OBJECTIVES: Evidence indicates the association between breast density and risk of breast cancer. Unlike other risk factors, breast density is determined from mammography. This presents a challenge for screening policy, because breast density is obtained with screening mammography yet the screening initiation age varies across the screening guidelines. This study explores breast cancer screening strategies by incorporating information of breast density.

METHODS: We extended a previously validated microsimulation model for women at average risk for breast cancer to assess the cost-effectiveness of screening strategies that incorporates information on breast density. We consider strategies with a baseline mammography screening at age of 40 (vs. 45, vs. 50). For women without dense breast, the model considered three guideline-recommended strategies for average-risk women (annual screening starting at 40, biennial starting at 50, and a hybrid strategy with annual screening starting at 45 and switching to biennial at 55). For those with dense breast, we explore strategies that augment screening mammography with ultrasound and/or MRI. We conducted deterministic CEA and probabilistic CEA from the simulations.

RESULTS: Preliminary results supported screening strategies that involve a baseline assessment of breast density with mammography at age 40. Upon determination of women’s breast density, the optimal screening for women without dense breast was the hybrid strategy with cessation age 75, yielding an incremental post-effectiveness ratio slightly above $40,000 per quality-adjusted life years (QALYs) and the highest probability of being optimal at the societal willingness-to-pay (WTP) of $50,000/QALY and $100,000/QALY. Among women with dense breast, strategies that augment mammography with ultrasound dominated those that augment mammography with MRI, regardless of screening intervals as well as initiation ages.

CONCLUSIONS: Our study suggests that the optimal screening strategy would involve a baseline breast density assessment at age 40, followed by a strategy with screening mammography combining ultrasound for women with dense breast.