Screening mammography reduces disparities by improving triple negative breast cancer (TNBC) early detection and outcomes.
Burns JA, Bensenhaver J, Chen Y, Susick LL, Petersen L, Proctor E, Nathanson SD, Mandava S, Davis M, and Newman LA. Screening mammography reduces disparities by improving triple negative breast cancer (TNBC) early detection and outcomes. Ann Surg Oncol 2019; 26(Suppl 1):S100.
Ann Surg Oncol
TNBC is more common in African American (AA) compared to White American (WA) women, thereby contributing to higher breast cancer mortality in the AA population. The extent to which screening can reduce breast cancer disparities is uncertain, as TNBC (compared to non-TNBC) is more likely to present as an interval breast cancer detected following a normal screening mammogram. Methods: We compared 106 AA (median follow-up 50.3 months) and 87 WA (median follow-up 47.5 months) patients (pts) with TNBC managed 2010-2015 in an urban hospital system. Results: Mean age at diagnosis was 61 yrs for both AA and WA pts. Mean tumor size was also similar (2.2 and 2.7em, respectively; p=0.3); 23.6% of AA and 19.5% of WA pts had node-positive TNBC (p=0.6). Disease was detected by screening mammography in 58.5% of AA and 44.8% of WA pts (p=0.13). Surgical and systemic therapy patterns were comparable. Compared to non-screen-detected disease, screen-detected TNBC was more likely to be T1 for AA (79% versus 32%; p<0.001) and WA pts (80% versus 42%; p=0.001); and also more likely to be node-negative (92% versus 54% for AA pts; p<0.0001 and 92% versus 68% for WA pts; p=0.017). Distant metastasis developed in 16% of both AA and WA pts. AA pts with screen-detected TNBC had longer 4-year overall survival (OS)- 93% (95% CI 87.0-99.9%) compared to those with non-screen-detected TNBC- 59.1% (95% CI 45.8-76.2%). Similar patterns were seen for WA pts: 4-year OS for screen-detected TNBC 87.5% (95% CI 76.5%-100%) versus 74.8% (95% CI 62.3-89.7%). Other univariate predictors of better survival included age <50 years; small tumor size; non-high-grade disease; absence of lymphovascular invasion; and node-negative disease, but not race/ethnicity. On multivariate analysis, mammography screen-detected disease remained associated with overall survival; mortality hazard 0.21 (95% CI 0.10-0.45; p<0.0001). Conclusions: Screening mammography is effective for early detection of TNBC in AA and WA pts, resulting in improved survival. It can therefore minimize breast cancer disparities related to the disproportionate burden of TNBC in the AA population.