Correlation Between Estrogen Receptor Alpha and Progesterone Receptor Expression in Stromal Tissue and Tumor Size of Archived Fibroadenoma Mammae Specimens

Fibroadenoma of the Breast (FAM) is a benign fibroepithelial breast tumor influenced by estrogen and progesterone through their binding to Estrogen Receptor-a (ER-a) and Progesterone Receptor (PR). These receptors are thought to contribute to mammary tissue proliferation; however, the role of stromal ER-a and PR in determining tumor size remains unclear. This study aimed to analyze the correlation between stromal ER-a and PR expression and FAM tumor size using archived specimens from RSI UNISMA. An analytic observational study with a cross-sectional design was conducted on 24 archived FAM tissue samples, with tumor size obtained from medical records. ER-a and PR expression in stromal tissue were evaluated using immunohistochemistry and quantified with ImageJ software. Data were analyzed using Spearman correlation with p<0.05. Tumor sizes ranged from 2-10 cm, with a mean ER-a expression of 2.46% and PR expression of 5.58%. Spearman test showed no significant correlation between stromal ER-a or PR expression and tumor size (p>0.05), although ER-a and PR contributed 23% and 11% respectively to tumor size variation. In conclusion, stromal ER-a and PR expression were not significantly associated with FAM tumor size, likely due to their dominant expression in ductal epithelial rather than stromal tissue.