Outcome assessment
Overall survival (OS) and event-free survival (EFS) were the primary endpoints. OS was defined as the period from date of diagnosis to death due to any cause. EFS was defined as the period from the date of diagnosis to relapse, progression, or death. Complete remission (CR) of primary disease was defined as the absence of mediastinal disease on radiological examination. Bone marrow blasts <5% in those with initial marrow involvement was also needed to define CR. Partial remission (PR) was defined as residual disease on radiological examination and /or bone marrow blasts 5-25%.