Bone Abstracts

Giant cell tumour of bone (GCTb) is an osteolytic neoplasia with tendency to local recurrence (10–25%), while metastases or malignant transformation are described in 1–4% of cases.

It is composed by three distinct populations that cross-talk each other generating unbalance in bone remodeling and activation of NF-kB signaling pathway.

To identify new candidate biological markers useful for improving clinical management of GCTb we investigate the expression of key proteins involved in cell tumour-bone microenvironment interaction and related their immunostaining intensity and frequency with clinical features of the patients.

The protein expression was evaluated by tissue microarray technique on a series of primary GCTb from 83 disease-free, 72 locally relapsed, and 33 metastatic patients.

The most important proteins promoting osteolysis such as RANKL, RANK, MMP2, interleukins were more strongly and frequently expressed in relapsed group when compared with disease free group, also showing a significant association with pro-survival signaling proteins including NFIB and c-Fos. The metastatic rate based on protein immunoreactivity indicated a significantly higher probability of metastasis in patients with moderate to high than low or absent positive expression.

These data demonstrated that the linkage between matrix remodelling and tumour cell activity could recognize pathway interconnection endpoints useful for new therapeutic strategies.