YO19 - Denosumab in Giant Cell Tumor of The Spine
|Date||18 December 2016|
|Event||ESMO Asia 2016 Congress|
|Presenter||Syadwa Abdul Shukor|
S. Abdul Shukor, M.R. Ngu, G.F. Ho
A 24-year-old lady presented with 6 month history of back pain with no neurological deficit. Magnetic Resonance Imaging (MRI) done in February 2016 showed L5 sacralisation with 6.8cmX5.0cmX4.4cm lesion seen from posterior elements of L5 compressing the spinal canal. Biopsy from L5 vertebral column confirmed giant cell tumour (GCT). She was referred by the spine team to down stage the tumour as the surgery is associated with high morbidity in view of close proximity of neural structures and the need for reconstruction.
Denosumab 120mg was administered monthly with initial additional loading doses on days 8 and 15.The pain disappeared after 2 doses of Denosumab and she did not require any painkiller. Repeat MRI after 4 months of Denosumab showed significantly smaller lesion measuring 2.5cmx4.0cmx3.9cm and she was offered for surgery which she refused due to significant improvement of the symptoms.
Giant cell tumour of bone is a locally aggressive, benign osteolytic tumour that mainly affects young female population. The most common site is the long bone and usual presentation is pain and swelling. The incidence of GCT in the spine above the sacrum is estimated at between 0.1% and 0.25% of all bone tumours. Surgery is the mainstay of treatment but associated with high morbidity and recurrence rates of 15-25%.
Benefit of Denosumab in patients with giant cell tumour of the bone (GCTB) was shown in a phase II study (Thomas D et al) in which 37 patients with recurrent or unresectable GCTB were treated with denosumab. 86% (30 patients) had an objective response to therapy, which was defined as either ≥90% elimination of giant cells on histologic evaluation or the absence of radiographic progression of the target lesion.
Pain improvement was shown in a phase II (Martin-Broto et al) study which about 30% of the patients (resectable or unresectable) had pain improvement as early as week 1. In this case, she experienced rapid pain relief post 2 doses of Denosumab. Guidelines from the National Comprehensive Cancer Network recommended Denosumab in patients who is unresectable or high morbidity surgery. In conclusion, for patients with possibly resectable GCTB, denosumab therapy resulted in beneficial surgical down staging, including either no surgery or a less morbid surgical procedure.