Diagnostic value of serum tumor markers in skeletal metastasis of carcinomas.

Levels of serum tumor markers including tissue polypeptide antigen (TPA), CA 15-3, CA 19-9, squamous cell carcinoma antigen, carcinoembryonic antigen, alpha-fetoprotein, and PAP were measured in 26 patients with bone metastasis and in 9 patients with primary bone tumors. More than one markers was elevated in 19 of the 26 patients with bone metastasis, although there was no elevation of the markers in 3 patients with renal cell carcinoma. TPA was the most sensitive marker in the diagnosis of metastasis. CA 15-3 was also a sensitive marker in this study, since metastasis from breast carcinoma may be the most common of all metastases in the skeleton. On the other hand, alpha-fetoprotein was uniformly unresponsive except in one case of gastric cancer. Combinations of markers are valuable for metastasis screening tests. No definite correlations were found between the markers in this study. On the other hand, there was a slight elevation of the markers observed in two of the nine patients with primary bone lesions. Serum tumor markers are useful in the diagnosis of bone metastasis to differentiate it from primary bone lesions. Especially in solitary bone lesions, serum markers may be the only way to make a differential diagnosis between the two.