Kroman Niels, Jensen Maj-Britt, Wohlfahrt Jan, Ejlertsen Bent
Department of Breast and Endocrine Surgery, Rigshospitalet, Copenhagen, Denmark.
Acta Oncol. 2008;47(4):545-9. doi: 10.1080/02841860801935491.
Estrogen is an established growth factor in breast cancer and it has been hypothesized that pregnancy associated estrogens may increase the risk of recurrence of breast cancer. In 1997 we published a population-based Danish study indicating no negative prognostic effect of pregnancy after breast cancer treatment. The present study is a ten-year update.
Danish Breast Cancer Cooperative Group has since 1977 collected population-based data on tumour characteristics, treatment regimes, and follow-up status on Danish women with breast cancer. Pregnancy history was added from the Danish Civil Registration System, the National Birth Registry, and the National Induced Abortion registry. Cox regression was used to estimate the risk ratio of dying among women with a pregnancy after breast cancer treatment compared with women without such experience.
In all, 10 236 women with primary breast cancer aged 45 years or less at the time of diagnosis were followed for 95 616 person years. Among these, 371 women experienced pregnancy after treatment of breast cancer. In a multivariate analysis that included age at diagnosis, stage of disease, and pregnancy history prior to diagnosis, women who had a full-term pregnancy subsequent to breast cancer treatment were found to have a reduced risk of dying (relative risk: 0.73; 95% confidence interval: 0.54-0.99) compared with other women with breast cancer. The effect was not significantly modified by age at diagnosis, tumour size, nodal status, or pregnancy history before diagnosis of breast cancer. Neither spontaneous abortions nor induced abortions subsequent to breast cancer treatment had a negative impact on prognosis.
In line with our previous study, but based on more than twice the patient material, we found no evidence that a pregnancy after treatment of breast cancer has a negative influence the prognosis.
雌激素是乳腺癌中一种已确定的生长因子，据推测，与妊娠相关的雌激素可能会增加乳腺癌复发风险。1997年，我们发表了一项基于丹麦人群的研究，表明乳腺癌治疗后妊娠并无负面预后影响。本研究是一项为期十年的更新研究。
自1977年以来，丹麦乳腺癌协作组收集了丹麦乳腺癌女性的肿瘤特征、治疗方案及随访状况等基于人群的数据。妊娠史信息来自丹麦民事登记系统、国家出生登记处和国家人工流产登记处。采用Cox回归分析来估计乳腺癌治疗后妊娠女性与未经历妊娠女性的死亡风险比。
总共对10236例诊断时年龄在45岁及以下的原发性乳腺癌女性进行了95616人年的随访。其中，371例女性在乳腺癌治疗后经历了妊娠。在一项包含诊断时年龄、疾病分期及诊断前妊娠史的多因素分析中，发现乳腺癌治疗后足月妊娠的女性与其他乳腺癌女性相比，死亡风险降低（相对风险：0.73；95%置信区间：0.54 - 0.99）。该效应未因诊断时年龄、肿瘤大小、淋巴结状态或乳腺癌诊断前妊娠史而有显著改变。乳腺癌治疗后的自然流产和人工流产均未对预后产生负面影响。
与我们之前的研究一致，但基于两倍多的患者资料，我们未发现证据表明乳腺癌治疗后妊娠会对预后产生负面影响。
