Early Breast Cancer Screenings Reduce Mortality, Health Disparities

October 21, 2021 - According to analyses performed by the Cancer Intervention and Surveillance Modeling Network (CISNET), having Black women begin mammography screenings every other year starting at the age of 40 could reduce breast cancer deaths by 57 percent, eliminating health disparities.

The analyses are the first to use modeling to examine which modern breast cancer screening strategies prove the best results while also reducing health disparities. According to the researchers, breast cancer screening recommendations over the past two decades have not accounted for how the role of racism impacts treatment, length of survival, and deaths among Black women.

“There is an increasing focus on eliminating race-based medicine,” lead study author and adjunct assistant professor in the Department of Radiation Oncology at the University of Michigan, Christina Hunter Chapman, MD, MS, said in a press release.

 “However, calls to end race-based medicine that ask for the immediate cessation of any discussion on race are not likely to eliminate racial disparities. Carefully selected solutions for health inequity may involve tailoring interventions to specific racial groups.”

To address health disparities, CISNET created a model using self-reported race as a proxy for who is likely to experience the effects of racism to test a range of screening strategies. The model also accounts for breast density, distribution of breast cancer molecular subtypes, age, stage, and subtype-specific treatment effects, and non-breast cancer mortality for Blacks and Whites.

To gain data insights, the model compared the benefits and harms of different screening strategies in Black women to those of White women screened biennially from ages 50 to 74.

“For Black women, three biennial screening strategies (beginning at age 40, 45, or 50) yielded benefit-to-harm ratios that were greater than or equal to those seen in white women who started screening at age 50,” Chapman explained.

“Among those three strategies, initiating mammograms at age 40 yielded the greatest mortality reduction and reduced Black-white mortality disparities by 57 percent. This approach is consistent with the US Preventive Services Task Force’s overarching guidance for when women may want to consider beginning biennial mammography.”

The model researchers showed the lifetime impact of digital mammography under different starting ages and intervals between screening for women age 40 in the year 2020. In addition, it compared a variety of benefits and harms, including undergoing many mammograms and having false-positive screening results.

“Black women have higher rates of aggressive cancers at younger ages than white women, and treatments for those types of tumors are not as effective. However, even when we account for cancer subtypes, mortality is higher for black women largely due to factors that are ultimately rooted in racism,” senior study author Jeanne S. Mandelblatt, MD, MPH, continued.

“Therefore, in our analyses we accounted for differences in treatment attributable to racism, including access to medication, delays in treatment, dose reductions, and discontinuation of treatment⁠ — all factors that have been shown to be sub-optimal more often in Black than white women.”