Serum tumor markers in skeletal metastasis.

BACKGROUND There have been no well-documented reports detailing the relationship between skeletal metastasis and tumor markers in a large series of patients. The purpose of our study was to assess the relationship between the clinical features of skeletal metastasis and serum tumor markers and to determine whether tumor markers are a useful modality in the differential diagnosis of skeletal metastasis. METHODS We retrospectively reviewed consecutive 458 patients with skeletal metastasis and divided the patients into two groups according to six clinical presenting factors. We assessed whether these groups influenced the level of the tumor markers in univariate and multivariate analysis. RESULTS Patients with skeletal metastasis of carcinoma had a higher level of markers CEA (P < 0.0001) and CA19-9 (P = 0.0008) than patients with primary bone tumors and hematological malignancies. Univariate analysis of clinical variables revealed that metastasis on axial skeleton, multiple skeletal metastases and visceral metastasis were associated with the serum CEA and CA19-9 levels. By multivariate analysis, metastasis on axial skeleton, multiple skeletal metastases and visceral metastasis were found to be associated with the serum CEA and CA19-9 levels. At least one of the tumor markers was elevated in 73% of all patients. CONCLUSIONS The higher tumor marker level (CEA, CA19-9) is predictive of metastasis on the axial skeleton, multiple skeletal metastases and visceral metastasis. Tumor markers are useful as a screening test to distinguish skeletal metastases of carcinoma from primary bone tumors or hematological malignancy from primary bone tumor and hematological malignancy.