Long-term outcomes among survivors of childhood osteosarcoma: A report from the Childhood Cancer Survivor Study (CCSS).

Purpose: Treatment strategies for osteosarcoma evolving between 1970 and 1999 improved 5-year survival and continue as standard of care today. This report evaluates the impact of these evolving therapies on long-term health outcomes.

Methods: Five-year survivors of childhood osteosarcoma in CCSS treated from 1970 to 1999 were evaluated for late (>5 years from diagnosis) mortality, chronic health conditions (CHCs), and health status using piecewise-exponential and logistical models. Comparisons were made between survivors and siblings without cancer, and among survivors examining historical and current standard chemotherapies (e.g., methotrexate/doxorubicin/cisplatin [MAP] vs. others), specific chemotherapy agents and surgical approaches (amputation vs. limb salvage [LS]). Models were evaluated adjusting for attained age, sex, race, ethnicity, and age at diagnosis.

Results: A total of 1257 survivors of osteosarcoma were followed on average for 24.4 years. Twenty-year all-cause late mortality was 13.3% (95% confidence interval [CI]: 11.7%-14.9%) overall and 11.7% (95% CI: 6.9%-16.5%) for the subset treated with MAP plus LS. Survivors were at higher risk of CHCs (rate ratio [RR] 3.7, 95% CI: 3.2-4.3) than the sibling cohort, most notably having more serious cardiac, musculoskeletal, and hearing CHCs. Within the survivor cohort, the risk of severe CHCs was twice as high with MAP versus no chemotherapy (RR 2.1, 95% CI: 1.3-3.4). Compared with primary amputation, serious musculoskeletal CHCs were higher after LS (RR 6.6, 95% CI: 3.6-13.4), without discernable differences in health status.

Conclusion: Contemporary osteosarcoma therapy with MAP plus LS, while improving 5-year disease-free survival, continues to be associated with a high burden of late mortality, CHCs, and health status limitations.