Proteomic approach to breast cancer.

BACKGROUND Breast cancer is the most common cancer affecting women worldwide. Despite tremendous advances in screening, diagnosis, and treatment, the causes of this disease remain elusive and complex. Proteomics is a rapidly developing field that can explore the heterogeneity of breast cancer and supplement the wealth of information gained from genomics. METHODS This article serves as an overview of the application of matrix-assisted laser desorption/ionization source with a time-of-flight (MALDI-TOF) proteomic techniques as applied to breast cancer. Examples of the clinical applicability of MALDI-TOF mass spectrometry are provided but represent only a fraction of the potential uses yet to be discovered. In addition, a brief summary of the bioinformatics issues that surround proteomics is included. RESULTS Mass spectrometry has provided new proteomic approaches to unravel the complexities of clinical specimens relevant to breast cancer diagnostics. In particular, MALDI-TOF mass spectrometry analysis has been used to differentiate cancer profiles from benign profiles in samples from sera, plasma, tissue, nipple fluid, and ductal lavage. Some discriminating proteins have subsequently been identified. CONCLUSIONS Mass spectrometry applications to breast cancer diagnostics continue to be developed but are evolving faster than bioinformatics/statistical analysis can adapt. The future of these techniques in terms of clinical investigation is limitless, but in terms of general applicability, these applications are currently cost-prohibitive.