Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
Swedish eScience Research Centre (SeRC), Karolinska Institutet, Stockholm, Sweden.
Breast Cancer Res. 2023 Jun 9;25(1):64. doi: 10.1186/s13058-023-01667-8.
Researchers have suggested that longitudinal trajectories of mammographic breast density (MD) can be used to understand changes in breast cancer (BC) risk over a woman's lifetime. Some have suggested, based on biological arguments, that the cumulative trajectory of MD encapsulates the risk of BC across time. Others have tried to connect changes in MD to the risk of BC.
To summarize the MD-BC association, we jointly model longitudinal trajectories of MD and time to diagnosis using data from a large ([Formula: see text]) mammography cohort of Swedish women aged 40-80 years. Five hundred eighteen women were diagnosed with BC during follow-up. We fitted three joint models (JMs) with different association structures; Cumulative, current value and slope, and current value association structures.
All models showed evidence of an association between MD trajectory and BC risk ([Formula: see text] for current value of MD, [Formula: see text] and [Formula: see text] for current value and slope of MD respectively, and [Formula: see text] for cumulative value of MD). Models with cumulative association structure and with current value and slope association structure had better goodness of fit than a model based only on current value. The JM with current value and slope structure suggested that a decrease in MD may be associated with an increased (instantaneous) BC risk. It is possible that this is because of increased screening sensitivity rather than being related to biology.
We argue that a JM with a cumulative association structure may be the most appropriate/biologically relevant model in this context.
研究人员提出，乳腺密度（MD）的纵向轨迹可以用于了解女性一生中乳腺癌（BC）风险的变化。一些人基于生物学论据提出，MD 的累积轨迹包含了随时间推移的 BC 风险。其他人试图将 MD 的变化与 BC 的风险联系起来。
为了总结 MD-BC 相关性，我们使用来自瑞典 40-80 岁女性大型（[Formula: see text]）乳腺摄影队列的数据，联合使用纵向 MD 轨迹和诊断时间的模型来总结 MD-BC 相关性。在随访期间，有 518 名女性被诊断为 BC。我们拟合了三个具有不同关联结构的联合模型（JMs）：累积、当前值和斜率，以及当前值关联结构。
所有模型都显示 MD 轨迹与 BC 风险之间存在关联（MD 当前值的[Formula: see text]，MD 当前值和斜率的[Formula: see text]和[Formula: see text]，以及 MD 累积值的[Formula: see text]）。具有累积关联结构和具有当前值和斜率关联结构的模型比仅基于当前值的模型具有更好的拟合优度。具有当前值和斜率结构的 JM 表明，MD 的减少可能与 BC 风险的增加（瞬时）相关。这可能是因为筛查敏感性增加，而不是与生物学相关。
我们认为，在这种情况下，具有累积关联结构的 JM 可能是最合适/最相关的模型。
