Prognostic factors in osteosarcomas. A regression analysis

Abstract

A multivariate regression analysis of survival data, using the Cox proportional hazards model (PHM), was performed on the retrospective material of 184 osteosarcoma patients treated at the Aarhus and Copenhagen oncology centers, Denmark, from 1963 to 1984. All patients were previously untreated. Radical surgery, in general ablative when possible, was the primary treatment goal throughout this period. A number of clinical and pathologic variables were tested in the model to elucidate their prognostic importance. Tumors localized to the trunk, pelvis, or femur, and symptom duration of less than 6 months were poor prognostic signs. Tumors dominated by fibroblastic cells and a patient age of approximately 25 to 30 years were associated with an especially good prognosis. The prognosis worsened with advancing age. Children, adolescents, and adults ages 5 to 25 years had significantly poorer prognosis than young adults 25 to 30 years of age. Sex, radiologic appearance, and year of referral had no significant prognostic value in this series. Based on the regression model, a prognostic index is derived and survival is calculated for a good and a poor prognostic case. The overall 10-year survival with one standard deviation was 28.6 ± 3.5%. Cancer deaths continue to occur 10 years after initial treatment, and the estimated hazard rate is still four times greater than that of a sex- and age-matched group of healthy individuals.