Importance Racial disparities in time to surgery (TTS) after a breast cancer diagnosis and whether these differences account for disparities in overall survival have been understudied in the US population.

Objectives To compare TTS in non-Hispanic black (NHB) and non-Hispanic white (NHW) women with breast cancer and to examine whether racial differences in TTS may explain possible racial disparities in overall survival in a universal health care system.

Design, Setting, and Participants Retrospective cohort identified from the Department of Defense Central Cancer Registry and Military Health System Data Repository linked databases containing records between January 1, 1998, and December 31, 2008, of 998 NHB women and 3899 NHW women who received a diagnosis of stages I to III breast cancer and underwent breast-conserving surgery (BCS) or mastectomy in the US Military Health System during the study period. Data analyses were conducted from July 5, 2017, to December 29, 2017.

Main Outcomes and Measures The main outcome was time to breast cancer surgery. Non-Hispanic black and NHW women were compared at the 25th, 50th (median), 75th, and 90th percentiles of TTS by using multivariable quantile regression. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% CIs for all-cause death in NHB compared with NHW women after controlling for potential confounders first without and then with TTS.

Results Among the 4887 NHB and NHW women in the cohort, the mean (SD) age was 50.0 (9.4) years. The median TTS was 21 days (95% CI, 20.6-21.4 days) among NHW women and 22 days (95% CI, 20.6-23.4 days) among NHB women. Non-Hispanic black women had a significantly greater estimated TTS at the 75th (3.6 days; 95% CI, 1.6-5.5 days) and 90th (8.9 days; 95% CI, 5.1-12.6 days) percentiles than NHW women in multivariable models. The estimated differences were similar by surgery type. Non-Hispanic black women had a higher adjusted risk for death (HR, 1.45; 95% CI, 1.06-2.01) compared with NHW women among patients receiving breast-conserving surgery. The risks were similar between races among those receiving mastectomy (HR, 1.06; 95% CI, 0.76-1.48). The HRs remained similar after adding TTS to the Cox proportional hazards regression models.

Conclusions and Relevance This study’s results indicate that time to breast cancer surgery was delayed for NHB compared with NHW women in the Military Health System. However, the racial differences in TTS did not explain the observed racial differences in overall survival among women who received breast-conserving surgery.

重要性 在美国人群中，对乳腺癌诊断后的手术时间差异（TTS）以及这些差异是否导致总体生存差异进行了研究。

目的 比较非西班牙裔黑人（NHB）和非西班牙裔白人（NHW）乳腺癌妇女的TTS，并检查TTS的种族差异是否可以解释全民医疗体系总体生存中可能存在的种族差异。

设计，设置和参加者 回顾性队列是从国防部中央癌症登记处和军事卫生系统数据存储库链接的数据库中确定的，该数据库包含1998年1月1日至2008年12月31日期间998名NHB妇女和3899 NHW妇女的记录。在研究期间，对I至III期乳腺癌进行了诊断，并在美国军事卫生系统中进行了保乳手术（BCS）或乳房切除术。数据分析于2017年7月5日至2017年12月29日进行。

主要结果和措施 主要结果是进行乳腺癌手术的时间。通过使用多变量分位数回归，比较了非西班牙裔黑人和NHW妇女在TTS的第25、50（中位数），75和90％百分位数。使用Cox比例风险回归模型来估算在先控制好潜在混杂因素后再不使用TTS的情况下，与NHW妇女相比，NHB的全因死亡的危险比（HRs）和95％CI。

结果 在该队列中的4887名NHB和NHW妇女中，平均（SD）年龄为50.0（9.4）岁。NHW妇女中位TTS为21天（95％CI，20.6-21.4天），NHB妇女中位TTS为22天（95％CI，20.6-23.4天）。在多变量模型中，非西班牙裔黑人女性的TTS估计值在第75位（3.6天； 95％CI，1.6-5.5天）和第90位（8.9天； 95％CI，5.1-12.6天）显着高于NHW女人。估计的差异在手术类型上相似。在接受保乳手术的患者中，非西班牙裔黑人女性的经调整死亡风险较高（HR，1.45； 95％CI，1.06-2.01）。接受乳房切除术的种族之间的风险相似（HR，1.06； 95％CI，0.76-1.48）。将TTS添加到Cox比例风险回归模型后，HR保持相似。

结论与相关性 这项研究的结果表明，与军事卫生系统中的NHW妇女相比，NHB的乳腺癌手术时间延迟。但是，TTS中的种族差异并未解释观察到的接受保乳手术的妇女在总体生存率方面的种族差异。