Using a computer model, this study sought to determine the threshold breast cancer risk at which the balance of benefits and harms of starting mammography screening at age 40 years equals that of c... Background: Timing of initiation of screening for breast cancer is controversial in the United States. Objective: To determine the threshold relative risk (RR) at which the harm–benefit ratio of sc...

Background: U.S. Black women have higher breast cancer mortality rates than White women despite lower incidence. The aim of this study is to investigate how much of the mortality disparity can be attributed to racial differences in natural history, uptake of mammography screening, and use of adjuvant therapy. Methods: Two simulation models use common national race, and age-specific data for incidence, screening and treatment dissemination, stage distributions, survival, and competing mortality from 1975 to 2010. Treatment effectiveness and mammography sensitivity are assumed to be the same for both races. We sequentially substituted Black parameters into the White model to identify parameters that drive the higher mortality for Black women in the current time period. Results: Both models accurately reproduced observed breast cancer incidence, stage and tumor size distributions, and breast cancer mortality for White women. The higher mortality for Black women could be attributed to differences in natural history parameters (26–44%), use of adjuvant therapy (11–19%), and uptake of mammography screening (7–8%), leaving 38% to 46% unexplained. Conclusion: Black women appear to have benefited less from cancer control advances than White women, with a greater race-related gap in the use of adjuvant therapy than screening. However, a greater portion of the disparity in mortality appears to be due to differences in natural history and undetermined factors. Impact: Breast cancer mortality may be reduced substantially by ensuring that Black women receive equal adjuvant treatment and screening as White women. More research on racial variation in breast cancer biology and treatment utilization is needed. Cancer Epidemiol Biomarkers Prev; 20(1); 112–22. ©2011 AACR.

The aim of this study was to quantify the benefits and harms of mammography screening after age 74 years, focusing on the amount of overdiagnosis of invasive breast cancer and ductal carcinoma in situ (DCIS). Three well-established microsimulation models were used to simulate a cohort of American women born in 1960. All women received biennial screening starting at age 50 years with cessation ages varying from 74 up to 96 years. We estimated the number of life-years gained (LYG), quality-adjusted life-years, breast cancer deaths averted, false-positives, and overdiagnosed women per 1000 screens. The models predicted that there were 7.8 to 11.4 LYG per 1000 screens at age 74 years (range across models), decreasing to 4.8 to 7.8 LYG per 1000 screens at age 80 years, and 1.4 to 2.4 LYG per 1000 screens at age 90 years. When adjusted for quality-of-life decrements, the LYG decreased by 5% to 13% at age 74 years and 11% to 22% at age 80 years. At age 90 to 92 years, all LYG were counterbalanced by a loss in quality-of-life, mainly because of the increasing number of overdiagnosed breast cancers per 1000 screens: 1.2 to 5.0 at age 74 years, 1.8 to 6.0 at age 80 years, and 3.7 to 7.5 at age 90 years. The age at which harms began to outweigh benefits shifted to a younger age when larger or longer utility losses because of a breast cancer diagnosis were assumed. The balance between screening benefits and harms becomes less favorable after age 74 years. At age 90 years, harms outweigh benefits, largely as a consequence of overdiagnosis. This age was the same across the three models, despite important model differences in assumptions on DCIS.

Many European countries offer organised population-based breast, cervical, and colorectal cancer screening programmes. Around age 55 and 60, Dutch women are invited to all three screening programmes. We examined the extent to which participation concurs and identified factors influencing concurrent participation. Individual level data from breast, cervical, and colorectal cancer screening invitations between 2017 and 2019 were extracted from the Dutch screening registry. The percentages of women participating in all three, two, one, or none of the programmes around age 55 and 60, and before subsequent round invitation were determined. Multivariate ordinal regression analyses were performed to estimate whether population density, socio-economic status (SES) per postal code area, and time between the three invitations (6 months) were associated with concurrent participation. Data from 332,484 women were analysed. At age 55, 53.7% participated in all three programmes, 22.1% in two, 11.7% in one, and 12.6% did not participate at all. At age 60, a similar participation pattern was observed. Women living in areas with higher population density were less likely (odds ratios 0.75-0.94) and women in higher SES groups were more likely (odds ratios 1.12-1.60) to participate in more screening programmes, although this positive association was smaller for the highest SES group. No substantial association was found between concurrent participation and timing of invitations. More than half of Dutch women participated in all three screening programmes and around 12% did not participate in any. Concurrent participation was lower in cities and lower SES groups.

Breast cancer screening with digital breast tomosynthesis compared with digital mammography was predicted to increase life-years gained by 7% and decrease false-positive results by 2% and was cost-... BackgroundDigital breast tomosynthesis (DBT) is a promising screening test, but its outcomes and cost-effectiveness remain uncertain.PurposeTo determine if biennial DBT is cost-effective in a scree...

Background: A paucity of research addresses breast cancer screening strategies for women at lower-than-average breast cancer risk. The aim of this study was to examine screening harms and benefits among women aged 50-74 years at lower-than-average breast cancer risk by breast density. Methods: Three well-established, validated Cancer Intervention and Surveillance Network models were used to estimate the lifetime benefits and harms of different screening scenarios, varying by screening interval (biennial, triennial). Breast cancer deaths averted, life-years and quality-adjusted life-years gained, false-positives, benign biopsies, and overdiagnosis were assessed by relative risk (RR) level (0.6, 0.7, 0.85, 1 [average risk]) and breast density category, for US women born in 1970. Results: Screening benefits decreased proportionally with decreasing risk and with lower breast density. False-positives, unnecessary biopsies, and the percentage overdiagnosis also varied substantially by breast density category; false-positives and unnecessary biopsies were highest in the heterogeneously dense category. For women with fatty or scattered fibroglandular breast density and a relative risk of no more than 0.85, the additional deaths averted and life-years gained were small with biennial vs triennial screening. For these groups, undergoing 4 additional screens (screening biennially [13 screens] vs triennially [9 screens]) averted no more than 1 additional breast cancer death and gained no more than 16 life-years and no more than 10 quality-adjusted life-years per 1000 women but resulted in up to 232 more false-positives per 1000 women. Conclusion: Triennial screening from age 50 to 74 years may be a reasonable screening strategy for women with lower-than-average breast cancer risk and fatty or scattered fibroglandular breast density.