Early diagnosis for bone metastasis of breast cancer based on bone metabolism.

Bone metabolism was investigated in 152 patients with breast cancer comprising 109 without bone metastasis (negative group), 9 with suspicious bone metastasis (suspicious group) and 34 with bone metastasis (positive group). Bone scintigraphy had high sensitivity (100%) for diagnosis of bone metastasis, but its specificity was 79.8%. The levels of serum calcium corrected by serum albumin (CaC), ionized calcium (CaF) and serum alkaline phosphatase (ALP) were significantly higher in the positive group than in the negative one. Serum osteocalcin (OC) level was significantly higher in the positive and suspicious groups than in the negative group. The level of procollagen Type III N-peptide (PIIINP) was also higher in the positive group than in the other two groups. Microdensitometric parameters (MCI and sigma GS/D) showed significantly lower values in the positive group than in the negative and suspicious groups. Hormone receptors (ER and PgR) status and tumor markers (CEA, TPA, NCC-ST439 and CA15-3) were not related to the presence of bone metastasis. We conclude that repeated measurements of serum CaC, CaF, ALP, OC and PIIINP, and MCI and sigma GS/D are required to predict bone metastasis, and bone scintigraphy to confirm the site of lesion on the bone system and finally X-ray examination to make an exact diagnosis of pathological changes of the bone.