Association of reproductive and menstrual factors with the risk of breast cancer in women: a population-based study

作者：Zhuo Song, Ming Ding, Qianhao Zang, Lei Wang, Dan Ma, Gang Ren, Yingjie Wang, Ying Feng · 发表于：BMC Cancer · 年份：2025 · DOI：10.1186/s12885-025-15048-1 · 被引用次数：2 · 研究领域：Cancer Risks and Factors、Reproductive Biology and Fertility、BRCA gene mutations in cancer

BACKGROUND: Reproductive factors significantly impact the incidence of breast cancer (BC), a concerning trend. This study aims to reassess this association and provide recommendations for fertility policies to delay the onset of BC. METHODS: Utilizing data from a national survey, we applied weighted Cox and restricted cubic spline (RCS) methods to evaluate the impact of various modifiable and non-modifiable reproductive factors on breast cancer (BC) incidence. Interaction and subgroup analyses were conducted to investigate favorable fertility combinations and identify target populations. RESULTS: Our analysis included 15,938 cases, representing 63,247,160 women in the United States, with 4.06% diagnosed as BC survivors. Multiple models consistently demonstrated that a later age at menarche (AM), higher parities, and an earlier age at first birth (AFB) were associated with a delayed BC onset. Specifically, women with four or more parities experienced a 32% reduction in BC risk (hazard ratio [HR] 0.68, 95% confidence interval [CI] 0.48-0.95), while those with an AFB of 25 years or older faced a 51% increased risk (HR 1.51, 95% CI 1.17-1.94). Women with an AM of 13 years or older had a 26% decreased risk in multivariate Cox analysis. Restricted cubic spline (RCS) analysis revealed a negative linear relationship between parities and BC risk. However, interaction and subgroup analyses indicated that these factors were less impactful than an earlier AFB, particularly in the high-ri...