Background

Metastasis from breast cancer (BC) has a predilection for the skeleton. Due to its osteolytic nature, breast cancer bone metastasis (BCBM) appears to increase fracture risk. The association between obesity and its effect on bone seems to be skeletal site-specific. The incidence of pathological fractures often involves the axial skeleton even though the most debilitating effects of fractures are caused in the appendicular skeleton. Whether obesity increases fracture risk in BCBM remains inconclusive, however. At present, there is no literature that examines the effects of obesity on BCBM, and fracture risk are as such we sought to determine the effect of obesity on fracture risk in BC. This is the focus of the review.

Objectives

This scoping review aims to examine the link between fracture outcomes of women with BC and obesity as reported by Body Mass Index (BMI). The purpose of this study is to determine if current literature suggests obesity increases fracture risk in women with BC.

Design

We conducted a comprehensive literature search for breast cancer bone metastasis, obesity, and fracture risk in PubMed, Cochrane Library, NIH Clinical Trials, and OpenGrey. Articles that included BC, obesity, and fracture risk were included for analysis. Data were pooled, charted, analysed, and reported according to PRISMA-ScR standards.

Data synthesis and results

Each outcome was stratified by BMI (obese or non-obese) status in women with breast cancer. Five studies were eligible for analysis and relevant data was charted to allow results to be synthesised. We found four out of five studies reported a positive association between BMI and fracture risk in females with breast cancer.

Conclusions

We found a potential association of obesity and fracture risk in breast cancer. However, as we conducted this study it was evident that there is limited literature available on this topic and none for breast cancer bone metastasis. This poses an important direction for future research. Larger and robust pre-clinical and clinical randomized control trials are needed to better understand the relation between obesity and metastatic breast cancer.

中文翻译：

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乳腺癌骨折风险：肥胖有影响吗？范围审查

 背景

乳腺癌（BC）转移偏向于骨骼。由于其溶骨性质，乳腺癌骨转移（BCBM）似乎会增加骨折风险。肥胖及其对骨骼的影响之间的关联似乎是骨骼部位特异性的。病理性骨折的发生通常涉及中轴骨骼，尽管骨折最严重的影响是在附肢骨骼中引起的。然而，肥胖是否会增加 BCBM 骨折风险仍无定论。目前，还没有文献研究肥胖对 BCBM 的影响，因此我们试图确定肥胖对 BC 骨折风险的影响。这是审查的重点。

 目标

本次范围审查旨在研究 BC 女性骨折结果与体重指数 (BMI) 报告的肥胖之间的联系。本研究的目的是确定当前文献是否表明肥胖会增加患有 BC 的女性骨折风险。

 设计

我们在 PubMed、Cochrane Library、NIH Clinical Trials 和 OpenGrey 中对乳腺癌骨转移、肥胖和骨折风险进行了全面的文献检索。包括 BC、肥胖和骨折风险的文章均被纳入分析。根据 PRISMA-ScR 标准汇总、制图、分析和报告数据。

数据综合和结果

每个结果均根据乳腺癌女性的 BMI（肥胖或非肥胖）状况进行分层。五项研究符合分析条件，并绘制了相关数据图表以综合结果。我们发现，五分之四的研究报告称，女性乳腺癌患者的体重指数与骨折风险呈正相关。

 结论

我们发现肥胖与乳腺癌骨折风险存在潜在关联。然而，当我们进行这项研究时，很明显，关于这个主题的文献有限，而且没有关于乳腺癌骨转移的文献。这为未来的研究提供了一个重要的方向。需要更大规模、更稳健的临床前和临床随机对照试验，以更好地了解肥胖与转移性乳腺癌之间的关系。