骨代谢生化指标在乳腺癌骨转移中的意义

The significance of bone metabolic markers in bone metastasis of breast cancer

乳腺癌是一种容易引起骨转移的女性常见的恶性肿瘤，其机制以溶骨性骨转移为主。在正常骨代谢中，由成骨细胞介导的骨形成作用和由破骨细胞介导的骨吸收作用之间呈动态平衡，而发生骨转移时，转移的肿瘤细胞可打破这种平衡，并引起相应骨代谢指标的改变，而这种改变可通过血液及尿液化验检测。近年来研究的骨特异性标记物可总结为骨吸收标记物及骨形成标记物，前者包括抗酒石酸酸性磷酸酶（TRACP）异构体5b，Ⅰ型胶原吡啶交联终肽（ICTP），Ⅰ型胶原蛋白交联氨基末端肽和羧基末端肽（NTx／CTx）及吡啶酚（PYD）和脱氧吡啶酚（D-PYD）。后者包括骨特异性碱性磷酸酶（BAP），Ⅰ型前胶原氨基端前肽（PINP）和Ⅰ型前胶原羧基端前肽（PICP）、骨唾液酸蛋白（BSP）、骨钙素（OC）等。这些实验室检测为早期乳腺癌骨转移的诊断提供了更多的依据。

Breast cancer ranks among the most prevalent malignancies in women to cause bone metastasis, which the main mechanism is osteolytic bone metastasis. There is a balance between the formation of new bone by osteoblasts and the resorption of old bone by osteoclasts in normal bone metabolism. Cancer cells within bone marrow interfere this balance and cause the change of the corresponding bone metabolism indicators, and this change can be detected through blood or ufine. Bone-specific markers researched recently can be summarized as bone resorption markers and bone formation markers, the former include tartrate-resistant acid phosphatase 5b（ TracpSb）, carboxy-terminal telopeptide of type Ⅰ collagen （ICTP）, N-terminal and C-terminal cross-linked telopeptide of type Ⅰ collagen （NTx/CTx）, pyridinoline（PYD） and droxypyridinoline （D-PYD）, while the latter consist of bone isoenzyme of alkaline phosphatase（ BAP）, N-terminal propeptide of type Ⅰ procolⅠlagen（ PINP）, carboxy-terminal propeptide of type Ⅰ procollagen （ PICP）, bone sialoprotein（BSP）, osteocalcin （OC）, et al. These laboratory tests can provide more evidences for an early diagnosis of breast cancer with bone metastases.