Tao Li, Gomez Scarlett Lin, Keegan Theresa H M, Kurian Allison W, Clarke Christina A
Cancer Prevention Institute of California, Fremont, California.
Cancer Prevention Institute of California, Fremont, California. Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California.
Cancer Epidemiol Biomarkers Prev. 2015 Jul;24(7):1039-45. doi: 10.1158/1055-9965.EPI-15-0243. Epub 2015 May 12.
Higher breast cancer mortality rates for African-American than non-Hispanic White women are well documented; however, it remains uncertain if this disparity occurs in disease subgroups defined by tumor molecular markers and stage at diagnosis. We examined racial differences in outcome according to subtype and stage in a diverse, population-based series of 103,498 patients.
We obtained data for all invasive breast cancers diagnosed between January 1, 2005, and December 31, 2012, and followed through December 31, 2012, among 93,760 non-Hispanic White and 9,738 African-American women in California. Molecular subtypes were categorized according to tumor expression of hormone receptor (HR, based on estrogen and progesterone receptors) and human epidermal growth factor receptor 2 (HER2). Cox proportional hazards models were used to calculate relative hazard (RH) and 95% confidence intervals (CI) for breast cancer-specific mortality.
After adjustment for patient, tumor, and treatment characteristics, outcomes were comparable by race for stage I or IV cancer regardless of subtype, and HR(+)/HER2(+) or HR(-)/HER2(+) cancer regardless of stage. We found substantially higher hazards of breast cancer death among African-American women with stage II/III HR(+)/HER2(-) (RH, 1.31; 95% CI, 1.03-1.65; and RH, 1.39; 95% CI, 1.10-1.75, respectively) and stage III triple-negative cancers relative to Whites.
There are substantial racial/ethnic disparities among patients with stages II/III HR(+)/HER2(-) and stage III triple-negative breast cancers but not for other subtype and stage.
These data provide insights to assess barriers to targeted treatment (e.g., trastuzumab or endocrine therapy) of particular subtypes of breast cancer among African-American patients.
有充分文献记载，非裔美国女性的乳腺癌死亡率高于非西班牙裔白人女性；然而，在由肿瘤分子标志物和诊断时分期所定义的疾病亚组中，这种差异是否存在仍不确定。我们在一个基于人群的、包含103498例患者的多样化队列中，根据亚型和分期研究了种族差异对预后的影响。
我们获取了2005年1月1日至2012年12月31日期间在加利福尼亚州诊断出的所有浸润性乳腺癌的数据，并对93760名非西班牙裔白人女性和9738名非裔美国女性进行随访，直至2012年12月31日。分子亚型根据肿瘤激素受体（HR，基于雌激素和孕激素受体）和人表皮生长因子受体2（HER2）的表达进行分类。采用Cox比例风险模型计算乳腺癌特异性死亡率的相对风险（RH）和95%置信区间（CI）。
在对患者、肿瘤和治疗特征进行调整后，无论亚型如何，I期或IV期癌症的种族预后相当，无论分期如何，HR(+)/HER2(+)或HR(-)/HER2(+)癌症的种族预后也相当。我们发现，与白人相比，II/III期HR(+)/HER2(-)（RH分别为1.31；95%CI为1.03 - 1.65；以及RH为1.39；95%CI为1.10 - 1.75）和III期三阴性癌症的非裔美国女性乳腺癌死亡风险显著更高。
II/III期HR(+)/HER2(-)和III期三阴性乳腺癌患者存在显著的种族/民族差异，但其他亚型和分期则不存在。
这些数据为评估非裔美国患者中特定亚型乳腺癌（如曲妥珠单抗或内分泌治疗）的靶向治疗障碍提供了见解。
