The present study shows that an 8 cm maximal tumor diameter cutoff is useful for subdividing AJCC stage II osteosarcoma patients in terms of predicting of a subsequent metastatic event. Our results suggest that the IIA and IIB subdivision in the AJCC staging system provides a basis for risk-adapted therapy when used in combination with other prognostic factors.

This study shows that a cutoff value of 15% for tumor volume increase is useful for predicting subsequent metastasis or local recurrence. Our results suggest that tumor enlargement after chemotherapy serves as an easily assessable clinical parameter for risk-adapted therapy.