Rosner B, Colditz G A, Willett W C
Am J Epidemiol. 1994 Apr 15;139(8):819-35. doi: 10.1093/oxfordjournals.aje.a117079.
A modification of the model of Pike et al. (Nature 1983;303: 767-70) was applied to 91,523 women in the Nurses' Health Study who did not report prevalent cancer initially and who were followed for 14 years (1,212,855 person-years and 2,341 incident breast cancers). The model took into account current age, age at all births, age at menopause, and age at menarche in predicting the annual and cumulative incidence of breast cancer. The authors found that ages both at first birth and at subsequent births have long-term influence on breast cancer incidence. The incidence density for parous women was greater than for nulliparous women for 20-30 years after the time of the first birth. However, cumulative incidence up to age 70 years was about 20% lower, 10% lower, or 5% higher for parous versus nulliparous women if their first birth was at age 20, 25, or 35 years, respectively. The authors also observed a significantly lower incidence after each additional birth as well as after menopause for women of the same age. Overall, the effect of reproductive factors (other than age at menarche) appears to influence cumulative incidence to age 70 years by a maximum of approximately 50% when women with multiple births with an early age at first birth are compared with women with a single birth at a late age.
派克等人（《自然》，1983年；303卷：767 - 70页）的模型经过修改后应用于护士健康研究中的91523名女性，这些女性最初未报告患有癌症，并被随访了14年（共1212855人年，发生2341例浸润性乳腺癌）。该模型在预测乳腺癌的年发病率和累积发病率时，考虑了当前年龄、各次生育时的年龄、绝经年龄和初潮年龄。作者发现，首次生育及后续生育时的年龄对乳腺癌发病率都有长期影响。首次生育后20 - 30年，经产妇的发病密度高于未生育女性。然而，如果首次生育年龄分别为20岁、25岁或35岁，那么到70岁时，经产妇的累积发病率比未生育女性分别低约20%、低10%或高5%。作者还观察到，对于同一年龄的女性，每增加一次生育以及绝经后发病率都会显著降低。总体而言，与晚育单胎女性相比，早育多胎女性的生殖因素（初潮年龄除外）对70岁时累积发病率的影响似乎最大约为50%。
