Results of neoadjuvant denosumab in giant cell tumor of the bone depending of the tumor location and the surgical grade

Abstract

Background. The standard treatment for giant-cell tumors of the bone includes radical surgery. However, specific anatomical location of the tumor and/or its spread may hinder its complete excision or result in poor functional outcomes. Currently, combination treatment that includes preoperative denosumab and surgery is preferable. It saves patients’ lives and improves their quality of life. Reduction of local recurrence rate by combination therapy for giant-cell tumors of the bone is being actively studied now.Objective – to analyze treatment outcomes of patients with giant-cell tumors of the bone, including those who received combination treatment that included preoperative therapy with denosumab followed by surgery.Materials and methods. This study included 277 patients with giant-cell tumors treated in N.N. Blokhin National Cancer Research Center between 2005 and 2020. The mean duration of follow-up was 56 months. Study participants were divided into two groups. Group 1 included patients who received surgical treatment alone (n = 212), whereas Group 2 comprised patients who received combination treatment (n = 65). Neoadjuvant therapy included subcutaneous denosumab 120 mg on days 1, 8, 15, and 28, then every 4 weeks until stable effect. There were two variants of surgical treatment: radical (removal by a single block or segmental resection with defect replacement, with or without fixation) and non-radical (excochleation or marginal resection with defect replacement, with or without fixation).Results. During treatment, patients in Group 2 had a significantly milder pain syndrome (assessed both using the visual analog scale for pain and Watkins scale) compared to Group 1. In case of radical surgery, the incidence of local recurrence was 12 % and 0 % in Groups 1 and 2, respectively; the difference was significant (р <0.05). Tumor location and volume of surgery played an important role in disease recurrence (р <0.05). The incidence of complications after radical surgery was 36.9 % and 12.5 % in Groups 1 and 2, respectively; the difference was significant (р <0.05). In addition to that, neoadjuvant therapy with denosumab substantially reduced the duration of surgery and blood loss in patients with challenging anatomical location of the tumor (р <0.05).Conclusion. Combination treatment for giant-cell tumors that includes neoadjuvant therapy with denosumab reduces the risk of recurrence, duration of surgery, blood loss, and the risk of postoperative complications. However, it is important to consider tumor location and the volume of surgery. Since the disease is quite rare, further study of long-term efficacy and safety of combination treatment for giant-cell tumors, including rare ones and those with challenging anatomical location, is necessary.