BREAST-CANCER IN SWEDISH WOMEN BEFORE AGE 50 - EVIDENCE OF A DUAL EFFECT OF COMPLETED PREGNANCY
BREAST-CANCER IN SWEDISH WOMEN BEFORE AGE 50 - EVIDENCE OF A DUAL EFFECT OF COMPLETED PREGNANCY
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DOI：
10.1007/bf00051403
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发表时间：
1995-07-01
影响因子：
2.3
通讯作者：
MURPHY, MFG
中科院分区：
文献类型：
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作者：
LEON, DA;CARPENTER, LM;MURPHY, MFG
我们开始检测分娩后乳腺癌风险的短暂增加，这种情况的存在已经被假设，但经验证据是矛盾的。在1939年以后出生的瑞典妇女中，乳腺癌和分娩之间存在联系，产生了3，439例病例和25，140例年龄匹配的对照组，至少有两个孩子。在最后一次分娩后的三年内，妇女患乳腺癌的估计比率为1.21（95%置信区间[CI] = 1.02-1.44），是最后一次分娩时间为10年或更早的妇女的1.21倍，调整了第一次分娩的产次和年龄。进一步的分析表明，这种影响部分反映了乳腺癌风险的短暂增加，这种增加持续约三年。首次生育年龄对乳腺癌风险的影响似乎受到自上次生育以来的时间的混淆;在对自上次生育以来的时间进行额外调整后，35岁或以上首次生育与20岁以下首次生育的经产次调整率比从1.72（CI = 1.14-2.58）降至1.36（CI = 0.88-2.09）。因此，分娩后乳腺癌风险的短暂增加似乎可以部分解释第一次生育年龄对乳腺癌风险的影响。
We set out to detect a transient increase in risk of breast cancer following childbirth, the existence of which has been postulated, but for which empirical evidence is contradictory. Breast cancers and births occurring among the cohort of Swedish women born after 1939 were linked, yielding 3,439 cases and 25,140 age-matched controls with at least two children. Within three years of their last childbirth, women had an estimated rate of breast cancer of 1.21 (95 percent confidence interval [CI] = 1.02-1.44) times that of women whose last birth was 10 or more years earlier, after adjustment for parity and age at first birth. Further analyses suggested that this effect reflected, in part, a small transient increase in breast cancer risk that lasts for about three years following completed pregnancy. The effect of age at first birth on breast cancer risk appears to be confounded by time since last birth; the parity-adjusted rate ratio for having a first birth at age 35 years or more compared with under 20 years is reduced from 1.72 (CI = 1.14-2.58) to 1.36 (CI = 0.88-2.09) on additional adjustment for time since last birth. A transient increase in breast cancer risk after childbirth thus appears to account for part of the effect of age at first birth on breast cancer risk.