Stromal expression of CD10 in invasive breast carcinoma and its association with tumour stage, grade, ER, PR and HER2 status

Tumour microenvironment (TME) has been postulated to be involved in cancer development and disease progression. Studies have shown CD10 expressed in cancer-associated fibroblasts (CAF) within TME is associated with aggressive biological behaviour and poor prognosis. The aim of this study was to evaluate stromal CD10 expression in invasive breast cancer and its correlation with tumour stage, grade, Estrogen receptor (ER), Progesterone receptor (PR) and HER2 status. A total of 226 invasive breast carcinoma cases were selected and assembled into tissue microarrays (TMAs). The stromal expression of CD10 was immunohistochemically analysed. Stromal CD10 was positive in 67 (29.6%) cases of invasive breast carcinoma. The frequency of positive stromal staining was significantly higher in the cases with ER-negative (P=0.000). CD10 stromal negativity was significantly higher in luminaltype cases (P=0.001). However, there was no correlation between stromal CD10 expression with tumour grade, stage, PR and HER2 status. Positive CD10 stromal expression correlates with ER-negative invasive breast carcinomas, while negative CD10 stromal expression correlates with luminal type invasive breast carcinomas. This demonstrates that stromal CD10 expression within the TME constitutes a potential prognostic marker and therapeutic target. Future studies are necessary to evaluate other stromal markers within the TME immunohistochemically as well as its molecular basis in order to confirm the definite role of stromal CD10.