Rajaram Nadia, Mariapun Shivaani, Eriksson Mikael, Tapia Jose, Kwan Pui Yoke, Ho Weang Kee, Harun Faizah, Rahmat Kartini, Czene Kamila, Taib Nur Aishah Mohd, Hall Per, Teo Soo Hwang
Cancer Research Malaysia, 1 Jalan SS12/1A, 47500, Subang Jaya, Selangor, Malaysia.
Department of Applied Mathematics, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor, Malaysia.
Breast Cancer Res Treat. 2017 Jan;161(2):353-362. doi: 10.1007/s10549-016-4054-y. Epub 2016 Nov 18.
Mammographic density is a measurable and modifiable biomarker that is strongly and independently associated with breast cancer risk. Paradoxically, although Asian women have lower risk of breast cancer, studies of minority Asian women in predominantly Caucasian populations have found that Asian women have higher percent density. In this cross-sectional study, we compared the distribution of mammographic density for a matched cohort of Asian women from Malaysia and Caucasian women from Sweden, and determined if variations in mammographic density could be attributed to population differences in breast cancer risk factors.
Volumetric mammographic density was compared for 1501 Malaysian and 4501 Swedish healthy women, matched on age and body mass index. We used multivariable log-linear regression to determine the risk factors associated with mammographic density and mediation analysis to identify factors that account for differences in mammographic density between the two cohorts.
Compared to Caucasian women, percent density was 2.0% higher among Asian women (p < 0.001), and dense volume was 5.7 cm higher among pre-menopausal Asian women (p < 0.001). Dense volume was 3.0 cm lower among post-menopausal Asian women (p = 0.009) compared to post-menopausal Caucasian women, and this difference was attributed to population differences in height, weight, and parity (p < 0.001).
Our analysis suggests that among post-menopausal women, population differences in mammographic density and risk to breast cancer may be accounted for by height, weight, and parity. Given that pre-menopausal Asian and Caucasian women have similar population risk to breast cancer but different dense volume, development of more appropriate biomarkers of risk in pre-menopausal women is required.
乳腺X线密度是一种可测量且可改变的生物标志物，与乳腺癌风险密切且独立相关。矛盾的是，尽管亚洲女性患乳腺癌的风险较低，但对主要为白种人群体中的少数亚洲女性进行的研究发现，亚洲女性的乳腺密度百分比更高。在这项横断面研究中，我们比较了来自马来西亚的亚洲女性和来自瑞典的白种女性匹配队列的乳腺X线密度分布，并确定乳腺X线密度的差异是否可归因于乳腺癌风险因素的人群差异。
比较了1501名马来西亚健康女性和4501名瑞典健康女性的乳腺体积密度，这些女性在年龄和体重指数上进行了匹配。我们使用多变量对数线性回归来确定与乳腺X线密度相关的风险因素，并进行中介分析以识别导致两个队列之间乳腺X线密度差异的因素。
与白种女性相比，亚洲女性的密度百分比高2.0%（p < 0.001），绝经前亚洲女性的致密体积高5.7 cm（p < 0.001）。与绝经后白种女性相比，绝经后亚洲女性的致密体积低3.0 cm（p = 0.009），这种差异归因于身高、体重和生育情况的人群差异（p < 0.001）。
我们的分析表明，在绝经后女性中，乳腺X线密度和乳腺癌风险的人群差异可能由身高、体重和生育情况来解释。鉴于绝经前亚洲和白种女性患乳腺癌的人群风险相似但致密体积不同，需要开发更适用于绝经前女性的风险生物标志物。
