There Are Racial and Ethnic Differences in Cancer Detection Rates Among Women With a Breast Lump

New BCSC study finds that reducing racial and ethnic disparities in breast cancer survival among women with a breast lump requires targeted efforts to reduce the risk of poor prognosis tumors in addition to improved accuracy of cancer detection

---

Breast lumps are one of the most commonly reported breast symptoms and are associated with a higher cancer detection rate and higher positive predictive value (PPV). Among those diagnosed with breast cancer, a breast lump is associated with a higher risk of death. Thus, the ability to accurately identify lumps with a high likelihood of malignancy is a key task for breast diagnostic imaging, including diagnostic mammography. A prior study from the BCSC showed that digital diagnostic mammography performance varied across racial and ethnic groups among women receiving diagnostic mammography after a screening examination (Nyante et al, 2022. CEBP 31(7): 1324-1333), but whether these same performance differences existed for women with a breast lump was unknown. In this study, BCSC researchers evaluated diagnostic mammography performance statistics, including measures of cancer detection, assessment accuracy, and follow-up recommendations, among women of different racial and ethnic groups who reported a breast lump at the time of imaging.

Using 51,014 digital mammograms conducted among non-Hispanic White (75%), non-Hispanic Black (7%), Asian/Pacific Islander (12%) and Hispanic (6%) women, researchers found that cancer detection rates were highest among Asian/Pacific Islander (per 1000 exams, 84.2 [95%CI 72.0-98.2]) and Black women (81.4 95%CI 69.4-95.2]) and lowest among Hispanic women (42.9 [95%CI 34.2-53.6]). Positive predictive values for a cancer diagnosis following a positive mammogram were highest among Black (37.0% [95%CI 31.2%, 43.3%]) and White (37.0% [95%CI 30.0%, 44.6%]) women and lower among Asian/Pacific Islander (31.4% [95%CI 23.6%, 40.4%]) and Hispanic/Latina (22.0% [95%CI 17.2%, 27.7%]) women. False-positive results were most common among Asian/Pacific Islander women (per 1000 exams, 183.9 [95%CI 126.7-259.2]) and lowest among White women (112.4 [95%CI 86.1-145.5]). Among the 3233 invasive breast carcinomas and 220 DCIS diagnosed following a positive diagnostic mammogram assessment, Asian/Pacific Islander women had a higher proportion of DCIS and HER2-positive tumors and lower proportion of advanced cancers (prognostic stage II-IV) compared to women of other racial and ethnic groups. Black women had higher proportions of tumors that were high grade, ER-negative, PR-negative, or triple negative compared to women in other racial and ethnic groups (all p<0.02).

The study’s main conclusion was that, among women with a breast lump, Asian/Pacific Islander and Black women were most likely to have cancer detected compared with White and Hispanic/Latina women. Despite similarly high rates of cancer detection for Asian/Pacific Islander and Black women, the tumor profiles of Black women displayed a poorer prognosis, similar to previously published patterns. Thus, efforts to reduce racial and ethnic disparities in breast cancer survival will require targeted efforts to reduce the risk of poor prognosis tumors in addition to improving the accuracy of cancer detection among women with a breast lump.

 

Posted by: Sarah Nyante