PURPOSEWe evaluated the impact of 21-gene test results on treatment decisions for patients with early-stage breast cancer treated under the public health care system in Brazil, Sistema Único de Saú...

This study intends to verify the expression levels and correlation of aromatase, matrix metalloproteinase 2 (MMP-2), matrix metalloproteinase 9 (MMP-9) and CD44 in ductal carcinoma in situ (DCIS) and infiltrating ductal carcinoma (IDC) when both are found in the same breast. One hundred and ten cases were evaluated by tissue microarray (TMA) and immunohistochemically screened with anti-aromatase polyclonal antibodies, anti-MMP-2 monoclonal antibodies, anti-MMP-9 polyclonal antibodies and anti-CD44 monoclonal antibodies. Aromatase was expressed in IDC and DCIS in 63 (57.3%) and 60 (67%) of the cases respectively; MMP-2 was similarly expressed in IDC and DCIS in 15 (13.60%) cases; MMP-9 was positively expressed in IDC and DCIS in 83 (75.50%) and 82 (74.50%) cases, respectively; CD44 was positively expressed in IDC and DCIS in 49 (44.50%) and 48 (42.60%) of the cases, respectively; all of them were highly correlated (p<0,001). The correlation analysis found positive, statistically significant correlation, in IDC between aromatase and MMP-2 (p<0.001) and between aromatase and MMP-9 (p=0.034). Positive correlation between aromatase and MMP-2 (p<0.001) and between MMP-9 and CD44 (p=0.030) were found in DCIS. These results allow us to conclude that aromatase through local estrogen synthesis in breast tissue plays an important role in breast carcinogenesis, mainly influencing MMP-2 and MMP-9 which are important participants in tumor cell invasion and dependence of their connection to CD44 for action.