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Bone Marrow Transplantation (2006) 38, 739–743 & 2006 Nature Publishing Group All rights reserved 0268-3369/06 $30.00

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ORIGINAL ARTICLE

Comparative outcome of hematopoietic stem cell transplantation for pediatric acute lymphoblastic leukemia following cyclophosphamide and total body irradiation or VP16 and total body irradiation conditioning regimens A Gassas, L Sung, EF Saunders and JJ Doyle Division of Hematology/Oncology/Bone Marrow Transplantation, The Hospital for Sick Children, University of Toronto, Ontario, Canada

To compare the outcome of hematopoietic stem cell transplantation (HSCT) in pediatric acute lymphoblastic leukemia (ALL) conditioned with two different regimens: (1) single dose of VP16 (60 mg/kg over 4 h) and total body irradiation (TBI; 1200 cGy, in six fractions) or (2) Cyclophosphamide 50 mg/kg over 1 h daily for 4 days followed by the same dose of TBI. One hundred and seven children with ALL received fully matched HSCT from 1990 to 2003 in the Hospital for Sick Children, Toronto. All received cyclosporin A and a short course of methotrexate for graft-versus-host disease (GVHD) prophylaxis. The VP16 group, there were 36 matched related donor transplants (MRD) and 26 matched unrelated donor transplants (MUD), and in the cyclophosphamide group there were 23 MRD and 22 MUD transplants. Neutrophil engraftment occurred at a median of 18 and 17 days for the VP16/TBI and the CY/TBI groups, respectively. The 3 year event-free survival and overall survival were 4777 and 5577% for those receiving VP16/TBI, and 5178 and 5378% for the CY/TBI group. There were no significant differences in the prevalence of acute or chronic GVHD and transplant-related mortality between the two groups. Both VP16/FTBI and CY/FTBI regimen are equally effective regimens. Bone Marrow Transplantation (2006) 38, 739–743. doi:10.1038/sj.bmt.1705515; published online 2 October 2006 Keywords: acute lymphoblastic leukemia; hematopoietic stem cell transplantation; VP16; cyclophosphamide; children

Correspondence: Dr A Gassas, Division of Hematology/Oncology/Bone Marrow Transplantation, Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8. E-mail: [email protected] Received 3 April 2006; revised 11 August 2006; accepted 6 September 2006; published online 2 October 2006

Introduction Hematopoietic stem cell transplantation (HSCT) has become a common therapy for many children with either relapsed acute lymphoblastic leukemia (ALL) or very highrisk features at diagnosis. The combination of chemotherapy and total body irradiation (TBI) conditioning regimens is associated with superior outcome when compared to chemotherapy-only regimens.1–6 The chemotherapy component of the preparative regimens varied in different studies with cyclophosphamide being the most commonly used along with TBI. However, VP16 has a wellknown anti-leukemic effect and its effectiveness as part of a preparative regimen for leukemia HSCT is well documented, especially in high-risk ALL patients.7–9 Furthermore, some protocols have added VP16 to the cyclophosphamide and TBI preparative regimens for patients with very highrisk acute leukemias in an attempt to improve survival.10–12 Therefore, we conducted this retrospective study to compare the outcome of HSCT in pediatric ALL conditioned with two different regimens: (1) single dose of VP16 (60 mg/kg over 4 h) and fractionated TBI (1200 cGy in six fractions over 3 days) (VP16/TBI) and (2) Cyclophosphamide 50 mg/kg over 1 h daily for 4 days followed by the same fractionated TBI (CY/TBI).

Patients and methods This study was approved by our institutional review board. The health records of children who received HSCT for a diagnosis of ALL (B- and T-cell lineage) in the Hospital for Sick Children, Toronto, Canada from July 1990 to December 2003 were reviewed in a retrospective analysis. The conditioning regimen for pediatric ALL in our institution was VP16/TBI from 1990 to 1998 and CY/TBI from 1998 to 2003. The change from VP16/TBI to CY/TBI in 1998 was made for administrative reasons and to follow what was felt a more commonly used conditioning regimen in North American institutions. The criteria for inclusion of patients were the following: (1) Recipients of a T-cellreplete fully matched related (MRD) or unrelated (MUD)

VP16 or cyclophosphamide for acute lymphoblastic leukemia A Gassas et al

740

bone marrow graft; human leukocyte antigen (HLA) matching consisted of either serologic or low-resolution molecular typing of HLA-A and HLA-B, whereas serologic typing was used for DRB1 until 1992 and then molecular typing since that time using high-resolution techniques. Before 1992, only related donors were utilized. From 1992 to 2002, all unrelated donors HLA matching included serology testing for class I (A and B antigens) and highresolution molecular typing for class II (DRB1). After 2002, a further serology testing for the Cw antigen and a high-resolution molecular typing for the DQ antigen was performed. (2) A myeloablative conditioning regimen of either VP16/TBI or CY/TBI. (3) Graft-versus-host disease (GVHD) prophylaxis with cyclosporin A at 3 mg/kg/day starting at day 1 and a short course methotrexate at a dose of 10 mg/m2 intravenously at day þ 3, þ 6, þ 11 and þ 18. Unmanipulated bone marrow was collected according to established methods.13 All patients had indwelling central venous catheters, and the majority received nutritional support with total parentral nutrition. Infection prophylaxis included fluconazole for fungal prophylaxis,14 acyclovir for cytomegalovirus (CMV) prophylaxis for the VP16/TBI group and ganciclovir for CY/TBI group if the donor or recipient pre-HSCT CMV serology status was positive.15,16 Growth factors with granulocyte colonystimulating factor, subcutaneously between 1990 and 1997 and intravenously thereafter, were used from day plus 1 until neutrophil engraftment and intravenous immunoglobulin as well as the use of laminar airflow rooms from day 0 onwards. Pneumocystis jiroveci pneumonia prophylaxis was given for at least 6 months post HSCT and pneumococcal prophylaxis with penicillin continued for at least 1 year or until the administration of pneumococcal vaccine.

Patient characteristics (Table 1) One hundred and seven children with ALL were included in the study, 59 received matched related donor HSCT and 48 received matched unrelated donor HSCT. More than half of the patients in both groups were in second complete remission (CR2) at the time of HSCT and there was only one patient in the VP16/TBI group who was transplanted in relapse. Indications for HSCT in CR1 (n ¼ 17 in the VP16/TBI group and n ¼ 10 in the Cy/TBI group) are summarized in Table 1. There were no significant differences in any of the patient characteristics between the two groups. Definitions Neutrophil engraftment was defined as the first of 3 consecutive days, following the neutrophil nadir, of absolute neutrophil count (ANC) 40.5 109/l and platelet engraftment was defined as the first of three consecutive days of unsupported platelets 420 109/l. Primary graft failure was defined in patients surviving beyond day þ 28 as failure to attain an ANC 40.5 109/l before death or receipt of a second graft. Clinical grading of acute graft-versus-host disease (aGVHD) was performed according to previously reported criteria.17 Chronic graft-versus-host disease (cGVHD) was Bone Marrow Transplantation

Table 1

Baseline demographicsa VP16/TBI (n ¼ 62)

CY/TBI (n ¼ 45)

Age at HSCT Median (years) Range (years)

9.4 (0.8-17.8)

8.7 (1-17.5)

Sex Male (%) Female (%)

36 (58%) 26 (42%)

32 (71%) 13 (29%)

Donor source MRD (%) MUD (%)

36 (58%) 26 (42%)

23 (51%) 22 (49%)

ALL phenotype B lineage (%) T lineage (%)

53 (85%) 9 (15%)

38 (84%) 7 (16%)

Remission at HSCT CR 1 (%) CR 2 (%) CR 3 (%) Relapse (%)

17 32 12 1

(27%) (52%) (19%) (2%)

10 (22%) 29 (65%) 6 (13%) 0

8 5 3 1

(47%) (29%) (18%) (6%)

Characteristic

Indications of HSCT in CR1 BCR/ABL Extreme hyper-leucocytosis MLL gene rearrangement Induction failure

4 2 2 2

(40%) (20%) (20%) (20%)

Abbreviations: ALL ¼ acute lymphoblastic leukemia; CR ¼ complete remission; CY ¼ cyclophosphamide; HSCT ¼ hematopoietic stem cell transplantation; MRD ¼ matched related donor; MUD ¼ matched unrelated donor; TBI ¼ total body irradiation. a All P-values comparing the two group’s demographics were nonsignificant.

diagnosed and classified according to standard criteria.18 Tissue biopsy samples were obtained to confirm GVHD diagnosis whenever clinically indicated and feasible.

Statistical analysis Differences in continuous outcomes between the VP16/TBI and CY/TBI groups were compared using the Wilcoxon’s rank-sum test. Categorical variables were compared using the w2 test or Fisher’s exact test as appropriate. Event-free survival (EFS), overall survival (OS), cumulative incidence of transplant-related mortality (TRM) and cumulative incidence of relapse were described according to the Kaplan Meier method and groups were compared using the log rank test. In the determination of EFS, death, relapse, graft rejection and graft failure were considered as events. TRM was defined as any death in remission.

Results Engraftment and GVHD occurrence In the VP16/TBI group, two patients died as a result of sepsis before day þ 28 and were not evaluable for engraftment. Two patients had primary graft failure. One of these patients engrafted promptly after a second infusion from the same unrelated donor following re-conditioning with cyclophosphamide and anti-thymocyte globulin. The


741 Table 2 Outcome of HSCT in pediatric ALL following VP16/TBI versus CY/TBI VP16/TBI (n ¼ 62)

CY/TBI (n ¼ 45)

P-value

Engraftment (days) Neutrophils Median (range) Platelets Median (range)

18 (10, 33)

17 (10, 28)

0.1

31 (17, 167)

29 (14, 139)

0.1

3-year TRM MRD MUD

20.277.6 32.6711.0

17.4712.0 22.779.0

3-year relapse MRD MUD

40.679.4 27.6712.0

3-year EFS by CR CR1 CR2 CR3 3-year EFS MRD MUD

CY/TBI (n ¼ 44) VP16/TBI MRD 23 MUD (n ¼ 58) MRD 21a (%) 32a MUD 26 (%)

GVHD

P-value

MRD No GVHD Acute (I–II) Acute (III–IV)

17 (55) 13 (40) 2 (5)

10 (43) 11 (49) 2 (8)

0.6

0.4 0.7

MUD No GVHD Acute (I–II) Acute (III–IV)

9 (36) 10 (38) 7 (26)

2 (10) 11 (53) 8 (37)

0.1

64.9713.4 16.979.1

0.2 0.8

Chronic extensive MRD MUD

2 (6) 3 (12)

2 (8) 4 (16)

1 0.9

58.3715.5 59.179.3 41.7714.2

62.3715.0 50.0710.3 33.3719.3

0.7 0.4 0.8

Abbreviations: CY ¼ cyclophosphamide; GVHD ¼ graft-versus-host disease; MRD ¼ matched related donor; MUD ¼ matched unrelated donor; TBI ¼ total body irradiation. a Patients died before day +28 and were not evaluable for GVHD.

47.478.8 48.8711.4

29.4711.9 63.7710.4

0.5 0.6

Abbreviations: ALL ¼ acute lymphoblastic leukemia; CR ¼ complete remission; CY ¼ cyclophosphamide; EFS ¼ event-free survival; HSCT ¼ haematopoietic stem cell transplantation; MRD ¼ matched related donor; MUD ¼ matched unrelated donor; TBI ¼ total body irradiation.

other patient who was a recipient of MRD transplantation sustained a fatal intracranial hemorrhage. Neutrophil engraftment for the remaining patients occurred at a median of 18 days (range, 10–33 days). Platelet engraftment failed in three recipients of MUD transplants who died from GVHD-related complications between 2 and 7 months post HSCT. Platelet engraftment for the rest of the patients occurred at a median of 31 days (range, 17–167 days). In the CY/TBI group, one patient died as a result of sepsis before day þ 28 and was not evaluable for engraftment. There was no primary graft failure. Platelet engraftment occurred at 29 days (range, 14–139 days). There was no significant difference in time to neutrophil or platelet engraftment between the two study groups (Table 2). Table 3 demonstrates that acute severe (grade III–IV) GVHD occurred in nine and 10 patients in the VP16/TBI and CY/TBI groups, respectively. In both groups, severe aGVHD occurred more frequently in MUD HSCT recipients compared to MRD recipients. As demonstrated in Table 3, no significant differences in aGVHD or cGVHD were seen between the VP16/TBI and CY/TBI groups when stratified by related and unrelated donor HSCT.

TRM and relapse incidence Thirteen patients died of transplantation-related causes in the VP16/TBI group and seven patients in the CY/TBI group. The 3-year cumulative incidence of TRM and relapse were not significantly different between the study groups when stratified by related and unrelated donor SCT.

1.0

Cy TBI VP16 TBI

0.8 Event free survival

Parameter

Acute and chronic GVHD

Table 3

0.6

0.4

0.2

0.0 0

500

1000 1500 2000 Time (days)

2500

3000

Figure 1 EFS of children conditioned with cyclophosphamide/TBI versus VP16/TBI.

Infection and aGVHD were the causes of death in most of the patients in both groups. Although CMV prophylaxis differed between the two groups, there were no CMVrelated deaths in either group.

Survival, leukemia-free survival and graft-versus-leukemia effect Three years EFS and OS were 4777% and 5577% for the VP16/TBI, and 5178% and 5378% for the CY/TBI group (P ¼ NS, Figure 1). There were no significant differences in the OS based on remission status at HSCT between the two groups. Furthermore, there was no significant difference in survival between MRD and MUD HSCT in both groups. However, there was a nonsignificant trend towards a higher relapse rate among recipients of MRD grafts compared to MUD grafts. Bone Marrow Transplantation


742

Relapse rate according to aGVHD as a measure of graftversus-leukemia (GVL) effect was calculated for all patients and the rate of relapse was 52, 39 and 7% for no aGVHD, mild (grade I–II) aGVHD and severe (grade III–IV) aGVHD, respectively (P ¼ 0.09). There was no significant difference in relapse rate based on aGVHD status between the two groups.

Discussion We found that there was no significant difference in outcomes between a cyclophosphamide versus a VP16containing preparative regimen for pediatric ALL in a single-center experience. This report represents the largest series so far for children with ALL comparing the outcome following allogeneic HSCT after a TBI-based conditioning regimen with two different chemotherapy components, VP16 versus cyclophosphamide. Given the retrospective nature of the study with a historical comparison of the two conditioning regimens (VP16/TBI, 1990–1998; CY/TBI, 1998–2003), there could be potential confounding factors especially in terms of different management or different technology of HSCT between the two periods. Nonetheless, this is a single-center experience and therapy, including supportive care, has not changed dramatically between the two periods. HLA typing has improved over the years; however, all unrelated donors, apart from six donors after 2002, were matched for 6/6 antigens, serology for HLA-A and HLA-B and high-resolution molecular typing for DRB1. The six patients after 2002 were matched for 10/10 antigens including serology for Cw and molecular for DQ antigens. Although in recent years, better risk stratification methods for upfront ALL therapy were implemented, the upfront protocols did not differ dramatically between the two groups. The salvage chemotherapy for relapsed ALL has changed over the years. However, all patients, apart from one in the VP16/TBI group achieved complete remission in a timely manner and maintained remission before proceeding to HSCT. The two groups were well balanced with respect to patient numbers, age, ALL phenotype and remission status. GVHD prophylaxis and supportive care were the same for all patients. The choice of adopting a preparative regimen consisting of VP16/TBI in the 1990s was based on published reports demonstrating that the combination of fractionated TBI and high-dose VP-16 is an effective antileukemic regimen for children with advanced leukemias.9,19 The TBI-containing conditioning regimen is widely used in HSCT for childhood ALL including the more aggressive infant form.20,21 Although cyclophosphamide is more widely used along with TBI as a conditioning regimen, several reports have demonstrated the feasibility and efficacy of VP16 to replace cyclophosphamide. Jamieson et al.22 reported 61% EFS and 62% OS for children transplanted in CR2 after a conditioning regimen of FTBI (1320 cGY) and 60 mg/kg VP16 with accepted regimenrelated toxicity and TRM. In a study of 51 children between 26 and 214 months of age (median, 100 months) with ALL as part of the BFM- and CoALL-protocols, the conditioning regimens were different consisting of CY and Bone Marrow Transplantation

TBI (n ¼ 27), VP16 and TBI (n ¼ 23), and CY/TBI and ARA-C (n ¼ 1). Kaplan–Meier analysis yielded an EFS of 0.5270.08 with a nonsignificant trend towards superior survival for patients grafted after conditioning with VP 16 plus TBI.23 Our data does not suggest such a trend. Locatelli et al.24 noted that, the 2-year probability of EFS for children transplanted from unrelated donors before and after 1 January 1998 was 27% (10–44) and 58% (42–75), respectively (P ¼ 0.02) and concluded that EFS of unrelated donor HSCT in children with ALL in second CR has improved in the last few years, mainly owing to a decreased TRM. In our series, there has been improvement in survival of unrelated transplant recipients after 1998 with reduction in TRM. EFS was 48.8711.4 before 1998 compared to 64.2710.2 after 1998. However, this improvement was not statistically significant. Several reports have demonstrated a lower relapse rate associated with GVHD, especially the chronic form of GVHD.25–29 In the current series, we aimed to measure the GVL effect by acute GVHD. There was a nonsignificant trend (P ¼ 0.09) towards a higher relapse rate among children without aGVHD compared to those with moderate or severe GVHD. In conclusion, this study indicates that both VP16/TBI and cyclophosphamide/TBI are effective conditioning regimens for children with ALL. Disease recurrence remains the major cause of treatment failure especially in the matched related transplantation, novel strategies to lower the risk of leukemia relapse post HSCT are warranted.

References 1 Davies SM, Ramsay NK, Klein JP, Weisdorf DJ, Bolwell B, Cahn JY et al. Comparison of preparative regimens in transplants for children with acute lymphoblastic leukemia. J Clin Oncol 2000; 18: 340–347. 2 Ringden O, Labopin M, Tura S, Arcese W, Iriondo A, Zittoun R et al. A comparison of busulphan versus total body irradiation combined with cyclophosphamide as conditioning for autograft or allograft bone marrow transplantation in patients with acute leukaemia. Acute Leukaemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT). Br J Haematol 1996; 93: 637–645. 3 Ringden O, Ruutu T, Remberger M, Nikoskelainen J, Volin L, Vindelov L et al. A randomized trial comparing busulfan with total body irradiation as conditioning in allogeneic marrow transplant recipients with leukemia: a report from the Nordic Bone Marrow Transplantation Group. Blood 1994; 83: 2723–2730. 4 Wachowiak J, Bettoni C, Lange A, Malicki J, KaczmarekKanold M, Gluszak B et al. Can busulfan replace fractionated total body irradiation as conditioning regimen for allogeneic bone marrow transplantation in children with acute lymphoblastic leukemia. Acta Haematol Pol 1995; 26: 377–384. 5 Shah AJ, Lenarsky C, Kapoor N, Crooks GM, Kohn DB, Parkman R et al. Busulfan and cyclophosphamide as a conditioning regimen for pediatric acute lymphoblastic leukemia patients undergoing bone marrow transplantation. J Pediatr Hematol Oncol 2004; 26: 91–97. 6 Dai QY, Souillet G, Bertrand Y, Galambrun C, Bleyzac N, Manel AM et al. Antileukemic and long-term effects of two regimens with or without TBI in allogeneic bone marrow


743

7

8

9

10

11

12

13

14

15

16

17

18

transplantation for childhood acute lymphoblastic leukemia. Bone Marrow Transplant 2004; 34: 667–673. Blume KG, Long GD, Negrin RS, Chao NJ, Kusnierz-Glaz C, Amylon MD. Role of etoposide (VP-16) in preparatory regimens for patients with leukemia or lymphoma undergoing allogeneic bone marrow transplantation. Bone Marrow Transplant 1994; 14 (Suppl 4): S9–S10. Amylon MD, Co JP, Snyder DS, Donaldson SS, Blume KG, Forman SJ. Allogeneic bone marrow transplant in pediatric patients with high-risk hematopoietic malignancies early in the course of their disease. J Pediatr Hematol Oncol 1997; 19: 54–61. Suttorp M, Schmitz N, Leuschner S, Appelt M, Rister M, Schaub J. Fractionated total body irradiation plus high-dose VP-16 prior to allogeneic bone marrow transplantation in children with poor risk acute leukaemias. Bone Marrow Transplant 1989; 4 (Suppl 4): 144–148. Long GD, Amylon MD, Stockerl-Goldstein KE, Negrin RS, Chao NJ, Hu WW et al. Fractionated total-body irradiation, etoposide, and cyclophosphamide followed by allogeneic bone marrow transplantation for patients with high-risk or advanced-stage hematological malignancies. Biol Blood Marrow Transplant 1997; 3: 324–330. Duerst RE, Horan JT, Liesveld JL, Abboud CN, Zwetsch LM, Senf ES et al. Allogeneic bone marrow transplantation for children with acute leukemia: cytoreduction with fractionated total body irradiation, high-dose etoposide and cyclophosphamide. Bone Marrow Transplant 2000; 25: 489–494. Toubai T, Tanaka J, Mori A, Hashino S, Kobayashi S, Ota S et al. Efficacy of etoposide, cyclophosphamide, and total body irradiation in allogeneic bone marrow transplantation for adult patients with hematological malignancies. Clin Transplant 2004; 18: 552–557. Thomas ED, Storb R, Clift RA, Fefer A, Johnson L, Neiman PE et al. Bone-marrow transplantation. N Engl J Med 1975; 292: 832–843, 895–902. Goodman JL, Winston DJ, Greenfield RA, Chandrasekar PH, Fox B, Kaizer H et al. A controlled trial of fluconazole to prevent infections in patients undergoing bone marrow transplantation. N Engl J Med 1992; 326: 845–851. Goodrich JM, Bowden RA, Fisher L, Keller C, Schoch G, Meyers JD. Ganciclovir prophylaxis to prevent cytomegalovirus disease after allogeneic marrow transplant. Ann Intern Med 1993; 18: 173–178. Boeckh M, Gooley TA, Myerson D, Cunningham T, Schoch G, Bowden RA. Cytomegalovirus pp65 antigenemia-guided early treatment with ganciclovir versus ganciclovir at engraftment after allogeneic marrow transplantation: a randomizedblind study. Blood 1996; 88: 4063–4071. Glucksberg H, Storb R, Fefer A, Buckner CD, Neiman PE, Clift RA et al. Clinical manifestation of graft-versus-host disease in human recipients of marrow from HLA-matched sibling donors. Transplantation 1974; 18: 295–304. Atkinson K, Horowitz MM, Gale RP, Lee MB, Rimm AA, Bortin MM. Consensus among bone marrow transplanters for diagnosis, grading and treatment of chronic graft-versus-host disease. Committee of the International Bone Marrow

19

20

21

22

23

24

25

26

27

28

29

Transplant Registry. Bone Marrow Transplant 1989; 4: 247–254. Schwerdtfeger R, Schmid H, Baurmann H, Kleiner S, Zeiler T, Henze G et al. VP16 and TBI as conditioning regimen for allogeneic BMT in patients with high risk and relapsed ALL and NHL. Bone Marrow Transplant 1991; 7 (Suppl 2): 131. Kosaka Y, Koh K, Kinukawa N, Wakazono Y, Isoyama K, Oda T et al. Infant acute lymphoblastic leukemia with MLL gene rearrangements: outcome following intensive chemotherapy and hematopoietic stem cell transplantation. Blood 2004; 104: 3527–3534. Sanders JE, Im HJ, Hoffmeister PA, Gooley TA, Woolfrey AE, Carpenter PA et al. Allogeneic hematopoietic cell transplantation for infants with acute lymphoblastic leukemia. Blood 2005; 105: 3749–3756. Jamieson CH, Amylon MD, Wong RM, Blume KG. Allogeneic hematopoietic cell transplantation for patients with high-risk acute lymphoblastic leukemia in first or second complete remission using fractionated total-body irradiation and high-dose etoposide: a 15-year experience. Exp Hematol 2003; 31: 981–986. Dopfer R, Henze G, Bender-Gotze C, Ebell W, Ehninger G, Friedrich W et al. Allogeneic bone marrow transplantation for childhood acute lymphoblastic leukemia in second remission after intensive primary and relapse therapy according to the BFM- and CoALL-protocols: results of the German Cooperative Study. Blood 1991; 78: 2780–2784. Locatelli F, Zecca M, Messina C, Rondelli R, Lanino E, Sacchi N et al. Improvement over time in outcome for children with acute lymphoblastic leukemia in second remission given hematopoietic stem cell transplantation from unrelated donors. Leukemia 2002; 16: 2228–2237. Zikos P, Van Lint MT, Lamparelli T, Gualandi F, Occhini D, Bregante S et al. Allogeneic hemopoietic stem cell transplantation for patients with high risk acute lympho blastic leukemia: favorable impact of chronic graft-versus-host disease on survival and relapse. Haematologica 1998; 83: 896–903. Gustafsson Jernberg A, Remberger M, Ringden O, Winiarski J. Graft-versus-leukaemia effect in children: chronic GVHD has a significant impact on relapse and survival. Bone Marrow Transplant 2003; 31: 175–181. Locatelli F, Zecca M, Rondelli R, Bonetti F, Dini G, Prete A et al. Graft versus host disease prophylaxis with low-dose cyclosporine-A reduces the risk of relapse in children with acute leukemia given HLA-identical sibling bone marrow transplantation: results of a randomized trial. Blood 2000; 95: 1572–1579. Zecca M, Prete A, Rondelli R, Lanino E, Balduzzi A, Messina C et al. Chronic graft-versus-host disease in children: incidence, risk factors, and impact on outcome. Blood 2002; 100: 1192–1200. Nordlander A, Mattsson J, Ringden O, Leblanc K, Gustafsson B, Ljungman P et al. Graft-versus-host disease is associated with a lower relapse incidence after hematopoietic stem cell transplantation in patients with acute lymphoblastic leukemia. Biol Blood Marrow Transplant 2004; 10: 195–203.

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