García-Pérez Javier, Pollán Marina, Pérez-Gómez Beatriz, González-Sánchez Mario, Cortés Barragán Rosa Ana, Maqueda Blasco Jerónimo, González-Galarzo María Carmen, Alba Miguel Ángel, van der Haar Rudolf, Casas Silvia, Vicente Cándida, Medina Pilar, Ederra María, Santamariña Carmen, Moreno María Pilar, Casanova Francisco, Pedraz-Pingarrón Carmen, Moreo Pilar, Ascunce Nieves, García Montse, Salas-Trejo Dolores, Sánchez-Contador Carmen, Llobet Rafael, Lope Virginia
Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain; Consortium for Biomedical Research in Epidemiology & Public Health (CIBER Epidemiología y Salud Pública - CIBERESP), Spain.
Escuela Nacional de Medicina del Trabajo, Carlos III Institute of Health, Madrid, Spain.
Environ Res. 2017 Nov;159:355-361. doi: 10.1016/j.envres.2017.08.028. Epub 2017 Sep 18.
High mammographic density is one of the main risk factors for breast cancer. Although several occupations have been associated with breast cancer, there are no previous occupational studies exploring the association with mammographic density. Our objective was to identify occupations associated with high mammographic density in Spanish female workers.
We conducted a population-based cross-sectional study of occupational determinants of high mammographic density in Spain, based on 1476 women, aged 45-68 years, recruited from seven screening centers within the Spanish Breast Cancer Screening Program network. Reproductive, family, personal, and occupational history data were collected. The latest occupation of each woman was collected and coded according to the 1994 National Classification of Occupations. Mammographic density was assessed from the cranio-caudal mammogram of the left breast using a semi-automated computer-assisted tool. Association between mammographic density and occupation was evaluated by using mixed linear regression models, using log-transformed percentage of mammographic density as dependent variable. Models were adjusted for age, body mass index, menopausal status, parity, smoking, alcohol intake, educational level, type of mammography, first-degree relative with breast cancer, and hormonal replacement therapy use. Screening center and professional reader were included as random effects terms.
Mammographic density was higher, although non-statistically significant, among secondary school teachers (e = 1.41; 95%CI = 0.98-2.03) and nurses (e = 1.23; 95%CI = 0.96-1.59), whereas workers engaged in the care of people (e = 0.81; 95%CI = 0.66-1.00) and housewives (e = 0.87; 95%CI = 0.79-0.95) showed an inverse association with mammographic density. A positive trend for every 5 years working as secondary school teachers was also detected (p-value = 0.035).
Nurses and secondary school teachers were the occupations with the highest mammographic density in our study, showing the latter a positive trend with duration of employment. Future studies are necessary to confirm if these results are due to chance or are the result of a true association whose causal hypothesis is, for the moment, unknown.
乳腺钼靶高密度是乳腺癌的主要危险因素之一。虽然已有几种职业与乳腺癌相关，但此前尚无职业研究探讨其与乳腺钼靶密度的关联。我们的目的是确定西班牙职业女性中与乳腺钼靶高密度相关的职业。
我们基于从西班牙乳腺癌筛查项目网络内的7个筛查中心招募的1476名年龄在45 - 68岁的女性，开展了一项关于西班牙乳腺钼靶高密度职业决定因素的基于人群的横断面研究。收集了生殖、家庭、个人和职业史数据。收集每位女性的最新职业，并根据1994年《国家职业分类》进行编码。使用半自动计算机辅助工具从左乳房的头尾位乳腺钼靶片中评估乳腺钼靶密度。以乳腺钼靶密度的对数转换百分比作为因变量，通过混合线性回归模型评估乳腺钼靶密度与职业之间的关联。模型针对年龄、体重指数、绝经状态、产次、吸烟、饮酒、教育程度、乳腺钼靶类型、患乳腺癌的一级亲属以及激素替代疗法的使用情况进行了调整。将筛查中心和专业阅片者作为随机效应项纳入。
中学教师（e = 1.41；95%置信区间 = 0.98 - 2.03）和护士（e = 1.23；95%置信区间 = 0.96 - 1.59）的乳腺钼靶密度较高，尽管无统计学意义，而从事护理工作的人员（e = 0.81；95%置信区间 = 0.66 - 1.00）和家庭主妇（e = 0.87；95%置信区间 = 0.79 - 0.95）与乳腺钼靶密度呈负相关。还发现中学教师每工作5年有一个正相关趋势（p值 = 0.035）。
在我们的研究中，护士和中学教师是乳腺钼靶密度最高的职业，中学教师的乳腺钼靶密度随工作年限呈正相关趋势。未来有必要进行研究以确认这些结果是偶然所致，还是真实关联的结果，目前其因果假设尚不清楚。
