Analysis of Breast Tissue Calcifications using FTIR Spectroscopy

Microalcifications can be found in both benign and malignant breast lesions and their composition can indicate the disease state. Type I microcalcifications are composed of calcium oxalate dihydrate (COD) and are associated mainly with benign tissue, whereas hydroxyapatite (HAP) can be present in both tissue types. As current practices such as mammography and histopathology examine the morphology of the specimen, they can not reliably distinguish between the two types of calcification, which frequently are the only mammographic features that indicate the presence of a cancerous lesion. Analysis of tissue by Fourier transform infrared microspectroscopy (FTIR) allows biochemical information to be achieved from the sample. Spectral maps have been carried out on paraffinized sections of breast tissue from 9 patients of different pathology types containing calcification. The chemical composition of the calcifications and surrounding tissue has been analysed and correlated with tissue pathology. This preliminary study has demonstrated the ability to conduct FTIR in paraffinized sections of breast tissue, and initial observations show a correlation between HAP carbonate substitution and tissue pathology. It is hoped that this and further studies will give insight into how the calcifications are linked to the disease process and will give an increased understanding of the significance of calcifications in breast tissue. If type II microcalcifications can be differentiated in benign and malignant tissue by spectroscopic techniques, this may have positive implications in early diagnosis if the techniques can be applied in vivo and spectroscopy of paraffin sections enables biochemical information to accompany histopathology of the sample.