Fourier-transform infrared spectroscopic study of characteristic molecular structure in cancer cells of esophagus: An exploratory study

Objective: To investigate the structural changes at the molecular level and to assess the usefulness of Fourier-transform infrared (FTIR) spectroscopy in the diagnosis of esophageal cancer. Methods: A pilot study was established of 10 consecutive patients with adenocarcinoma of the esophagus. Tissue samples from the diseased and normal sites of the resected specimens were analyzed and compared using FTIR spectroscopy and histopathology. Results: Specific changes were observed in the FTIR spectral features of esophageal cancer and thus spectral criteria were established for the detection of malignancy in esophagus tissues by FTIR spectroscopy. The spectral changes in cancer were the results of characteristic structural alterations at the molecular level in the esophageal cancer specimens. These alternations included an increase in the nuclei-to-cytoplasm ratio, an increase in the relative amount of DNA while a decrease in the relative amount of RNA, an enhancement in the phosphorylation of proteins, a decrease in the glycogen level, a loss of hydrogen bonding of the COH groups in the amino acid residues of proteins, a tighter intermolecular packing and a stronger intermolecular interaction among the DNA molecules, an increase in the distribution of protein segments with the conformation of β-sheet and unordered turns and a tighter packing of the α-helical segments in overall tissue proteins, a decrease in the overall CH3-to-CH2 ratio and an accumulation of triglycerides. Conclusions: FTIR is an automated method that has shown promise in differentiating cancer in the esophagus and may play a role in surveillance programs in premalignant conditions.