NIPPLE ASPIRATE FLUID - A PROMISING NONINVASIVE METHOD TO IDENTIFY CELLULAR MARKERS OF BREAST-CANCER RISK

To evaluate the feasibility of nipple aspiration and to identify inter mediate markers of breast cancer risk, nipple aspirate fluid (NAF) was collected from 177 subjects using a modified breast pump. The first 3 3 subjects demonstrated that we could obtain NAF quickly, reliably and repeatedly. Specimens from the remaining 144 subjects were collected to evaluate promising cellular biomarkers. NAF was obtained in 167 out of 177 (94%) subjects overall and in 99% of the 144 most recent subje cts. Sufficient NAF was obtained to evaluate cytology in 160 out of 16 7 (96%) cases and specimens were sufficiently cellular to analyse DNA markers in 53% of cases. Among the last 144 subjects, menopausal statu s did not influence the ability to obtain NAF. NAF cytology correlated with increased breast cancer risk (P = 0.002), Using computerized ima ge analysis of NAF epithelial cells, DNA index (P = 0.0002), percentag e of cells in G(2)M (P = 0.05) and percentage of cells with hypertetra ploidy (P = 0.002) increased as cytology became more abnormal, Our dat a indicate that NAF can be obtained in essentially all eligible subjec ts; that breast epithelial cells are evaluable in > 95% of NAF samples for cytology and in over half of NAF samples for DNA index (ploidy) a nd cell cycle analysis; and that abnormal NAF cytology correlates with increased breast cancer risk, This suggests that biomarkers identifie d in nipple aspirate fluid may prove useful either as an adjunct to cu rrently accepted breast cancer screening methods, or to evaluate respo nse to a chemopreventive agent.