Apter D, Reinilä M, Vihko R
Department of Obstetrics and Gynaecology, University of Helsinki, Finland.
Int J Cancer. 1989 Nov 15;44(5):783-7. doi: 10.1002/ijc.2910440506.
Early menarche is a risk factor for breast cancer. In a longitudinal manner, we have investigated the endocrine features of girls with early menarche. This study extends our investigations to the third decade of life in a cohort of girls followed up for 13 years. The group studied comprised 44 women, 20-31 years of age. Eleven women had had their menarche before 12.0 years, 14 women at 12.0-12.9 years and 19 women at 13.0 years or more. The women who had had early menarche had higher serum oestradiol concentrations during the follicular phase of the menstrual cycle than the women who had had their menarche later. The serum oestradiol concentrations increased rapidly at the beginning of cycle in these "early menarche" women. If there is a threshold which serum oestradiol concentrations must exceed to increase the risk of breast cancer, then these women have more days at risk than other women. In addition, the serum SHBG (sex-hormone-binding globulin) concentration was about 30% lower in the follicular-phase specimens of the women who had had their menarche before 12.0 years compared with those who had had their menarche at 13.0 years. Our data therefore indicate that women with early menarche are subject to a high degree of oestrogen stimulation at least until approximately 30 years of age. Our findings may have important consequences for the design of intervention programs for breast cancer prevention.
初潮过早是乳腺癌的一个风险因素。我们以纵向方式研究了初潮过早女孩的内分泌特征。本研究将我们的调查扩展到了一组随访13年的女孩的30岁年龄段。所研究的组包括44名年龄在20至31岁之间的女性。11名女性初潮年龄在12.0岁之前，14名女性初潮年龄在12.0至12.9岁之间，19名女性初潮年龄在13.0岁及以上。初潮过早的女性在月经周期的卵泡期血清雌二醇浓度高于初潮较晚的女性。在这些“初潮过早”的女性中，血清雌二醇浓度在周期开始时迅速升高。如果存在血清雌二醇浓度必须超过才能增加乳腺癌风险的阈值，那么这些女性处于风险中的天数比其他女性更多。此外，初潮年龄在12.0岁之前的女性在卵泡期样本中的血清性激素结合球蛋白（SHBG）浓度比初潮年龄在13.0岁的女性低约30%。因此，我们的数据表明，初潮过早的女性至少在大约30岁之前受到高度的雌激素刺激。我们的发现可能对乳腺癌预防干预项目的设计产生重要影响。
