Intratumoral aromatase as a prognostic factor in human breast carcinoma.

Intratumoral aromatase activity (AA) was measured in 145 samples of human primary breast carcinoma using the tritiated water release assay which quantifies the tritium lost to water during the aromatization of 1 beta-[3H]androstenedione to estrone. Significant AA was detected in 91/145 (63%) tumors. The possibility of a relationship between AA and a variety of clinical prognostic factors such as estrogen receptors, menopausal status, site, size, and histological grade of tumor was investigated. Possible relationship with time to relapse, overall survival, and survival of patients after relapse were also studied to determine whether intratumoral AA itself was of any prognostic value. There was no relationship between AA and tumor size, site, nodal status, menopausal status or estrogen receptors. However there was a significant correlation between AA and histological grade with an excess of AA-positive tumors having high grade (P = 0.03). There was no significant relationship between AA and overall survival (P greater than 0.1), but there was a marginal inverse correlation between AA and time to relapse (P less than 0.1). A statistically significant correlation was found between AA and survival of patients after relapse (P less than 0.05).