Original article S194 Journal of Research in Medical Sciences | March 2012 Special Issue (2) | CD10 expression in stromal component of invasive breast carcinoma: A potential prognostic determinant Fereshteh Mohammadizadeh 1 , Majid Salavati 2 , Noushin Afshar Moghaddam 1 1 Associate Professor, Department of Pathology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. 2 Resident, Department of Pathology, School of Medicine And Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran. BACKGROUND: CD10 is a cell surface metalloproteinase which inactivates various biologically active peptides. Earlier studies have suggested CD10 expression in the stroma of various carcinomas to be associated with more aggressive behavior of the tumor. The aim of this study was to assess CD10 expression in stromal component of invasive breast carcinoma and its relationship with well-known clinicopathologic parameters. METHODS: This study included 49 formalin-fixed and paraffin-embedded tissue speci- mens of invasive breast carcinoma from the pathology archive of a referral hospital. CD10 expression was detected by immunohisto- chemistry and scored based on the staining intensity and percentage of the stained cells. Kruskal-Wallis and Mann-Whitney tests, along with Spearman's correlation coefficients were used to determine the relationship between CD10 expression and clinicopatho- logic parameters. RESULTS: No association was found between stromal CD10 expression and age, carcinoma subtype, and HER2/neu status. A significant positive correlation was seen between stromal CD10 expression and tumor size (p = 0.01), axillary lymph node status (p = 0.02), and tumor grade (p = 0.004). Although negative correlations were detected between stromal CD10 ex- pression and estrogen receptor and progesterone receptor status, these correlations were not statistically significant. CONCLUSIONS: Tumor grade is a major prognostic indicator of breast carcinoma. Tumor size and nodal status on the other hand, are important determinants of tumor stage. Therefore, our findings concerning the positive correlations between stromal CD10 ex- pression and tumor grade, tumor size, and nodal status suggest a strong effect of stromal CD10 expression on aggressive behavior of breast carcinoma and introduce this marker as a potential prognostic determinant in breast cancer. KEYWORDS: Invasive Breast Carcinoma, Stroma, CD10 BACKGROUND CD10, also known as common acute lymphoblastic leukemia antigen (CALLA) and neprilysin, is a 90‐ to 110‐ kDa cell surface zinc dependent metalloprotease that inactivates various kinds of biologically active peptides. First thought to be specific to acute lym‐ phoblastic leukemia, it was shown in subsequent stu‐ dies to be expressed on the surface of a variety of normal and neoplastic cells. [1] CD10 expression is commonly seen in bone mar‐ row lymphoid stem cells, pre‐B lymphocytes, ma‐ ture neutrophils, breast myoepithelial cells, bile ca‐ naliculi, and renal epithelial cells. Expression of CD10 by tumor cells is seen in some lymphoid ma‐ lignancies including lymphoblastic, Burkittʹs and follicular lymphomas, as well as some nonlympho‐ id malignancies such as endometrial stromal sar‐ coma. Moreover, CD10 positive cells have also been reported in the stroma of prostate, and breast, colo‐ rectal and lung carcinomas. [1] Stromal CD10 expression is associated with more aggressive behavior in various epithelial ma‐ lignancies. [1‐3] In gastric carcinoma, CD10 positive stromal cells are correlated with vascular invasion and metastasis. [4] In nasopharyngeal carcinoma, stromal CD10 expression correlates with tumor progression. [5] To the best of our knowledge, until 2012, only 5 studies have addressed the clinical significance of stromal CD10 expression in invasive breast carci‐ noma. These studies have indicated an association between CD10 expression and poorer prognosis. [1‐3,6,7] The small number of the previous studies in this field and some discrepancies in their results led us to do the present study. In the present study, we examined the expression of CD10 in the stroma of invasive breast carcinoma and its relationship with some well‐known clinicopathologic prognostic de‐ terminants of cancer. METHODS This study was performed on 49 women who had undergone modified radical mastectomy for Address for correspondence: Majid Salavati, Resident, Department of Pathology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. E-mail: msslvt@yahoo.com Received: 22.11.2011; Revised: 24.12.2011; Accepted: 26.01.2012 www.mui.ac.ir