Optical spectral fingerprints of tissues from patients with different breast cancer histologies using a novel fluorescence spectroscopic device.

The fluorescence of paired human breast malignant and normal tissue samples was investigated using a novel fluorescence spectroscopic (S3-LED) ratiometer unit with no moving parts. This device can measure the emission spectra of key native organic biomolecules such as tryptophan, tyrosine, collagen and elastin within tissues by using LED (light emitting diode) excitation sources coupled to an optical fiber. With this device, the spectral profiles of 11 paired breast cancerous and normal samples from 11 patients with breast carcinoma were obtained. In each of the 11 cases, marked increases in the tryptophan levels were found in the breast carcinoma samples when compared to the normal breast tissues. In the breast cancer samples, there were also consistently higher ratios of the 340 to 440 nm and the 340 to 460 nm intensity peaks after 280 nm excitation, likely representing an increased tryptophan to NADH ratio in the breast cancer samples. This difference was seen in the spectral profiles of the breast cancer patients regardless of whether they were HER2 positive or negative or hormone receptor positive or negative, and was found regardless of menopausal status, histology, stage, or tumor grade.