Steroid sulfatase expression is an independent predictor of recurrence in human breast cancer

Steroid sulfatase (STS) hydrolyzes several sulfated steroids such as estron e sulfate, dehydroepiandrosterone sulfate, and cholesterol sulfate. Zn the present study, we have measured STS mRNA levels in 97 breast cancers by rev erse transcription-PCR using a fluorescent primer in the presence of an int ernal standard RNA and evaluated its association with disease-free and over all survival. The median value was 728.0 amol/ng RNA (range, 0-11,778 amol/ ng RNA), Levels were significantly higher in tumors demonstrating lymph nod e metastasis than in those without nodal involvement (P = 0.033) and in pat ients who experienced a recurrence during the follow-up period (mean, 40.8 months; median, 39 months) compared with those with no evidence of further disease (mean, 49.2 months; median, 48 months; P = 0.029), No significant a ssociations were found between STS mRNA expression and age, menopausal stat us, tumor size, histological grade, estrogen receptor status, or postoperat ive adjuvant therapy. High levels of STS mRNA proved to be a significant pr edictor of reduced relapse-free survival as a continuous variable (log STS mRNA; P = 0.028). As a dichotomous variable with an optimized cutoff point of 1,240 amol/ng RNA, expression was also associated with a significantly s horter relapse-free survival rate (P = 0.002), but no significant correlati on was found between the STS mRNA level and overall survival, Expression wa s found to be an independent factor for predicting relapse-free survival on multivariate analysis. The results thus support a putative role of STS in breast cancer growth and metastasis.