Osteosarcoma and Ewing's sarcoma in children and adolescents: retrospective clinicopathological study.

Aim: Almost 20 different prognostic factors have so far been investigated in childhood bone tumors, but apart from clinical stage the results have been inconclusive. We evaluated possible prognostic factors of malignant bone tumors in children and adolescents.

Methods: Seventy children and adolescents, who have been treated for bone sarcomas (36 with osteosarcoma and 34 with Ewing's sarcoma) at the Children's Hospital in Zagreb and the Orthopedic Clinic of the Zagreb University School of Medicine were included in the study. We analyzed 9 variables: clinical stage, patient age and sex, tumor size and location, location of metastases, chemotherapy response, concentration of lactate dehydrogenase (LDH) and erythrocyte sedimentation rate (ESR), and chondroid differentiation in osteosarcoma.

Results: The clinical stage was the most important prognostic factor for both type of tumors. Lactate dehydrogenase in patients with Ewing's sarcoma (p=0.033) and in patients with osteosarcoma (p=0.015) as well as erythrocyte sedimentation rate (p<0.001 and p=0.014, respectively) may also be of predictive value.

Conclusion: Elevated erythrocyte sedimentation rate and high LDH concentration seem to be of importance in both Ewing's sarcoma and osteosarcoma, regardless of their different pathogenesis or pathohistology.