The similar distribution of these characteristics between the two groups, reflected in the p-values (all above 0.05 except for a marginally significant difference in ER status with p=0.053), supports the external validity of the findings derived from this dataset.
Introduction Breast cancer is the most prevalent malignancy affecting women worldwide, with a significant trend toward the increasing incidence of early-onset breast cancer—defined as cases diagnosed before the age of 50. 1 These early-onset cases often exhibit more aggressive behaviors and have less favorable outcomes compared to later-onset breast cancer. 2 This emphasizes the urgent need for improved diagnostic and prognostic methods specifically tailored to this younger demographic, to enhance their clinical management and improve survival rates.