Prevention of local recurrences of Osteosarcoma in xsenograft in vivo model

Aim: Osteosarcoma which is very aggressive, usually occurs in childhood and young adulthood. Limb salvage surgery has provided successful results in the treatment of these tumors. However, residual tumor which may remain at the microscopic level, increases the likelihood of recurrence. Apart from surgery, the residual tumor is observed despite the high-dose methotrexate, cisplatin chemotherapy regimens. Therefore, new approaches are needed for the treatment of osteosarcoma. The aim of the study was to evaluate the preventive efficacy of cadmium in cement was placed locally after surgical resection on residual tumor and recurrence in an in-vivo animal model. Method: K7M2 tumorigenic osteosarcoma cell line was cultivated in vitro. Then, the xenograft tumor model was formed by giving the tumor cells subcucateously to athymic nude mice. After tumor growth; control tumor, total resected tumor group, subtotal resected tumor group, subtotal resected group with saline in cement and subtotal resected group with cadmium in cement groups were formed randomly with 7 animals in each group. Animals were observed for 15 days for recurrences in tumor site. After sacrification, the presence of residual tumor was checked histopathologically in each group. Results: Tumor was formed within one month after subcutanous injection. Recurrent tumor was formed in all animals in subtotal resected group, subtotal resected group with saline in cement. No or small tumor formation was observed in cadmium group. No systemic toxic effect was observed. Conclusion: Our data suggest that local application of cadmium in cement might help local therapy of osteosarcoma after surgery. Postoperative local treatment with agents within orthopedic biyomechanic substances might be an option of additive treatment to overcome the recurrences in osteosarcoma. Keywords: Osteosarcoma, cadmium, local therapy