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. 2026 Jan;134(2):259-268.
doi: 10.1038/s41416-025-03247-3. Epub 2025 Nov 12.

Breast cancer risk prediction with a modified BOADICEA model in Danish women

Sif Ingibergsdóttir Novitski #  1   2 , Rikke Louise Jacobsen #  3 , Timo Röder  1   2 , Peter Christoffer Holm  1   2 , Michael Schwinn  3 , Ilse Vejborg  4 , My Catarina von Euler-Chelpin  2 , Elsebeth Lynge  2 , Sisse R Ostrowski  3   5 , Erik Sørensen  3 , Ole Birger Pedersen  5   6 , Christian Erikstrup  7   8 , Bitten Aagaard  9 , Henrik Hjalgrim  5   10   11   12 ; DBDS Genomic Consortium; Thórunn Rafnar  13 , Kari Stefansson  13 , Nasim Mavaddat  14 , Lorenzo Ficorella  14 , Antonis C Antoniou  14 , Henrik Ullum  15 , Karina Banasik  1   2   16 , Søren Brunak  1   2 , Stig Egil Bojesen  17   18
Collaborators, Affiliations

Breast cancer risk prediction with a modified BOADICEA model in Danish women

Sif Ingibergsdóttir Novitski et al. Br J Cancer. 2026 Jan.

Abstract

Background: Breast cancer risk prediction approaches clinical practice. The BOADICEA risk model has been updated to consider common breast cancer risk variants, lifestyle/hormonal risk factors and mammographic density (MD).

Methods: 49,494 women from the Danish Blood Donor Study were followed for up to 10 years. Modified BOADICEA risks within 5 and 10 years were calculated based on a polygenic breast cancer risk score combined with lifestyle/hormonal risk factors. MD was only known for 4608 women. Calibration was assessed by comparing observed and predicted risks. AUC and Harrell's concordance index (C-index) were used to assess discriminative ability and sensitivities and specificities were obtained for high and low-risk groups.

Results: Within 5 and 10 years, 367 and 617 women had breast cancer. The 5-year model achieved an AUC of 0.80 (95% CI:0.78-0.81), sensitivity of 0.34 and specificity of 0.92 for all and an AUC of 0.61 (95% CI:0.58-0.65) for the 50-69-year-aged. For this age-group, the sensitivity was 0.46 in the 10-year model. 50% of women with the highest 5-year risk predictions, identified 94.8% of those with incident breast cancers.

Conclusion: The modified BOADICEA risk model provided valid risks among a large retrospective cohort of Danish women.

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Conflict of interest statement

Competing interests: ACA and LF are listed as creators of the BOADICEA model, which has been licensed from Cambridge Enterprise (University of Cambridge) for commercial purposes. SB has ownerships in Intomics A/S, Hoba Therapeutics Aps, Novo Nordisk A/S, Lundbeck A/S, ALK abello A/S, Eli Lilly and Co and managing board memberships in Proscion A/S and Intomics A/S. All other authors declare no competing interests. Consent for publication: All authors consented to publication of this manuscript. Ethics approval and consent to participate: All DBDS participants gave informed consent. All methods were performed in accordance with the relevant guidelines and regulations. This study was approved by the National Committee on Health Research Ethics (M-20090237/1-10-72-95-13, NVK-1700407 and SJ-740) and the data protection in the Capital Region of Denmark (P-2019-99).

Figures

Fig. 1
Fig. 1. STROBE diagram.
Flow chart describing participant inclusions and exclusions applied to define the study cohort.
Fig. 2
Fig. 2. Calibration plots of breast cancer risk prediction in the full cohort of 49,494 women.
a Predicted risk of breast cancer within 5 years, grouped into deciles and compared with the observed risks. Four different models were evaluated: age alone, age and risk factors, age and PRS, age with both PRS and risk factors. Mean Harrell’s C-index and 95% confidence intervals (bootstrapped with 1,000 iterations) are presented for each model. The dashed line shows the identity function y = x. b Same comparisons as above, but for breast cancer risk within 10 years.
Fig. 3
Fig. 3. AUC based on minimum baseline age.
AUCs were calculated for the full 5-year (blue) and 10-year (red) breast cancer risk models (age, risk factors, PRS) across subsets defined by the minimum study baseline age. The age range considered all women in the cohort until the age of 60. The total number of women included, and the number of breast cancer cases, is listed for both models and minimum baseline age groups of 18, 20, 30, 40, and 50. Sensitivity and specificity were calculated for these groups with risk thresholds of 1.67% (5-year risk) and 3.34% (10-year risk).
See this image and copyright information in PMC

References

    1. Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin. 2021;71:209–49. - PubMed
    1. Larønningen S, Ferlay J, Beydogan H, Bray F, Engholm G, Ervik M, et al. (2022). NORDCAN: Cancer Incidence, Mortality, Prevalence and Survival in the Nordic Countries, Version 9.2 (23.06.2022). Association of the Nordic Cancer Registries. [cited 2023 Sep 8]. Available from: https://nordcan.iarc.fr/
    1. Dafni U, Tsourti Z, Alatsathianos I. Breast Cancer Statistics in the European Union: Incidence and Survival across European Countries. Breast Care. 2019;14:344–53. - DOI - PMC - PubMed
    1. McTiernan A. Behavioral risk factors in breast cancer: can risk be modified?. Oncologist. 2003;8:326–34. - DOI - PubMed
    1. Cardoso F, Kyriakides S, Ohno S, Penault-Llorca F, Poortmans P, Rubio IT, et al. Early breast cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2019;30:1674. - DOI - PubMed

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