Distribution and prognostic value of the fibroblast growth factor-2 low-affinity binding sites in human breast cancer

We performed a competitive binding study with 125I-labelled FGF (fibroblast growth factor)-2 and unlabelled FGF-2 in an unselected series of two hundred and thirty human primary breast cancers. One hundred and ninety-two breast cancer biopsies possessed FGF-2 low-affinity binding sites (FGF-2 LABS). The median dissociation constant was 2.4 nM (range, 1.03-18) and the median concentration of membrane protein was 6187.5 fmol/mg (range, 831-90,000). FGF-2 LABS concentrations were positively correlated to the progesterone receptor level. Cox univariate analyses showed that the FGF-2 LABS (> or = upper quartile) was associated to a longer overall survival (p = 0.05; RR = 0.042); node involvement, estrogen receptor progesterone receptor and histoprognostic grading were also prognostic. In Cox multivariate analyses, only the progesterone receptor, estrogen receptor, node involvement and FGF-2 LABS were prognostic factors; the FGF-2 LABS were associated with a longer overall survival (p = 0.033; RR = 0.068). The present study showed that FGF-2 LABS have only a limited role as a prognostic factor in breast cancer.