Screening mammography is important for reducing race/ethnicity-associated triple-negative breast cancer disparities among African American and white patients.
For African American and white patients with triple-negative breast cancer (TNBC), equal treatment resulted in similar outcomes, according to a research letter.
Authors from Detroit and New York City identified and studied 243 TNBC cases diagnosed between 2011 and 2015 in order to evaluate outcomes among patients who had self-reported as African American or white. The patients, of which 106 were African American and 87 were white, were followed up with until death, loss to follow-up, or study termination in April 2018. The investigators wrote that mammography screening-detected cancers were found on routinely scheduled mammography in cases where there was an absence of clinical symptoms.
The study authors said that a 2-fold higher incidence of TNBC can partly explain why there is a 40% higher mortality rate among African American women compared to white women. While screening mammography improves breast cancer survival through early detection, they said, TNBC is more challenging to detect compared to non-TNBC.
The study authors reported that there were no significant differences among African American and white patients based on mean age at diagnosis, mean tumor size, or nodal status. The 2 groups of TNBC patients had similar frequency for screening-detected disease, and most of the tumors among the two groups were invasive ductal tumors. The study authors also noted that family histories of breast cancers were also the same between the groups.
A majority of the patients (95% of African American patients and 88% of white patients) had some form of nonpublic insurance, including Medicare, the study authors said.
African American patients had higher mean body mass index scores, the investigators found. Additionally, fewer African American patients were referred for genetic testing or counseling compared to white patients (23 vs. 33 patients, respectively).
Treatment methods were relatively similar between the 2 groups. There were lumpectomies performed in 55% of African American cases, compared to 59% of white patients. African American patients received postoperative or adjuvant chemotherapy at a rate of 57% and neoadjuvant chemotherapy at a rate of 22%. To compare, white patients received postoperative or adjuvant chemotherapy at a rate of 60% and neoadjuvant chemotherapy at a rate of 19%, the investigators determined. The African American patients were also less likely to undergo contralateral prophylactic mastectomy, they added.
The frequency of local recurrence and distant relapse did not appear statistically significant between the 2 groups, the study authors reported.
Finding TNBC through screening was associated with an improved 4-year overall survival for African American patients, but did not significantly improve for white patients, the investigators said. For African American patients, the median follow up time was 50 months compared to 47 months for white patients. No race/ethnicity, age, histology, MIB1 status, body mass index, insurance status, or parity was associated with survival, the study authors found.
“Screening mammography successfully detected early stage TNBC, improving outcomes for both African American and white American patients,” the study authors wrote in conclusion. “Screening mammography is therefore an important strategy for reducing race/ethnicity-associated breast cancer disparities by optimizing overall survival for both population subsets.”
The letter, titled “Evaluation of Triple-Negative Breast Cancer Early Detection via Mammography Screening and Outcomes in African American and White American Patients,” was published in JAMA Surgery.
Chen Y, Susick L, Davis M, et al. Evaluation of triple-negative breast cancer early detection via mammography screening and outcomes in African American and white American patients [published online February 19, 2020]. JAMA Surg. doi:10.1001/jamasurg.2019.6032.