Evaluating the Impact of Screening Mammography Research

Lars Grimm, MD, MHS, Chair of the National Mammography Database (NMD) Research Committee, contributed this piece.

Although primarily a quality improvement resource, the NMD is one of the largest breast imaging databases using clinical practice data in the United States and therefore provides a unique opportunity to perform clinically relevant breast imaging research. In recent months, members of the NMD Research Committee published two papers which explore screening mammography performance. In this Q&A, the lead authors of each paper Eniola Oluyemi, MD, and Cindy Lee, MD, join me to discuss the impact of their research.

The Rate and Timeliness of Diagnostic Evaluation and Biopsy After Recall From Screening Mammography in the National Mammography Database paper aims to build upon the growing awareness that breast cancer screening and outcomes differ by patient demographics. Though the reasons behind these differences are multifactorial, the NMD allows us to use population level data to understand screening metrics with the goal of improving healthcare equity.

What are the key factors found to influence the rate of follow up and the timeliness to diagnosis after an abnormal screening mammogram?

Dr. Oluyemi: Lower rates of diagnostic evaluation following an abnormal screening mammogram were observed in younger women, Black and American Indian women, and women with no breast cancer family history. Longer amount of time between screening and diagnostic evaluation was noted in women of Black, other or mixed race, and in Hispanic women.

For the subset of women who were recommended to undergo biopsy after the diagnostic evaluation, we found that women of ages 80 and above and those of Black or American Indian race had lower rates of having the recommended biopsy procedure. At the facility level, lower annual examination volumes and location in an area ranked as highly disadvantaged socioeconomically were some of the characteristics associated with lower biopsy rates. Women aged 80 and above, women of Black, other or mixed race, and Hispanic women experienced longer times from diagnostic evaluation to biopsy in addition to rural and community hospital-affiliated facilities.

What are steps practices can take to improve care for patients who have had an abnormal screening mammogram?

Dr. Oluyemi: Consider offering same-day diagnostic appointments after an abnormal screening mammogram and/or same-day biopsies for diagnostic patients recommended to undergo biopsy. Additionally, employing a patient navigator to provide support to women experiencing barriers that could make it more difficult for them to follow-up with diagnostic evaluation or biopsy recommendations may be helpful, particularly for those with specific needs that could benefit from individualized support.

The Screening Mammographic Performance by Race and Age in the National Mammography Database paper helps establish the norms for how long breast imaging procedures take to be performed. Each practice has its own unique challenges, but it is important to understand typical ranges so practices can identify when they might need to take steps to improve their access. This is also an opportunity to understand what patient and practice demographics might be subjected to longer weight times to identify targeted strategies for improvement.

What factors did you consider for mammographic performance and which factors did you find had the most impact?

Dr. Lee: We considered all the NMD clinical practice data collected by the facilities, including patient demographics, exam type, indication, screening and diagnostic mammography interpretations, and biopsy results. Patients aged 30–100 years with ≥ 1 year follow up were included in our study. Patients were stratified by 10-year age intervals and five racial groups. Incidence of patient risk factors, availability of prior mammogram in the NMD and time since prior mammograms were compared. Five widely used and validated screening mammography metrics were calculated for each age and racial group: recall rate (RR); cancer detection rate (CDR); positive predictive value for recalled exams (PPV1), biopsy recommended (PPV2) and biopsy performed (PPV3).

We found patient ethnicity and age to significantly impact the screening performance metrics. Consistent with prior literature, with advancing age, recall rate significantly decreases, while CDR, PPV1, PPV2 and PPV3 significantly increase, across all racial groups. While Black women have the highest false positive rates from mammographic screening, which are typically considered as a harm from screening, they also have the lowest breast cancer detection rates.

As we attempt to explain the racial disparity, we observed that rates of patients returning for recommended imaging and biopsy following abnormal mammograms demonstrate significant variations by race. The first source of patients lost to follow-up occurs at the screening recall; the second source of patients lost to follow-up occurs following biopsy recommendation. Significantly lower proportion of Black women returned for recall following abnormal screening mammograms and for the recommended biopsies within the 90-day window compared to white women and all women.

What are steps practices can take to increase high-quality screening mammography across all racial groups?

Dr. Lee: Successful breast cancer screening relies on timely follow-up of abnormal mammograms with potentially clinically significant findings. Delayed or missed follow-up undermines the potential benefits of screening and is associated with poorer patient morbidity and mortality outcomes. Additionally, improved physician–patient communication may help overcome patient-related barriers to follow-up and in turn improve patient outcomes. Effective primary care physician-patient communication is key to ensuring women understand their abnormal mammogram results and the need for follow-up.

The results of these studies are incredibly valuable for screening mammography programs because they provide insights into how practices can improve their access to care and healthcare equity. Practices can use these findings to evaluate their local data and develop tailored solutions to improve patient care.