Overall survival by SCT versus observation in first complete remission. Kaplan-Meier curves demonstrating overall survival (OS) by (A) use of SCT compared with observation among those in first complete remission (CR); OS by (B) those who were positive for central nervous system (CNS) involvement at the time of diagnosis compared with those who did and did not receive CNS-directed prophylaxis (PPX); and OS for (C) those with relapsed/refractory disease based on whether salvage therapy was administered (those who were not known to receive salvage therapy are included with those confirmed to have not received salvage therapy).