Relapsed Childhood Acute Lymphoblastic Leukemia Research Articles

Exon 5 mutations in the p53 gene in relapsed childhood acute lymphoblastic leukemia

Thirty seven children with relapsed acute lymphoblastic leukemia (ALL), 25 B-lineage and 12 T-lineage, were analyzed for p53 alterations at different stages of the disease. Loss of heterozygosity (LOH) was detected in the relapse phase in three patients. p53 mutations were identified by single strand conformation polymorphism (SSCP) and sequencing analyzes in seven of the 37 ALL patients (19%); three B-lineage (12%) and four T-lineage (33%). Most of the mutations were identified in the relapse phase. In two exceptional cases, one of the mutations was indicated as a germ line and the other was already present at diagnosis. No p53 mutation was identified in any of the other 20 available bone marrow samples obtained at diagnosis. No correlation between the p53 status and clinical outcome could be determined. The majority of the mutations (four out of seven, 57%) were clustered at exon 5. Our data implicate that p53 exon 5 is a frequent site of mutations in relapsed childhood ALL.

Apoptotic index, Fas and bcl-2 in initial and relapsed childhood acute lymphoblastic leukaemia.

Seventy-two samples with initial and 23 samples with relapsed childhood acute lymphoblastic leukaemia (ALL) were investigated for apoptotic index (AI) and for Fas expression. AI was determined by DNA-fragmentation using deoxynucleotidyl terminal transferase and Fas expression by immunocytochemistry. bcl-2 mRNA expression was measured in 50 initial and 20 relapsed ALL. The patients were discriminated in groups with low and high AI, Fas-protein expression and bcl-2mRNA expression by the mean value. AI was higher in relapsed than in initial ALL. The mean survival was significantly higher in patients with low AI (p= 0.034). This was also true for the relapse-free interval, however, this result was borderline significant (p= 0.064). AI was directly correlated with expression of Fas and inversely correlated with bcl-2 mRNA expression. These results suggest that Fas and - with limitations - bcl-2 may influence the apoptotic process in childhood ALL and that enhanced apoptotic activity predicts poor prognosis.

Peripheral blast counts at diagnosis of late isolated bone marrow relapse of childhood acute lymphoblastic leukemia predict response to salvage chemotherapy and outcome. Berlin-Frankfurt-Münster Relapse Study Group.

In newly diagnosed childhood acute lymphoblastic leukemia (ALL), a high tumor burden indicates a poor prognosis, while no such link has been established yet after relapse. The impact of the absolute peripheral blast count (PBC) at the time of relapse on the response to salvage chemotherapy after a late isolated bone marrow (BM) relapse is the subject of this prospective analysis. Since 1983, 260 children with a first isolated BM relapse of ALL that occurred 6 months or later after elective cessation of front-line therapy were enrolled onto four consecutive multicenter trials of the Berlin-Frankfurt-Münster (BFM) Relapse Study Group. All patients received intensive multiagent induction and consolidation chemotherapy for 6 months, followed by maintenance therapy with methotrexate (MTX) and thioguanine for 2 years. Treatment of subclinical meningeal leukemia consisted of high-dose intravenous MTX and intrathecally administered cytostatic drugs, which was augmented by cranial irradiation since 1988. At the time relapse was diagnosed, PBC varied considerably among patients (median, 1,060/microL; range, 0 to 106,800/microL). Achievement of a second complete remission (CR) was not significantly different in children without detectable circulating blasts at relapse (37 of 38) and those with moderate (1 to 9,999/microL) PBC (165 of 171). In contrast, only 42 of 51 children with high PBC (> or = 10,000/microL) achieved a second CR (P = .0015). At a median follow-up time of 40 months, the 10-year event-free survival (EFS) probability was significantly (P = .0001) higher in children without circulating blasts (.64) than in children with moderate PBC (.32) or high PBC (.10). There was a preponderance of boys in the group without detectable circulating blasts, while the three PBC-defined groups did not differ with respect to frontline treatment, age at initial diagnosis, age at relapse, time off therapy, or salvage treatment protocol. On sequential univariate and multivariate analysis, only duration of first remission > or = 48 months was an additional independent indicator of adverse prognosis, while preventive cranial irradiation improved outcome independently of PBC. The absence of blasts on peripheral-blood smears at the time of a first late isolated BM relapse of childhood ALL is associated with a favorable response and prognosis in chemotherapy-treated children, who should be regarded as ineligible for bone marrow transplantation (BMT) unless a second round of chemotherapy has failed to produce a response.

Unrelated donor bone marrow transplantation for children with relapsed acute lymphoblastic leukaemia in second complete remission.

Allogeneic sibling bone marrow transplantation (BMT) is the recommended treatment for relapsed childhood acute lymphoblastic leukaemia (ALL), but appropriate donors are only available in 30% of cases. Unfortunately, BMT from unrelated donors (UD) has been associated with high rates of severe graft-versus-host disease (GvHD) and transplant-related mortality (TRM). In an attempt to improve outcome in UD-BMT we have assessed the impact of T-cell depletion using CAMPATH-1 (anti-CD52) monoclonal antibodies in 50 consecutively referred patients with relapsed ALL in second remission. All were previously treated according to MRC protocols UKALL X and XI, and then given chemotherapy on MRC R1 from relapse until UD-BMT, 19 patients had relapsed on and 31 off therapy. Patients and donors were fully matched at HLA-A, -B, -DR and -DQ loci in 29 cases and mismatched in 21 (four mismatched for more than one antigen). Pre-transplant conditioning comprised CAMPATH-1G, cyclophosphamide and total body irradiation. Bone marrow was T-cell depleted in vitro using CAMPATH-1 antibodies. Additional GvHD prophylaxis consisted of cyclosporin A (42 cases), cyclosporin plus methotrexate (four) or none (four). 47 patients engrafted. The incidence of acute GvHD was very low: two patients with grade II disease in the matched group, four with grade II-IV in the mismatched group. Only four patients have chronic GvHD. The actuarial event-free survival (EFS) at 2 years is 53%, with no significant difference between the matched and mismatched group. Further leukaemic relapse was the most important cause of failure. These results are similar to the most favourable published reports for HLA-matched sibling BMT in relapsed ALL.

Induction toxicity of a modified Memorial Sloan-Kettering-New York II protocol in children with relapsed acute lymphoblastic leukemia: A single institution study

Although the chance of cure for children with acute lymphoblastic leukaemia (ALL) is high, their outlook with subsequent relapse is poor. Bone marrow transplantation may be an option for some, but the need for intensive reinduction chemotherapy regimens remains the best hope for effecting cure in the majority of relapsed children. The authors report the experience of using an intensive chemotherapy protocol (Memorial Sloan-Kettering-New York II Protocol, MSK-NY-II) in a series of relapsed children with ALL. Thirty children presenting to the Royal Alexandra Hospital for Children, Sydney, in their first relapse of ALL were treated according to a modification of the original MSK-NY-II protocol. Three children (10%) died during induction therapy, two from overwhelming Gram-negative sepsis, and one from intracerebral haemorrhage. Of 27 children completing induction, two children failed to enter remission; however, both had planned deviations from the protocol. Infectious complications were prominent with a total of 55 admissions for febrile neutropenic episodes. Eight children required the support of the intensive care unit for infectious complications. A total of 36 microbiological isolates were obtained from the patients during induction therapy. Ten bone marrow transplant procedures have been subsequently performed in these children, of whom five are alive and disease free at the time of writing. The MSK-NY-II protocol is an intensive regimen but with encouraging early remission rates in relapsed childhood ALL. Early sepsis in previously immunosuppressed children is an important cause of induction death.

Expression and prognostic value of the retinoblastoma tumour suppressor gene (RB-1) in childhood acute lymphoblastic leukaemia.

In a retrospective analysis, acute lymphoblastic leukaemia (ALL) blast cells of 102 children were investigated for the expression of the retinoblastoma susceptibility (RB)-1 gene at mRNA level by dot blot hybridization and semiquantitative RT-PCR. 56 patients were analysed by dot blot hybridization and 35 representative patients out of this group by semiquantitative RT-PCR. Two additional groups of patients (23 patients with initial and 23 patients with relapsed ALL) were also investigated by semiquantitative RT-PCR. RB-1 gene expression was detectable in all investigated ALL at different levels. According to the relative mRNA expression the patients were discriminated by the median value in groups with low or high RB-1 expression. The Kaplan-Meier estimates showed that patients with low RB-1 expression had a lower probability of remaining in first remission (P = 0.03) and a significantly higher risk to succumb to their disease (P = 0.03). Furthermore, the comparison of the results between initial and relapsed ALL showed that the relapses had significantly lower RB-1 mRNA expression (P = 0.02). The overall survival of the patients was shorter in both groups when RB-1 gene expression was low. A multivariate analysis, including age, sex, immunological subtype, initial white blood cell count and RB-1 expression, identified RB-1 as an independent prognostic predictor (P = 0.017) in addition to the initial white blood cell count (P = 0.00001). In conclusion, low RB-1 expression is an unfavourable prognostic predictor in initial and relapsed childhood ALL. The RB-1 gene expression in relapsed ALL is significantly lower than in initial ALL.

Resistance-related proteins in initial and relapsed childhood acute lymphoblastic leukemia

One hundred and eleven children with initial ALL and 28 children with relapsed ALL were analyzed immunohistochemically for expression of resistance-related proteins. P-glycoprotein (P-170) was found in 35% (initial ALL) vs 54% (relapsed ALL; p=0.07), glutathione S-transferase-pi (GST) in 49% vs 68% (p=0.07), thymidylate-synthase (TS) in 42% vs 64% (p=0.03), dihydrofolate-reductase (DHFR) in 20% vs 32% and metallothionein (MT) in 33% vs 32% of the cases. In initial ALL, the resistance proteins P-170 and GST were expressed more frequently in patients who relapsed under therapy and the frequency was similar to relapsed ALL. These results indicate that P-170 and GST-pi were already present before treatment. In contrast, expression of TS increased during treatment.

In Vitro Cellular Drug Resistance in Children With Relapsed/Refractory Acute Lymphoblastic Leukemia

Cellular drug resistance is thought to be an important cause of the poor prognosis for children with relapsed or refractory acute lymphoblastic leukemia (ALL), but it is unknown when, to which drugs, and to what extent resistance is present. We determined in vitro resistance to 13 drugs with the MTT assay. Compared with 141 children with initial ALL, cells from 137 children with relapsed ALL were significantly more resistant to glucocorticoids, L-asparaginase, anthracyclines, and thiopurines, but not to vinca-alkaloids, cytarabine, ifosfamide, and epipodophyllotoxins. Relapsed ALL cells expressed the highest level of resistance to glucocorticoids, with a median level 357- and >24-fold more resistant to prednisolone and dexamethasone, respectively, than initial ALL cells, whereas the resistance ratios for the other drugs differed from 0.8- to 1.9-fold, intraindividual comparisons between initial and relapsed samples from 16 children with ALL showed that both de novo and acquired drug resistance were involved. Specific in vitro drug-resistance profiles were associated with high-risk relapsed ALL groups. In vitro drug resistance was also related to the clinical response to chemotherapy in relapsed/refractory childhood ALL. We conclude that drug resistance may explain the poor prognosis for children with relapsed/refractory ALL. These day may be helpful to design alternative treatment regimens for relapsed childhood ALL.

Ifosfamide and etoposide in recurrent childhood acute lymphoblastic leukemia.

The activity of the drug combination ifosfamide and etoposide (VP16) in refractory and relapsed childhood acute lymphoblastic leukemia (ALL) was assessed in a phase II study. Twenty children with ALL, all heavily pretreated and in bone marrow relapse, were entered on the study. Drugs were given i.v. each day for 5 days at the following doses: ifosfamide 1.8 g/m2/day, VP16 100 mg/m2/day, and MESNA 2,880 mg/m2/day (as a uroprotectant); cycles were repeated every 28 days. At study entry, eight patients were in first relapse (five of whom had failed intensive reinduction regimens), seven were in second relapse, and five were in third relapse. All patients had received cyclophosphamide in regimens before relapse. Eight patients (40%; 95% confidence interval 19-64%) achieved complete bone marrow remission with ifosfamide/VP16. Three patients subsequently relapsed in the bone marrow while on ifosfamide/VP16 therapy. Duration of remission ranged from 21 to 247 days. Treatment was generally well tolerated, with myelosuppression the most common toxicity; fever and neutropenia occurred in 18 of 31 evaluable cycles. The combination of ifosfamide/VP16 has significant activity in recurrent and refractory childhood ALL with tolerable toxicity.

Expression of metallothionein in initial and relapsed childhood acute lymphoblastic leukemia

In a retrospective study we analyzed the expression of metallothionein (MT) in initial acute lymphoblastic leukemia (ALL) of 92 children and in relapsed ALL of 27 children using immunohistochemistry. MT expression was detectable in 33% of the patients with initial ALL and in 33% of the patients with relapsed ALL. No differences were seen concerning the intensity and the proportion of positively stained cells between initial and relapsed patients. The expression of MT was independent of clinical prognostic factors such as age, sex, immunological subtype, and initial blast cell count. Patients with initial ALL and MT expression tended to have a lower probability of disease-free survival compared with the MT-negative group. The relapsed patients with MT expression showed also a trend toward a shorter survival in comparison to the MT-negative group. However, the differences were not statistically significant. Thus, the results show that MT expression is not an important prognostic factor in the clinical drug resistance of childhood All.

High‐dose chemotherapy and blood stem cell autografts for children with first relapsed acute lymphoblastic leukemia: A pilot study of the children's cancer and leukemia study group of Japan (CCLSG)

This study was performed to determine the value of high-dose chemotherapy and peripheral blood stem cell autografts (PBSCT) in the treatment of children with first relapsed acute lymphoblastic leukemia (ALL). Eighteen children underwent PBSCT during the second complete remission (CR) and had a minimum 10 month follow-up. The median age of the patients was 11 yr (range, 2-17 yr). Fifteen patients received the "MCVAC" regimen, one received high-dose MCNU+busulfan therapy, one received high-dose melphalan+VP-16, and one received melphalan+carboplatin+cytosine arabinoside+MCNU. None of these regimens included total body irradiation. Eight patients developed recurrence of the disease at 1 to 19 mo (median, 3 mo) after PBSCT. Patients in whom the first relapse occurred sooner, that is, within 16 mo of initial therapy, tended to have a better survival rate than those who developed relapse after 30 mo (six of seven survived versus four of 11; not significant). Although the preliminary data provided little conclusive information, it did suggest that incorporation of PBSCT in the salvage protocol of relapsed childhood ALL can be justified.

Randomized comparison of 36-hour intermediate-dose versus 4-hour high-dose methotrexate infusions for remission induction in relapsed childhood acute lymphoblastic leukemia.

Pharmacokinetics, toxicity, and therapeutic efficacy of two different methotrexate (MTX) infusions for remission induction of relapsed childhood acute lymphoblastic leukemia (ALL) were investigated in a randomized multicenter trial. Sixty patients with early bone marrow relapse received a polychemotherapy induction protocol starting with either 12 g/m2 MTX as a 4-hour infusion (high-dose [HDM]) or 1 g/m2 as a 36-hour infusion (intermediate-dose [IDM]). In HDM, leucovorin (LCV) was administered orally (12 times, 15 mg/m2 every 6 hours), beginning at hour 24. In IDM, only two doses were administered at hours 48 and 54. Median serum MTX concentrations during infusion were 716 mumol/L in HDM and 7.2 mumol/L in IDM. In HDM, MTX serum levels at hour 24 (median, 2.8 mumol/L) were significantly less than steady-state levels of IDM. Concentrations greater than 1 mumol/L were maintained for 36 hours with HDM and 45 hours with IDM. General tolerance to treatment was better in the HDM group. Mucosal lesions occurred significantly more often and were more severe after IDM treatment. A median treatment delay of 3 days was required in the IDM group but not in the HDM group. At day 15, complete remission (CR) was documented in 45% of IDM- and 48% of HDM-treated patients. Persistent blasts (> 5%) appeared more frequently in HDM than in IDM (35% v 19% of patients; P = NS). After completion of induction therapy, 28 of 30 patients in each group achieved CR. Both regimens produced the same remission rates. The tendency to better antileukemic activity of IDM was accompanied by more severe side effects as a consequence of long-lasting cytotoxic MTX levels. Hence, long-term infusion of IDM followed by low-dose LCV is an effective treatment for recurrent ALL.

High‐dose methylprednisolone sodium succinate as a single agent in relapsed childhood acute lymphoblastic leukaemia

Twenty children received methylprednisolone (1 g/m2), daily for 5 to 8 days, as initial single agent therapy for relapsed acute lymphoblastic leukaemia. Bone marrow blasts were reduced to less than 5% in 2 and 5-10% in 3 of 12 patients with bone marrow relapses. In 3/9 with central nervous system relapses the cerebrospinal fluid (CSF) blasts completely cleared and were reduced in 4 others. In two patients with testicular relapses there was shrinkage of tumour and one patient with a navicular bone relapse became pain free. Toxicity was minimal. These results indicate high-dose methylprednisolone is an effective agent, particularly in the treatment of established central nervous system (CNS) disease and could contribute to early CNS directed therapy in acute lymphoblastic leukaemia.

Clinical Importance of Myeloid-Antigen Expression in Acute Lymphoblastic Leukemia of Childhood

Leukemic cells in 15 to 25 percent of patients with acute lymphoblastic leukemia (ALL) express myeloid antigens as well as lymphoid antigens (the latter reflecting B-cell or T-cell lineage). The relations of myeloid-antigen expression to other features of ALL and to prognosis have been controversial. We analyzed clinical and laboratory features present at diagnosis in 236 consecutive cases of ALL in children. Immunophenotyping, including single- and dual-fluorescence analyses, was used to classify leukemic cells as B or T lymphoblasts and also to identify myeloid-antigen expression--the simultaneous expression of lymphoid-associated antigens and at least one of three myeloid-associated antigens (CD33, CD13, and CD14) on cells classified as L1 or L2 according to the French-American-British system. Forty-five of 185 patients with B-lineage ALL had myeloid-antigen expression, as did 8 of 41 patients with T-lineage ALL. In 10 patients, the lineage could not be determined. Myeloid-antigen expression was associated with L2 morphology (P less than 0.05), but it did not correlate with other prognostic features recognized previously. Multivariate analysis showed that myeloid-antigen expression was an important predictor of relapse in childhood ALL and the most significant prognostic factor statistically (P less than 0.0001). A white-cell count greater than or equal to 50 x 10(9) per liter at diagnosis was also an important and highly significant prognostic feature (P less than 0.001). After 40 months, the estimated disease-free survival for patients with ALL was 84 percent for those without myeloid-antigen expression and with a low white-cell count, 57 percent for those without myeloid-antigen expression and with a high white-cell count, 47 percent for those with myeloid-antigen expression and a low white-cell count, and 26 percent for those with myeloid-antigen expression and a high white-cell count (P less than 0.00001). Myeloid-antigen expression is an important independent predictor of a poor response to chemotherapy in childhood ALL.

A phase II study of combined methotrexate and teniposide infusions prior to reinduction therapy in relapsed childhood acute lymphoblastic leukemia: a Pediatric Oncology Group study.

Teniposide (VM-26) can increase intracellular methotrexate (MTX) and its polyglutamate derivatives in vitro and thus has the potential to improve the therapeutic index of regimens containing MTX. In this phase II study, children and adolescents with acute lymphoblastic leukemia (ALL) in first or second marrow relapse were randomly assigned to receive either simultaneous (n = 11) or sequential (n = 12) continuous infusions of MTX and VM-26 prior to reinduction. Infusions of VM-26 were begun 12 hours after completion of MTX infusion in the sequential group. Dosages were individually adjusted to maintain plasma concentration levels of 10 microns for MTX and 15 microns for VM-26; total infusion times were 24 and 72 hours, respectively. Significant toxicity in the first six patients who received the scheduled 72-hour VM-26 infusion (including one drug-related death) prompted a 50% reduction in infusion duration. The reduced dose was associated with similar but more manageable toxicity. Examination of bone marrow aspirates 10 days after therapy was begun showed one complete and two partial marrow remissions; a fourth patient who had an aplastic marrow on day 10 received no further chemotherapy and had a complete remission (CR) documented on day 31. There was no obvious clinical advantage associated with either infusion schedule, although small sample sizes preclude definitive conclusions. The 17% response rate to the MTX/VM-26 therapeutic window in patients with refractory disease suggests the need for further investigation to evaluate alternative schedules and concomitant therapy for this drug combination.