Abstract
Cancer is a dreaded disease; a large number of deaths occur every year due to this disease. Oral squamous cell carcinoma (OSCC) is the most common cancer of the head and neck, which is approximately 16% to 40% of all malignancies. In this study, Laser induced fluorescence (LIF) spectroscopy
has been utilized to discriminate OSCC against healthy (normal) tissues and to investigate whether the LIF could provide information from formalin-fixed paraffin-embedded (FFPE) tissue samples similar to that reported using fresh tissues. Samples were prepared after biopsy from ten patients
using standard FFPE tissues methods. LIF system consists of a continuous wave (CW) He-Cd laser at 325 nm, a seven-core optical fiber cable coupled to the laser, a spectrometer with cooled charge coupled device (CCD) detector, and a computer for acquisition of the LIF spectra. Spectra
were decomposed using second derivative and curve fitting analysis to reveal the changes in molecular composition of the samples. Moreover, samples spectra were discriminated by hierarchical cluster analysis (HCA) and principal components analysis (PCA). Spectral results showed differences
in peak areas and positions between normal and OSCC tissues. LIF spectroscopy revealed significant decrease in the peak area of collagen and decrease in peak area of coenzymes of OSCC tissues. In addition, significant shift in the peak position of coenzymes was recorded. HCA and PCA of LIF
indicated a very clear discrimination of the normal and FFPE-OSCC tissues. The achieved discrimination between elliptic polygons of normal and OSCC tissues was 96.3% by PCA. This study confirms that the LIF spectroscopy is a good diagnostic tool for OSCC and it could be used with samples that
are prepared using FFPE tissues methods.