高乳房 X 光密度是乳腺癌的一个公认的危险因素；然而，来自黑人女性的数据有限。目前尚不清楚乳房X线照相密度与黑人女性乳腺癌亚型之间的关系。我们研究了黑人女性健康研究参与者的乳房 X 光密度百分比 (PMD) 与乳腺癌风险之间的关联。对 363 例病例和 5541 例非病例进行了数字化筛查乳房 X 光检查。 Cumulus 软件用于评估 PMD。我们使用抽样权重的逆概率和 Cox 比例风险模型，根据年龄和体重指数进行调整，以估计总体风险比 (HR) 和 95% 置信区间 (CI)，并按乳房 X 光检查年龄和雌激素受体 (ER) 状态乳腺肿瘤。多变量模型包括额外的乳腺癌危险因素。统计显着性检验是双向的。在简单模型中，PMD 最高四分位数的女性与最低四分位数的女性相比，患乳腺癌的几率增加 53%（HR 1.53；95% CI：1.11，2.11）。 55 岁以下女性的 HR 为 1.37（95% CI：0.83，2.24），55 岁以上女性的 HR 为 1.68（95% CI：1.10，2.56）。 ER 癌症的 HR 为 1.49 (95% CI: 1.02, 2.16)，ER 癌症的 HR 为 1.45 (95% CI: 0.73, 2.87)。多变量模型中的关联性基本没有变化。在这项针对美国黑人女性的研究中，较高的 PMD 与 ER 和 ER- 乳腺癌风险相关。这项研究的结果强调了乳腺密度作为黑人女性乳腺癌危险因素的重要性。© 2024 UICC。

High mammographic density is a well-established risk factor for breast cancer; however, data from Black women are limited. It is largely unknown how mammographic density is associated with breast cancer subtypes among Black women. We examined the association between percent mammographic density (PMD) and breast cancer risk among participants in the Black Women's Health Study. Digital screening mammograms were available for 363 cases and 5541 non-cases. Cumulus software was used to assess PMD. We used inverse probability of sampling weights and Cox proportional hazards models, adjusted for age and body mass index, to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) overall and by age at mammography and estrogen receptor (ER) status of the breast tumors. Multivariable models included additional breast cancer risk factors. Tests of statistical significance were 2-sided. In simple models, women in the highest quartile of PMD had 53% increased odds of breast cancer compared to those in the lowest quartile (HR 1.53; 95% CI: 1.11, 2.11). HRs were 1.37 (95% CI: 0.83, 2.24) among women <55 years of age and 1.68 (95% CI: 1.10, 2.56) among women aged ≥55 years. HRs were 1.49 (95% CI: 1.02, 2.16) for ER+ cancer and 1.45 (95% CI: 0.73, 2.87) for ER- cancer. Associations were largely unchanged in multivariable models. In this study of U.S. Black women, higher PMD was associated with ER+ and ER- breast cancer risk. Findings from this study reinforce the importance of breast density as a risk factor for breast cancer in Black women.© 2024 UICC.