乳腺癌（BC）存活的种族差异源于多级原因，这些原因可能在BC进展的不同阶段产生影响。澄清遗传和社会因素的重要性可能有助于优先考虑干预措施。为了共同研究非洲遗传祖先、社会环境与黑人乳腺癌幸存者任何死亡原因和乳腺癌之间的关联性，进行了这个基于人群的队列研究。研究对象为年龄在20至75岁之间、自我确认为黑人的乳腺癌患者，病理学上确认为乳腺癌，选取了2005年6月至2019年5月期间的病例，并对其进行随访，直至2021年9月的死亡或截尾。参与者居住在新泽西州的10个县。数据分析于2022年12月至2023年4月间进行。根据诊断时的居住地址，将由人口普查区域措施（教育、收入、财富、就业状况和职业）组成的社会经济地位（nSES）指数与之关联。使用ADMIXTURE程序估计了非洲祖先的百分比。运用序贯调整的（年龄调整：年龄和采访年份；全面调整：年龄调整加上个人社会经济地位、生活方式因素和共病因素）逻辑回归模型来估计与肿瘤亚型（雌激素受体阴性 [ER-] 对雌激素受体阳性 [ER+]；三阴性乳腺癌 [TNBC] 对内腺A）的关联，使用Cox模型来估计与全因死亡（ACM）和乳腺癌特异性死亡（BCSM）的关联。BCSM模型使用Fine-Gray竞争风险模型进行拟合，并使用健壮标准误以考虑人口普查区域的聚类效应。在1575名参与者中，非洲祖先的中位数（IQR）为85%（76% -90%），年龄的中位数（IQR）为55岁（46 -63岁）。非洲祖先每增加10个百分点，ER-与ER+之间的几率较高 （调整后的优势比 [aOR]，1.08；95% CI，0.98-1.18），TNBC与内腺A之间的几率较高（aOR，1.15；95% CI，1.02-1.31），但与ACM或BCSM无关。 nSES的IQR增加1个单位与较低的ACM （调整后的风险比 [aHR]，0.76；95% CI，0.63-0.93）有关，而对于BCSM的HR小于1，但在年龄调整模型中统计学上不显著（aHR，0.81；95% CI，0.62-1.04），但在进一步调整潜在中介变量（个人SES、生活方式和共病）后，相关性有所减弱。在这个黑人女性乳腺癌幸存者的队列研究中，非洲祖先的增加与恶性肿瘤亚型有关。与遗传祖先相比，与社会环境相关的中介途径可能对这些患者的生存更为重要。

Racial disparities in breast cancer (BC) survival arise from multilevel causes, which may exert influence at different stages of BC progression. Clarifying the importance of genetic and social factors could help prioritize interventions.To jointly examine associations between African genetic ancestry, social environment, and mortality from any cause and BC in Black BC survivors.This population-based cohort study enrolled self-identified Black women aged 20 to 75 years with histologically confirmed BC from June 2005 to May 2019 and followed them up until death or censoring in September 2021. Participants lived in 10 New Jersey counties. Data were analyzed between December 2022 and April 2023.A neighborhood socioeconomic status (nSES) index composed of census tract measures (education, income, wealth, employment status, and occupation) was linked to residential addresses at diagnosis. Percentage African ancestry was estimated using the ADMIXTURE program.Sequentially adjusted (age adjusted: age and interview year; fully adjusted: age adjusted with individual SES, lifestyle factors, and comorbidities) logistic regression models were fit to estimate associations with tumor subtypes (estrogen receptor-negative [ER-] vs estrogen receptor-positive [ER+]; triple-negative breast cancer [TNBC] vs luminal A), and Cox models were fit for associations with all-cause mortality (ACM) and breast cancer-specific mortality (BCSM). Models for BCSM were fit using Fine-Gray competing risks models, and robust standard errors were used to account for census tract-level clustering.Among 1575 participants, median (IQR) African ancestry was 85% (76%-90%), and median (IQR) age was 55 (46-63) years. A 10-percentage point increase in African ancestry was associated with higher odds of ER- vs ER+ (adjusted odds ratio [aOR], 1.08; 95% CI, 0.98-1.18) and TNBC vs luminal (aOR, 1.15; 95% CI, 1.02-1.31) tumors, but not with ACM or BCSM. A 1-IQR increase in nSES was associated with lower ACM (adjusted hazard ratio [aHR], 0.76; 95% CI, 0.63-0.93), and the HR for BCSM was less than 1 but not statistically significant (aHR, 0.81; 95% CI, 0.62-1.04) in age-adjusted models, but associations attenuated following further adjustment for potential mediators (individual SES, lifestyles, comorbidities).In this cohort study of Black female BC survivors, higher African ancestry was associated with aggressive tumor subtypes. Compared with genetic ancestry, mediating pathways related to social environments may be more important for survival in these patients.