Chondrosarcoma is currently defined as a
malignant cartilage tumour arising de novo or within a
pre-existing benign cartilage tumour. Chondrosarcoma
can be surgically resected, but all grades have significant
rates of local recurrence. The purpose of the present
study was to develop an animal intraosseous
chondrosarcoma model simulating the progression of
human chondrosarcoma and elucidating its behaviour
and biology. An intraosseous Swarm rat model was
designed to assess interactions between bone and
chondrosarcoma. A comparison of tumour grading was
carried out according to transplantation site. The effects
of chondrosarcoma cells (SRC cells) on the
mineralisation capacities of osteoblasts and on osteoclast
differentiation were studied in relation to modifications
observed in vivo at the cellular level. Transplantation of
Swarm rat chondrosarcoma within bone marrow or
contiguous to induced periosteal lesions led to extensive
bone remodelling with trabecular bone rarefaction and
periosteal apposition. Transplantation in close contact to
bone but without any periosteal lesion had no effect on
bone, suggesting that bone healing factors interact with
tumour development. With the intramedullary model, the
development of tumours of different grade confirms that
bone environment is an important factor in malignancy.
A decrease of bone nodule formation was noted after cocultures
of SRC cells with rat bone marrow, but there
was no modification of osteoclast differentiation after
cultures of total rabbit bone cells with SRC cells. These
data reveal the importance of interactions between bone
environment and tumour in inducing bone remodelling and variations in tumour malignancy