Biophysical characterization of human breast tissues by photoluminescence excitation-emission spectroscopy

Abstract

Fluorescence excitation-emission spectroscopy was used to investigate specimens of normal and malignant human breast tissues. Measurements were performed in two spectral regions: in the excitation range from 335nm to 400nm and emission range from 430nm to 625 nm, and in the excitation range from 400nm to 470nm and emission range from 500nm to 640 nm. It was found that fluorescence spectra are composed mainly of the emissions of extracellular proteins and that the differences in the intensity of their emissions reveal the changes in the tissue structure and morphology. These differences could be best observed in the emission spectra excited with 370 nm, 425nm and 455nm radiation. Statistical analysis revealed several spectral subregions that exhibited extremely significant statistical difference between normal and malignant breast tissues. The origin of these differences was elaborated, and prospects for optical diagnostics of breast cancer was discussed.

Using Fluorescence Spectroscopy to Diagnose Breast Cancer

“…Regarding breast cancer, it has been shown that distinct fluorescence response of tumors compared to one ordinary tissue is a result of notable differences in concentrations of collagen, elastin, NADH, and flavin adenine dinucleotide (FAD) [10]. Generally, fluorescence measurements have indicated lower concentrations of collagen and FAD and increased concentrations of NAD(P)H in malignant tissues compared to normal breast tissue [11]. Transformation from normal to malignant tissue leads to degradation and changes in the cross-links of collagen; breaking the cross-links in collagen is a consequence of the increased presence of collagenase in the tumor cells [12].…”

Emerging clinical applications in oncology for non‐invasive multi‐ and hyperspectral imaging of cell and tissue autofluorescence

“…Changes in the metabolic environment of cells (e.g., normal vs. cancer cells, changes after treatment) can be explored through the fluorescence spectra and abundance of fluorophores. Endogenous fluorophores including NADH, NADPH, FAD and porphyrins have generally been explored to analyse metabolic changes [24,25], whereas elastin [26] and collagen have been used to look at structural changes [27].…”

“…The changes in metabolism in cancerous and noncancerous tissue have been studied by analysing the fluorescence spectra of fluorophores [24,25]. NADH and FAD are the main coenzymes involved in cellular metabolism and are generally the predominate fluorescent signals present, thus are often used as metabolic markers [30].…”

“…NADH and FAD are the main coenzymes involved in cellular metabolism and are generally the predominate fluorescent signals present, thus are often used as metabolic markers [30]. Dramicanin et al found increased NADH concentration in malignant breast tissue, suggesting that this was due to damaged mitochondrial metabolism and a shift to anaerobic metabolism [25]. They also found an increase in intensity of PpIX in the malignant tissue, due to the tissue having better vascularity [25].…”

“…Dramicanin et al found increased NADH concentration in malignant breast tissue, suggesting that this was due to damaged mitochondrial metabolism and a shift to anaerobic metabolism [25]. They also found an increase in intensity of PpIX in the malignant tissue, due to the tissue having better vascularity [25]. Similar results were found by Pu et al who observed an increase in NADH and FAD content in breast tissue compared to normal tissue, however, there was a decrease in collagen [24].…”