High levels of stromelysin-3 correlate with poor prognosis in patients with breast carcinoma.

Stromelysin 3 (ST3) is a matrix metalloprotease (MMP) expressed in fibroblast-like cells of most human invasive carcinomas. In this investigation, ST3 was measured by semiquantitative immunohistochemistry in 111 primary breast cancers. ST3 levels showed no correlation with tumor size, axillary-node status or tumor grade (Scarff-Bloom-Richardson system; SBR) but were significantly associated with higher nuclear grade (modified SBR). In addition, ST3 levels were significantly higher in ductal than in lobular cancers. Patients with high scores of ST3 staining had a shorter disease-free interval and shorter overall survival than patients with low scores. ST3 is thus one of the first MMPs to correlate with patient outcome in breast cancer. These findings are consistent with earlier clinical and experimental observations suggesting that ST3 contributes to breast-cancer progression.