Prognostic significance of aromatase and estrone sulfatase enzymes in human breast cancer.

The aromatase and estrone sulfatase enzymes are important sources of local synthesis of biologically active estrogens in human breast cancer. Significant intratumoral aromatase activity was detected in 91/145 (63%) of tumors and estrone sulfatase was detected in 93/104 (89%) of tumors. There was no relationship between aromatase activity and tumor size, site, nodal status, menopausal status or estrogen receptor status. There was a significant correlation between the aromatase activity and histological grade, with an excess of aromatase-positive in the high grade tumors (P = 0.03). There was a marginally inverse correlation between the aromatase activity and time to relapse (P < 0.1), a significant correlation between aromatase activity and survival after relapse (P < 0.05) but not with overall survival (P > 0.1). Intratumoral estrone sulfatase activity was not significantly correlated to any putative prognostic factors, nor with time to relapse nor overall survival time.