IBCCS aims to improve the understanding of genetic, lifestyle, and environmental factors associated with breast and ovarian and other BRCA1/2-related cancers risks, prevention and outcome. Established in 1997, the study involves contributions from 15 European countries and includes (in 2024) data from over 30,000 BRCA1/2 pathogenic variants carriers. IBCCS includes mainly prospective data. Key aspects of the study include the collection of self-reported questionnaires, pathology data, and outcomes tracked through medical registries. This comprehensive approach ensures a robust foundation for impactful research. Future plans include broadening the study scope to include male carriers and fostering further collaboration with initiatives like CIMBA to drive innovation in hereditary cancer research.

Coordination is through the Netherlands Cancer Institute. The IBCCS research work is currently supported by University of Pennsylvania Basser Center External Research Grant. Research at the Netherlands Cancer Institute is supported by institutional grants of the Dutch Cancer Society and of the Dutch Ministry of Health, Welfare and Sport. The individual participating centers and studies of the IBCCS are supported by a number of research grants. The Dutch HEBON study is supported by the Dutch Cancer Society grants NKI1998-1854, NKI2004-3088, NKI2007-3756, NKI 12535, the Netherlands Organisation of Scientific Research grant NWO 91109024, the Pink Ribbon grants 110005 and 2014-187.WO76, the BBMRI grant NWO 184.021.007/CP46, and the Transcan grant JTC 2023 Cancer 12-054.