Communicating the benefits and harms of cancer screening.

Breast and cervical screening each have a distinct balance of benefits and harms. While they are both likely to reduce mortality, breast screening is associated with a greater relative frequency of serious harms than cervical screening. A unique approach has been adopted in England with respect to providing information on cancer screening with the goal of facilitating informed choice. The new materials provide more detail than previous information about the benefits and harms of screening as well as the scientific uncertainties. While there is a uniform format and the information covers the same key issues in both breast and cervical screening programmes, the emphasis and detail varies according to balance of benefits and harms within these programmes.