In a retrospective post hoc analysis reported in JAMA Surgery, Olga Kantor, MD, and colleagues found that locoregional recurrence was more common among Black and Asian vs White patients with hormone receptor (HR)-positive, HER2-negative, node-negative breast cancer in the context of similar access to care in the TAILORx trial. Locoregional recurrence was associated with a greater risk of breast cancer mortality.
Study Details
In TAILORx, patients were randomly assigned to treatment based on Oncotype DX recurrence score (RS): endocrine therapy alone (RS < 11); endocrine therapy alone vs chemotherapy followed by endocrine therapy (RS = 11–25); or chemotherapy followed by endocrine therapy (RS > 25). Of the total of 10,273 patients enrolled, those with unknown race and ethnicity or lack of follow-up were excluded from the current analysis, with the analysis population consisting of 9,369 patients with T1-2N0 disease.
Olga Kantor, MD
Key Findings
Among the 9,369 patients, 4.6% were Asian, 9.4% were Hispanic, 7.2% were Black, and 78.8% were White. Receipt of assigned treatment was high, with 9.3% of patients crossing over to other study treatments and median endocrine therapy duration ranging from 61.1 to 65.9 months across groups. Asian and Black patients had higher rates of endocrine therapy duration of ≥ 5 years vs White patients (67.5% and 62.6% vs 60.7%; overall P < .001). Radiation therapy was received by 72.6% of patients, in 96.1% after breast-conserving surgery and in 13.0% after mastectomy.
At a median follow-up of 94.8 months (range = 1–138 months), 8-year locoregional recurrence rates were 3.6% (95% confidence interval [CI] = 1.6%–5.6%) among Asian patients, 3.9% (95% CI = 2.2%–5.4%) among Black patients, 3.1% (95% CI = 1.7%–4.5%) among Hispanic patients, and 1.8% (95% CI = 1.5%–2.3%) among White patients (overall P < .001).
In analysis adjusting for patient demographics, clinical features, and treatment factors, compared with White patients, Asian (hazard ratio [HR] = 1.91, 95% CI = 1.12–3.29) and Black race (HR = 1.78, 95% CI = 1.15–2.77) were independently associated with increased risk of locoregional recurrence.
In adjusted analysis, locoregional recurrence was associated with a significantly increased risk of breast cancer mortality (HR = 5.71, 95% CI = 3.50–9.31).
Compared with White patients, Asian patients (HR = 0.81, 95% CI = 0.33–1.99) and Black patients (HR = 1.50, 95% CI = 0.93–2.42) did not have a significantly different risk of breast cancer mortality, whereas Hispanic patients had a significantly lower risk (HR = 0.21, 95% CI = 0.07–0.65).
The investigators concluded, “In this post hoc analysis, racial and ethnic differences in locoregional recurrence were observed among patients with T1-2N0, HR-positive, [HER2]-negative breast cancer despite high rates of treatment receipt in this clinical trial population, with the highest locoregional recurrence rates in Asian and Black patients. Further study is needed to understand whether failure to rescue after locoregional recurrence may contribute to racial disparities in breast cancer mortality.”
Elizabeth A. Mittendorf, MD, PhD, of Dana-Farber Brigham Cancer Center, is the corresponding author for the JAMA Surgery article.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
