Multivariable ordinal logistic regression was used to investigate the association between T2D/insulin and breast cancer characteristics, including TNM classification (tumor size, lymph node status, metastasis), morphology, grade, estrogen receptor and progesterone receptor (PR), human epidermal growth factor receptor 2, and molecular subtype.
We conducted a retrospective multi-center population-based case-case study consisting of 4,557 breast cancer cases to evaluate the impact of type II diabetes and diabetes medications on the risk of different breast cancer molecular subtypes [ER<sup>+</sup>/HER2<sup>-</sup>, ER<sup>+</sup>/HER2<sup>+</sup>, triple negative (ER<sup>-</sup>/PR<sup>-</sup>/HER2<sup>-</sup>), and HER2 overexpressing (H2E, ER<sup>-</sup>/PR<sup>-</sup>/HER2<sup>+</sup>)].