Tailoring breast cancer screening intervals by breast density and risk for women 50 and older: Collaborative modeling of screening outcomes

Abstract

Background

Biennial screening is generally recommended for average-risk women aged 50–74 years, but tailored screening may provide greater benefits.

Objective

To estimate outcomes for varying screening intervals after age 50 based on breast density and risk.

Design

Collaborative simulation modeling using national incidence, breast density, and screening performance data.

Setting

U.S. population.

Patients

Women ages ≥50 with combinations of breast density and relative risk (RR: 1.0, 1.3, 2.0, 4.0).

Interventions

Annual, biennial, or triennial digital mammography screening from age 50 to 74 (versus no screening) and age 65 to 74 (versus biennial 50–64).

Measurements

Lifetime breast cancer deaths, life expectancy and quality-adjusted life years (QALYs), false-positives, benign biopsies, overdiagnoses, cost-effectiveness and ratio of false-positives to breast cancer deaths averted.

Results

Screening benefits and overdiagnosis increase with breast density and risk. False-positives and benign biopsies decrease with increasing risk. Among women with fatty or scattered fibroglandular breast density and RR=1.0–1.3, breast cancer deaths averted were similar for triennial versus biennial screening for both age groups (medians: age 50–74, 3.4–5.1 vs. 4.1–6.5; age 65–74, 1.5–2.1 vs. 1.8–2.6). Breast cancer deaths averted increased with annual versus biennial screening for ages 50–74 years with all levels of breast density and RR=4.0, and ages 65–74 years with heterogeneously or extremely dense breasts and RR=4.0, but harms were almost 2-fold higher. Triennial screening for average-risk and annual screening for highest-risk subgroups cost <$100,000 per QALY gained.

Limitations

Models did not consider ages <50, RR< 1, or other imaging modalities.

Conclusions

Average-risk/low-breast density women undergoing triennial screening and higher-risk/high-breast density women receiving annual screening will maintain a similar or better balance of benefits and harms compared to biennial screening of average-risk women.

Primary Funding Source

National Cancer Institute