Nomogram prediction for breast cancer-specific survival in patients with ER⁻/PR⁻/HER2⁺ breast cancer: an analysis based on the SEER population

Estrogen receptor (ER)⁻/progesterone receptor (PR)⁻/human epidermal growth factor receptor 2 (HER2)⁺ breast cancer (BC) represents a distinct molecular subtype with a unique pathogenesis that differentiates it from other subtypes. This study aims to investigate the clinical characteristics and prognostic factors of patients diagnosed with this specific form of BC.