitting models on 90% of the data. Calibration, discrimination, and reclassification then expressed prognostic performance on the left-out folds. Results: A total of 101 (3.33‰) and 185 (6.1‰) incident breast cancers were observed within 3 and 5 years, respectively. For women in the current Estonian screening age (50-62 years), the ratio of observed vs PRS-age modelled 3-year incidence was 0.86 for women in the 75-85% PRS-group, 1.34 for the 85-95% PRS-group, and 1.41 for the top 5% PRS-group. For 5-year incidence, this was respectively 0.94, 1.15, and 1.08. Yet, the number of breast cancer events were relatively low in each PRS-subgroup. The model’s AUC was 0.720 (95% CI: 0.675-0.765) for 3-year and 0.704 (95% CI: 0.670-0.737) for 5-year, respectively, just 0.022 and 0.023 higher than for the model with age alone. Using a 1% risk prediction threshold, the 3-year NRI for the PRS-age model was 0.09 and 0.05 for 5 years.Conclusion: The model including PRS had modest incremental performance. This suggests that the potential benefit of adding PRS to age for guiding screening likely affects a relatively small proportion of women. A larger, independent study is needed to assess whether and how the PRS can meaningfully contribute to developing more efficient screening strategies.

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Stratification of Breast Cancer Risk in Women With Atypia: A Mayo Cohort Study

Journal of Clinical Oncology ◽

10.1200/jco.2006.09.0217 ◽

2007 ◽

Vol 25 (19) ◽

pp. 2671-2677 ◽

Cited By ~ 173

Author(s):

Amy C. Degnim ◽

Daniel W. Visscher ◽

Hal K. Berman ◽

Marlene H. Frost ◽

Thomas A. Sellers ◽

...

Keyword(s):

Breast Cancer ◽

Family History ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Breast Cancer Incidence ◽

Positive Family History ◽

Significant Risk ◽

Atypical Hyperplasia ◽

Breast Cancers ◽

Increased Risk

Purpose Atypical hyperplasia is a well-recognized risk factor for breast cancer, conveying an approximately four-fold increased risk. Data regarding long-term absolute risk and factors for risk stratification are needed. Patients and Methods Women with atypical hyperplasia in the Mayo Benign Breast Disease Cohort were identified through pathology review. Subsequent breast cancers were identified via medical records and a questionnaire. Relative risks (RRs) were estimated using standardized incidence ratios, comparing the observed number of breast cancers with those expected based on Iowa Surveillance, Epidemiology, and End Results (SEER) data. Age, histologic factors, and family history were evaluated as risk modifiers. Plots of cumulative breast cancer incidence provided estimates of risk over time. Results With mean follow-up of 13.7 years, 66 breast cancers (19.9%) occurred among 331 women with atypia. RR of breast cancer with atypia was 3.88 (95% CI, 3.00 to 4.94). Marked elevations in risk were seen with multifocal atypia (eg, three or more foci with calcifications [RR, 10.35; 95% CI, 6.13 to 16.4]). RR was higher for younger women (< 45; RR, 6.76; 95% CI, 3.24 to 12.4). Risk was similar for atypical ductal and atypical lobular hyperplasia, and family history added no significant risk. Breast cancer risk remained elevated over 20 years, and the cumulative incidence approached 35% at 30 years. Conclusion Among women with atypical hyperplasia, multiple foci of atypia and the presence of histologic calcifications may indicate “very high risk” status (> 50% risk at 20 years). A positive family history does not further increase risk in women with atypia.

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A Group Therapy Approach to Facilitate Integration of Risk Information for Women at Risk for Breast Cancer

The Canadian Journal of Psychiatry ◽

10.1177/070674379804300405 ◽

1998 ◽

Vol 43 (4) ◽

pp. 375-380 ◽

Cited By ~ 17

Author(s):

Mary Jane Esplen ◽

Brenda Toner ◽

Jonathan Hunter ◽

Gordon Glendon ◽

Kate Butler ◽

...

Keyword(s):

Breast Cancer ◽

At Risk ◽

Family History ◽

Group Therapy ◽

Perceived Risk ◽

Positive Family History ◽

Risk Information ◽

Degree Relative ◽

Therapy Approach ◽

History Of

Objective: To describe and illustrate elements of a group counselling approach designed to enhance the communication of risk information on breast cancer (BC) to women with a family history of this disease. Breast cancer is a leading cause of female cancer death. The most important risk factor for BC is a positive family history in at least 1 first-degree relative, and approximately one-third of women with BC have a family history of the disease. Recent evidence suggests that there is a significant psychological impact associated with having a family history of BC, and this may influence the psychological adjustment and response to being counselled for personal risk. New counselling approaches are required. Method: This paper describes a group therapy approach that incorporates principles of supportive-expressive therapy designed to address the emotional impact of being at risk for BC and to promote accuracy of perceived risk. The key elements of the intervention are described along with clinical illustrations from groups that are part of an ongoing study to develop and standardize the group therapy. Conclusion: Qualitative data from the groups suggest that this model of therapy is both feasible and effective.

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