Objective: To determine whether the conclusions of a 1991 study, which showed that adults with acute lymphoblastic leukemia in first remission had similar leukemia-free survival rates when treated with chemotherapy or HLA-identical sibling bone marrow transplantation, remain valid after more than 4 years of additional follow-up.
Design: Retrospective comparison of two cohorts of patients using left-truncated Cox regression to adjust for differences in baseline characteristics and time to treatment.
Setting and Patients: Chemotherapy recipients were 484 consecutive patients with acute lymphoblastic leukemia in first remission treated in 44 hospitals in Germany that were participating in two consecutive trials of the German Acute Lymphoblastic Leukemia Therapy Trials Group. Transplant recipients were 234 consecutive recipients of HLA-identical sibling bone marrow transplants for acute lymphoblastic leukemia in first remission in 98 centers, worldwide, reporting data to the International Bone Marrow Transplant Registry.
Interventions: Intensive combination chemotherapy or HLA-identical sibling bone marrow transplantation preceded by high-dose chemotherapy with or without total body irradiation.
Measurements: Relapse, treatment-related mortality, and leukemia-free survival rate 9 years after first complete remission.
Results: The conclusions of our previous analyses were confirmed. Actuarial relapse probabilities at 9 years were 66% (95% CI, 61% to 70%) for chemotherapy and 30% (CI, 22% to 37%) for transplantation (P < 0.0001). The leukemia-free survival rates at 9 years were 32% (CI, 27% to 37%) for chemotherapy and 34% (CI, 28% to 40%) for transplantation (P < 0.02).
Conclusions: Fewer relapses but more treatment-related deaths were seen with transplantation than with chemotherapy. Thus, leukemia-free survival rates were similar in adults receiving transplantation and adults receiving chemotherapy for acute lymphoblastic leukemia in first remission.