Fourier Transform Infrared Spectroscopic Characterization of Human Breast Tissue: Implications for Breast Cancer Diagnosis

Some remarkable spectral differences are observed among normal, benign, and malignant breast tissue samples: (1) characteristic spectral patterns of fibroadenoma and carcinoma tissues appear in the frequency regions of 950–1150 cm⁻¹ and 2800–3050 cm⁻¹; (2) the peak at 970 cm⁻¹ is sharper and stronger, and the prominent bands at 1204, 1280, and 1338 cm⁻¹ are weaker and broader for carcinoma tissue, whereas the band near 970 cm⁻¹ is weaker, and the prominent peaks of collagen are sharper and stronger for benign tissues; (3) the band near 1163 cm⁻¹ in benign tissues shifts to 1171 cm⁻¹ in carcinoma tissue; (4) A₁₀₃₂/A₁₀₈₃ and A₂₉₅₈/A₂₈₅₃ ratios in carcinoma tissue are the smallest, whereas they are the highest in fibroadenoma tissue among the corresponding ratios; and (5) A₁₄₅₉/A₁₂₄₁ > 1.0 for normal tissue, A₁₄₅₃/A₁₂₃₉ > 1.0 for fibroadenoma, and A₁₄₅₆/A₁₂₃₉ < 1.0 for hyperplasia and carcinoma tissues. These significant differences reveal the differences in the relative contents of nucleic acids and collagen proteins in breast tissues. Furthermore, these differences have important implications not only for probing and analyzing the developing process of the breast lesion at the molecular level but also for evaluating the histological types and grades of breast diseases.