Department of Population Health Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah.
Department of Oncology, Intermountain Healthcare, Salt Lake City, Utah.
Cancer Epidemiol Biomarkers Prev. 2022 Jul 1;31(7):1313-1323. doi: 10.1158/1055-9965.EPI-21-1249.
Mammographic density (MD) is strongly associated with breast cancer risk. We examined whether body mass index (BMI) partially explains racial and ethnic variation in MD.
We used multivariable Poisson regression to estimate associations between BMI and binary MD [Breast Imaging Reporting and Database System (BI-RADS) A&B versus BI-RADS C&D] among 160,804 women in the Utah mammography cohort. We estimated associations overall and within racial and ethnic subgroups and calculated population attributable risk percents (PAR%).
We observed the lowest BMI and highest MD among Asian women, the highest BMI among Native Hawaiian and Pacific Islander women, and the lowest MD among American Indian and Alaska Native (AIAN) and Black women. BMI was inversely associated with MD [RRBMI≥30 vs. BMI<25 = 0.43; 95% confidence interval (CI), 0.42-0.44] in the full cohort, and estimates in all racial and ethnic subgroups were consistent with this strong inverse association. For women less than 45 years of age, although there was statistical evidence of heterogeneity in associations between BMI and MD by race and ethnicity (P = 0.009), magnitudes of association were similar across groups. PAR%s for BMI and MD among women less than 45 years were considerably higher in White women (PAR% = 29.2, 95% CI = 28.4-29.9) compared with all other groups with estimates ranging from PAR%Asain = 17.2%; 95% CI, 8.5 to 25.8 to PAR%Hispanic = 21.5%; 95% CI, 19.4 to 23.6. For women ≥55 years, PAR%s for BMI and MD were highest among AIAN women (PAR% = 37.5; 95% CI, 28.1-46.9).
While we observed substantial differences in the distributions of BMI and MD by race and ethnicity, associations between BMI and MD were generally similar across groups.
Distributions of BMI and MD may be important contributors to breast cancer disparities.
乳腺密度（MD）与乳腺癌风险密切相关。我们研究了体重指数（BMI）是否部分解释了 MD 在种族和族裔之间的差异。
我们使用多变量泊松回归分析，估计了 160804 名犹他州乳腺摄影队列女性中 BMI 与二分类 MD（乳腺影像报告和数据系统（BI-RADS）A&B 与 BI-RADS C&D）之间的关联。我们总体上以及在种族和族裔亚组内估计了关联，并计算了人群归因风险百分比（PAR%）。
我们观察到亚洲女性的 BMI 最低，MD 最高；夏威夷和太平洋岛民女性的 BMI 最高；美洲印第安人和阿拉斯加原住民（AIAN）和黑人女性的 MD 最低。BMI 与 MD 呈负相关[BMI≥30 与 BMI<25=0.43；95%置信区间（CI），0.42-0.44]，在整个队列中，所有种族和族裔亚组的估计值均与这种强烈的负相关一致。对于年龄小于 45 岁的女性，尽管 BMI 和 MD 之间的关联在种族和族裔之间存在统计学上的异质性（P=0.009），但各组之间的关联幅度相似。年龄小于 45 岁的白人女性 BMI 和 MD 的 PAR%相当高（PAR%=29.2，95%CI=28.4-29.9），而其他所有组的估计值范围从 PAR%Asain=17.2%；95%CI，8.5-25.8 到 PAR%Hispanic=21.5%；95%CI，19.4-23.6。对于年龄≥55 岁的女性，AIAN 女性 BMI 和 MD 的 PAR%最高（PAR%=37.5；95%CI，28.1-46.9）。
尽管我们观察到 BMI 和 MD 在种族和族裔之间的分布存在很大差异，但 BMI 和 MD 之间的关联在各群组中基本相似。
BMI 和 MD 的分布可能是乳腺癌差异的重要因素。
