Mapping structural changes in breast tissue disease using x-ray scattering

Abstract

Spread of invasive carcinoma throughout breast tissue is believed to occur at supramolecular levels, beyond the range of standard histopathology identification. Small angle x-ray scattering (SAXS) is capable of characterizing the structural properties of collagen and tissue found in the breast at the scale of tens to hundreds of nanometers. Fifty-six patients who were treated with wide-local excision or mastectomy had tissue biopsy samples analyzed at 2 cm intervals along two perpendicular axes over their excised mass, up to 6 cm away from the primary site of the tumor. Two SAXS parameters, the integrated amorphous scatter and the third order collagen axial d spacing, showed significant differences between the center (0 cm) and distant tissues (2, 4, or 6 cm from the primary lesion). There was no evidence of directional trends (superior, inferior, or lateral sides of the nipple) of these two parameters over the breast. Mapping of these two variables over a two-dimensional grid showed good matching with independent histopathology diagnosis. These results suggest that SAXS may be capable of identifying areas of invasion or directional spread of disease as well as providing more information at the supramolecular level for aiding tissue diagnosis.