RESUMO
BACKGROUND/AIM: The early diagnosis of breast cancer plays an important role in reducing mortality and optimizing the prognosis of the disease. The existing visual and histopathological methods do not give any information at a molecular level. Fourier transform infrared spectroscopy does not require any preparation, such as fixation and histological stains. The collected infrared spectral "biomarker bands" give information at a molecular level and could be used for biomarker screening, in order to minimize the false-positive or false-negative results. MATERIALS AND METHODS: For this prospective study, nine biopsies of lobular carcinoma (7 in situ and 2 invasive) and the adjacent healthy region of the biopsies were used. Each infrared spectrum consisted of 120 scans/spectrum (120 co-added spectra) at a spectral resolution of 4 cm -1 . RESULTS: The infrared spectral analysis revealed three important "diagnostic spectral regions" between 3,300-2,850 cm -1 , 1,700-1,500 cm -1 , and 850-800 cm -1 , which are related to membrane, collagen, and DNA configuration damage, respectively. The shift of the absorption band at 1,161 cm -1 at higher wave numbers up to 1,172 cm -1 is assigned to vC-O-C bonds due to membrane, protein, and DNA glycosylation. CONCLUSION: The "biomarker bands" at 1,172 cm -1 can be used as "diagnostic marker bands" for cancer progression. The shift of the absorbance band at 825 cm -1 of the native configuration of B-DNA to lower wavenumbers at 810 cm -1 Z-DNA in grade III, suggests the irreversible stage of the disease. The detection and possibility to differentiate the DNA structures may allow detection of carcinogenesis at the early stage of the disease, and development of new anticancer therapies.
