Background: Late relapse and solitary lesion are positive prognostic factors in recurrent osteosarcoma.
Methods: We reviewed the records of 39 patients treated at three major centres for recurrent osteosarcoma with a single pulmonary metastasis more than 1 year after diagnosis. We analysed their outcomes with respect to clinical factors and treatment with chemotherapy.
Results: Median age at diagnosis was 14.6 years. Relapse occurred at a median of 2.5 years (range, 1.2-8.2 years) after initial diagnosis. At relapse, all patients were treated by metastasectomy; 12 (31%) patients also received chemotherapy. There was no difference in time to recurrence or nodule size between the patients who received or did not receive chemotherapy at relapse. Sixteen patients had no subsequent recurrence, 13 of whom survive without evidence of disease. The 5-year and 10-year estimates of post-relapse event-free survival (PREFS) were 33.0±7.5% and 33.0±9.6%, respectively, and of post-relapse survival (PRS) 56.8±8.6% and 53.0±11.0%, respectively. There was a trend for nodules <1.5 cm to correlate positively with PREFS (P=0.070) but not PRS (P=0.49). Chemotherapy at first relapse was not associated with PREFS or PRS.
Conclusion: Approximately half of the patients with recurrent osteosarcoma presenting as a single pulmonary metastasis more than 1 year after diagnosis were long-term survivors. Metastasectomy was the primary treatment; chemotherapy did not add benefit.