Breast cancer is associated with phosphate toxicity, the toxic effect from dysregulated phosphate metabolism that can stimulate tumorigenesis. Phosphate toxicity and dysregulated phosphate metabolism are also associated with bone mineral abnormalities, including excessive bone mineral loss and deposition. Based on shared associations with dysregulated phosphate metabolism and phosphate toxicity, a hypothesis proposed in the present mixed methods–grounded theory study posits that middle-aged women with incidence of breast cancer had a greater magnitude of changes in bone mineral density over time compared with women who remained cancer-free. To test this hypothesis, a mixed-effects model was used to analyze the associations of breast cancer incidence with spinal bone mineral density changes in the U.S. Study of Women’s Health Across the Nation. Compared with women in the cohort who remained cancer-free, women who self-reported breast cancer had higher bone mineral density at baseline, but had more rapid losses in bone mineral density during follow-up visits. These findings agree with the hypothesis that a greater magnitude of changes in bone mineral density over time is associated with breast cancer in a cohort of middle-aged women. The findings also have implications for studies investigating dysregulated phosphate metabolism and phosphate toxicity as causative factors of bone metastasis in metastatic breast cancer. Additionally, the authors previously found increased breast cancer risk associated with high dietary phosphate intake in the same cohort of middle-aged women, and more studies should investigate a low-phosphorus diet to reduce bone mineral abnormalities and tumorigenesis in breast cancer patients.
乳腺癌与磷酸盐毒性相关，即磷酸盐代谢失调产生的毒性效应可刺激肿瘤发生。磷酸盐毒性及磷酸盐代谢失调同时与骨矿物质异常相关联，包括过度骨矿物质流失与沉积。基于二者共同存在的磷酸盐代谢失调与磷酸盐毒性关联，本混合方法-扎根理论研究提出假设：与未患癌症的女性相比，中年乳腺癌患者的骨密度随时间推移会出现更显著的变化。为验证该假设，本研究采用混合效应模型分析美国"全国妇女健康研究"数据中乳腺癌发病率与脊柱骨密度变化的关系。与队列中未患癌症的女性相比，自报乳腺癌的女性基线骨密度较高，但在随访期间骨密度下降更快。这些发现证实了中年女性队列中骨密度随时间变化幅度与乳腺癌存在关联的假设。该结果对探究磷酸盐代谢失调和磷酸盐毒性作为转移性乳腺癌骨转移致病因素的研究具有启示意义。此外，作者先前在同一中年女性队列中发现高膳食磷酸盐摄入会增加乳腺癌风险，后续研究应深入探讨低磷饮食对减少乳腺癌患者骨矿物质异常和肿瘤发生的作用。
肿瘤(癌症)患者之家