B2B

Background

Improved individualized risk estimations are needed for breast cancer patients. The risk of contralateral breast cancer (CBC) can be very high for BRCA1/2 carriers and non-BRCA1/2 familial breast cancer patients. On the other hand breast cancer patients in whom CBC risk is only moderately elevated increasingly request contralateral mastectomy.

Aim

The purpose of this project is to provide accurate risk predictions for CBC and make these available in a decision aid. The decision aid aims to support shared decision-making by women and physicians for risk reducing strategies, treatment and follow-up decisions, both for women at high risk as well as to prevent unnecessary surgery in women at low risk of developing a CBC.

Collaboration

The project is a close collaboration between NKI-AVL (Prof. Marjanka K. Schmidt), LUMC (Prof. Ewout W. Steyerberg) and Erasmus MC (Dr. Maartje J. Hooning).
Both institutional, national (Netherlands Cancer Registry) and international databases (Breast Cancer Association Consortium, chair: Prof. Douglas Easton, Cambridge University UK) are being used for the development of the prediction model.

Impact on patient care

In current clinical practice no tool is available for individualized decision making related to CBC.

The decision aid aims to support shared decision-making by women and physicians for risk reducing strategies, treatment and follow-up decisions, both for women at high risk as well as to prevent unnecessary surgery in women at low risk of developing a CBC.

The 3 phases of the project

In phase I we determined the most important factors that need to be included in the CBC risk prediction model. We performed literature reviews to assess summary estimates for CBC risk predictors, and data analysis is ongoing in available breast cancer cohorts, including additional data collection (e.g. on breast density).

In phase II, we developed and validated a risk prediction model including only those factors for which there was sufficient evidence. A second upgraded version, using additional factors, is being developed.

Phase III implies implementation of the risk prediction model in an online tool.

The project is funded by Alpe d’HuZes/Dutch Cancer Society.

Internal collaborations

We work in close collaboration with other departments involved in the care and research of breast cancer: Surgical Oncology, Radiotherapy, Pathology, Radiology, Clinical Genetics.

External collaborations

• Netherlands Cancer Institute, Molecular Pathology/Epidemiology; Prof. Marjanka K. Schmidt
• Leiden UMC, Biomedical Data Sciences; Prof. Ewout W. Steyerberg
• Netherlands Cancer Registry, IKNL
• HEBON: Netherlands Collaborative Group on Hereditary Breast and Ovarian Cancer
• BCAC: Breast Cancer Association Consortium

Prediction and clinical utility of a contralateral breast cancer risk model.
Giardiello D, Steyerberg EW, Hauptmann M, …, Hooning MJ, Schmidt MK. Breast Cancer Research 2019 In press.

Risk factors for metachronous contralateral breast cancer: A systematic review and meta-analysis. Akdeniz D, Schmidt MK, Seynaeve CM, McCool D, Giardiello D, van den Broek AJ, Hauptmann M, Steyerberg EW, Hooning MJ. Breast. 2018 Dec 6;44:1-14.

Adjuvant radiotherapy for primary breast cancer in BRCA1 and BRCA2 mutation carriers and risk of contralateral breast cancer with special attention to patients irradiated at younger age. Drooger J, Akdeniz D, Pignol JP, Koppert LB, McCool D, Seynaeve CM, Hooning MJ, Jager A. Breast Cancer Res Treat. 2015 Nov;154(1):171-80.

• Maartje Hooning, principal investigator
• Delal Akdeniz
• Jannet Blom-Leenheer
• Saskia Pelders

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