Conclusion: The accuracy of diagnostic mammograms varied between racial and ethnic groups, with variations in various measures of diagnostic performance.
Journal in which the study was published: Cancer Epidemiology, Biomarkers, and Prevention, a journal of the American Association for Cancer Research.
Authors: Sarah J. Nyante, PhD, Associate Professor of Radiology at the University of North Carolina School of Medicine.
Background: Racial disparities in breast cancer are well documented and research has identified multiple socioeconomic and biological factors as possible causes of the disparities. Some aspects of breast cancer screening have also been studied, such as the timely reception of screening mammograms, but less attention has been paid to possible differences related to the diagnostic mammography process, he added.
Women are usually given diagnostic mammograms if a screening mammogram has detected potential signs of breast cancer, Nyante said. “Breast imaging is an important first step in being diagnosed and getting on the treatment pathway. It is reasonable to think that differences in early care would affect subsequent outcomes,” she said.
How the study was conducted: In this study, Nyante and colleagues used data from 267,868 diagnostic mammograms performed at 98 Breast Cancer Surveillance Consortium facilities between 2005 and 2017. researchers used evaluations of breast imaging and reporting systems (BI-RADS) to identify mammograms that radiologists considered likely to be positive (malignant) and likely negative (benign). The racial distribution of the women whose mammograms were studied was 70% non-Hispanic white; 13 percent non-Hispanic blacks; 10 percent Asian / Pacific Islander; and 7 percent Hispanic.
Results: Researchers found that the rate of invasive cancer screening (the number of cancers detected after a mammogram, per 1,000 mammograms performed) was higher among non-Hispanic whites (35.8); followed by Asia / Pacific Island (31.6); non-Hispanic black (29.5); and Hispanic (22.3).
The researchers evaluated the positive predictive value, which measures cancer performance among positive mammograms, and found it to be higher among non-Hispanic whites (27.8); followed by Asia / Pacific Island (24.3); non-Hispanic black (23.4); and Hispanic (19.4).
Asian and Pacific island women were the most likely to receive a false positive report. The rate of false positives per 1,000 mammograms was 169.2 for Asians / Pacific Islanders, 136.1 for Hispanics, 133.7 for blacks, and 126.5 for whites.
Non-Hispanic black women were more likely to receive a false negative report. The rate of false negatives per 1,000 mammograms was 4.6 for blacks, 4.0 for whites, 3.3 for Asians / Pacific Islanders, and 2.6 for Hispanics.
Non-Hispanic black women were the most likely to receive “short-term follow-up recommendations,” with 31% of women recommended for more images in six months. In comparison, 22.1% of white women, 16.1% of Asian and island women in the Pacific, and 23.6% of Hispanic women received this recommendation.
There were also differences in tumors detected by diagnostic mammograms. In general, Asian and Pacific Islander women had the highest proportion of ductal carcinoma in situ (DCIS), a non-invasive subtype. Meanwhile, black women were more likely to be diagnosed with advanced tumors and a higher tumor grade. As previous research has shown, they were also more likely to be diagnosed with the triple negative negative aggressive breast cancer subtype.
Author’s comments: Nyante noted that the control of patient-level characteristics did not explain the differences in performance statistics in this study, suggesting that the role of the facility should be further studied. diagnosis in the treatment of breast cancer in women. He added that this study highlights the importance of including women of all backgrounds in clinical trials so that the risks and benefits at the population level of mammography can be better understood.
“Examining the differences in the performance of diagnostic digital mammography and the characteristic results of tumor by race and ethnicity can help us understand why disparities persist in cancer screening and quality of care for some demographic groups, “Nyante said.
Limitations of the study: Although the study included full-field digital mammograms and digital mammary tomosynthesis (DBT), DBT has become much more widely available in recent years. Therefore, the findings of the study may not be entirely generalizable to the current imaging industry.
Funding and Outreach: This study was funded by grants from the National Cancer Institute, the Patient-Centered Results Research Institute, and the Agency for Health Research and Quality. Nyante does not declare any conflict of interest.
Source:
American Association for Cancer Research
Magazine reference:
Nyante, SJ, et al. (2022) Performance of diagnostic mammography between racial and ethnic groups in a national network of community-based breast imaging facilities. Epidemiology, biomarkers and cancer prevention. doi.org/10.1158/1055-9965.EPI-21-1379.