Beyond 5-year survival. A report from the Cooperative Osteosarcoma Study Group (COSS)

Area of Science:

• Oncology
• Medical Statistics

Background:

• Prognostic factors for osteosarcoma are established, yet the long-term outcomes of survivors are understudied.
• Large-scale analyses of osteosarcoma survivors are needed to identify factors influencing long-term prognosis.

Purpose of the Study:

• To analyze the long-term survival outcomes of 5-year survivors of primary high-grade central osteosarcoma.
• To identify prognostic and predictive factors influencing the course of osteosarcoma survivors.

Main Methods:

• Utilized the Cooperative Osteosarcoma Study Group (COSS) database (1980-2019) including 2009 five-year survivors of primary high-grade central osteosarcoma.
• Analyzed survival outcomes, recurrence patterns, and prognostic factors evident at initial diagnosis and during the first five years of follow-up.
• Employed multivariate Cox regression to identify significant predictors of long-term survival.

Main Results:

• Overall survival rates after 5, 10, 15, and 20 years were 91.7%, 88.9%, 85.8%, and 83.4%, respectively.
• Patients in remission during the first 5 years had significantly better survival (97.5% at 5 years) compared to those with recurrence (62.7% at 5 years).
• Multivariate analysis identified recurrence within the first 5 years (p<0.001), older age at diagnosis (p=0.009), and secondary malignancy (p=0.013) as significant predictors of mortality.

Conclusions:

• Tumor response to chemotherapy is a critical prognostic factor early on but loses significance in long-term survivors.
• Individual history of malignancies and their outcomes become increasingly important for predicting long-term survival in osteosarcoma patients.
• This study highlights the need for large databases and extended follow-up periods to understand osteosarcoma survivor trajectories and identify novel risk factors.