A case–control study to estimate the impact on breast cancer death of the breast screening programme in Wales

Twenty-five years after its first description the p53 protein has been shown to play a key role in both cancer and ageing. The p53 protein is activated by many different stress pathways, including oncogene action and DNA damage. The elucidation of the p53 response, which is aberrant in most cancers (including breast, lung, stomach and colorectal cancer), has provided many new targets for drug development and p53 gene therapy is now approved in China. In tumours where p53 is mutant small molecules may be able to restore its function. In many tumours the wild-type p53 gene remains intact but its function is compromised by loss of upstream signalling pathways or downstream effectors.