Early breast cancer detection

Early detection is critical for the clinical management of breast cancer. In the February 27 Proceedings of the National Academy of Science, Martin et al. describe a highly sensitive blood-based assay to detect and classify solid tumours (Proc Natl Acad Sci USA 2001, 98:2646-2651). The high-throughput assay involves a two-step approach, combining differential display with cDNA microarrays. Martin et al. analysed blood samples from 26 breast cancer patients for the expression of 12 breast cancer marker genes. The markers were elevated in 77% of untreated invasive cancer patients, but not in those treated with chemotherapy. The authors suggest that their technique is particularly sensitive as a result of the use of P32 labelling, membrane filters and longer cDNA tags. The assay can detect as few as five tumor cells per millilitre of blood, making it suitable for clinical screening and early detection.