Raman spectroscopy of normal and diseased human breast tissues

Raman spectra of histologically normal human breast biopsy samples were compared to those exhibiting infiltrating ductal carcinoma (IDC) or fibrocystic change. Experiments at 784 nm with CCD detectors reduced fluorescence interference and produced high SNR spectra with relatively low (10-200 mW) laser power. Sample to sample and patient to patient variation for normal specimens were less than 5% for the ratios of major Raman bands. The Raman spectra changed dramatically in diseased specimens, with much weaker lipid bands being evident. The spectrum of infiltrating ductal carcinoma samples is similar to that of human collagen. Differences between benign (fibrocystic) and malignant (IDC) lesions were smaller than those between normal and IDC specimens, but were still reproducible. Fiberoptic sampling through a hypodermic needle and with a remote probe were demonstrated. The possibility of rapid diagnosis with Raman spectroscopy is considered.