Childhood Acute Nonlymphoblastic Leukemia Research Articles

Individualized Tumor Response Testing (ITRT) Profile Has a Prognostic Value in Childhood Acute Lymphoblastic Leukemia (ALL) and Acute Non-Lymphoblastic Leukemia (ANLL): The Multicenter Non-Interventional Long-Term Follow-up Study of Polish Pediatric Leukemia Study Group

Abstract 1456▪▪This icon denotes a clinically relevant abstract BACKGROUND:Individualized tumor response testing (ITRT) is a recently accepted term for ex vivo drug resistance profile testing in cancer patients. Previous studies have shown that ITRT results in children correspond with clinical response in initial acute lymphoblastic leukemia (iALL), but not in initial acute myeloid leukemia (iAML). ITRT combined profile to prednisolone, vincristine, and L-asparaginase (PVA score) showed a strong association with clinical outcome in iALL (Den Boer et al JCO; Hollemann et al, NEJM). OBJECTIVE: Polish Pediatric Leukemia Study Group carried out between 1999–2010 a multi-institutional, non-interventional study on correlation between ITRT profile and clinical response in long-term follow-up. The objective of the study was to assess the role of ITRT profile as prognostic factor in childhood iALL and iAML. MATERIALS AND METHODS: A total number of 998 children (median age 6.5 yrs, range 3 days - 21 yrs) were enrolled into the study, including 817 with initial ALL (iALL) and 181 children with initial AML (iAML). The median follow-up was 4.6 yrs (range 0–10,4). ITRT (ex vivo drug resistance profile) was determined by the MTT assay. Following drugs were tested: prednisolone (P), vincristine (V), L-asparaginase (A), daunorubicin (D), doxorubicin (Dox), idarubicin (I), mitoxantrone (M), cytarabine (C), busulfan (B) and etoposide (E). Apart from ITRT to single drugs, combined ex vivo drug resistance profiles PVA, PVADC, PVADoxC in iALL and CVIDM in iAML were also determined. Probability of DFS was estimated by the Kaplan-Meier method and compared by the log-rank test. Univariate and multivariate analyses were performed in Cox regression model. RESULTS: (1) For iALL patients, neither single drug nor 3-drugs PVA combined ITRT profile had prognostic value for pDFS. 5-drug PVADC and PVADoxC profiles had predictive values, with p-values 0.049 and 0.017, respectively. For 295 iALL patients with ITRT-sensitive PVADC profile, 5-year pDFS=0.892. No ITRT factor was discriminative between very early, early and late ALL relapses. In univariate analysis in Cox model, following factors had prognostic value for pDFS in iALL: steroid resistance by day 8 (p=0.002), bone marrow (BM) response by day 15 (p=0.005), BM response by day 33 (p=0.001) and PVADC ITRT profile (p=0.052). In multivariate analysis in Cox model, only BM response by day 33 (p=0.001) had prognostic value for pDFS in iALL, while bone marrow BM by day 15 had borderline significance (p=0.055). (2) For iAML patients, ITRT to cytarabine had an impact on pDFS (0.81 vs 0.63, p=0.047). For 55 iAML patients with ITRT-sensitive to cytarabine, 5-year pDFS=0.816. 5-drug CVIDM profile had also predictive values, with p-value 0.020. No ITRT factor was discriminative between very early, and late AML relapses. In univariate analysis in Cox model, no factor had prognostic value for pDFS in iAML, while ITRT to cytarabine almost reached significance (p=0.054). Multivariate analysis for iAML was not performed. CONCLUSION: Ex vivo drug resistance profile (ITRT) can be regarded as a risk factor in childhood acute leukemias. Combined ITRT profile to prednisolone, vincristine, L-asparaginase, daunorubicin and cytarabine (PVADC) has predictive value in pediatric iALL, while ITRT profile to cytarabine has prognostic value in pediatric iAML. ACKNOWLEDGEMENTS: Supported by grants: EFS-POKL.04.01.01-00-191/08-00 nr 1/2010; MNiSW Nr N N407 541339; MNiSW Nr N407 078 32/2964; UMK 09/2009; UMK 10/2009. Disclosures:No relevant conflicts of interest to declare.

Characterization of MTHFR, GSTM1, GSTT1, GSTP1, and CYP1A1 genotypes in childhood acute leukemia.

The role of methylenetetrahydrofolate reductase (MTHFR C677T), glutathione S-transferases (GSTM1 and GSTT1 null, GSTP1 Ile105Val), and cytochromes p450 (CYP1A1*2A) genotypes in the etiology of childhood leukemia was simultaneously investigated. 144 Turkish children with acute lymphoblastic leukemia (ALL) and 33 with acute nonlymphoblastic leukemia (ANLL) were studied and compared with 185 healthy pediatric controls. The frequency of MTHFR genotype was insignificantly higher in ALL (7.7%) and ANLL (6.3%) than in controls (4.4%). Equal distribution of the GSTM1 null genotype was detected between ALL patients and controls (55%), while its incidence was slightly higher in ANLL patients (61.3%). Although GSTT1 null genotype was insignificantly lower in ALL patients (20.9%) than controls (22.7%), it was significantly underrepresented in ANLL patients (6.5%) (P = 0.05, OR 0.24, 95% CI 0.05-1.03). The homozygous frequency of GSTP1 genotype did not differ significantly between groups of ALL (3.7%), ANLL patients (9.1%) and controls (4.9%). Homozygous CYP1A1*2A genotype was underrepresented in ALL patients (1%) as compared to control (4.8%) but the differences did not reach to statistical significance (OR 0.21; 95% CI 0.03-1.72). Homozygosity for this genotype was not detected in ANLL patients. No particular association was noted between different combinations of combined genotypes and risk of development of childhood ALL and ANLL. These results suggested that there are no significant associations between the studied genotypes and the risk of developing either form of acute leukemia except GSTT1 null and homozygosity for CYP1A1 genotypes that may play protective roles in the development of ANLL in Turkish children.

Cross-resistance to five glucocorticoids in childhood acute lymphoblastic and non-lymphoblastic leukemia samples tested by the MTT assay: preliminary report.

In vitro antileukemic activity of five glucocorticoids and their cross-resistance pattern in childhood acute lymphoblastic and non-lymphoblastic leukemia were determined by means of the MTT assay in 25 leukemia cell samples of childhood acute leukemias. The equivalent antileukemic concentrations of the drugs tested were: 34 microM hydrocortisone (HC), 8 microM prednisolone (PRE), 1.5 microM methylprednisolone (MPR), 0.44 microM dexamethasone (DX) and 0.22 microM betamethasone (BET). In comparison with initial ALL cell samples, the relapsed ALL group was more resistant to PRE (38-fold, p = 0.044), DX (> 34-fold, p = 0.04), MPR (38-fold), BET (45-fold) and HC (33-fold). The AML cell samples were even more resistant to: PRE (> 85-fold, p = 0.001), DX (> 34-fold, p = 0.004), MPR (> 69-fold, p = 0.036), BET (> 69-fold, p = 0.038) and HC (54-fold, p = 0.059) when compared with ALL on initial diagnosis. A significant cross-resistance among all the glucocorticoids used was found. Only in some individual cases the cross-resistance was less pronounced.

The role of impaired transport in (pre)clinical resistance to methotrexate: insights on new antifolates

Impaired transport appears to be a common mechanism of resistance of neoplastic cells to the antifolate methotrexate. The extensive knowledge of the molecular, biochemical and functional properties of the membrane transport systems for folates, in particular the reduced folate carrier (RFC) and membrane folate receptors (MFR), has made an important contribution to the rational design of novel antifolates that are either more efficiently internalized via these transporters or can simply bypass these transport routes. The current status of exploiting the RFC and MFR for transport of novel antifolates active in preclinical model systems and a clinical setting will be reviewed, with a special reference to childhood acute lymphoblastic leukemia (ALL) and acute non-lymphoblastic leukemia (ANLL).

Acute leukemia in children.

Childhood leukemia comprises approximately one third of cancer cases in children younger than 15 years of age. The incidence of childhood acute lymphoblastic leukemia is increasing. Outcomes have improved for childhood acute lymphoblastic leukemia over past decades and we may be at the dawn of improvement for childhood acute nonlymphoblastic leukemia. Technology has advanced to where submicroscopic bone marrow involvement may be detected in some patients with acute lymphoblastic leukemia in remission or with isolated extramedullary relapse by conventional criteria. Outcome may be predicted by in vitro chemosensitivity assays like the methyl thiazol tetrachium assay. Estimation of end-induction residual leukemic burden by polymerase chain reaction-based clonotypic assays has prognostic significance and provides a strategy for quantitative assessment of new therapeutic interventions. The relation of outcome to the intracellular accumulation of 6-thioguanine nucleotides provides an additional therapeutic avenue. Improved cure rates require increased attention to the health status of long-term survivors.

Treatment of childhood acute nonlymphoblastic leukemia: a review.

Recommendations for the treatment of ANLL in general, and in pediatrics more specifically, are still conflicting. Overall, a child diagnosed with ANLL has a 35-50% of remaining alive long term, without disease. Induction chemotherapy with cytarabine and daunorubicin will achieve remission in about 80% of children with ANLL. So far, intensifying induction chemotherapy by adding more agents has not changed this result significantly. Major changes in induction chemotherapy may come from either new chemotherapeutic agents or biological agents that hasten bone marrow recovery after treatment. Such an approach might allow more dose-intensive drug administration without increased toxicity. Another question that is slowly being answered with the ongoing trials is the one concerning maintenance. So far, all the pediatric trials that have tried to shorten the maintenance therapy of this disease were able to do so without jeopardizing the final outcome. The final optimal minimal duration of therapy has yet to be established. The best therapy for a patient who has achieved a remission is still the most difficult question regarding the treatment of this disease. So far, allogeneic BMT has yielded the best results, with a disease-free interval varying between 55 and 65%. However, one-third of these patients have chronic GvHD and, therefore, a somewhat diminished quality of life. As preparative regimens and marrow purging protocols evolve, the results of autologous bone marrow transplantation seem to be improving, with disease-free intervals of 35-50% reported.

Outcome with central nervous system involvement at diagnosis in childhood acute nonlymphoblastic leukemia

Outcome with central nervous system involvement at diagnosis in childhood acute nonlymphoblastic leukemia

N- ras gene mutations in childhood acute non-lymphoblastic leukemia

In view of the potential role for ras activation in leukemogenesis, we have screened a number of children with acute non-lymphoblastic leukemia (ANLL) for activating point mutations at codons 12, 13 and 61 of the N- ras proto-oncogene using panels of oligonucleotide probes in conjunction with polymerase chain reaction (PCR) gene amplification. In contrast to the frequent occurrence (∼ 30%) of N- ras mutation reported in adult ANLL, 6 of 46 cases (13%) at the time of diagnosis had N- ras mutations involving codons 12 and 13. In these patients we also determine whether presenting clinical symptoms, cellular pathology, karyotype, or eventual outcome distinguished them from the ras-negative group. N- ras activation tended to be associated with a higher white blood cell count at diagnosis (mean of 225 000/μl vs 91 000/μl) and fewer remissions obtained after 28 days of therapy ( 3 6 , 50% vs 24 32 , 75% ). It is possible that activation of N- ras oncogene may be involved in the progression of some cases of childhood ANLL.

Diaziquone and 2,2′-anhydro-arabinosyl-5-fluorocytosine for the treatment of children with relapsed or refractory acute nonlymphoblastic leukemia

The authors treated 30 patients ages 1 to 19 with relapsed or refractory acute non-lymphoblastic leukemia (ANLL) with the combination of diaziquone (AZQ) and 2,2'-anhydro-arabinosyl-5-fluorocytosine (AAFC) intravenously in two dose schedules. The first 12 patients were treated with 19 courses of AZQ 30 mg/m2 X 3 days and AAFC 600 mg/m2/dose every 12 hours X 10 doses. An additional patient was treated with three courses at 80% of the above doses. Hepatic toxicity was National Cancer Institute Grade III in eight of 22 and Grade IV in one of 22 courses. Infectious complications were severe in all patients, including responders. One patient achieved a complete remission and one a partial remission; the latter died with marrow aplasia after a second course. Altogether three patients developed profound aplasia and died before marrow recovery. The authors treated a second group of 17 patients with AZQ 22.5 mg/m2/day X 3 days and AAFC 450 mg/m2/dose every 12 hours X 10 doses. Three patients achieved a complete remission and one patient a partial remission for 3, 4, 9, and 9 months, respectively. The remainder had progressive disease or no response. All patients developed profound myelosuppression but no toxic deaths occurred. Hepatic toxicity was reduced. Therapy induced cytoreduction of bone marrow was determined by flow cytometry in ten patients; none of these patients responded during the interval studied. Although AZQ and AAFC are active in childhood ANLL with acceptable toxicity, the combination does not appear more active than AZQ used alone. Future studies should define the role of AZQ in combination with other agents.

Maternal drug use and risk of childhood nonlymphoblastic leukemia among offspring. An epidemiologic investigation implicating marijuana (a report from the childrens cancer study group)

The Childrens Cancer Study Group conducted a case-control study designed to assess in utero and postnatal exposures in children with acute nonlymphoblastic leukemia (ANLL). Analyses were performed for reported maternal use of medications and drugs in the year preceding and during the index pregnancy of the 204 case-control pairs. An 11-fold risk (P = 0.003) was found for maternal use of mind-altering drugs just prior to or during the index pregnancy. Compared with ANLL cases not exposed to marijuana, exposed cases were significantly younger at diagnosis of ANLL (P less than 0.01) and were more often of the myelomonocytic and monocytic subtypes (P less than 0.01). Use of antinausea medication for more than 11 weeks was also associated with a significantly elevated relative risk of 2.81 and a dose-response relationship was noted (P = 0.05 for trend). These results suggest that maternal drug use of marijuana may have an etiologic role in childhood ANLL and may be specific for morphologically defined subgroups.

High‐dose methylprednisolone for remission induction in children with acute nonlymphoblastic leukemia

The effectiveness of high-dose intravenous methylprednisolone (HIVMP) in inducing an initial remission was examined in a child with acute nonlymphoblastic leukemia (ANLL). Dramatic clinical and hematological improvement with 7% marrow blasts was obtained in 3 weeks with HIVMP treatment without giving any other antileukemic drugs. Based on the results of this preliminary observation we suggest that high-dose methylprednisolone (20-30 mg/kg) might be a useful approach when applied as an initial short treatment in childhood ANLL.

Surface Marker Analysis in Childhood Acute Non-Lymphoblastic Leukemia

Surface Marker Analysis in Childhood Acute Non-Lymphoblastic Leukemia

Clinical significance of low levels of myeloperoxidase positivity in childhood acute nonlymphoblastic leukemia

The clinical significance of a low percentage of myeloperoxidase- positive blast cells in childhood acute nonlymphoblastic leukemia was determined. Of 155 consecutive cases studied by cytochemical staining methods, 14 were characterized by 4% to 15% (median 6%) myeloperoxidase- positive blasts. All 14 cases showed reactivity to Sudan black B stain, and 7 had Auer rods. The morphological subtypes of leukemia were M1 (8 cases), M2 (3), M4 (1), and M5 (2). Immunological marker studies disclosed the lymphoid-associated T11 antigen on cells from 8 of the 11 cases tested. Other lymphoid-related findings in these 8 cases included the T3 antigen and E rosette formation in 1 case each. Among cases that were prospectively studied for the expression of lymphoid-associated markers, 6 of 8 with low levels of myeloperoxidase positivity compared with only 1 of 44 with higher levels (greater than 15%) possessed such features (P less than 0.001). We conclude that low levels of myeloperoxidase reactivity distinguish cases of acute leukemia in which the blast cells coexpress lymphoid (T11 antigen) and myeloid markers.

Clinical Significance of Low Levels of Myeloperoxidase Positivity in Childhood Acute Nonlymphoblastic Leukemia

The clinical significance of a low percentage of myeloperoxidase-positive blast cells in childhood acute nonlymphoblastic leukemia was determined. Of 155 consecutive cases studied by cytochemical staining methods, 14 were characterized by 4% to 15% (median 6%) myeloperoxidase-positive blasts. All 14 cases showed reactivity to Sudan black B stain, and 7 had Auer rods. The morphological subtypes of leukemia were M1 (8 cases), M2 (3), M4 (1), and M5 (2). Immunological marker studies disclosed the lymphoid-associated T11 antigen on cells from 8 of the 11 cases tested. Other lymphoid-related findings in these 8 cases included the T3 antigen and E rosette formation in 1 case each. Among cases that were prospectively studied for the expression of lymphoid-associated markers, 6 of 8 with low levels of myeloperoxidase positivity compared with only 1 of 44 with higher levels (greater than 15%) possessed such features (P less than 0.001). We conclude that low levels of myeloperoxidase reactivity distinguish cases of acute leukemia in which the blast cells coexpress lymphoid (T11 antigen) and myeloid markers.

Results of a pilot study for the treatment of childhood acute nonlymphoblastic leukemia.

Eighteen children with acute nonlymphoblastic leukemia were entered on a pilot protocol. The drugs used were vincristine, daunorubicin, cytosine arabinoside, and prednisolone for remission induction, high-dose cyclophosphamide together with vincristine and mercaptopurine for consolidation, and cycles of vincristine, prednisolone, mercaptopurine, methotrexate, and daunorubicin for maintenance therapy. Prophylactic central nervous system therapy (cranial radiotherapy 2400 rad and intrathecal methotrexate 10 mg/m2 for five doses) was given once remission had been achieved. Fourteen of the 18 children (78%) achieved complete remission (CR) and 50% of those achieving CR remain in CR for 35+ to 87+ months. Survival for all children ranges from 2 to 88+ months with 50% remaining alive for 36+ to 88+ months. The protocol was well tolerated with minimal side effects. These results together with those of other recently reported studies indicate an improving prognosis for acute nonlymphoblastic leukemia in childhood.

Use of high-dose cytarabine and L-asparaginase as consolidation therapy for childhood acute non-lymphoblastic leukemia

Eight children with previously untreated ANLL received an induction regimen consisting of daunomycin and ara-C. All patients achieved complete remission. Post-remission chemotherapy was ara-C 3 g/m2 given i.v. over 3 h, at 12-h intervals, for four doses, and L-asparaginase 6000 IU/m2 i.m. 3 h after the fourth infusion of ara-C; four cycles were given over a period of five to eight months. Two patients received additional treatment. All eight patients relapsed 2–14 months after the treatment was stopped. No benefit was demonstrated by consolidation treatment given with these modalities.

Treatment of acute nonlymphoblastic leukemia in children with a multiple-drug protocol.

Twenty-one children with acute nonlymphoblastic leukemia (ANLL) were treated with a combination regimen consisting of arabinosyl cytosine (Ara-C), 6-thioguanine (TG), and Adriamycin, The incidence of complete remission was 74%. For consolidation, addition courses of Ara-C and TG were given, followed by L-asparaginase. The maintenance program was the same as that for the lymphoblastic type (L-2) including intrathecal methotrexate for prophylaxis of meningeal leukemia. Of the 16 who were evaluable for the duration of complete remission, six developed bone marrow relapse, one meningeal leukemia within 3-14 months after entering complete remission and one was lost to follow-up. Eight remain in complete remission for 9-72 months. In five of eight, chemotherapy has been terminated after 3 years, and all continue in remission for 11-32 months post-treatment. Although the results do not compare well to those of the lymphoblastic morphology, long-term disease-free survival can be achieved with multiple-drug intensive treatment in childhood ANLL.