Racial Differences in Time to Breast Cancer Surgery and Survival in the U.S. Military Health System
In a retrospective cohort study reported in JAMA Surgery, Eaglehouse et al found that time to breast cancer surgery was delayed for non-Hispanic black vs non-Hispanic white women in the Military Health System but that this difference did not account for poorer overall survival in non-Hispanic black women receiving breast-conserving surgery.
Study Details
The study analyzed data from 998 non-Hispanic black women and 3,899 non-Hispanic white women included in the Department of Defense Central Cancer Registry and Military Health System Data Repository. The records from these linked databases identified women who were diagnosed with stage I to III breast cancer and underwent breast-conserving surgery or mastectomy in the U.S. Military Health System between January 1998 and December 2008.
The main outcome was time to surgery, with non-Hispanic black and non-Hispanic white women being compared at the 25th, 50th, 75th, and 90th percentiles of time to surgery using multivariable quantile regression. Cox proportional hazards regression analysis was used to determine hazard ratios (HRs) for all-cause death in non-Hispanic black women compared with non-Hispanic white women after controlling for potential confounders first without, and then with, time to surgery.
Time to Surgery and Survival
Median time to surgery was 21 days among non-Hispanic white women vs 22 days among non-Hispanic black women. On multivariate analysis, non-Hispanic black women had significantly greater estimated delay to time to surgery (both P < .05) at the 75th (+3.6 days, 95% confidence interval [CI] = 1.6–5.5 days) and 90th percentiles (+8.9 days, 95% CI = 5.1–12.6 days). The estimated differences were similar across surgery types.
In multivariate analysis not including time to surgery, non-Hispanic black women had a higher adjusted risk for death (HR = 1.45, 95% CI = 1.06–2.01) among patients receiving breast-conserving surgery but not among those receiving mastectomy (HR = 1.06, 95% CI = 0.76–1.48). In multivariate analysis including time to surgery, hazard ratios remained similar among patients receiving breast-conserving surgery (HR = 1.47, 95% CI = 1.06–2.03) and those receiving mastectomy (HR = 1.04, 95% CI = 0.75–1.45).
The investigators concluded, “This study’s results indicate that time to breast cancer surgery was delayed for non-Hispanic black [women] compared with non-Hispanic white women in the [U.S.] Military Health System. However, the racial differences in time to surgery did not explain the observed racial differences in overall survival among women who received breast-conserving surgery.”
Kangmin Zhu, MD, PhD, of the John P. Murtha Cancer Center, Uniformed Services University of the Health Sciences, Rockville, is the corresponding author for the JAMA Surgery article.
Disclosure: The study was supported by the John P. Murtha Cancer Center of the Uniformed Services University of the Health Sciences and Walter Reed National Military Medical Center under the auspices of the Henry M. Jackson Foundation for the Advancement of Military Medicine. The study authors’ full disclosures can be found at jamanetwork.com.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
