Type 2 diabetes (T2D) and breast cancer (BC) are complex diseases. Genetic, environmental and lifestyle factors are thought to interplay in their pathogenesis. Little is known about the biological mechanisms by which diabetes may affect breast cancer incidence and mortality. Specifically, the role of diabetes treatment in breast carcinogenesis remains unknown. My stage at the International Agency for Research on Cancer (IARC) will allow me to access information of large cohort studies and I will be able to learn how to handle and analyse complex data. Among my acquired skills will be to do risk to BC assessment using Cox Regression; to conduct a meta-analysis and to analyse direct, indirect and interactive effects between obesity and BC, and also between physical activity and BC using Structural equation models.