6-Year survival rates for SEER-Whites, SEER-Asians, and ABCCG-Asians. Survival rates for patients with breast cancer with (A) all subtypes and (B) HR+/HER2− were compared across three age groups: young (<40 years), alleged premenopausal mid-age (40-49 years), and alleged postmenopausal age (≥50 years) in SEER-Whites, SEER-Asians, and ABCCG-Asians. ABCCG, Asian Breast Cancer Cooperative Group; HER2, human epidermal growth factor receptor 2; HR, hormone receptor; SEER, Surveillance, Epidemiology, and End Results Program.