Autologous stem cell transplantation (ASCT) still plays an role in treatment of acute lymphoblastic leukemia (ALL). A myeloablative conditioning therapy should be done before ASCT. Many trials comparing regimens with total body irradiation (TBI) and non-TBI in allogeneic stem cell tansplantation have been reported. However, very limited analysis focused on patients with ALL undergoing ASCT.
The present study was undertaken to analyse retrospectively the outcome following conditioning with TBI regimens versus non-TBI regimens in ASCT in adolescents and young adults with Philadelphia chromosome-negative ALL patient cohorts.
We defined 14–29 years of age as AYAs. Seventy four AYAs of all 95 patients with ALL undergoing consecutive ASCT between January 2007 and December 2016 were included in the study at Lymphoma Center at Blood Disease Hospital of Chinese Academy of Medical Sciences. Patients were chose based on the following criteria: (1) CR1 before ASCT; (2) first ASCT; (3) peripheral blood stem cell; (4) Philadelphia chromosome-negative; (5) no definite central nervous system disease. According to the conditioning regimens administered, patients were divided into the following two groups: TBI group (consisting of TBI and chemotherapy, n = 38) and non-TBI group (consisting of only chemotherapy, n = 36). The details of TBI-based conditioning were TBI plus melphalan ± etoposide(n = 21), TBI plus cyclophosphamide ± cytosine arabinoside or etoposide (n = 14), others (n = 3). The details of non-TBI conditioning were busulfan plus melphalan (n = 6), busulfan plus cyclophosphamide and etoposide (n = 16), busulfan plus cyclophosphamide and cytosine arabinoside (n = 3), busulfan plus cyclophosphamide and idarubicin (n = 6), others (n = 5). All of patients were received with VDCP ± L induction regimen for 28 days, then patients were administered with four courses of intensive chemotherapy. All of patients received 8–10 intrathecal injections for preventing central nervous system disease. After ASCT, maintenance chemotherapy based on VP regimen was continued for 1–1.5 years.
The main features at the time of diagnosis and transplant characteristics (sex, age, number of leukocytes, phenotype, karyotype and molecular biology, interval from treatment to MRD negative, interval between CR1 to patients transplanted) are parallel between the two groups. The median follow-up for the survivors was 56 months (range, 30 - 130 months) for TBI group and 65 months (range, 27 - 126 months) for non-TBI group after ASCT, respectively (P = 0.563). The median neutrophil engraftment days were 11days (range, 8–19 days) and 12 days (range, 9–30 days) for TBI group and non-TBI group (P = 0.432), respectively. The median days to platelet engraftment were 15days (range, 10–95 days) and 14.5 days (range, 9–90 days) (P = 0.656), respectively. Hepatic vein occlusion syndrome occurred in 1 patients administered by busulfan plus melphalan conditioning at the day of 32 from transplantation. Cataract occurred in TBI plus melphalan (n = 1) conditioning group and TBI plus melphalan and etoposide conditioning group (n = 1).Non TRM occurred. The 5-year disease-free survival (DFS) was 68.1 ± 7.6% in TBI cohort and 62.3 ± 8.4% in non-TBI cohort (P = 0.906). The 5-year overall survival (OS) was 67.5 ± 7.8% and 63.8 ± 8.6% (P = 0.694). The DFS and OS results were no differences between the two regimens in univariate analysis.
These data indicate similar survival with non-TBI conditioning, compared with TBI-based conditioning, for ASCT in adolescents and young adults with Philadelphia chromosome-negative ALL.