Abstract B10: Design of the DENSE trial: MRI as an additional screening modality to detect breast cancer in women aged 50-75 years with extremely dense breasts

Background: Women with high mammographic density have an increased breast cancer risk and also a lower mammographic tumor detectability. Nevertheless, these women are currently screened with mammography only. MRI could lead to earlier tumor detection, because of its higher sensitivity. To study the additional value of MRI, a parallel-group randomized controlled trial design is needed with one group receiving mammography and the other group receiving mammography and MRI. With this design it is possible to determine the proportion of interval tumors within each arm. A reduction in interval tumors is a precondition of effectiveness, because this represents clinically relevant cancer detection, rather than overdiagnosis. Study design: DENSE is a multicenter randomized trial, carried out in the Dutch biennial screening program (age range 50-75 years). Mammographic density is measured using a fully-automated volumetric method (Volpara™). Participants with extremely dense breasts (ACR4) and a negative mammogram are randomized to ‘additional MRI’ (n=7,237) versus ‘current practice’ (n=28,948). After randomization, only the intervention arm is asked for consent (single-consent prerandomized design). The intervention consists of a dynamic breast MRI with gadolinium-based contrast medium (Gadovist®) and is carried out for 3 screening rounds. The primary outcome is the difference in proportion of interval tumors between the arms. Secondary outcomes are the number of MRI screen-detected tumors, proportion false-positives, quality of life, breast cancer mortality and costs. Conclusion: DENSE investigates the (cost-)effectiveness of screening with mammography and MRI compared to mammography alone in women with extremely dense breasts aged 50-75 years. Inclusion started in December 2011. Citation Format: Marleen Emaus, Wouter Veldhuis, Marije Bakker, Evelyn Monninkhof, Nico Karssemeijer, Maurice van den Bosch, Petra Peeters, Willem Mali, Carla van Gils. Design of the DENSE trial: MRI as an additional screening modality to detect breast cancer in women aged 50-75 years with extremely dense breasts. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr B10.