Fig. 1.

Flow chart of patient identification and selection. Stratified by age at breast cancer diagnosis (≤50 and > 50 years), women with diabetes were 2:1 frequency-matched on year of birth and age at breast cancer diagnosis (both in 10-year categories) to women without diabetes, to select ~ 300 patients with tumor tissue available. ǂ Exact numbers < 5 cannot be shown according to regulations of Statistics Denmark