Abstract:
Previous research has shown that diagnostic information could be obtained from small
angle X-ray scattering from breast tissues. The observed differences were attributed to
two possible causes, the production of a new type of collagen around tumours and the
action of matrix metalloproteinases degrading the collagen around tumours. Using
both synchrotron radiation and conventional X-ray sources data was collected to
investigate these hypotheses. 225 X-ray scattering profiles were collected from breast
tissue samples from 82 individual patients using synchrotron radiation. The
differences between normal, malignant and benign tissues were investigated and
structural differences in the collagen were determined. The effects of
metalloproteinase action on collagen were also investigated and computer modelling
was used to simulate the diffraction profiles from collagen with structural alterations.
The structural differences in diseased tissues were attributed to a difference in the
structure of collagen which was observed as a reduction in peak intensity and
increased axial D spacing (0.3 nm increase in D period) compared to normal tissues.
The differences between malignant and benign disease were attributed to
metalloproteinase action degrading the collagen around tumours. Automatic
classification was applied using principal component analysis to tissue samples from
up to 6 cm away from the tumour site, approximately 90 % of the tissue samples at 6
cm were classified as cancer using the X-ray scattering profile but which were
diagnosed as normal by standard histopathological methods. The results of this
research have shown that X-ray scattering profiles contain diagnostic information
relating to the structure of collagen. The changes associated with disease may be
observed at up to 6 cm from the tumour site and that these differences in the X-ray
scattering profile may be measured using a conventional X-ray source.
