A prospective study of the effects of early life growth on adult mammographic density

现在大家都知道，通过乳房扫描测量的女性乳房密度可以预测她未来患乳腺癌的风险。人们还知道，婴儿时期体重较重、7岁前发育较快的女性在成年后更容易患乳腺癌。这种影响在青春期提前的女性身上表现得最为明显。有人认为，在生命早期的生长过程中，有一些临界点会导致中年时乳房密度较高。有必要对大量从出生到成年的妇女进行基于人口的早期生长数据调查，以准确估计早期生长与中年乳房密度之间的关系。很少有这样的研究存在；塔斯马尼亚哮喘研究就是其中之一。1968年，对1961年出生的4194名塔斯马尼亚女学生进行了调查，并测量了他们的身高和体重。随后，对该队列的样本进行了体重和身高测量。目前，我们正对助教进行为期37年的跟进工作，迄今为止，我们已追踪了87%的邮件调查，并取得了77%的回应率（2,850人）。这包括自我报告的体重和身高测量，以及生殖史和激素使用的详细信息。目前对600名受访者的体重、身高和腰臀比进行了测量。我们可以获得整个队列的学校医疗记录，其中有整个学年在学校医疗检查中测量的体重和身高数据，以及迄今为止总队列中一半的产妇记录，其中有出生体重、身高和妊娠期的信息。因此，TAS现在提供了一个理想的机会，在澳大利亚独特的，前瞻性地调查中年妇女早期生命生长和乳房x线摄影密度之间的关系。我们将使用墨尔本大学的澳大利亚乳房x线摄影密度研究机构来测量这些40多岁的女性的乳房密度。

It is now well-known that a woman's breast density, as measured by a breast scan, is a predictor of her future risk of breast cancer. It is also known that women who are heavier as babies and grow rapidly before age 7 are more likely to develop breast cancer in adult life. The effects were strongest in women who had early puberty. It has been suggested that there are critical points in early life growth that contribute to higher breast density in middle-age. Population-based surveys with early life growth data on large numbers of women that span birth to adulthood are necessary to estimate accurately the association between early life growth and breast density in middle age. Few such studies exist; Tasmanian Asthma Study is one of them. In 1968, all 4,194 female Tasmanian school children born in 1961 were surveyed and height and weight measured. Subsequently, weight and height measurements were carried out on samples of this cohort. We are currently conducting the 37-year follow-up of the TAS and to date have traced 87% and achieved a response rate of 77% (2,850) for a postal survey. This included self-reported weight and height measurements and detailed information reproductive history and the use of hormones. Weight, height and waist to hip ratio are currently measured on 600 of these respondents. We have access to school medical records of the full cohort, which have weight and height data measured at school medical inspections throughout school years, and maternal records so far for half of the total cohort, which have information on birth weight and length, and period of gestation. Hence, TAS now provides an ideal opportunity, unique within Australia, to investigate prospectively the association between early life growth and mammographic density in middle-age women. We will measure breast density in these women now they are in their late 40s, using the Australian Mammographic Density Research Facility at The University of Melbourne.