Allogeneic bone marrow transplantation vs chemotherapy for the treatment of childhood acute lymphoblastic leukaemia in second complete remission (revisited 10 years on)

How to treat relapsed acute lymphoblastic leukemia: transplant vs. conventional chemotherapy

Management of relapsed acute lymphoblastic leukemia (ALL) is challenging and far from satisfactory. The treatment approaches are often varied and controversial. The duration of first remission, site of relapse, immunophenotypic and molecular characteristics of relapsed disease and response to therapy influence treatment outcome. There are three main therapeutic options i.e., chemotherapy alone, induction chemotherapy followed by HLA matched allogeneic transplant and palliation. These may be chosen based on the above mentioned factors. The response to therapy may be evaluated morphologically or by minimal residual disease (MRD). Persistence of MRD, as assessed by molecular techniques or through flowcytometry, clearly influences prognosis in children with relapsed ALL. It not only helps in identifying the subset of patients likely to benefit from allogeneic bone marrow transplant (ABMT) but also in determining the timing of transplant. Patients with non-T phenotype, with late relapsing disease and good response to re-induction therapy have been shown to do equally well with chemotherapy alone. On the other hand patients with early relapse and poor initial response are selected for ABMT. With the improvement in supportive care, better selection of HLA match donors and better immunosuppressive therapies, transplant related mortality has decreased considerably. Despite all of these overall salvage rates are still poor and novel agents are being tested in various trials to establish their role in relapsed ALL therapy.

Treatment of relapsed acute lymphoblastic leukemia: approaches used by pediatric oncologists and bone marrow transplant physicians

BACKGROUND

Management of relapsed B-precursor acute lymphoblastic leukemia (ALL) is challenging and varied. We hypothesized that treatment approaches differ between pediatric oncologists and bone marrow transplant (BMT) physicians.

PROCEDURE

A survey addressing management of relapsed ALL was sent to pediatric oncologists (n = 883) and BMT (n = 86) physicians across North America.

RESULTS

A number of similarities in treatment approaches were identified including: choice of chemotherapy for re-induction/consolidation, preference for unrelated donors (URDs) in very early marrow relapse and the choice to not use URD donors in late marrow relapse. However, differences between the two disciplines were noted. For patients who relapsed 18-36 months from diagnosis, the majority of oncologists (53.7%) would retreat with chemotherapy while a majority BMT physicians (70.3%) recommended URD transplant (P < 0.001). Oncologists were also less likely to use minimal residual disease (MRD) in relapse assessment compared to BMT physicians (52% vs. 67.2%; P = 0.028) and more oncologists believed MRD testing was experimental and/or not proven in relapsed ALL (27.1% vs. 12.3%; P = 0.011).

CONCLUSIONS

This study highlights management differences in children with ALL between pediatric oncologists and BMT physicians, identifying opportunities for collaborative clinical trials.

Allogeneic hematopoietic cell transplantation outcomes for children with B-precursor acute lymphoblastic leukemia and early or late BM relapse

Large registry studies have shown superior disease-free survival (DFS) with matched sibling donor (MSD) allogeneic hematopoietic cell transplantation (allo-HCT) over chemotherapy alone for patients with B-precursor acute lymphoblastic leukemia (ALL) and a late BM relapse. As most of these patients will not have an MSD, the decision to pursue an unrelated allo-HCT in second remission (CR2) or await a future relapse and perform HCT in third remission (CR3) continues to be debated. Between 1990 and 2006, 41 children with relapsed B-precursor ALL received a myeloablative allo-HCT at the University of Minnesota. Graft sources consisted of matched related donor (n=11), matched unrelated donor (n=9), and unrelated umbilical cord blood (n=21). Before allo-HCT, 15 patients had an early relapse (<36 months from diagnosis) and 26 had an initial late relapse (36 months from diagnosis). In all, 30 patients (73%) were in CR2 and 11 were in CR3 (27%) at time of allo-HCT. Five year OS/DFS were similar for patients with an early or late marrow relapse, but there was inferior DFS among late-relapse patients transplanted in CR3 compared with CR2 (30% vs 75%, P=0.04). These results suggest that allo-HCT should be pursued in children after a first marrow relapse, rather than waiting for subsequent recurrence.

Hematopoietic cell transplantation for children with acute lymphoblastic leukemia in second complete remission: similar outcomes in recipients of unrelated marrow and umbilical cord blood versus marrow from HLA matched sibling donors

Transplant decisions for children with acute lymphoblastic leukemia (ALL) in second complete remission (CR2) are often based on the type of available donor. In many cases, allogeneic hematopoietic cell transplantation (HCT) is considered only if a human leukocyte antigen (HLA) matched sibling donor (MSD) is available. The role of unrelated donor (URD) HCT in this patient population is not well established. As advances in supportive care and donor selection have improved, the use of URD HCT in such patients should be reevaluated. We analyzed the outcomes of 87 consecutive children with ALL in CR2 who underwent allogeneic HCT at the University of Minnesota between 1990 and 2007. Donor sources included MSD bone marrow (n = 32), well and partially matched (M, n = 18) and mismatched (MM, n = 16) URD bone marrow and URD umbilical cord blood (UCB, n = 21). Although the incidence of neutrophil recovery was similar in all groups, the overall incidence of grades II-IV acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD) was 37% and 9%, respectively, with a higher incidence of aGVHD in recipients of URD grafts. Leukemia-free survival (LFS) at 5 years was lower in recipients of MM-URD grafts, but was comparable in all other groups. Although relapse at 5 years was highest in recipients of MSD (50%), results were not significantly different compared to recipients of M-URD (17%), MM-URD (6%), and UCB (33%) (P = .17). The development of grades II-IV aGVHD and a first remission >3 years were associated with a lower risk of relapse (relative risk [RR] 0.2, P = .03; RR 0.2. P = .01 respectively). Together, these results support the continued investigation of URD HCT for ALL in CR2, and suggest the timing of HCT in these children should be based primarily on the risk of relapse with conventional chemotherapy and not on the type of donor available.

Long-term outcome of initially homogenously treated and relapsed childhood acute lymphoblastic leukaemia in Austria--a population-based report of the Austrian Berlin-Frankfurt-Münster (BFM) Study Group

Relapsed acute lymphoblastic leukaemia (ALL) is the most common cause for a fatal outcome in paediatric oncology. Although initial ALL cure rates have improved up to 80%, the prognosis of recurrent ALL remains dismal with event-free-survival (EFS) rates about 35%. In order to analyse a population-based cohort with uniform treatment of initial disease, we examined the outcome of children suffering from relapsed ALL in Austria for the past 20 years and the validity of the currently used prognostic factors (e.g. time to and site of relapse, immunophenotype). Furthermore, we compared survival rates after chemotherapy alone with those after allogeneic stem cell transplantation (SCT). All 896 patients who suffered from ALL in Austria between 1981 and 1999 were registered in a prospectively designed database and treated according to trials ALL-Berlin-Frankfurt-Münster (BFM)-Austria (A) 81, ALL-A 84 and ALL-BFM-A 86, 90 and 95. Of these, 203 (23%) suffered from recurrent disease. One-hundred-and-seventy-two patients (85%) achieved second complete remission. The probability of 10-year EFS for the total group was 34 +/- 3%. Clinical prognostic markers that independently influenced survival were time to relapse, site of relapse and the immunophenotype. Additionally, a Cox regression model demonstrated that allogeneic SCT after first relapse was associated with a superior EFS compared with chemo/radiotherapy only (hazard ratio = 0.254; P = 0.0017).

Outcome After Relapse Among Children With Standard-Risk Acute Lymphoblastic Leukemia: Children's Oncology Group Study CCG-1952

Purpose

The event-free survival (EFS) of children with standard-risk acute lymphoblastic leukemia (SR-ALL) is now more than 80%. However, prognosis after relapse continues to be poor. We examined postrelapse outcomes of children initially treated on the Children's Cancer Group CCG-1952 study.

Patients and Methods

We evaluated outcomes after bone marrow (BM) relapse and isolated extramedullary (EM) relapse for 347 patients with SR-ALL (WBC < 50,000/μL; age, 1 to 9 years). The prognostic significance of several factors for EFS after relapse (EFS2) was assessed by Cox regression analysis. Stem-cell transplant (SCT) was compared with chemotherapy as salvage treatment.

Results

The mean ± SE times to isolated central nervous system relapse, BM relapse, and isolated testicular relapse were 23 ± 1 months (range, 1 to 88 months), 36 ± 1 months (range, 2 to 79 months), and 40 ± 2 months (range, 16 to 64 months), respectively. The estimated percent ± SE 3-year EFS2 and overall survival rates after BM relapse were 37% ± 4% and 46% ± 4%, respectively, and rates after isolated EM relapse were 57% ± 5% and 71% ± 5%, respectively. By multivariate analysis, we found the duration of first remission to be the most significant predictor of EFS2 for either BM relapse or isolated EM relapse. Outcome was equivalent with SCT or chemotherapy after early or late relapse of SR-ALL at any site.

Conclusion

Duration of first remission remains the most significant predictor of outcome after either BM or isolated EM relapse of SR-ALL. Prognosis after early BM relapse remains poor and is not improved with SCT in this cohort.

Outcome after first relapse in childhood acute lymphoblastic leukaemia - lessons from the United Kingdom R2 trial

A retrospective analysis of children with first relapse of acute lymphoblastic leukaemia (ALL), treated on the UKALL R2 protocol at four different hospitals, between June 1995 and December 2002 was performed. Of the 150 children 139 (93%) achieved a second complete remission. The overall survival (OS) and event-free survival (EFS) for the whole group was 56% and 47% respectively. The duration of first complete remission and immunophenotype, but not sites of relapse, were predictive for survival. Using the Berlin-Frankfürt-Münster risk stratification for relapsed ALL, the OS and EFS for standard, intermediate (IR) and high risk (HR) groups were 92% and 92%, 64% and 51%, and 14% and 15%, respectively; P < 0.0001 for both OS and EFS. In the IR group, those with a very early isolated central nervous system relapse also had a significantly worse outcome (P = 0.0001). Given the poor outcome of a second relapse, clear strategies are required to identify those in the IR group who will most benefit from stem cell transplantation (SCT). A higher proportion (16%) of induction failures in the HR group suggest the need for novel agents during this phase of treatment, but SCT was associated with a lower relapse rate and better outcome than those treated with chemotherapy alone.

Long-term outcome of allogeneic or autologous haemopoietic cell transplantation for acute lymphoblastic leukaemia in second remission in children. GETMON experience 1983–1998

We present a retrospective study of long-term outcome and predictive factors of survival and relapse in 219 paediatric patients with acute lymphoblastic leukaemia (ALL) in second remission. They received allogeneic (allo) or autologous (auto) haemopoietic cell transplantation (HCT) depending on the availability of a matched sibling donor. The probability of event-free survival (EFS) for the total patient group was 0.35+0.03 at 14 years. No significant differences were observed for EFS between allo- and auto-HCT: 0.39+0.05 vs 0.32+0.04 (P=0.43). A better EFS was seen in patients with a late relapse (LR) (P=0.06 and 0.02, for allogeneic and autologous respectively). Significantly better EFS was observed in allo-HCT patients under 10 years of age and in auto-HCT patients with leukocytes at diagnosis below 25 x 109/l and late relapse. Predictive factors of failure in both groups were early relapse (ER), medullary relapse and age over 10 years. The probability of relapse (RP) for the total group of patients was 0.57+0.03, and it was significantly higher in auto-HCT patients: 0.65+0.04 vs 0.42+0.06 (P=0.002). Factors predictive for relapse were medullary and early relapse, auto-HCT and WBC >25 x 109/l at diagnosis.

Allogeneic bone marrow transplantation for childhood relapsed acute lymphoblastic leukemia: comparison of outcome in patients with and without a matched family donor

We evaluated the role of BMT in a cohort of 56 children with ALL relapsing after uniform initial treatment protocols in a single institution between 1990 and 1997. The patients were commenced on a single intensive chemotherapy regimen. All patients with a matched family donor (MFD) were recommended to receive BMT. The outcome was significantly better for patients with a MFD. The overall survival at 8 years was 60.0% (95% CI 35.7-77.6%) and 13.5% (95% CI 4.0-28.6%) for patients with and without MFDs (log-rank chi = 7.50 P = 0.0062). The event-free survival at 8 years was 55.0% (95% CI 11.1-31.3%) and 9.2% (95% CI 2.0-23.3%) for patients with and without MFDs (log-rank chi = 8.87 P = 0.0029). Multivariate analysis confirmed the survival advantage of BMT. There was no statistically significant difference in survival for patients initially relapsing within 3 years of first remission compared to children relapsing beyond 3 years. BMT provides a clear survival advantage for children following their first relapse of ALL. We recommend BMT for all children following first relapse of ALL if a MFD is available.

Unrelated marrow transplantation for children with acute lymphoblastic leukemia in second remission

Allogeneic bone marrow transplantation (BMT) may be curative for more patients than chemotherapy for the child with relapsed acute lymphoblastic leukemia. This study reviewed the outcomes of 363 children with acute lymphoblastic leukemia in second remission who received unrelated donor BMT from 1988 to 2000 in order to define prognostic factors that affect leukemia-free survival (LFS). Median patient age was 9 years (range, 0-19 years), and median follow-up 29 was months (range, 0-125 months). The median duration of first remission was 24 months (range, 0-109 months). Prognostic factors, including age, duration of first remission, HLA matching, and graft-versus-host (GVH) disease, were analyzed using both univariate and multivariate analyses. Overall survival was 38%, and LFS was 36% at 5 years. LFS was significantly worse for patients 15 years or older (log-rank, P =.009). HLA matching was associated with improved LFS. Acute GVH disease developed in 71%, with 29% having grades III-IV. The incidence of chronic GVH disease was 39% for patients who survived more than 80 days and was significantly higher for female patients receiving marrow from female donors (P =.0009). Transplantation-related mortality was 42% and was associated with HLA mismatches, age 15 years and older, and first remission less than 12 months. The 5-year estimate for relapse was 22%, with first remission at least 6 months associated with a lower risk. Results of unrelated donor BMT appear similar to multi-institutional studies of matched related donor BMT, and this approach appears to be curative for many patients. However, innovative approaches are needed for patients with initial remissions of less than 6 months and for older teenagers.

Clinical value of immunological monitoring of minimal residual disease in acute lymphoblastic leukaemia after allogeneic transplantation

In this study, we used multiparameter flow cytometry to quantify minimal residual disease (MRD) in 165 serial bone marrow samples from 40 patients diagnosed with acute lymphoblastic leukaemia (ALL) who underwent allogeneic stem cell transplantation (allo-SCT) from siblings (n = 34) or unrelated donors (n = 6). Samples were prospectively taken from 24 patients before starting the conditioning regimen, at days +30, +60 and +90 and subsequently every 2-3 months. Samples from 16 patients in complete remission (CR) after allo-SCT were taken at least twice. Six of 24 patients harboured MRD (0.2-10% of mononuclear cells) at transplant and 18 were negative. Estimated disease-free survival for the MRD+ and MRD- groups at transplant was 33.3% and 73.5% respectively (P = 0.03). During follow-up, increasing MRD levels were detected in nine patients, a finding that preceded marrow relapse by 1-6 months. Two patients with stable low MRD levels remained in CR. When we used flow cytometry to test the effect of donor leucocyte infusions (DLI) in six patients, we observed that the only sustained remission was achieved when DLI was applied prior to overt relapse. We conclude that MRD by flow cytometry can rapidly assess tumoral burden before transplant to predict outcome, and can be clinically useful for the timing of DLI for increasing levels of leukaemia after transplant.

No disadvantage in outcome of using matched unrelated donors as compared with matched sibling donors for bone marrow transplantation in children with acute lymphoblastic leukemia in second remission

PURPOSE

We evaluated the outcome of children with acute lymphoblastic leukemia (ALL) in second remission (2CR), comparing bone marrow transplantation (BMT) using either matched sibling donors or unrelated donors (URDs).

PATIENTS AND METHODS

A total of 65 patients, aged 2 months to 20 years at BMT, with ALL in 2CR underwent allogeneic BMT at seven Nordic centers during 1990 to 1997. Of the first relapses, 85% were in bone marrow; 46% occurred on therapy, and 54%, off therapy. The preparative regimens were cyclophosphamide plus total-body irradiation +/- antithymocyte/antilymphocyte globulin, busulfan plus cyclophosphamide +/- antithymocyte/antilymphocyte globulin, or cytarabine plus total-body irradiation. Of the allografts, 37 were from HLA-matched siblings and 28 were from URDs.

RESULTS

In the sibling versus URD graft recipient groups, the posttransplantation 5-year event-free survival was 39% versus 54% (P =.4), the estimated posttransplantation relapse rate was 76% versus 40% (P = not significant [NS]), and the toxic death rate was 19% versus 11% (P = NS). The incidence of significant (grade 2 to 4) acute graft-versus-host disease (GVHD) was 38% versus 64% (P <.05) and was 14% versus 32% (P <.10) for severe (grade 3 to 4) acute GVHD; the incidence of chronic GVHD was 26% versus 57% (P <.05) and was 13% versus 22% (P = NS) for extensive chronic GVHD in the sibling and URD groups.

CONCLUSION

BMT with matched URD allografts offers at least equal survival for children with ALL in 2CR, as compared with allografts from matched sibling donors. URD allografts were not associated with a higher toxic mortality rate, although both acute and chronic GVHD were more frequent with URD. Indications for using matched URD allografts in ALL 2CR can be considered the same as for using matched sibling donors.

Long-term outcome of treatment with protocols AL841, AL851, and ALHR88 in children with acute lymphoblastic leukemia: results obtained by the Kyushu-Yamaguchi Children's Cancer Study Group

We analyzed the long-term outcome and late effects of treatment in 187 patients with childhood acute lymphoblastic leukemia (ALL) diagnosed between 1984 and 1990. Overall survival and event-free survival rates were 68.2% +/- 3.7% and 63.2% +/- 3.6% at 15 years, respectively. Of 55 patients who relapsed after achieving the first complete remission (CR), only 17.4% were rescued by salvage therapy. The advantage of stem cell transplantation over chemotherapy was observed only in those patients with bone marrow relapse during therapy. The SD for score height in patients maintaining the first CR significantly decreased at the time of final follow-up compared with that at diagnosis: 0.059 to -0.800 (P < .0001). The decrease was remarkable in patients younger than 5 years at diagnosis. Other late effects included mild liver dysfunction in 18% and hepatitis C virus infection in 9%. Congestive heart failure was observed in only 2.9% of patients despite the high cumulative dose of daunorubicin (450 mg/m2). Although the survival rates of patients on our protocols were comparable to those of other study groups, some modification, including reduction in dose of cranial irradiation and/or anticancer drugs, should be considered to reduce late adverse effects in survivors of childhood ALL.