PTH and neoplasm: Correlation analysis revealed that patients with higher serum PTH and calcium levels had higher serum levels of β-CTX (r=0.665, P<0.001), OC (r=0.605, P<0.001) and ALP (r=0.675, P<0.001), and larger tumor sizes (r=0.579, P<0.001) but exhibited lower serum 25OHD concentrations and younger age (P<0.001) (Table 4).