Study Examines Racial Differences in Mammography and Ultrasound Imaging Characteristics of Breast Cancer

Noting that the last research to examine racial differences in breast cancer imaging characteristics was published nearly 25 years ago, researchers recently compared imaging findings between African American women and non-Latina White women in a new study of over 800 women with invasive breast cancer or ductal carcinoma in situ (DCIS).

For the retrospective study, recently published in Clinical Imaging, the authors examined data from 270 African-American women and 586 non-Latina women. According to the study, there were 278 cancers in the African-American cohort, including 166 screen-detected cancers and 112 clinical cancers. In the non-Latina White women cohort, there were 599 cancers, including 397 screen-detected cancers and 202 clinical cancers.

In comparison to non-Latina White women, the researchers found that African-American women in the screen-directed cohort had a lower rate of architectural distortion (6.1 percent) on mammography than non-Latina White women (15.9 percent), and a higher rate of calcification (38.8 percent vs. 28 percent).

However, the researchers pointed out that the higher calcification rates were primarily seen in women with DCIS as calcification rates were comparable between African-American women and non-Latina White women who had invasive breast cancer (9.5 percent vs. 8.5 percent). African-American women with screen-detected breast cancer not only had a higher rate of DCIS in comparison to non-Latina White women (42.2 percent vs. 29 percent), they also had a significantly higher rate of pure DCIS, a finding that had not been reported in previous research, according to the study authors.

“The higher rate of DCIS in our study may reflect racial differences in screening mammography utilization as this was not demonstrated in the clinical cohort,” wrote Steven P. Poplack, M.D., who is affiliated with the Department of Radiology at the Stanford University School of Medicine, and colleagues.

In women who had invasive breast cancer, the study authors noted a higher frequency of masses among African-American women in comparison to non-Latina White women (77.9 percent vs. 64.9 percent). Overall, African-American women had higher rates of oval or round masses on mammography (43.1 percent vs. 21.4 percent) and ultrasound screening (24.1 percent vs. 13.1 percent) in comparison to non-Latina White women, according to the study.

While mass margin differences were not apparent in the clinical cohort, Poplack and colleagues said ultrasound imaging revealed a higher percentage of circumscribed mass margins in African-American women (17.5 percent) in contrast to non-Latina White women (2.7 percent). Mammography imaging showed a higher rate of spiculated margins in non-Latina White women (65.1 percent) in comparison to African-American women (39.7 percent), according to the study.

“Familiarity with these imaging appearances and consideration of underlying socioeconomic differences may provide breast imagers with a better framework to approach breast cancer diagnosis in the (African-American) population in their clinical practice,” noted Dr. Poplack and colleagues.

In regard to study limitations, the authors noted that it wasn’t clear in the data whether digital mammography or digital breast tomosynthesis (DBT) was utilized in screening. They acknowledged the study findings were subject to incomplete or inaccurate reporting as the extracted data was derived from exam reports without image review. Programmatic cost constraints prevented consistent use of DBT screening in navigator-based programs for lower-income patients, most of whom were African American women, according to the study authors.