In Reply Syn expresses concern that our analysis of the long-term accuracy of breast cancer risk assessment in a cohort of women who underwent breast cancer screening could be inadequate because some women could have undergone risk-reducing surgery or preventive therapy.1 Although we do not have data to directly assess this issue, we believe that our findings are robust; this is an average-risk cohort, and very few women are likely to have received these interventions.2-5 This view is supported by 4 observations.