Insulin-like growth factor-1 (IGF-1) is an important
growth factor for
breast cancer cells and
insulin-like growth factor binding protein-3 (IGFBP-3) its most prevalent
binding protein.
Prostate-specific antigen (PSA) enzymatically cleaves
IGFBP-3 into fragments (BP3-FR). Our purpose was to determine the association of these markers in nipple aspirate fluid (NAF) and serum with the presence of
breast cancer. NAF from 175 and serum from 215 subjects were collected from women with or without
breast cancer. In unadjusted analysis low NAFPSA (P < 0.001) and high NAFIGFBP-3 (P = 0.023) were associated with
breast cancer. Low serum PSA was associated with postmenopausal
breast cancer (P = 0.034). In separate multivariate analyses, controlling for age, menopausal status, and age at menarche, NAF PSA and
IGFBP-3 were each associated with
breast cancer. The association was significant for NAF
IGFBP-3 in all women (P = 0.031), but for NAF PSA only in premenopausal women (P < 0.001). When considered jointly, only NAF PSA was significant. Therefore, NAF PSA, and to a lesser extent NAF
IGFBP-3 and serum PSA, seem to be important predictors of
breast cancer.