Response: Re: Breast Tissue Composition and Susceptibility to Breast Cancer

Extract

Colin and Schott raise a number of issues related to mammographic density and risk of breast cancer, which was the subject of our recent review. They point out that variations in mammographic technique may influence the appearance of density. However, despite this potential source of variation, there has been great consistency in descriptions of the association between mammographic density and the risk of breast cancer. This consistency is seen across countries, study designs, methods of assessing density, subsets of women defined by age and menopausal status ( 1 ), screening programs ( 2 ), and time ( 2 , 3 ). The risk of breast cancer associated with mammographic density at a single point in time has been shown to persist for at least 10 years ( 3 ), is present in both screen-detected and interval breast cancers ( 2 ), and cannot be explained by the “masking” of breast cancer by dense breast tissue.