The Calman-Hine report was published in the UK in April 1995. It recommended the reorganization of cancer services into high-volume specialist units. This study analyzes Health Episode Statistics from the West Midlands Region of the UK NHS in order to establish whether--for breast cancer--specialization is occurring. We believe it is. Each year since the start of our analysis (1992) the proportion of procedures performed by 'high-volume' firms increased. The number of firms undertaking breast cancer procedures fell.