PERINATAL FACTORS AND BREAST CANCER

尽管在这一领域开展了大量的研究活动，但乳腺癌的流行病学是复杂的，而且只有部分人了解。有人假设，宫内因素和围产期事件或情况可能会影响女性后代患成年乳腺癌的风险。出生体重似乎是最能提供信息的围产期因素；然而，探索这一潜在预测因素的研究得出了不同的结论。这项拟议研究的主要目标是检验围产期和宫内因素将影响女性胎儿未来患乳腺癌风险的假设。为此，将解决以下具体目标：调查癌症风险与胎儿大小指标之间是否存在正相关；确认乳腺癌风险与母亲先兆子痫之间的负相关；检查观察到的乳腺癌风险与早产和新生儿黄疸之间的正相关；以及研究其他宫内环境指标，如母亲超重、产次、出生时年龄以及胎盘特征，对女性后代发生乳腺癌的影响。为了检验这些关系，将在挪威妇女中进行一项与乳腺癌相关的围产期因素的配对嵌套病例对照研究。这项研究的人口基数将是特隆赫姆和卑尔根的所有女性居民，她们在1930年至1970年期间出生在这两个县的大学医院。事故乳腺癌病例将从挪威国家癌症登记处确认，该登记处自1952年以来一直存在。使用分配给所有挪威人的唯一个人身份证来获取有关出生地和母亲姓名的信息，然后将其与病例在大学医院的出生记录联系起来。对于每个病例，将选择与病例出生在同一分娩诊所的三名年龄和居住地匹配的对照妇女。预计到1997年，在特隆赫姆和卑尔根出生和居住的妇女中将出现1000例新的乳腺癌病例；因此，3000名配对对照也将包括在这项研究中。有关感兴趣的围产期因素的暴露信息将从出生记录中获得。获得如此高质量的数据将为批判性地评估乳腺癌起源于宫内的假说提供一个重要机会。

The epidemiology of breast cancer is complicated and only partially understood, despite an enormous research activity in this area. It has been hypothesized that intrauterine factors and perinatal events or conditions could affect adult breast cancer risk in the female offspring. The factor that appears to be the most informative perinatal factor is birth weight; however, the studies exploring this potential predictor have reached different conclusions. The primary goal of the proposed study is to examine the hypothesis that perinatal and intrauterine factors will influence the female fetus' future risk of breast cancer. To this end, the following specific aims will be addressed: to investigate if there is a positive association between cancer risk and indicators of fetal size; to confirm the negative association between breast cancer risk and maternal eclampsial pre-eclampsia; to examine the observed positive association between breast cancer risk and prematurity and neonatal jaundice; and, to study the effect of other indicators of intrauterine environment, such as maternal overweight, parity, and age at time of birth as well as placenta characteristics, on the occurrence of breast cancer in the female offspring. To examine these relationships, a matched, nested case-control study of perinatal factors associated with breast cancer will be conducted among women in Norway. The population base for this study will be all female residents of Trondheim and Bergen who were born at the University hospitals in those two counties between 1930 and 1970. Incident breast cancer cases will be identified from the national Norwegian Cancer Registry, which has been in existence since 1952. Using the unique personal identification assigned to all Norwegians to obtain information on birthplace and mother's name, linkage would then be made to the case's birth record at the University hospitals. For each case, three age- and residence-matched control women who were born in the same birthing clinic as the case will be selected. It is anticipated that 1,000 new cases of breast cancer will have occurred through 1997 among the women born and residing in Trondheim and Bergen; thus, 3,000 matched controls would also be included in the study. Exposure information concerning the perinatal factors of interest will be obtained from the birth records. Access to data of such superb quality will provide an important opportunity to critically evaluate the intrauterine origin of breast cancer hypothesis.