-Original-

Characteristics of Patients with Giant Cell Tumor of Bone and High Serum Tartrate-Resistant Acid Phosphatase 5b Levels: Comparison of Tumor Volume and Clinical Factors

Kenta Hayashida¹, Yusuke Kawabata¹, Tomotaka Yoshida¹, Keiju Saito¹, Shintaro Fujita¹, Hyonmin Choe¹, Ikuma Kato², Masanobu Takeyama¹ and Yutaka Inaba¹

¹Department of Orthopaedic Surgery, Yokohama City University, Yokohama, Japan
²Department of Molecular Pathology, Yokohama City University, Yokohama, Japan

Background: Serum tartrate-resistant acid phosphatase 5b is well known to be increased in giant cell tumors of bone. However, there are only a few studies that analyzed the association with tartrate-resistant acid phosphatase 5b expression in those patients. Therefore, we analyzed the characteristics of patients with giant cell tumors of bone and high tartrate-resistant acid phosphatase 5b expression.
Methods: This retrospective study included 26 patients with giant cell tumors of bone. The correlation between tartrate-resistant acid phosphatase 5b before initial treatment and tumor volume was evaluated. Patients were divided into two groups according to tartrate-resistant acid phosphatase 5b level. Statistical analysis was performed between the two groups.
Results: Tartrate-resistant acid phosphatase 5b was elevated in 17/26 patients, and the mean value was 852 mU/dL. There was no correlation with tumor volume (r = 0.034, P = 0.86). The mean age of 34.5 years in the HT group was significantly younger than the mean age of 47.4 years in the LT group (P = 0.040). Pathologically, 19/26 cases showed at least one focal area with features of typical giant cell tumor of bone. Although 11/18 patients in the LT group exhibited relatively noticeable secondary changes, all patients in the HT group exhibited typical features (P = 0.0074).
Conclusions: Tartrate-resistant acid phosphatase 5b levels were not elevated in some giant cell tumors of bone. This study suggested that tartrate-resistant acid phosphatase 5b may be elevated in younger patients and in cases with fewer pathological secondary changes, regardless of tumor volume.

J Nippon Med Sch 2022; 89: 572-579

Keywords
tartrate-resistant acid phosphatase 5b, TRACP 5b, giant cell tumor of bone, GCTB

Correspondence to
Yusuke Kawabata, MD, PhD, Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan
yusuke0807kawabata@yahoo.co., jpmd09061181766@gmail.com

Received, March 21, 2022
Accepted, June 1, 2022