Comparison of outcome following allogeneic bone marrow transplantation with cyclophosphamide-total...

Comparison of outcome following allogeneic bone marrow

transplantation with cyclophosphamide–total body irradiation

versus busulphan–cyclophosphamide conditioning regimens

for acute myelogenous leukaemia in first remission

Mark R. Litzow,1

Waleska S. Perez,2

John P. Klein,2

Brian J. Bolwell,3

Bruce Camitta,4

Edward A. Copelan,5

Robert Peter Gale,6

Sergio A. Giralt,7

Armand Keating,8

Hillard M. Lazarus,9

David I. Marks,10

Philip L. McCarthy,11

Carole B. Miller,12

Gustavo Milone,13

H. Grant Prentice,14

James A. Russell,15

Kirk R. Schultz,16

Michael E. Trigg,17

Daniel J. Weisdorf18

and Mary M. Horowitz2 1Mayo Clinic & Foundation, Rochester,

MN, 2Acute Leukaemia Working Committee of the International Bone Marrow Transplant Registry, Health Policy

Institute, Medical College of Wisconsin, Milwaukee, WI, 3Cleveland Clinic Foundation, Cleveland, OH, 4Midwest

Children’s Cancer Center, Medical College of Wisconsin, Milwaukee, WI, 5The Ohio State University Hospital, Columbus,

OH, 6Salick Health Care, Inc., Los Angeles, CA, 7MD Anderson Cancer Center, Houston, TX, USA, 8Princess Margaret

Hospital, Toronto, Ontario, Canada, 9University Hospitals of Cleveland, Ireland Cancer Center, Cleveland, OH, USA,10Bristol Children’s Hospital, Bristol, UK, 11Roswell Park Cancer Institute, Buffalo, NY, 12Johns Hopkins Oncology

Center, Baltimore, MD, USA, 13Fundaleu/Angelica Ocampo, Buenos Aires, Capital Fe, Argentina, 14Royal Free Hospital

and School of Medicine, Hampstead, London, UK, 15Tom Baker Cancer Center, Calgary, Alberta, 16British Columbia’s

Children’s Hospital, Vancouver, British Columbia, Canada, 17A.I. Dupont Hospital for Children, Wilmington, DE, and18University of Minnesota, Minneapolis, MN, USA

Received 29 May 2002; accepted for publication 2 July 2002

Summary. We evaluated transplant-related mortality(TRM), leukaemia relapse, leukaemia-free survival (LFS)and overall survival (OS) in patients receiving busulphanand cyclophosphamide (BuCy) or cyclophosphamide andtotal body irradiation (CyTBI) prior to allogeneic bonemarrow transplantation (BMT) for acute myelogenousleukaemia (AML) in first remission. Outcomes of 381 humanleucocyte antigen (HLA)-matched sibling transplants usingBuCy were compared with 200 transplants using CyTBIperformed between 1988 and 1996. The incidence of hep-atic veno-occlusive disease was higher with BuCy (13%)than with CyTBI (6%) (P ¼ 0Æ009). Risks of acute andchronic GVHD were similar. In multivariate analysis,

relapse risk was higher in the BuCy group [relative risk(RR) ¼ 1Æ72; 95% confidence interval (CI), 1Æ05–2Æ81;P ¼ 0Æ031]. Eleven of 373 evaluable patients in the BuCygroup had a central nervous system relapse in contrastto none of 194 evaluable patients in the CyTBI group (P ¼0Æ016). There were no differences in TRM, LFS and OS.CyTBI conditioning may lower relapse risk but producescomparable TRM, LFS and OS to BuCy for HLA-matchedsibling transplantation in first remission AML.

Keywords: total body irradiation, busulphan, conditioningregimen, bone marrow transplantation, acute myelogenousleukaemia.

Allogeneic bone marrow transplantation (BMT) is anestablished therapy for acute myelogenous leukaemia(AML) (Thomas et al, 1977). In 1979, two groups reportedimproved outcomes for AML patients when transplantationwas performed in first complete remission (compared withmore advanced disease) using a conditioning regimen of

Correspondence: Mary M. Horowitz, MD, MS, International Bone

Marrow Transplant Registry, Medical College of Wisconsin, 8701

Watertown Plank Road, PO Box 26509, Milwaukee, Wisconsin,

53226 USA. E-mail: [email protected]

British Journal of Haematology, 2002, 119, 1115–1124

� 2002 Blackwell Publishing Ltd 1115

cyclophosphamide and total body irradiation (CyTBI)(Beutler et al, 1979; Thomas et al, 1979).

Subsequently, a combination of busulphan and cyclo-phosphamide (BuCy) was introduced to provide an alter-native, radiation-free conditioning regimen (Santos, 1989).A refinement of this regimen reduced the total dose ofcyclophosphamide (120 mg/kg rather than 200 mg/kg)without compromising efficacy (Tutschka et al, 1987).CyTBI and BuCy are now the most commonly usedconditioning regimens for allogeneic and autologous BMTin patients with AML.

In recent years, several retrospective and randomizedtrials have compared outcome of allogeneic and autologoustransplants using CyTBI or BuCy (Blaise et al, 1992;Schwerdtfeger et al, 1993; Clift et al, 1994; Ringden et al,1994, 1996, 1999; Devergie et al, 1995; Dusenbery et al,1995; Hartman et al, 1998; Davies et al, 2000). These trialsreported either an advantage or an equivalence with theCyTBI regimen for various endpoints. The studies includedpatients with diverse diagnoses, ages and remission states.

Because of differing results comparing the BuCy andCyTBI regimens, we studied this issue in the large observa-tional database of the International Bone Marrow Trans-plant Registry (IBMTR). We evaluated the outcome of 581adults receiving human leucocyte antigen (HLA)-identicalsibling transplants for AML in first remission after pretrans-plant conditioning with BuCy or CyTBI.

PATIENTS AND METHODS

IBMTR. The IBMTR is a voluntary working group of over350 transplant teams worldwide that contribute detaileddata on their syngeneic and allogeneic blood and marrowtransplants to a Statistical Center at the Health PolicyInstitute of the Medical College of Wisconsin (Horowitz &Bortin, 1992). Participating centres are required to registerall transplantations consecutively; compliance is monitoredby on-site audits. The database of the IBMTR includes about40% of all allogeneic transplants performed since 1970.Patients are followed longitudinally, with yearly follow-up.Computerized checks for errors, physician reviews ofsubmitted data and on-site audits of participating centresensure the quality of the data.

Patients. This study included adult patients (age‡20 years) receiving non-T cell-depleted HLA-identicalsibling BMT for AML in first complete remission between1988 and 1996 after pretransplant conditioning with BuCyor with Cy and fractionated TBI at a dose > 11Æ25 Gy.Cyclosporine (CsA) with or without methotrexate (MTX)was used for graft-versus-host disease (GVHD) prophylaxis(Table I). A total of 5110 patients receiving their firstallogeneic transplant for AML between 1988 and 1996were reported to the IBMTR. Of these, 1342 were excludedfrom analysis because of age < 20 years, 999 because theirdonor was not an HLA-identical sibling, 394 because

Table I. Characteristics of patients ‡20 years of age receiving HLA-identical sibling transplants for AML in first complete remission, by

pretransplant conditioning regimen.

Conditioning regimen

BuCy CyTBI

Variable N Evaluable N (%) N Evaluable N (%) P-value*

Number of patients 381 200

Age, median (range), years 381 35 (20–57) 200 34 (20–53) 0Æ321

Age at transplant > 40 years 381 116 (30) 200 45 (23) 0Æ042

Male sex 381 189 (50) 200 114 (57) 0Æ090

Karnofsky score pretransplant < 90% 379 59 (16) 197 42 (21) 0Æ085

FAB subtype 381 200 0Æ115

AML unclassified 14 (4) 9 (4)

M1 53 (14) 38 (19)

M2 107 (28) 56 (28)

M3 58 (15) 24 (12)

M4 97 (25) 42 (21)

M5 39 (10) 24 (12)

M6 6 (2) 5 (3)

M7 7 (2) 0

Other 0 2 (1)

WBC at diagnosis, median (range) · 109/l 337 12 (< 1–827) 184 12 (1–418) 0Æ746

WBC at diagnosis 337 184 0Æ493

£ 10 · 109/l 161 (48) 87 (47)

10–100 · 109/l 148 (44) 76 (41)

‡ 100 · 109/l 28 (8) 21 (12)

Cytogenetics� 381 200 0Æ132

No abnormalities 115 (30) 56 (28)

Good prognosis 34 (9) 14 (7)

1116 M. R. Litzow et al

� 2002 Blackwell Publishing Ltd, British Journal of Haematology 119: 1115–1124

Table I. (continued)

Conditioning regimen

BuCy CyTBI

Variable N Evaluable N (%) N Evaluable N (%) P-value*

Intermediate prognosis 52 (14) 31 (16)

Poor prognosis 3 (1) 8 (4)

Tested but no evaluable metaphases 10 (2) 4 (2)

Unknown 167 (44) 87 (43)

Extramedullary disease at diagnosis 381 28 (7) 200 23 (12) 0Æ093

Prior myelodysplastic syndrome 377 12 (3) 199 6 (3) 0Æ912

> 1 cycle of chemotherapy to achieve 1st CR 358 96 (27) 183 69 (38) 0Æ009

Consolidation chemotherapy cycles 381 196 0Æ112

No consolidation therapy 61 (16) 31 (16)

< 2 cycles 116 (30) 31 (16)

‡ 2 cycles 75 (20) 45 (23)

Consolidation therapy given,

number of cycles unknown

129 (34) 35 (18)

High-dose ARA-C for induction or consolidation 377 113 (30) 188 47 (25) 0Æ216

Time from achievement CR1 to BMT,

median (range), months

378 4 (< 1–26) 194 4 (< 1–15) 0Æ822

Time from CR1 to BMT £ 3 months 378 143 (38) 194 72 (37) 0Æ867

Donor–recipient sex match 380 199 0Æ322

Male–male 103 (27) 66 (33)

Female–male 86 (23) 48 (24)

Male–female 105 (27) 49 (25)

Female–female 86 (23) 36 (18)

Donor–recipient CMV status 370 187 0Æ076

Positive–positive 176 (48) 73 (39)

Positive–negative 44 (12) 22 (12)

Negative–positive 61 (16) 28 (15)

Negative–negative 89 (24) 64 (34)

Nucleated cells, median (range), · 108/kg 346 3 (0–28) 182 3 (0–6) 0Æ077

TBI dose NA 200 –

11Æ25 Gy 4 (2)

12Æ00 Gy 146 (73)

12Æ01–13Æ99 Gy 32 (16)

‡ 14Æ00 Gy 18 (9)

Lung shielding NA 177 107 (60) –

Year of transplant 381 200 0Æ213

1988–1990 109 (29) 80 (41)

1991–1993 153 (40) 63 (31)

1994–1996 119 (31) 57 (28)

Cy dose, median (range), mg/kg 371 120 (43–240) 196 120 (47–240) 0Æ113

Cy dose > 130 mg/kg 371 85 (23) 196 12 (6) 0Æ001

Bu dose, median (range), mg/kg 360 16 (4–18) NA –

Bu dose > 15 mg/kg 360 274 (76) NA –

GVHD prophylaxis 381 200 0Æ117

CsA ± other (not MTX) 88 (23) 35 (18)

CsA + MTX ± other 293 (77) 165 (82)

GF post transplant: G-CSF or GM-CSF 364 71 (20) 184 55 (30) 0Æ006

*The chi square test was used for discrete covariates; the Kruskal–Wallis test was used for continuous covariates.

�Good prognosis includes: 16q; t(8;21); t(15;17); intermediate prognosis includes: +8; +21; t(1;7); t(6;9); t(8;16); other abnormalities; poor

prognosis includes: )5/5q–; )7/7q–; )20/20q–; 3q; 11q; t(5;7); t(9;22).

AML, acute myelogenous leukaemia; HLA, human leucocyte antigen; Bu, busulphan; Cy, cyclophosphamide; TBI, total body irradiation;

FAB, French–American–British classification; WBC, white blood cell count; CR, complete remission; BMT, bone marrow transplant; GVHD,

graft-versus-host disease; NA, not applicable; CsA, cyclosporine; MTX, methotrexate; GF, growth factors; G-CSF, granulocyte-colony stimu-

lating factor; GM-CSF, granulocyte-macrophage colony stimulating factor; CMV, cytomegalovirus; ARA-C, cytosine arabinoside.

CyTBI versus BuCy Prior to BMT for AML in CR1 1117


transplantation was not done in first complete remission,1621 because the conditioning regimen was not BuCy orCyTBI (including patients who received drugs in addition toBuCy or CyTBI), 100 because they received a GVHDprophylaxis regimen that was not CsA alone or combinedwith MTX and 73 because they received < 11Æ25 Gy TBI.Five hundred and eighty-one patients met the on-studycriteria: 381 patients had received BuCy and 200 hadreceived CyTBI. Eligible patients came from 122 reportingteams in 33 countries. Median follow-up of survivors was55 months (4–127) for BuCy patients and 45 months(3–117) for CyTBI patients.

Patients classified as having good prognosis cytogeneticsincluded those with 16q abnormalities, t(8;21) andt(15;17). Poor prognosis patients included those withabnormalities of chromosomes 5, 7 and 20 (either mono-somy or deletion of a portion of the long arm of thechromosome), abnormalities of 3q and 11q, t(5;7) andt(9;22). All other cytogenetic abnormalities were consideredintermediate prognosis (Gale et al, 1995).

Statistical analysis. Characteristics of patients in the BuCyand CyTBI cohorts were compared using the chi square testfor categorical variables and the Kruskal–Wallis test forcontinuous variables (Table I).

The primary endpoints of this study were transplant-related mortality (TRM), leukaemia relapse, leukaemia-freesurvival (LFS) and overall survival (OS). Haematologicalrecovery [achievement of absolute neutrophil count (ANC)> 0Æ5 · 109/l and platelet count > 20 · 109/l], veno-occlu-sive disease of the liver (VOD), interstitial pneumonia, acuteand chronic GVHD, and sites of post-transplant relapse werealso described. Probabilities of haematological recovery,acute and chronic GVHD, TRM, and relapse were calculatedusing cumulative incidence estimates to accommodatecompeting risks (Gooley et al, 1999). Survival and LFSwere calculated using Kaplan–Meier estimates. For analysisof TRM, failure was defined as death during a continuouscomplete remission; data were censored at time of relapseor, among patients in continuous remission, at time of lastfollow-up. For analysis of relapse, failure was defined asclinical or haematological recurrence of AML at any site;data were censored at the time of death in remission or atlast follow-up. For analyses of LFS, treatment was consid-ered to have failed at the time of clinical and/or haemato-logical relapse (not cytogenetic or molecular) at any site orat the time of death from any cause; data on patients whowere alive and in complete remission were censored at timeof last follow-up. For analyses of survival, failure was deathfrom any cause; data were censored at last follow-up forsurviving patients. Univariate comparisons used the log-rank test (Klein & Moeschberger, 1997) (Table II).

Comparison of primary outcomes between the BuCy andCyTBI groups was done using multivariate Cox proportionalhazards regression to adjust for potentially confoundingeffects of other risk factors. The variables considered inmultivariable analysis are listed in Table III. We tested theproportional hazards assumption for each factor in the Coxmodel using time-dependent covariates. When this indica-ted differential effects over time (non-proportional hazards),

models were constructed, breaking the post-transplant timecourse into two periods, using the maximized partiallikelihood method to find the most appropriate breakpoint.After modelling time-varying effects, the final multivariatemodel was built using a forward stepwise model selectionapproach. Each model contained the main effect (condi-tioning regimen: BuCy versus CyTBI). Factors significantlyassociated with the outcome variable at a 5% level werekept in the final model. Interactions between all covariatestested and the main variable of conditioning regimen weretested using the likelihood ratio test. Examination for centreeffects used a random effects or frailty model (Andersenet al, 1999); there was no evidence of confounding of maineffects by centre effects. All P-values are two sided.

RESULTS

Patient characteristicsCharacteristics of the CyTBI and BuCy groups are comparedin Table I. Significantly more patients in the BuCy groupwere older than 40 years. A higher proportion of patients inthe CyTBI group required more than one cycle of chemo-therapy to achieve first remission. As expected, a higherproportion of patients in the BuCy group received> 130 mg/kg cyclophosphamide. Finally, a higher propor-tion of patients in the CyTBI group received haematopoieticgrowth factors post transplant. The patients did not differsignificantly for any other factors analysed.

OutcomesUnivariate analysis. Table II demonstrates univariate

comparisons of transplant outcomes between the twocohorts. Neutrophil recovery was significantly faster in theBuCy group although the magnitude was only 1 day(median, 18 d vs 19 d). VOD was more frequent with BuCythan with CyTBI (13% vs 6%, P ¼ 0Æ009). The incidences ofacute and chronic GVHD and interstitial pneumonia weresimilar. The grade of acute or chronic GVHD did not differamong the patients (data not shown).

There was a significantly lower leukaemia relapse rate inthe CyTBI group. At 5 years, the cumulative incidence(95% confidence interval) of relapse was 19% (15–24%)with BuCy compared with 12% (7–17%) with CyTBI(P ¼ 0Æ042) (Fig 1). Sites of relapse also differed: therewere 11 central nervous system (CNS) relapses in the BuCygroup, but none in the CyTBI group (P ¼ 0Æ016) (Table II).Five of these 11 patients were classified as French–American–British (FAB)-M4 AML at diagnosis, two wereM5, two M1, one M2 and one was unknown FAB subtype.One hundred day mortality, TRM, LFS and OS rates weresimilar.

Multivariate analysis. Table III lists the variables tested inCox proportional hazards regression models for theirassociation with the primary outcome variables. Table IVshows the relative risks of relapse, TRM, treatment failure(inverse of LFS) and mortality with BuCy versus CyTBIbased on multivariate analyses. Multivariate analysis sup-ported the univariate finding of higher relapse risk in theBuCy group with a relative risk of 1Æ72 (95% CI 1Æ05–2Æ81,



P ¼ 0Æ03). Other factors also associated with a significantlyincreased risk of relapse were abnormal cytogenetics andmale-to-male transplants.

In multivariate analysis, TRM did not differ significantlybetween the regimens (Fig 2). Factors associated withincreased risk of TRM were age ‡40 years, prior myelodys-plastic syndrome and use of growth factors post transplant.

LFS and OS also did not differ significantly between theregimens (Fig 3). Factors associated with poorer LFS andOS were age ‡40 years, Karnofsky performance score< 90% prior to transplant and prior myelodysplasticsyndrome.

When patients in the BuCy group who had received< 130 mg/kg of cyclophosphamide were compared with

Table II. Univariate analysis of transplant outcomes among patients ‡ 20 years of age receiving HLA-identical sibling transplants for AML in

first complete remission, by pretransplant conditioning regimen.

Outcome event

Conditioning

regimen BuCy

N evaluable

CyTBI

N evaluable P-value

ANC > 0Æ5 · 109/l@100 d*� 379 98 (96–99)% 197 93 (90–96)% 0Æ008

Time to ANC > 0Æ5 · 109/l, median

(range)�371 18 (5–105) d 183 19 (9–47) d 0Æ003

Platelets > 20 · 109/l@100 d*� 373 90 (86–92)% 194 86 (81–90)% 0Æ254

Time to platelets > 20 · 109/kg, median

(range)�337 21 (8–157) d 171 23 (1–132)% 0Æ202

Extramedullary relapse, N (%)§ 373 194 0Æ016

None 310 (83) 175 (90) 0Æ016

CNS ± other 11 (3) 0

Other– 52 (14) 19 (10)

VOD of the liver, N (%)§ 373 50 (13%) 193 12 (6%) 0Æ009

Interstitial pneumonia, N (%)§ 380 56 (15%) 200 31 (16%) 0Æ807

Interstitial pneumonia, N (%)§ 48 31 0Æ439

£ 100 d post-transplant 32 (67%) 18 (58%)

> 100 d post-transplant 16 (33%) 13 (42%)

Grade 2–4 acute GVHD @100 d*� 379 30 (25–34)% 195 29 (23–35)% 0Æ794

Chronic GVHD*� 380 198 0Æ609

@1 years 35 (30–40)% 36 (29–43)%

@3 years 39 (34–44)% 37 (30–44)%

@5 years 39 (34–44)% 37 (30–44)%

100-day mortality*� 381 17 (13–20)% 199 17 (12–22)% 0Æ911

TRM*� 380 196 0Æ559

@1 years 23 (19–28)% 25 (19–31)%

@3 years 26 (22–31)% 29 (22–36)%

@5 years 27 (22–31)% 30 (23–37)%

Relapse*� 380 196 0Æ042

@1 years 12 (9–15)% 7 (4–12)%

@3 years 17 (13–21)% 11 (7–16)%

@5 years 19 (15–24)% 12 (7–17)%

LFS*� 380 196 0Æ438

@1 years 65 (60–69)% 68 (61–74)%

@3 years 57 (52–62)% 60 (53–67)%

@5 years 54 (48–59)% 58 (50–65)%

Overall survival*� 381 200 0Æ579

@1 years 68 (63–73)% 70 (63–76)%

@3 years 60 (55–65)% 62 (54–68)%

@5 years 55 (49–60)% 60 (52–66)%

*Probabilities of 100-d mortality, leukaemia-free survival and overall survival were calculated using the Kaplan–Meier product limit

estimate. Engraftment, acute and chronic GVHD, TRM, and relapse were calculated using the cumulative incidence estimate.

�The log-rank test was used for univariate comparisons between groups.

�The median test was used for univariate comparisons between groups.

§The chi-square test was used for comparison between groups.

–Sites include: skin, breast, peripheral nerve, other unspecified sites.

AML, acute myelogenous leukaemia; HLA, human leucocyte antigen; Bu, busulphan; Cy, cyclophosphamide; TBI, total body irradiation;

GVHD, graft-versus-host disease; TRM, treatment-related mortality; LFS, leukaemia-free survival; VOD, veno-occlusive disease; CI, confidence

interval; d, days.



those receiving > 130 mg/kg, no differences were noted inTRM (27% vs 25%, P ¼ 0Æ85), relapse (22% vs 19%,P ¼ 0Æ38), LFS (57% vs 61%, P ¼ 0Æ50) or OS (60% vs65%, P ¼ 0Æ52) respectively.

DISCUSSION

This study was undertaken to determine if any significantdifferences could be found between the outcomes of HLA-identical sibling transplantation using BuCy conditioningversus CyTBI for adults with AML in first remission.Proponents of the BuCy regimen argue that the regimen iseasier to administer than regimens containing TBI and isassociated with less mucositis, possibly more rapid haema-topoietic recovery and lower risk of late cancers (Rizzo et al,2000). An intravenous form of busulphan is now available.Studies demonstrate its effectiveness in the transplantsetting with good reproducibility between doses and limitedinterpatient variability in peak concentration, clearance andarea under the plasma concentration versus time curve(Andersson et al, 2000). Recent studies have shown thatmeasurement of busulphan pharmacokinetics with subse-quent dose adjustments can decrease the risk of rejectionand toxicity while minimizing relapse (Slattery et al, 1995;Ljungman et al, 1997). It is unknown whether any of thepatients in this study had busulphan levels measured, but itwas probably a small proportion. Proponents of TBI,however, argue that radiation provides more effectiveantileukaemic therapy and avoids some of the complicationsof busulphan, including VOD of the liver.

The data presented here demonstrated, in both univariateand multivariate analyses, a significantly lower post-trans-plant relapse rate in patients receiving CyTBI comparedwith those receiving BuCy, primarily attributable to ahigher risk of CNS and other extramedullary (skin, breastand other) relapses in the BuCy group. This increase in CNSrelapses has not, to our knowledge, been previouslyreported and is somewhat surprising given that busulphancrosses the blood–brain barrier and is associated with anincreased risk of seizures (Hassan et al, 1989; Meloni et al,1992). These data suggest that TBI more effectively treatsoccult disease in the CNS than busulphan. Bone marrow

Table III. Variables tested in Cox proportional hazards regression

models.

Main effect variable*

Conditioning regimen prior transplant: BuCy vs Cy-TBI

Patient-related variables

Age at transplant: £ 40 years vs > 40 years

Sex: female vs male

Karnofsky performance status at transplant: < 90% vs ‡90%

Disease-related variables at diagnosis

FAB subtype: M3 vs M1, M2 vs M4, M5, M6, M7 vs others vs

unknown

WBC at diagnosis: £ 10 · 109/l vs 10–100 · 109/l vs >

100 · 109/l vs missing

Cytogenetics: good prognosis vs intermediate prognosis vs poor

prognosis vs no abnormalities vs unknown

Extramedullary disease: yes vs no

Prior myelodysplastic syndrome: yes vs no

Disease-related variables at transplant

Time from diagnosis to first complete remission: £ 2 months

vs > 2 months

Cycles of chemotherapy to achieve first complete remission: 1

vs > 1 vs missing

Number of consolidation chemotherapy cycles: < 2 vs ‡2 vs

therapy given, number of cycles unknown

ARA-C for induction or consolidation: < 1 g/m2/d vs ‡ 1

g/m2/d vs none

Time from achievement of pretransplant disease status to BMT:

43 months vs > 3 months

Treatment-related

Donor-recipient sex match: male-male vs female-male vs

male-female vs female-female

Donor sex: parous female vs non-parous female vs male vs

female status unknown

Donor-recipient CMV status

Cyclophosphamide dose: £ 130 mg/kg vs > 130 mg/kg

Busulphan dose: £ 15 mg/kg vs > 15 mg/kg

Year of transplant

GVHD prophylaxis: CsA only vs CsA + MTX

Growth factors post transplant: yes vs no vs missing

*Included in all models.

CMV, cytomegalovirus.

Fig 1. Cumulative incidence of relapse after

HLA-identical sibling bone marrow trans-

plantation for AML in first complete remission,

by pretransplant conditioning regimen.



relapses were also higher in the BuCy group but this was ofborderline significance. Despite this difference in relapserates, LFS and OS of the two groups did not differ. The slightnon-significant increase in TRM in the CyTBI group mayhave been sufficient to negate a significant difference in LFSor OS, resulting from fewer relapses. Whether patients in theBuCy group received a higher or lower dose of cyclophos-phamide (< 130 mg/kg or > 130 mg/kg) did not influencetheir outcome, suggesting a threshold dose effect forcyclophosphamide in this setting.

Although the number of patients in this study with poorprognosis cytogenetics at diagnosis was low, it is importantto realize that the patients in this study were relativelyyoung adults (as one would expect in a group of patientsundergoing allogeneic BMT) and, therefore, were expected

to have a higher proportion of patients with more favour-able cytogenetics at diagnosis. Similarly, in the MedicalResearch Council AML 10 trial, only 10% of the 1612patients analysed had cytogenetic abnormalities of anadverse type (Grimwade et al, 1998). Additionally, as iscommonly seen in registry studies (Davies et al, 2000),nearly half the patients in the two groups in this study hadunknown cytogenetics at diagnosis. There is no reason tosuspect that the types of cytogenetic abnormalities seen inthe patients with unknown cytogenetics would differbetween the two groups.

Several randomized trials have compared these twoconditioning regimens. A French trial of 101 patients withAML in first remission compared CyTBI (varying TBIdoses and schedules) with busulphan (16 mg/kg) and

Table IV. Relative risks of relapse, treatment-related mortality, treatment failure and mortality with Bu/Cy

versus Cy/TBI in multivariate analysis.

Endpoint Relative risk of endpoint* 95% confidence interval P-value

Relapse� 1Æ72 1Æ05–2Æ81 0Æ031

Treatment-related mortality� 0Æ88 0Æ63–1Æ40 0Æ473

Treatment failure§ 1Æ07 0Æ81–1Æ41 0Æ627

Mortality– 1Æ03 0Æ78–1Æ37 0Æ815

*Risk with Bu/Cy versus Cy/TBI.

�Other significant covariates were cytogenetics (intermediate vs good: RR ¼ 0Æ64, 95% CI 0Æ34–1Æ23,

P ¼ 0Æ18; poor vs good: RR ¼ 1Æ41, 95% CI 0Æ48–4Æ10, P ¼ 0Æ18; no abnormalities vs good: RR ¼ 0Æ38,

95% CI 0Æ21–0Æ70, P ¼ 0Æ53; unknown vs good: RR ¼ 0Æ56, 95% CI 0Æ33–0Æ94, P ¼ 0Æ03) and donor–

recipient sex match (male–female vs male–male: RR ¼ 0Æ58, 95% CI 0Æ32–1Æ02, P ¼ 0Æ06; female–male vs

male–male: RR ¼ 0Æ60, 95% CI 0Æ36–1Æ01, P ¼ 0Æ06; female–female vs male–male: RR ¼ 0Æ44, 95%

CI 0Æ23–0Æ84, P ¼ 0Æ01).

�Other significant covariates were age ‡ 40 years (RR ¼ 1Æ48, 95% CI 1Æ09–2Æ12, P ¼ 0Æ01); prior

myelodysplastic syndrome (RR ¼ 2Æ89, 95% CI 1Æ50–5Æ57, P < 0Æ01) and administration of growth factors

post transplant (RR ¼ 1Æ48, 95% CI 1Æ03–2Æ14, P ¼ 0Æ04; missing: RR ¼ 1Æ54, 95% CI 0Æ84–2Æ83,

P ¼ 0Æ16).

§Other significant covariates were age ‡ 40 years (RR ¼ 1Æ35, 95% CI 1Æ03–1Æ77, P ¼ 0Æ03); prior

myelodysplastic syndrome (RR ¼ 2Æ11, 95% CI 1Æ16–3Æ82, P ¼ 0Æ01) and Karnofsky score prior to trans-

plant ‡ 90 (RR ¼ 0Æ64, 95% CI 0Æ47–0Æ87, P ¼ 0Æ01).

–Other significant covariates were age ‡ 40 years (RR ¼ 1Æ36, 95% CI 1Æ03–1Æ79, P ¼ 0Æ03); prior

myelodysplastic syndrome (RR ¼ 2Æ37, 95% CI 1Æ33–4Æ22, P < 0Æ01) and Karnofsky score prior to trans-

plant ‡ 90 (RR ¼ 0Æ61, 95% CI 0Æ45–0Æ84, P < 0Æ01).

Fig 2. Cumulative incidence of TRM after

HLA-identical sibling bone marrow trans-

plantation for AML in first complete remission,

by pretransplant conditioning regimen.



cyclophosphamide (60 mg/kg/d for 2 days) and foundimproved disease-free survival and OS, with fewer relapses,and lower TRM with CyTBI (Blaise et al, 1992, 2000). Atrial from Scandinavia evaluated the same conditioningregimens in 167 patients with AML (n ¼ 69), acutelymphoblastic leukaemia (n ¼ 38), chronic myelogenousleukaemia (n ¼ 57) and lymphoma (n ¼ 4) (Ringden et al,1994). This study found more VOD of the liver andhaemorrhagic cystitis in patients who received busulphan.Long-term follow-up of this trial demonstrated high rates ofchronic GVHD, alopecia and obstructive bronchiolitis inbusulphan-treated patients, and more cataracts in TBI-treated patients (Ringden et al, 1999). This contrasts withthe current study where a slightly higher incidence ofcutaneous chronic GVHD (data not shown) was seen in theBuCy group but no increase in overall incidence or othermanifestations of the disease. Also, LFS in the Scandinaviantrial was similar for both groups in patients with non-advanced disease, but better outcome was seen for patientswith advanced disease who received TBI rather thanbusulphan.

The European Group for Blood and Marrow Transplanta-tion (EBMT) retrospectively compared the outcome of 1842patients receiving BuCy or CyTBI prior to autologous orallogeneic transplants for acute leukaemia from January1987 to January 1994 (Ringden et al, 1996). VOD andhaemorrhagic cystitis were more common with BuCy com-

pared with CyTBI but TRM, relapse and LFS were similar. Aprevious IBMTR study retrospectively compared the outcomeof HLA-identical sibling allogeneic transplants in childrenwith ALL following CyTBI or BuCy conditioning and found asimilar relapse rate for the two regimens, but higher TRMwith BuCy, resulting in superior disease-free survival and OSfor children receiving CyTBI (Davies et al, 2000).

A recent meta-analysis included five of the randomizedtrials comparing BuCy with TBI regimens in the allogeneictransplant setting (Blaise et al, 1992; Blume et al, 1993; Cliftet al, 1994; Ringden et al, 1994; Devergie et al, 1995). All ofthe trials compared BuCy with CyTBI except one (Blumeet al, 1993), which compared BuCy with etoposide–TBI. Sixend-points were assessed, including disease-free survival, OS,VOD of the liver, acute and chronic GVHD, and interstitialpneumonitis (Hartman et al, 1998). Disease-free survivaland OS were higher with TBI-based regimens compared withBuCy but the differences were not statistically significant. Asensitivity analysis suggested that BuCy was not likely tohave a clinically relevant survival or disease-free survivaladvantage over TBI but could not exclude the possibility ofsuch an advantage for TBI-based regimens. A significantlyhigher incidence of VOD with the BuCy regimen was noted;there were no significant differences in the incidence of otherside-effects. The authors concluded that TBI-based regimenscaused less VOD than BuCy and were equivalent to BuCy fordisease-free survival and OS.

Fig 3. (A) Probability of LFS after HLA-iden-

tical sibling bone marrow transplantation for

AML in first complete remission, by pretrans-

plant conditioning regimen. (B) Probability of

survival after HLA-identical sibling bone

marrow transplantation for AML in first

complete remission, by pretransplant condi-

tioning regimen.



The major limitation of this study is its non-randomizeddesign. Although we carefully controlled for potentiallyconfounding differences in patient and disease characteris-tics between the two conditioning regimen groups, wecannot exclude effects of differences in unknown orunmeasured variables. The major strength of the study isthe very large number of patients with a single disease andremission state. In contrast, previous studies, randomized ornon-randomized, have had either relatively few patients orcombined patients with diverse diseases and disease states.As the IBMTR collects data from about 40% of activeallotransplant centres and participating centres must reportconsecutive transplants, this study gives a good indicationof the effectiveness of these conditioning regimens, asapplied during the study period.

In conclusion, this large retrospective analysis comparingconditioning regimens for HLA-matched sibling allogeneicBMT shows a lower risk of VOD and a reduced risk of relapsein patients receiving CyTBI compared with those receivingBuCy. However, these differences did not result in adifference in LFS or OS between the two groups. The studyhad > 90% power to detect a 15% difference in theseoutcomes; it cannot exclude smaller differences. In thisstudy, all patients received allogeneic bone marrow as theirstem cell source. It is possible the use of peripheral bloodstem cells could alter the outcomes noted. The choice ofconditioning regimen for patients undergoing HLA-matchedsibling BMT for AML in first remission will depend on theindividual investigator’s interpretation of the results of thisand other studies, and on the capability of their centre tooptimally deliver these regimens.

ACKNOWLEDGMENTS

Supported by Public Health Service Grant U24-CA76518from the National Cancer Institute, the National Institute ofAllergy and Infectious Diseases, and the National Heart,Lung and Blood Institute, and Contract No. CP-21161 fromthe National Cancer Institute of the U.S. Department ofHealth and Human Services Grant No. DAMD17-95-I-5002from the Department of the U.S. Army Medical Researchand Development Command, and grants from: Abgenix,Inc.; AmCell Corporation; American Cancer Society;American Society of Clinical Oncology; Amgen, Inc.;Anonymous; Aventis Pharmaceuticals; Berlex Laboratories;Blue Cross and Blue Shield Association; Lynde and HarryBradley Foundation; Bristol-Myers Squibb Oncology; Centerfor Advanced Studies in Leukaemia; Cerus Corporation;Chimeric Therapies; Chiron Therapeutics; Eleanor NaylorDana Charitable Trust; Deborah J. Dearholt Memorial Fund;Empire Blue Cross Blue Shield; Fujisawa Healthcare, Inc.;Gambro BCT, Inc.; Genentech, Inc.; GlaxoSmithKline, Inc.;Human Genome Sciences; ICN Pharmaceuticals, Inc.; IDECPharmaceuticals Corporation; Immunex Corporation; Intra-Biotics Pharmaceuticals; Kettering Family Foundation; KirinBrewery Company; Robert J. Kleberg, Jr, and HelenC. Kleberg Foundation; LifeTrac/Allianz; The LiposomeCompany; Nada and Herbert P. Mahler Charities; MarketCertitude, LLC; Mayer Ventures; MedImmune, Inc.; Merck &

Co., Inc.; Milliman & Robertson, Inc.; Milstein FamilyFoundation; The Greater Milwaukee Foundation/Elsa Scho-eneich Research Fund; NeoRx; Nexell Therapeutics; Novar-tis Pharmaceuticals; Orphan Medical; Ortho Biotech, Inc.;John Oster Family Foundation; Pfizer U.S. Pharmaceuticals;Pharmacia Corporation; Principal Life Insurance Company;Response Oncology, Inc.; RGK Foundation; Roche Laborat-ories, Inc.; SangStat; Schering AG; Schering Oncology/Biotech; Stackner Family Foundation; The Starr Founda-tion; SuperGen, Inc.; TheraTechnologies, Inc.; Unicare Life& Health Insurance; and Wyeth/Genetics Institute.

The contents of this article are solely the responsibility ofthe authors and do not necessarily represent the officialviews of the National Cancer Institute.

REFERENCES

Andersen, P.K., Klein, J.P. & Zhang, M.-J. (1999) Testing for center

effects in multi-centre survival studies: a Monte Carlo comparison

of fixed and random effects test. Statistics in Medicine, 18, 1489–

1500.

Andersson, B.S., Gajewski, J., Donato, M., Giralt, S., Gian, V.,

Wingard, J., Tarantolo, S., Fernandez, H., Hu, W.W., Blume, K.,

Kashyap, A., Forman, S.J. & Champlin, R.E. (2000) Allogeneic

stem cell transplantation (BMT) for AML and MDS following i.v.

busulfan and cyclophosphamide (i.v. BuCy). Bone Marrow

Transplantation, 25, s35–s38.

Beutler, E., Blume, K.G., Bross, K.J., Chillar, R.K., Ellington, O.B.,

Fahey, J.L., Farbstein, M.J., Schmidt, G.M., Spruce, W.E. &

Turner, M.A. (1979) Bone marrow transplantation as the

treatment of choice for �good risk� adult patients with acute

leukemia. Transactions of the Association of American Physicians,

92, 189–195.

Blaise, D., Maraninch, D., Archimbaud, E., Reiffers, J., Devergie, A.,

Jouet, J.P., Milpied, N., Attal, M., Michallet, M. & Ifrah, N. (1992)

Allogeneic bone marrow transplantation for acute myeloid leu-

kemia in first remission: a randomized trial of a busulfan–Cyt-

oxan versus Cytoxan–total body irradiation as preparative

regimen: a report from the Group d’Etudes de la Greffe de Moelle

Osseuse. Blood, 79, 2578–2582.

Blaise, D., Maraninchi, D., Michallet, M., Reiffers, J., Jouet, P.,

Milpied, N., Devergie, A., Attal, M., Sotto, J.J., Kuentz, M., Ifrah,

N., Dauriac, C., Bordigoni, P., Gratecos, N., Guilhot, F., Guyotat,

D., Gluckman, E. & Vernant, J.P. for the French Society of Bone

Marrow Graft (SFGM) (2000) Ten year follow-up of a national

randomized trial comparing CYTBI vs BUSCY as conditioning

regimen for patients administered HLA-identical marrow grafts

for CR1 AML. Blood, 96, 480a.

Blume, K.G., Kopecky, K.J., Henslee-Downey, J.P., Forman, S.J.,

Stiff, P.J., LeMaistre, C.F. & Appelbaum, F.R. (1993) A prospective

randomized comparison of total body irradiation–etoposide ver-

sus busulfan–cyclophosphamide as preparatory regimens for

bone marrow transplantation in patients with leukemia who

were not in first remission: a Southwest Oncology Group study.

Blood, 81, 2187–2193.

Clift, R.A., Buckner, C.D., Thomas, E.D., Bensinger, W.I., Bowden,

R., Bryant, E., Deeg, H.J., Doney, K.C., Fisher, L.D. & Hansen, J.A.

(1994) Marrow transplantation for chronic myeloid leukemia: a

randomized study comparing cyclophosphamide and total body

irradiation with busulfan and cyclophosphamide. Blood, 84,

2036–2043.

Davies, S.M., Ramsay, N.K.C., Klein, J.P., Weisdorf, D.J., Bolwell, B.,

Cahn, J.-Y., Camitta, B.M., Gale, R.P., Giralt, S., Heilmann, C.,



Henslee-Downey, P.J., Herzig, R.H., Hutchinson, R., Keating, A.,

Lazarus, H.M., Milone, G.A., Neudorf, S., Perez, W.S., Powles,

R.L., Prentice, H.G., Schiller, G., Socie, G., Vowels, M., Wiley, J.,

Yeager, A. & Horowitz, M.M. (2000) Comparison of preparative

regimens in transplants for children with acute lymphoblastic

leukemia. Journal of Clinical Oncology, 18, 340–347.

Devergie, A., Blaise, D., Attal, M., Tigaud, J.D., Jouet, J.P., Vernant,

J.P., Bordigoni, P., Ifrah, N., Dauriac, C., Cahn, J.-Y., Lioure, B.,

Troussard, X., Reiffers, J., Gratecos, N., Milpied, N., Belanger, C.,

Guyotat, D., Tilly, H., Michallet, M. & Gluckman, E. for the French

Society of Bone Marrow Graft (SFGM) (1995) Allogeneic bone

marrow transplantation for chronic myeloid leukemia in first

chronic phase: a randomized trial of busulfan–cytoxan versus

cytoxan–total body irradiation as preparative regimen: a report

from the French Society of Bone Marrow Graft (SFGM). Blood, 85,

2263–2268.

Dusenbery, K.E., Daniels, K.A., McClure, J.S., McGlave, P.B.,

Ramsay, N.K., Blazar, B.R., Neglia, J.P., Kersey, J.H. & Woods, W.

(1995) Randomized comparison of cyclophosphamide–total body

irradiation versus busulfan–cyclophosphamide conditioning in

autologous bone marrow transplantation for acute myeloid

leukemia. International Journal of Radiation Oncology, Biology,

Physics, 31, 119–128.

Gale, R.P., Horowitz, M.M., Weiner, R.S., Ash, R.C., Atkinson, K.,

Babu, R., Dicke, K.A., Klein, J.P., Lowenberg, B., Reiffers, J.,

Rimm, A.A., Rowlings, P.A., Sandberg, A.A., Sobocinski, K.A.,

Veum-Stone, J. & Bortin, M.M. (1995) Impact of cytogenetic

abnormalities on outcome of bone marrow transplants in acute

myelogenous leukemia in first remission. Bone Marrow Trans-

plantation, 16, 203–208.

Gooley, T.A., Leisenring, W., Crowley, J. & Storer, B.E. (1999)

Estimation of failure probabilities in the presence of competing

risks: new representations of old estimators. Statistics in Medicine,

18, 695–706.

Grimwade, D., Walker, H., Oliver, F., Wheatley, K., Harrison, C.,

Harrison, G., Rees, J., Hann, I., Stevens, R., Burnett, A. & Gold-

stone, A. (1998) The importance of diagnostic cytogenetics on

outcome in AML: analysis of 1,612 patients entered into the MRC

AML 10 trial. The Medical Research Council Adult and Children’s

Leukaemia Working Parties. Blood, 92, 2322–2333.

Hartman, A.R., Williams, S.F. & Dillon, J.J. (1998) Survival, disease-

free survival and adverse effects of conditioning for allogeneic

bone marrow transplantation with busulfan/cyclophosphamide

vs total body irradiation: a meta-analysis. Bone Marrow Trans-

plantation, 22, 439–443.

Hassan, M., Oberg, G., Ehrsson, H., Ehrnebo, M., Wallin, I.,

Smedmyr, B., Totterman, T., Eksborg, S. & Simonsson, B. (1989)

Pharmacokinetic and metabolic studies of high-dose busulphan

in adults. European Journal of Clinical Pharmacology, 36, 1525–

1530.

Horowitz, M.M. & Bortin, M.M. (1992) The role of registries in

evaluating the results of bone marrow transplantation. In: Bone

Marrow Transplantation in Practice (ed. by J. Trealeaven & A.J.

Barrett), pp. 367–377. Churchill Livingstone, Edinburgh.

Klein, J.P. & Moeschberger, M.L. (1997) Survival Analysis: Tech-

niques for Censored and Truncated Data. Springer-Verlag, New

York.

Ljungman, P., Hassan, M., Bekassy, A.N., Ringden, O. & Oberg, G.

(1997) High busulfan concentrations are associated with

increased transplant-related mortality in allogeneic bone marrow

transplant patients. Bone Marrow Transplantation, 20, 909–913.

Meloni, G., Raucci, U., Pinto, R.M., Spalice, A., Vignetti, M. &

Iannetti, P. (1992) Pretransplant conditioning with busulfan and

cyclophosphamide in acute leukemia patients: neurological and

electroencephalographic prospective study. Annals of Oncology, 3,

145–148.

Ringden, O., Ruutu, T., Remberger, M., Nikoskelainen, J., Volin, L.,

Vindelov, L., Parkkali, T., Lenhoff, S., Sallerfors, B. & Ljungman,

P. (1994) 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, 83, 2723–2730.

Ringden, O., Labopin, M., Tura, S., Arcese, W., Iriondo, A., Zittoun,

R., Sierra, J. & Gorin, N.C. (1996) A comparison of busulphan

versus total body irradiation combined with cyclophosphamide as

conditioning for autograft or allograft bone marrow transplan-

tation in patients with acute leukaemia. Acute Leukaemia

Working Party of the European Group for Blood and Marrow

Transplantation (EBMT). British Journal of Haematology, 93,

637–645.

Ringden, O., Remberger, M., Ruutu, T., Nikoskelainen, J., Volin, L.,

Vindelov, L., Parkkali, T., Lenhoff, S., Sallerfors, B., Mellander, L.,

Ljungman, P. & Jacobsen, N. for the Nordic Bone Marrow

Transplantation Group (1999) Increased risk of chronic graft-

versus-host disease, obstructive bronchiolitis, and alopecia with

busulfan versus total body irradiation: long-term results of a

randomized trial in allogeneic marrow recipients with leukemia.

Blood, 93, 2196–2201.

Rizzo, J., Curtis, R., Deeg, H., Socie, G., Travis, L., Flowers, M.,

Sobocinski, K. & Horowitz, M. (2000) Solid cancers in survivors

of allogeneic bone marrow transplantation (BMT). Blood, 96,

557a.

Santos, G.W. (1989) Busulfan and cyclophosphamide for marrow

transplantation. Bone Marrow Transplantation, 4, 236–239s.

Schwerdtfeger, R., Kirsch, A., Sonntag, S., Sauberlich, S. & Siegert,

W. (1993) Allogeneic bone marrow transplantation in chronic

myeloid leukemia: what is the best conditioning regime? Bone

Marrow Transplantation, 12, s13a.

Slattery, J.T., Sanders, J.E., Buckner, C.D., Schaffer, R.L., Lambert,

K.W., Langer, F.P., Anasetti, C., Bensinger, W.I., Fisher, L.D.,

Appelbaum, F.R. & Hansen, J.A. (1995) Graft rejection and

toxicity following bone marrow transplantation in relation to

busulfan pharmacokinetics. Bone Marrow Transplantation, 16,

31–42.

Thomas, E.D., Buckner, C.D., Banaji, M., Clift, R.A., Fefer, A.,

Flournoy, N., Goodell, B.W., Hickman, R.O., Lerner, K.G.,

Neiman, P.E., Sale, G.E., Sanders, J.E., Singer, J., Stevens, M.,

Storb, R. & Weiden, P.L. (1977) One hundred patients with acute

leukemia treated by chemotherapy, total body irradiation, and

allogeneic marrow transplantation. Blood, 49, 511–533.

Thomas, E.D., Buckner, C.D., Clift, R.A., Fefer, A., Johnson, F.L.,

Neiman, P.E., Sale, G.E., Sanders, J.E., Singer, J.W., Shulman, H.,

Storb, R. & Weiden, P.L. (1979) Marrow transplantation for

acute nonlymphoblastic leukemia in first remission. New England

Journal of Medicine, 301, 597–599.

Tutschka, P.J., Copelan, E.A. & Klein, J.P. (1987) Bone marrow

transplantation for leukemia following a new busulfan and

cyclophosphamide regimen. Blood, 70, 1382–1388.



Comparison of outcome following allogeneic bone marrow transplantation with cyclophosphamide-total...

Documents

Transcript of Comparison of outcome following allogeneic bone marrow transplantation with cyclophosphamide-total...