Application value of bone metabolism and immune cell indicators in screening for tumor bone metastasis: a...

To evaluate the diagnostic value of bone metabolism and immune cell indexes in screening for tumor bone metastasis.

A retrospective study was conducted on 247 patients with malignant tumors. conducted on 247 patients with malignant tumors. According the presence of tumor bone metastasis, patients were divided into a bone metastasis group (156 cases) and a non-bone metastasis group (91 cases). Bone metabolism markers [calcium ion (Ca²⁺), β-Carbox-terminal telopeptide of type I collagen (β-CTX), type I procollagen N-terminal peptide (P1NP), osteocalcin (OC)] and immune cell indicators (CD3⁺CD4⁺ T cells, CD3⁺CD8⁺ T cells, CD4⁺CD25⁺CD127^low Treg cells) were compared between groups. Correlations among these indices were analyzed using Pearson correlation, and interaction effects were evaluated using multiple linear regression with interaction terms. Receiver operating characteristic (ROC) curves were used to evaluate the screening efficacy of each index for tumor bone metastasis.

Compared with the non-bone metastasis group, the bone metastasis group showed significantly higher levels of Ca²⁺, β-CTX, P1NP, CD3⁺CD4⁺ T cells, and CD4⁺CD25⁺CD127^low Treg cells (P<0.05), and lower levels of OC and CD3⁺CD8⁺ T cells (P<0.05). According to the Soloway classification, levels of Ca²⁺, β-CTX, P1NP, CD3⁺CD4⁺ T cells, and CD4⁺CD25⁺CD127^low Treg cells increased progressively from grade I to grade III (P<0.05), whereas OC and CD3⁺CD8⁺ T cells decreased (grade I > grade II > grade III) (P<0.05). Ca²⁺, β-CTX and P1NP were positively correlated with CD3⁺CD4⁺ T cells and CD4⁺CD25⁺CD127^low Treg cells (P<0.05) but negatively correlated with CD3⁺CD8⁺ T cells (P<0.05). In contrast, OC was negatively correlated with CD3⁺CD4⁺ T cells and CD4⁺CD25⁺CD127^low Treg cells (P<0.05) and positively correlated with CD3⁺CD8⁺ T cells (P<0.05). A significant interactive effect was observed between bone metabolism and immune indicators (P<0.05). The AUC the combined model (0.899) was higher than that of individual indicators - Ca²⁺ (0.835), β-CTX (0.843), P1NP (0.817), OC (0.750), CD3⁺CD4⁺ T cells (0.837), CD3⁺CD8⁺ T cells (0.771), CD4⁺CD25⁺CD127^low Treg cells (0.848). Internal validation showed that the accuracy of the combined model in diagnosing tumor bone metastasis was 88.26%.

The combined assessment of bone metabolism and immune indicators provides high clinical value for screening tumor bone metastasis.