Tartrate-Resistant Acid Phosphatase 5b is a Useful Serum Marker for Diagnosis and Recurrence Detection of Giant Cell Tumor of Bone

Serum tartrate-resistant acid phosphatase (TRACP) 5b was investigated for use as a marker for diagnosis of giant cell tumor (GCT) of bone and for detection of its recurrence. Four patients with GCT of bone who were initially referred to our hospital were classified as a primary group. Three patients who had local recurrence following curettage were classified as a local recurrence group. Five with no recurrence were classified as a no-recurrence group. Eighteen patients with primary and metastatic malignant bone tumors were also enrolled in the study as a control group. Serum TRACP 5b was measured before the biopsy in all patients and was measured periodically after the operation in patients with GCT of bone. Student t-tests were used for statistical analyses. TRACP 5b was greater than 1500 Um/dL in all primary group patients. Mean TRACP 5b values decreased gradually with post-operative time, showing lower values until local recurrence. The mean value of TRACP 5b of the local recurrence group (753 ± 68.7 mU/dL) was significantly higher than that of the no-recurrence group (340.6 ± 78.3 mU/dL). The mean value of TRACP 5b of the control group (466.9 ± 130.3 mU/dL) was much lower than that of the primary group and markedly lower than that of the local recurrence group. However, no significant difference was found between the no-recurrence group and the control group. Serum TRACP 5b is a useful and convenient marker for diagnosing GCT of bone and for predicting its recurrence.