Diagnosis of Basal Cell Carcinoma by Raman Spectroscopy

Skin cancers are the most common form of malignant neoplasms in man. In this work, near-infrared Fourier transform (NIR-FT) Raman spectroscopy was used to study the molecular alterations in the most common skin cancer, basal cell carcinoma (BCC). Biopsies from 16 histopathologically verified BCC and 16 biopsies from normal skin were harvested and analysed by NIR-FT-Raman spectroscopy using a 1064 nm Nd:YAG laser as a radiation source. Differences in Raman spectra between BCC and normal skin indicated alterations in protein and lipid structure in skin cancer samples. Spectral changes were observed in protein bands, amide I (1640–1680 cm-1), amide III (1220–1300 cm-1) and ν(C–C) streching (probably in the amino acids proline and valine, 928–940 cm-1), and in bands characteristic of lipids, CH2 scissoring vibration (1420–1450 cm-1) and —(CH2)n— in-phase twist vibration around 1300 cm-1. Moreover, possible changes in polysaccharide structure were found in the region 840–860 cm-1. Analysis of the band intensities in the regions 1220–1360, 900–990 and 830–900 cm-1 allowed for a complete separation between BCC and normal skin spectra. In addition to a direct assessment of spectral intensities, a neural network analysis was performed, which confirmed the differences in spectra between BCC and normal skin. In conclusion, Raman spectra from BCC differ considerably from those of normal skin. Hence, Raman spectroscopy can be viewed as a promising tool for the diagnosis of skin cancer. © 1997 by John Wiley & Sons, Ltd.