Orgéas Chantal C, Hall Per, Rosenberg Lena U, Czene Kamila
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobels väg 12A, Stockholm, SE-17177, Sweden.
Breast Cancer Res. 2008;10(6):R107. doi: 10.1186/bcr2212. Epub 2008 Dec 16.
Hormonal factors are implicated in tumor progression and it is possible that factors influencing breast cancer induction could affect prognosis. Our study investigated the effects of menstrual risk factors on tumor characteristics and survival in postmenopausal breast cancer.
We used a nationwide, population-based, case-case design of 2,640 Swedish women who were 50 to 74 years old and had postmenopausal breast cancer during 1993 to 1995. Follow-up was conducted until 31 December 2000. We used polytomous multiple logistic regression to investigate the relationships between menstrual factors (age at menarche, cycle length, irregular menstruation, lifetime number of menstrual cycles, and age at menopause), tumor characteristics (size, grade, estrogen receptor and progesterone receptor [PR] status, lymph node involvement, and histology), and Cox proportional hazards modeling for 5-year survival.
Younger ages at menarche were significantly associated with grade and lymph node involvement. Women with an age at menarche of 11 years or younger had a more than twofold excess risk of medium-grade (odds ratio [OR] = 2.05; 95% confidence interval [CI] 1.00 to 4.18) and high-grade (OR = 2.04; 95% CI 1.01 to 4.16) tumors. Early menarche significantly increased the risk of lymph node metastases. Survival was poorest in women with the earliest age at menarche, with a 72% increased risk of dying within 5 years after diagnosis (hazard ratio = 1.72; 95% CI 1.02 to 2.89). No significant associations were observed for other menstrual factors with tumor characteristics or survival.
Age at menarche has a significant impact on breast cancer prognosis and survival. It remains to be established whether the associations are attributable to age at menarche directly or are associated with the early-life physiological events of breast development and carcinogenesis also taking place during childhood and puberty, as menarche is only the culmination of this series of events.
激素因素与肿瘤进展有关，影响乳腺癌诱发的因素可能会影响预后。我们的研究调查了月经风险因素对绝经后乳腺癌患者肿瘤特征和生存情况的影响。
我们采用了一项基于全国人口的病例对照研究设计，研究对象为1993年至1995年间年龄在50至74岁之间的2640名患绝经后乳腺癌的瑞典女性。随访至2000年12月31日。我们使用多分类多项逻辑回归来研究月经因素（初潮年龄、月经周期长度、月经不规律、月经周期总数和绝经年龄）、肿瘤特征（大小、分级、雌激素受体和孕激素受体[PR]状态、淋巴结受累情况和组织学类型）之间的关系，并使用Cox比例风险模型分析5年生存率。
初潮年龄较小与肿瘤分级和淋巴结受累显著相关。初潮年龄在11岁及以下的女性患中等级别（优势比[OR]=2.05；95%置信区间[CI]1.00至4.18）和高等级别（OR=2.04；95%CI1.01至4.16）肿瘤的风险高出两倍多。初潮过早显著增加了淋巴结转移的风险。初潮年龄最早的女性生存情况最差，诊断后5年内死亡风险增加72%（风险比=1.72；95%CI1.02至2.89）。未观察到其他月经因素与肿瘤特征或生存情况之间存在显著关联。
初潮年龄对乳腺癌预后和生存有显著影响。这些关联是直接归因于初潮年龄，还是与儿童期和青春期发生的早期生命生理事件（乳房发育和致癌作用）相关，仍有待确定，因为初潮只是这一系列事件的 culmination。 （注：此处“culmination”直译为“顶点”，结合语境可理解为“最终阶段”等意思，具体含义可根据上下文进一步确定）
