Prospective surveillance of women with a family history of breast cancer: auditing the risk threshold

To evaluate current guidelines criteria for inclusion of women in special 'breast cancer family history' surveillance programmes, records were reviewed of women referred to Scottish breast cancer family clinics between January 1994 and December 2003 but discharged as at 'less than 'moderate' familial risk'. The Scottish Cancer Registry was then interrogated to determine subsequent age-specific incidence of breast cancer in this cohort and corresponding Scottish population figures. Among 2074 women, with an average follow-up of 4.0 years, 28 invasive breast cancers were recorded up to December 2003, where 14.4 were expected, a relative risk (RR) of 1.94. Eleven further breast cancers were recorded between January 2004 and February 2006 (ascertainment incomplete for this period). The overall RR for women in the study cohort exceeded the accepted 'cutoff' level (RR = 1.7) for provision of special counselling and surveillance. The highest RR was found for the age group 45-59 years and this group also generated the majority of breast cancers. The National Institute for Clinical Excellence ('NICE') guidelines appear to be more accurate than those of the Scottish Intercollegiate Guidelines Network ('SIGN') in defining 'moderate' familial risk, and longer follow-up of this cohort could generate an evidence base for further modification of familial breast cancer services.