Most countries recommend that women receive breast cancer screening every 2 years between ages 50 and 69 years.1 In 2009 and 2016, the US Preventive Services Task Force (USPSTF) updated its recommendations to advise that women receive screening mammography every 2 years between ages 50 and 74 years, with the decision to begin screening earlier (ie, ages 40-49 years) based on individual evaluation of risks and benefits.2 The updated USPSTF recommendations acknowledged the risk of overdiagnosis and the lack of reduction in all-cause mortality associated with screening that starts at any age.2 In 2015, the American Cancer Society recommended annual screening between ages 45 and 55 years, with screening every 1 to 2 years thereafter.3
Based on the hypothesis that many specialized breast centers in the US issue screening recommendations that differ from those of national societies, we examined current recommendations provided by US breast centers. Recommendations by breast centers are influential, as physicians and the public look to specialists for guidance on this complex topic. Breast center recommendations may also reflect broader practice patterns in the US.
In this cross-sectional study, we reviewed recommendations for starting age and interval of screening mammography on the public websites of 606 breast cancer centers in the US between December 2019 and July 2020. Of those, 542 centers were accredited by the National Accreditation Program for Breast Centers, and 64 centers were designated as National Cancer Institute (NCI) facilities (17 of which were also accredited by the National Accreditation Program for Breast Centers). The Weill Cornell Medicine Institutional Review Board deemed this study to be exempt from review, as it was not human subjects research. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline for cross-sectional studies.
Statistical analyses were performed using a 2-tailed Fisher exact test with a significance threshold of P < .05. Data were analyzed from December 2019 to July 2020.
Among 606 breast cancer centers, 487 centers (80.4%) provided recommendations regarding screening mammography. A total of 119 centers (19.6%) did not provide recommendations (for starting age, screening interval, or discussion with physician); of those, 11 centers (9.2%) were NCI-designated facilities, and 108 centers (90.8%) were non–NCI-designated facilities.
Among 487 centers that provided recommendations, 431 centers (88.5%) specified a starting age for screening, 429 centers (88.1%) specified a starting age and screening interval, and 56 centers (11.5%) advised that women discuss screening with their physicians (Table). Of 431 centers that recommended a starting age, 376 centers (87.2%) provided recommendations different from those of national societies, advising that women begin screening at age 40 years; 35 centers (8.1%) recommended that screening begin at age 45 years; and 20 centers (4.6%) recommended that screening begin at age 50 years. Of 429 centers that recommended a starting age and screening interval, 347 centers (80.9%) provided recommendations that differed from those of national societies, advising that annual screening begin at age 40 years.
Among all centers that provided recommendations, NCI-designated centers less frequently recommended that women begin breast cancer screening at age 40 years (37 centers [69.8%] vs 339 centers [78.1%]; P = .22) compared with non–NCI-designated centers (Figure). However, NCI-designated centers more frequently advised that women speak with their physicians (9 centers [17.0%] vs 47 centers [10.8%]; P = .18) compared with non–NCI-designated centers. Neither of these differences was statistically significant.
Most US breast cancer centers recommended that women begin receiving screening mammography at an earlier age and more frequently than recommended by national societies. The American Cancer Society and USPSTF recommendations reflect data indicating the potential harms of earlier screening, which include false-positive findings, unnecessary biopsies and operations, anxiety and discomfort, overdiagnosis and overtreatment of indolent cancers, and costs of low-value care. These recommendations are now more consistent with the long-standing practices of health systems in most other countries.1
The public advice provided by high-volume breast centers in the US suggests that these centers may prioritize factors not reflected in the data, such as patient and physician preferences, recommendations from specialty (eg, radiology) societies, concerns about litigation, or possible financial considerations. However, our data could not address causal mechanisms.4
Adoption of USPSTF recommendations is estimated to be associated with reductions in false-positive mammography findings (61% vs 42% of women over 10 years) compared with nonadoption of recommendations, with fewer subsequent biopsies, surgeries, and other therapies for the treatment of benign tumors or indolent cancers.5 Earlier screening has both risks and benefits; patient decisions are based on complex individual factors that are best elicited and addressed through shared decision-making. The potential harms of cancer screening are challenging to communicate. Decision aids may help, as women and their physicians tend to overestimate the benefits and underestimate the harms of screening mammography.4 Optimal screening practices might differ for higher-risk populations (eg, Ashkenazi Jewish and Black women); this issue requires further study. Findings from ongoing clinical trials, such as the Women Informed to Screen Depending on Measures of Risk (WISDOM) study,6 may help to guide discussions with women, assist with decisions about advertising mammography services, and provide standards for appropriate screening intensity.
Barbara Jacoby is an award winning blogger that has contributed her writings to multiple online publications that have touched readers worldwide.