Raman microspectroscopic model of human breast tissue: implications for breast cancer diagnosis in vivo

Abstract Raman spectroscopy has the potential to provide real‐time, in situ diagnosis of breast cancer during needle biopsy or surgery via an optical fiber probe. Understanding the chemical/morphological basis of the Raman spectrum of breast tissue is a necessary step in developing Raman spectroscopy as a tool for in situ breast cancer diagnosis. To understand the relationship between the Raman spectrum of a sample of breast tissue and its disease state, near‐infrared Raman spectroscopic images of human breast tissue were acquired using a confocal microscope. These images were then compared with phase contrast and hematoxylin‐ and eosin‐stained images to develop a chemical/morphological model of breast tissue Raman spectra. This model fits macroscopic tissue spectra with a linear combination of basis spectra derived from spectra of the cell cytoplasm, cell nucleus, fat, β‐carotene, collagen, calcium hydroxyapatite, calcium oxalate dihydrate, cholesterol‐like lipid deposits and water. Each basis spectrum represents data acquired from multiple patients and, when appropriate, from a variety of normal and diseased states. The model explains the spectral features of a range of normal and diseased breast tissue samples, including breast cancer. It can be used to relate the Raman spectrum of a breast tissue sample to diagnostic parameters used by pathologists. Copyright © 2002 John Wiley & Sons, Ltd.