Application of Bone Turnover Markers PICP and β-CTx in the Diagnosis and Treatment of Breast Cancer with Bone Metastases.

Background: This study is to investigate the application of the bone turnover markers type I procollagen carboxyterminal propeptide (PICP) and beta-isomerized forms of type I collagen breakdown products (beta-CTx) in the diagnosis and treatment of breast cancer with bone metastases. Methods: A total of 162 breast cancer patients were included in this study. There were 70 cases with bone metastasis (BM group) and 92 cases without bone metastasis (non-bone metastasis, NBM group). The levels of the bone turnover markers PICP and beta-CTx were measured using Electro-Chemiluminescence Immunoassay to compare the difference between BM and NBM group, before and after treatments in the NBM group, and to analyse the relationship with therapeutic effects. Results: The BM group had higher PICP and beta-CTx levels than the NBM group and also higher in the non-luminal type group than the luminal type group, the differences were all statistically significant. However, no statistically significant differences were found among the pN0, pN1, pN2, and pN3 subgroups of the NBM group. Among the 70 cases of BM patient after 3 months of treatment, there were 48 cases that showed clinical benefits, with significantly reduced PICP and beta-CTx levels (p = 0.02, p = 0.00, respectively), but 22 cases showed disease progression with elevated PICP and beta-CTx levels (p = 0.01, p = 0.04, respectively). Conclusions: The bone turnover markers PICP and beta-CTx have crucial value in the diagnosis and treatment efficacy evaluation for women of breast cancer with bone metastases.