A Study of Matrix Metalloproteinase 9 and CD31 Expression through Immunohistochemistry in Invasive Breast Cancer

This study was performed to investigate possible relationships between the manifestation of stromal cells (fibroblasts and/or myofibroblasts) by focusing on expression of their matrix metalloproteinase 9 (MMP9) and possible angiogenesis based on CD31 and CD34 antigen expression during the various steps of hyperplastic changes to precancerous state and invasive breast cancer. Our study included 50 females with invasive ductal carcinoma. Samples were obtained by mastectomy or biopsy and were immunohistochemically stained for the MMP9, CD31, and CD34 antibody. microvessel count (MVC) was also carried out on samples. Statistical analysis of the data was performed using ANOVA and Student's t-test (P < 0.05). Findings were compared with our "Breast Cancer Data Bank" for reevaluation of their clinical staging. Positive significant correlations were observed between expression of MMP9 and invasive ductal carcinoma in situ (DCIS) and fibrocystic disease ± ductal intraepithelial neoplasia (FCD ± DIN) areas (P=0.001). MMP9 expression in invasive areas was more strongly positive than precancerous areas. Statistically significant correlations were observed between MMP9 expression and CD31 in grade II in invasive areas. MVC was evaluated by CD31 antibody. It was found to be inversely related to increased MVC from invasive areas, DCIS, DIN, and normal areas (P<0.001). No significant difference was observed in MVC based on age, tumor size or steroid receptors in stroma of an invasive cancer, DCIS, and FCD ± DIN. MMP9 expression in invasive areas was more strongly positive than precancerous areas, and negative in normal areas. Angiogenesis can be observed before any significant changes in preinvasive breast lesions. The elevated content of microvessel count of the tumor may be an indicator for worse prognostic factor. The progression from epithelial hyperplasia toward DCIS, and then, invasive carcinoma seems too complex to be assumed a linear progression.