Osteosarcoma is a rare primary bone
tumor, which mainly affects children and adolescents and has a poor prognosis, especially for patients with metastatic disease. A poor therapeutic response to the conventional
chemotherapy is observed with the development of lung
metastases, highlighting the need for improving the current regimens and the identification of early markers of the recurrent and metastatic disease. Circulating Tumour Cells (CTCs) play a key role in the metastatic process and could be powerful
biomarkers of the progressive disease. The present study aimed to isolate CTCs by using a pre-clinical model of human
osteosarcoma and to monitor their kinetic of release and their modulation by
ifosfamide. CTCs were detectable into the bloodstream before any palpable primary
tumors.
Ifosfamide increased CTCs count and in contrast decreased the number of lung
tumor nodules. On established
tumors,
ifosfamide slowed down the tumour growth and did not modulate CTC count that could be explained by a release of
cancer cells from the primary tumour with reduced properties for inducing lung
metastases. This report highlights the
biological interest of CTCs in
osteosarcoma.