BIOLOGIC AND CLINICAL-SIGNIFICANCE OF BASIC FIBROBLAST GROWTH-FACTOR IMMUNOSTAINING IN BREAST-CARCINOMA

Acetone-fixed cryostat sections of 79 breast carcinomas were immunosta ined with antibodies to basic fibroblast growth factor (bFGF) and urok inase-type plasminogen activator (uPA). Staining intensity was then co mpared with microvessel density assessed by manually counting vascular spaces highlighted by immunostaining vascular basal lamina (Type TV) collagen. Extensive (2+) bFGF immunoreactivity was present in neoplast ic cells of 30 tumors (38%) and in host-derived stromal cells of 29 ca ses (37%). Disease recurrence correlated with bFGF staining: 0 to 1+ s tromal staining, 30% recurred versus 2+ stromal staining, 73% recurred (P = 0.001) (54-mo median follow-up). Neither stromal nor epithelial bFGF staining correlated significantly with microvessel count; however , there was a statistically significant association between stromal ce ll bFGF staining and uPA staining of peritumor host cells: absent bFGF -0% 2+ uPA versus weak bFGF-9% 2+ uPA versus 2+ bFGF-29% 2+ uPA (P = 0 .01). We conclude that elevated expression of bFGF in breast carcinoma s is associated with aggressive clinical behavior. Its biologic signif icance, however, appears more closely related to extracellular matrix remodeling than to induction of prominent neovascularization per se.