ERBB2 and breast cancer: In terms of age distribution, the majority were adults aged 18 years and above (56.74%, n = 21,697), which is consistent with existing clinical trials and epidemiological BC data (Baselga et al., 2012; Blackwell et al., 2010; ‘Breast cancer incidence (invasive) statistics,’ 2024; Wang et al., 2021), as well as real-world studies on lapatinib/HER-2 inhibitors (Barbieri et al., 2022; Tang et al., 2025).