Biochemical correlation of Raman spectra of normal, benign and malignant breast tissues: A spectral deconvolution study

The aim of this study was to understand and correlate spectral features and biochemical changes in normal, fibroadenoma and infiltrating ductal carcinoma of breast tissues using Raman spectra that were part of the spectroscopic models developed and evaluated by us earlier. Spectra were subjected to curve fitting and intensities plots of resultant curve resolved bands were computed. This study has revealed that fat (1301 and 1440 cm^-1), collagen (1246, 1271, and 1671 cm^-1) and DNA (1340 and 1480 cm^-1) bands have strong presence in normal, benign and malignant breast tissues, respectively. Intensity plots of various combinations of curved resolved bands were also explored to classify tissue types. Combinations of fat (1301 cm⁺¹) and collagen (1246, 1271, and 1671 cm^-1)lamide I; DNA (1340 cm^-1) and fat (1301 cm^-1); collagen (1271 cm^-1) and DNA (1480 cm^-1) are found to be good discriminating parameters. These results are in tune with findings of earlier studies carried out on western population as well as our molecular biological understanding of normal tissues and neoplastic processes. Thus the finding of this study further demonstrates the efficacy Raman spectroscopic approaches in diagnostic applications as well as in understanding molecular phenomenon in breast cancers.