an increasing trendp = 0.001
Time trend analysis revealed that an increasing trend was observed for age at diagnosis ( p = 0.001), proportion of patients without a reproductive history ( p < 0.001), postmenopausal patients ( p = 0.001), invasive pathological cancer type ( p = 0.008), ER-positive rate ( p < 0.001), PR-positive rate ( p = 0.008), and HER2-positive rate ( p < 0.001).