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. 2019 Sep 19;3(4):pkz066.
doi: 10.1093/jncics/pkz066. eCollection 2019 Dec.

Accuracy of Risk Estimates From the iPrevent Breast Cancer Risk Assessment and Management Tool

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Free PMC article

Accuracy of Risk Estimates From the iPrevent Breast Cancer Risk Assessment and Management Tool

Kelly-Anne Phillips et al. JNCI Cancer Spectr. .
Free PMC article

Abstract

Background: iPrevent is an online breast cancer (BC) risk management decision support tool. It uses an internal switching algorithm, based on a woman's risk factor data, to estimate her absolute BC risk using either the International Breast Cancer Intervention Study (IBIS) version 7.02, or Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm version 3 models, and then provides tailored risk management information. This study assessed the accuracy of the 10-year risk estimates using prospective data.

Methods: iPrevent-assigned 10-year invasive BC risk was calculated for 15 732 women aged 20-70 years and without BC at recruitment to the Prospective Family Study Cohort. Calibration, the ratio of the expected (E) number of BCs to the observed (O) number and discriminatory accuracy were assessed.

Results: During the 10 years of follow-up, 619 women (3.9%) developed BC compared with 702 expected (E/O = 1.13; 95% confidence interval [CI] =1.05 to 1.23). For women younger than 50 years, 50 years and older, and BRCA1/2-mutation carriers and noncarriers, E/O was 1.04 (95% CI = 0.93 to 1.16), 1.24 (95% CI = 1.11 to 1.39), 1.13 (95% CI = 0.96 to 1.34), and 1.13 (95% CI = 1.04 to 1.24), respectively. The C-statistic was 0.70 (95% CI = 0.68 to 0.73) overall and 0.74 (95% CI = 0.71 to 0.77), 0.63 (95% CI = 0.59 to 0.66), 0.59 (95% CI = 0.53 to 0.64), and 0.65 (95% CI = 0.63 to 0.68), respectively, for the subgroups above. Applying the newer IBIS version 8.0b in the iPrevent switching algorithm improved calibration overall (E/O = 1.06, 95% CI = 0.98 to 1.15) and in all subgroups, without changing discriminatory accuracy.

Conclusions: For 10-year BC risk, iPrevent had good discriminatory accuracy overall and was well calibrated for women aged younger than 50 years. Calibration may be improved in the future by incorporating IBIS version 8.0b.

Figures

Figure 1.
Figure 1.
Screenshots of the Online iPrevent Breast Cancer Risk Assessment and Risk Management Decision Support Tool. A) iPrevent gathers information about lifestyle and medical and family history and, using that information, provides 10-year breast cancer risk estimates as well as lifetime risk estimates (not shown). B) iPrevent provides a menu of appropriate risk management options for each woman depending on her category of risk, based on her absolute risk estimate and Cancer Australia guidelines. An example for a woman at moderate risk of breast cancer. C) iPrevent provides personalized estimates of the absolute reduction in breast cancer risk that may be expected with prevention strategies such as tamoxifen.
Figure 2.
Figure 2.
iPrevent software algorithm for breast cancer risk estimation. Based on their personal and/or first- or second-degree family history of cancer and BRCA1/BRCA2-mutation status, the iPrevent 10-year breast cancer risk estimate was derived from the IBIS model for 9749 participants and the BOADICEA model for the remaining 5983 participants. # IBIS- or BOADICEA-derived risk estimates were further modified to obtain the iPrevent risk estimate by applying a 33% relative risk reduction for women who had taken tamoxifen for breast cancer prevention prior to baseline and a 50% relative risk reduction for women who had had a bilateral oophorectomy before age 45 years. AH = atypical hyperplasia; BOADICEA = Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm; BRCA mutation = BRCA1 or BRCA2 pathogenic germline mutation; IBIS = International Breast Cancer Intervention Study; LCIS = lobular carcinoma in situ.
Figure 3.
Figure 3.
Calibration of iPrevent 10-year estimates of invasive breast cancer for women in the Prospective Family Study Cohort by quantile, overall, and for subgroups by age and mutation carriers. Calibration of iPrevent estimated 10-year breast cancer risk by decile. The coordinates on the x-axis represent the mean 10-year expected risks from iPrevent. The coordinates on the y-axis represent the estimates of 10-year breast cancer probabilities based on the women’s observed breast cancer status, and the bars denote 95% confidence intervals for the observed risk. For each subgroup, calibration was assessed using BOADICEA V3 and IBIS V7.02 to emulate the current online version of iPrevent (A, C, E, G, I) and using BOADICEA V3 and IBIS V8.0b to simulate a future updated version of iPrevent (B, D, F, H, J). BOADICEA = Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm; IBIS = International Breast Cancer Intervention Study.
Figure 4.
Figure 4.
Receiver operating characteristic curves for iPrevent 10-year estimates of invasive breast cancer for women in the Prospective Family Study Cohort overall and by age and mutation status. BOADICEA = Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm; IBIS = International Breast Cancer Intervention Study.

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References

    1. McGinnis JM, Aisner D, Olsen L., et al. The Learning Healthcare System: Workshop Summary. Washington, DC: National Academies Press; 2007.
    1. Van de Velde S, Heselmans A, Delvaux N., et al. A systematic review of trials evaluating success factors of interventions with computerized clinical decision support. Implement Sci. 2018;13(1):114. - PMC - PubMed
    1. Peter MacCallum Cancer Centre. iPrevent. https://www.petermac.org/iprevent. Accessed December 13, 2018.
    1. Collins IM, Bickerstaffe A, Ranaweera T., et al. iPrevent: a tailored, web-based, decision support tool for breast cancer risk assessment and management. Breast Cancer Res Treat. 2016;156(1):171–182. - PMC - PubMed
    1. Antoniou AC, Cunningham AP, Peto J., et al. The BOADICEA model of genetic susceptibility to breast and ovarian cancers: updates and extensions. Br J Cancer. 2008;98(8):1457.. - PMC - PubMed

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