The debate around the optimal strategy for breast cancer screening—concerning both the age at which women should begin screening and the frequency of these screenings—serves as the backdrop for a detailed analysis conducted through the Cancer Intervention and Surveillance Modeling Network (CISNET).
This analysis sought to dissect and compare the outcomes of various breast cancer screening scenarios, aiming to delineate the balance between the benefits of early detection and the risks associated with screening processes.
CISNET’s methodology revolved around utilizing modeling estimates drawn from hypothetical female cohorts in the United States, focusing on those beginning screening at the age of 40.
The study meticulously assessed four distinct screening scenarios: biennial (every two years) screenings from ages 50 to 74, aligning with the recommendations set forth by the U.S. Preventive Services Task Force (USPSTF) in both 2009 and 2016; biennial screenings from ages 40 to 74, as proposed in the 2023 USPSTF draft recommendation; annual (every year) screenings from ages 40 to 74; and annual screenings from ages 40 to 79.
The core of this comparison was an analysis of median lifetime benefits associated with each scenario, alongside a quantitative evaluation of risks, specifically focusing on the prevalence of false-positive results and benign biopsies that occur per screening examination.
The findings of this comprehensive analysis revealed a notable differentiation in outcomes among the various scenarios. Annual screenings starting from age 40 and extending to age 79 demonstrated a superior efficacy in reducing breast cancer mortality rates—41.7%—when compared to both biennial screenings from ages 50 to 74 (25.4%) and from ages 40 to 74 (30%).
This most intensive screening regimen not only resulted in the highest reduction in mortality but also led to the highest number of averted breast cancer deaths (11.5 per 1000 women screened) and the most significant gain in life-years (230 per 1000 women screened), surpassing the outcomes of less frequent screening scenarios.
Additionally, this approach yielded the lowest incidence of false-positive results (6.5%) and benign biopsies (0.88%) per examination, suggesting a minimized risk of unnecessary anxiety and invasive procedures for the women screened.
An annual breast cancer screening strategy commencing at the age of 40 offers the most considerable benefits in terms of mortality reduction and life-years gained.
Moreover, this approach achieves these outcomes while simultaneously presenting the lowest risk per examination, characterized by minimal rates of false positives and benign biopsies.
This evidence suggests that annual screenings from age 40 to 79 may represent the most beneficial and least harmful breast cancer screening strategy for women, providing critical data to inform ongoing debates and recommendations regarding breast cancer screening practices.
