Tumor DNA samples from 387 breast carcinomas have been investigated for amplification of BEK and FLG genes, both of which have been shown to code for cell surface receptors to FGFs. BEK and FLG were found amplified in 11.5 and 12.7% of breast tumors respectively. Statistical analysis, performed on the subset of 297 primary cancers without presurgical therapy, showed for BEK a trend of preferential amplification in patients above 50 years (P = 0.055), whereas amplification of FLG could significantly be correlated with nodal involvement (P = 0.032) and seemed prevalent in steroid hormones receptor positive tumors. Since the same tumors were previously analysed for the amplification of MYC, ERBB2 and HST/INT2/BCL1 possible associations with BEK and FLG amplifications were looked for. BEK was found significantly correlated with MYC and FLG with HST/INT2/BLC1. The amplification of these two FGF receptor genes may therefore represent additional steps in the molecular phenotyping of breast cancer.