Radiological results of the Age Trial

Almost 500 cancers occurring within the study arm of the Age Trial have had their radiological features reviewed. The commonest radiological features of screen-detected cancers in this age group are granular microcalcification (28%), spiculate mass (22%), poorly defined mass (20%) and comedo calcification and parenchymal distortion both at 18%. Of the 254 cancers detected at screening that had a previous screen, 52% showed some mammographic feature on the previous screen. The most frequent abnormality in such cases was granular microcalcification 44%, parenchymal deformity 17% and poorly defined mass 17%. Of the 138 interval cancers reviewed, 30% had abnormalities visible on previous screens. The commonest features present on previous screens were microcalcification, asymmetric density and ill-defined mass.

The radiological features of cancers arising in younger women who are being screened are different to those occurring in older women. Spiculate masses are less common and microcalcification is more common in this age group. Microcalcification is also a common feature of screen-detected cancers visible on previous screens.

False negative interval cancers show a more varied distribution of radiological features, with asymmetric density, parenchymal deformity and microcalcification all being important features.