Background: Since 2010 the International Breast Cancer & Nutrition (IBCN) network has fostered transdisciplinary, integrative work to bring diversity into cancer prevention research. IBCN pilot countries, France, Ghana, Lebanon, Uruguay, Taiwan, and the USA represent six world-regions; their teams cover life and social sciences, engineering, public health, medicine, and pharmaceutical & nutritional sciences. A white paper written with members of the International Agency for Research on Cancer (IARC) launched this initiative, with epigenetics and nutrition as a thread to develop projects on risk assessment and reduction. Our rationale is that the epigenome controls cancer onset and progression and is sensitive to environmental risk modulators, notably unavoidable nutrition. Increasing breast cancer incidence in young women in both high-income countries (HIC) and low-and-middle-income countries (LMIC) emphasizes the key role of the environment on the organism to generate the exposome and makes primary prevention a persisting urgency. 

Objectives: (1) to co-develop primary prevention research questions informed by international diversity, and (2) to foster context-based prevention solutions through capacity building involving HIC-LMIC sustained partnerships.
Methods: Network structure and coordination encompassed steering committees, international external advisory board, and working groups with regular meetings, in addition to yearly symposia open to all.
Capacity building involved training early-career scientists, joint supervision of trainees, and visiting research activities. Research-based workshops enabled us to prepare local and international grant proposals on research directions defined through strategic plans covering nutrition, biomarkers and community-based interventions.
Research-centered solutions progressed through collaborative pilot projects and exploratory studies. Major advances in strategic planning were written into peer-reviewed perspective articles.

Results: The continuous progress made through the network interactions influenced the career of IBCN members, opening or strengthening key positions in their respective countries, hence reinforcing cancer prevention strategies at regional and national levels. The strategic consensus to consider prevention as a continuum promoted the use of information from breast cancer cases, available in most countries, to develop hypotheses on cancer initiation for primary prevention projects, further fed from actual data from women at high risk for breast cancer available from fewer countries. Using this approach and complementary cohorts from three HIC and LMIC pilot countries, the network has identified sets of common promising biomarkers for breast cancer risk assessment and/or detection that are ready to be tested in other pilot and IBCN-associated countries. Another IBCN consensus emphasizes context-dependent projects. Part of a research plan for risk reduction using foods with targeted epigenetic impact was recently published and submitted for international funding. Overall, this plan combines food diversity and local customs, with extensive exposome assessment for tailored interventions.

Conclusions/implications: Capacity building in the network is fostered by the ability and resources of its components locally and nationally that resulted from our collaborative research efforts. However, work conducted with multiple countries presenting different capacities and backgrounds demands great resilience when facing the lack of funding for such global endeavors. Shedding light on the positive impact of integrating diversity should further global, yet context-savvy, breast cancer prevention.