Secondary malignant neoplasms among children, adolescents, and young adults with osteosarcoma

As patients with osteosarcoma become long-term survivors, increasing attention has turned to the burden of late effects. The goal of the current study was to describe the incidence, characteristics, and outcomes of secondary malignant neoplasms (SMNs) in this population.

Patients aged birth to 40 years at time of primary diagnosis with osteosarcoma and reported to the Surveillance, Epidemiology, and End Results (SEER) program between 1973 and 2010 were eligible for inclusion in the cohort. Competing risks methods were used to estimate the cumulative incidence of SMNs and potential risk factors for developing an SMN. Standardized incidence ratios (SIR) and overall survival after an SMN were estimated.

The SEER database included 3379 patients who were diagnosed with osteosarcoma as their first malignancy. Of these, 89 patients were diagnosed with an SMN. The cumulative incidence of any SMN was 2.1% (95% confidence interval [95% CI], 1.6%-2.7%) at 10 years, 4.0% (95% CI, 3.1%-5.1%) at 20 years, and 7.4% (95% CI, 5.6%-9.5%) at 30 years. The median time from the primary diagnosis to an SMN diagnosis was 6.0 years. The SIR for SMNs for survivors of osteosarcoma compared with the general population was 1.6 (95% CI, 1.0-2.5) for patients diagnosed with osteosarcoma from 1973 through 1985 and 4.7 (95% CI, 3.3-6.4) for patients diagnosed with osteosarcoma from 1986 through 2010, with a 34-fold increased risk of leukemia in this most recent era. The overall survival rate at 5 years for patients with SMNs after a diagnosis of osteosarcoma was 44.5%.

Survivors of osteosarcoma are at an increased risk of developing SMNs compared with the baseline population, with an increased risk noted in patients treated in the more recent era.