A pilot study of intermediate-dose methotrexate and cytosine arabinoside, "spread-out" or "up-front," in continuation therapy for childhood non-T, non-B acute lymphoblastic leukemia. A Pediatric Oncology Group study

Age and high-dose methotrexate are associated to clinical acute encephalopathy in FRALLE 93 trial for acute lymphoblastic leukemia in children

The objective of the study was to assess acute neurotoxicity associated with triple intrathecal therapy (TIT)+/-high-dose methotrexate (HD MTX) in children with acute lymphoblastic leukemia (ALL). 1395 children were enrolled on FRALLE 93 protocol from 1993 to 1999. Lower-risk group (LR, n=182) were randomized to weekly low-dose MTX at 25 mg/m(2)/week (LD MTX, n=81) or HD MTX at 1.5 g/m(2)/2 weeks x 6 (n=77). Intermediate-risk group (IR, n=672) were randomized to LD MTX (n=290) or HD MTX at 8 g/m(2)/2 weeks x 4 (n=316). Higher-risk group (HR, n=541) prednisone-responder patients received LD MTX and cranial radiotherapy. HR group steroid resistant cases were grafted (autologous or allogenic). TIT (MTX, cytarabine and methylprednisolone) was given every 2 weeks during 16-18 weeks and every 3 months during maintenance therapy in LR and IR patients. 52 patients (3.7%) developed neurotoxicity. Isolated seizures: n=15 (1.1%), peripheral and spinal neuropathy: n=17 (1.2%) and encephalopathy: n=20 (1.4%). Age >10 years was significantly associated with neurotoxicity (P=0.01) and use of HD MTX is associated with encephalopathy (P=0.03). Sequels are reported respectively in 60 and 33% of spinal neuropathy and encephalopathy cases. Current strategies tailoring risk of neurological sequels has to be defined.

Expression of MxA protein in blood lymphocytes of children receiving anticancer chemotherapy

The aim of the study was to evaluate whether IFN-alpha/beta-inducible MxA protein expression in children receiving anticancer treatment can be used as an indicator for virus infections during the febrile episodes. Twenty-six children with mainly hematological malignancies entered the study. Children with laboratory-confirmed virus infections had clearly elevated MxA protein levels compared to their counterparts with bacterial or unknown etiology. MxA protein expression increased moderately following the administration of cytostatic agents, even though these children had no clinical signs of infection.

Value of high-dose cytarabine during interval therapy of a Berlin-Frankfurt-Munster-based protocol in increased-risk children with acute lymphoblastic leukemia and lymphoblastic lymphoma: results of the European Organization for Research and Treatment of Cancer 58881 randomized phase III trial

PURPOSE

The European Organization for Research and Treatment of Cancer 58881 study was designed to test in a prospective multicentric randomized trial the value of high-dose (HD) intravenous (IV) cytarabine (Ara-C) added to HD IV methotrexate (MTX) to reduce the incidence of CNS and systemic relapses in children with increased-risk acute lymphoblastic leukemia (ALL) or stage III and IV lymphoblastic lymphoma treated with a Berlin-Frankfurt-Munster (BFM)-based regimen.

PATIENTS AND METHODS

After completion of induction-consolidation phase, children with increased-risk (risk factor > 0.8 or T-lineage) ALL or stage III and IV lymphoblastic lymphoma were randomized to receive four courses of HD MTX (5 g/m(2) over 24 hours every 2 weeks) and four intrathecal administrations of MTX (Arm A) or the same treatment schedule with additional HD IV Ara-C (1 g/m(2) in bolus injection 12 and 24 hours after the start of each MTX infusion) (Arm B).

RESULTS

Between January 1990 and January 1996, 653 patients with ALL (593 patients) or lymphoblastic lymphoma (60 patients) were randomized: 323 were assigned to Arm A (without Ara-C) and 330 to Arm B (with Ara-C). A total of 190 events (177 relapses and 13 deaths without relapse) were reported, and the median follow up was 6.5 years (range, 2 to 10 years). The incidence rates of CNS relapse were similar in both arms whether isolated (5.6% and 3.3%, respectively) or combined (5.3% and 4.6%, respectively). The estimated 6-year disease-free survival (DFS) rate was similar (log-rank P =.67) in the two treatment groups: 70.4% (SE = 2.6%) in Arm A and 71.0% (SE = 2.5%) in Arm B. The 6-year DFS rate was similar for ALL and LL patients: 70.2% (SE = 1.9%) versus 76.3% (SE = 5.6%).

CONCLUSION

Prevention of CNS relapse was satisfactorily achieved with HD IV MTX and intrathecal injections of MTX in children with increased-risk ALL or stage III and IV lymphoblastic lymphoma treated with our BFM-based treatment protocol in which cranial irradiation was omitted. Disappointingly, with the dose schedule used in this protocol, HD Ara-C added to HD MTX, although well tolerated, failed to further decrease the incidence of CNS relapse or to improve the overall DFS.

Central nervous system involvement in adult acute lymphocytic leukemia

With effective CNS prophylaxis, most adults with ALL may remain free of CNS leukemia. Several combinations of IT chemotherapy, high-dose systemic chemotherapy, and cranial irradiation have been used with varying results. Excellent prophylaxis can be achieved without cranial irradiation, and in view of the potential acute and long-term toxicity of radiation, these methods may be preferable. A prophylactic approach tailored to the risk of CNS leukemia was shown to be valuable in childhood ALL and in at least one adult study. Further studies should focus on defining risk groups for CNS leukemia and designing effective prophylaxis for each group. More research is needed to define the intensity and duration of treatment and the role of cranial irradiation in the treatment of isolated CNS relapses.

Treatment of children with early pre-B and pre-B acute lymphocytic leukemia with antimetabolite-based intensification regimens: a Pediatric Oncology Group Study

Between May 1987 and January 1991, 1354 patients, 1-21 years old, with standard or poor prognosis B-lineage acute lymphocytic leukemia were treated on the Pediatric Oncology Group Study 8602. One thousand three hundred and twenty-three patients entered remission and 1051 patients were randomized on day 43 to an intensification regimen containing L-asparaginase and intermediate-dose methotrexate (regimen B) or cytarabine and intermediate dose methotrexate (regimen C). After completion of intensification at week 25, all patients received the same maintenance therapy until 3 years from diagnosis. Overall 5-year continuous complete remission (CCR) for regimen B was 72+/-2% (s.e.) and for regimen C, 73+/-2% (P = 0.72 by log-rank analysis). Significant differences between treatments for CCR, testicular, CNS relapses overall or with regard to phenotype (pre-B vs early pre-B), gender, or race were not detected. During intensification, regimen C had significantly more bacterial infections (P = 0.05) and days spent in the hospital (P < 0.001) compared with regimen B, while regimen B had significantly more allergic reactions (P < 0.0001). No significant differences in CCR were noted between patients with pre-B and early pre-B ALL (P = 0.22 stratified by risk group and treatment). This study was unable to detect statistical difference between asparaginase (regimen B) and cytarabine (regimen C) during the intensification phase of therapy in children with B-lineage acute lymphocytic leukemia.

Individualized methotrexate dosing in children with relapsed acute lymphoblastic leukemia

Although high-dose methotrexate has been extensively studied in children with newly diagnosed acute lymphoblastic leukemia (ALL), there are fewer data in children with relapsed ALL, many of whom have been heavily pretreated and have subclinical kidney dysfunction. We characterized the pharmacokinetics of adaptively controlled methotrexate given as a 24-h infusion during consolidation therapy in 24 children with relapsed ALL. To achieve the target steady-state concentration of 65 microM, dosage adjustments were required in 14 patients, with doses ranging from 2854 to 6700 mg/m2 per course. The mean steady-state plasma concentration (Cpss) of 68.0 microM was different (P = 0.025) than the predicted Cpss (mean = 87.4 microM; range 35.7-184 microM) had no adjustment in dose been made. The coefficient of variation in Cpss was reduced from 41% to 18% by individualizing doses. Predisposing factors that correlated with decreased methotrexate clearance were female sex (P = 0.03), age greater than 6 years (P = 0.01), and prior history of heavy amphotericin B treatment (>30 mg/kg) (P = 0.03), but no factor predicted low clearance as well as the measured initial methotrexate clearance during the infusion (P < 0.0001). There was no life-threatening toxicity with the regimen. We conclude that dosage individualization decreases interpatient variability and avoids potentially toxic methotrexate exposures in heavily pretreated ALL patients.

Improvement in CNS protective treatment in non-high-risk childhood acute lymphoblastic leukemia: report from the Japanese Children's Cancer and Leukemia Study Group

BACKGROUND

Prevention of central nervous system (CNS) leukemia by early introduction of therapy to this sanctuary site is an essential component of modern treatment strategy for acute lymphoblastic leukemia (ALL). However, the optimal form of preventive CNS therapy remains debatable.

PROCEDURE

To address this issue, we evaluated the efficacy of CNS preventive therapy for 572 children with ALL who achieved complete remission in the Children's Cancer and Leukemia Study Group (CCLSG) ALL874 (1987-1990) and ALL911 (1991-1993) studies. They received risk-directed therapy based on age and leukocyte count. In the ALL 874 study, the non-high-risk (low-risk [LR] + intermediate risk [IR]) patients were randomly assigned to the conventional cranial irradiation (CRT) regimen (L874A and I874A) and the high-dose methotrexate (HDMTX) regimen without CRT (L874B and I874B). The former patients received 18-Gy CRT plus 3 doses of intrathecal (i.t.) MTX and the latter patients received 3 courses of HDMTX at 2 g/m2 plus 13 doses of ITMTX (L874B) or 4 courses of HDMTX at 4.5 g/m2 plus 1 dose of ITMTX (I874B).

RESULTS

The 7-year probabilities (+/- SE) of CNS relapse-free survival were 97.3% +/- 2.6% (L874A, n = 41) vs. 90.3% +/- 5.3% (L874B, n = 39) (P = 0.25) in the LR patients, and 100% (I874A, n = 55) vs. 78.5% +/- 6.5% (I874B, n = 54) (P = 0.002) in the IR patients. The corresponding disease-free survival (DFS) rates were 79.4% +/- 6.5% vs. 74.4% +/- 7.3% (P = 0.62) in the LR group and 63.3% +/- 6.8% vs. 58.3% +/- 7.2% (P = 0.66) in the IR group. Thus, the HDMTX regimen could not provide better protection of CNS relapse as compared with the CRT regimen, although their overall efficacy was not significantly different. In the ALL 911 study, intensive systemic chemotherapy with extended i,t, injections of MTX plus cytarabine achieved a high CNS relapse-free survival (98% +/- 1.9% at 7 years) and a favorable DFS (85.5% +/- 5% at 7 years) in the IR patients. The patients in the high-risk (HR) group in both ALL874 and ALL911 studies received the 18-Gy or 24-Gy CRT with intensive systemic chemotherapy. Their 7-year probabilities of CNS relapse-free survival ranged from 88% to 95%, among which the T-ALL patients had a risk of CNS leukemia, which was 3-4 times higher compared with B-precursor ALL patients.

CONCLUSIONS

These results indicate that long-term intrathecal CNS prophylaxis as well as appropriate systemic therapy for the non-high-risk patients can provide protection against CNS relapse equivalent to that provided by cranial irradiation.

Intermediate-dose methotrexate versus cranial irradiation in childhood acute lymphoblastic leukemia: a ten-year follow-up

The cure rate of childhood acute lymphoblastic leukemia (ALL) has improved dramatically. Still there is a paucity of long-term data. With the improving cure rate, the quality of life and avoidance of second cancers have become important concerns. We evaluated 596 children and adolescents with ALL on Cancer and Leukemia Group B 7611 (CALGB 7611) who were randomized between 1976 and 1979 to receive intermediate-dose methotrexate (IDM) plus intrathecal methotrexate (IT MTX) or cranial radiation (CRT) plus IT MTX. After 10 additional years of follow-up, the pattern and significance of the results reported in 1983 are confirmed. IDM offered better hematologic protection (P < 0.0006), better testicular protection (P = 0.002), but CRT offered better central nervous system (CNS) protection (P < 0.0001). The retrieval rate for the 231 patients who relapsed while on therapy or within 6 months of elective cessation of therapy is 20 +/- 5%. For the 33 patients who relapsed more than 6 months after cessation of therapy, the retrieval rate is 49 +/- 10%. For all patients, the 12-year event-free survival was 37 +/- 3.6% and the overall survival was 49 +/- 3.5%. There were two cases of second malignancies reported in 3,502 person-years of survival. Both occurred following salvage therapy. There was no evidence of an excessive number of second primaries over the general population of children. There were no reported instances of clinical cardiopathy. After a median follow-up of 11 years, there have been no reports of cardiopathy and no evidence of an increased risk of second cancers in children treated on CALGB 7611. While the overall outcome is not what would be expected with modern therapy, one can conclude that CRT offered better CNS protection, but IDM offered better systemic and testicular protection. A small risk of second cancers or cardiac dys-function may be acceptable with therapies which produce long-term documented survival benefits.

Intensification of treatment and survival in all children with lymphoblastic leukaemia: results of UK Medical Research Council trial UKALL X. Medical Research Council Working Party on Childhood Leukaemia

The UK Medical Research Council trial MRC UKALL X was designed to investigate the benefit of one or two courses of additional intensification therapy in children with acute lymphoblastic leukaemia receiving standard treatment. From 1985 to 1990 1612 children, comprising more than 90% of eligible cases in the UK, were treated with intensive induction therapy, central nervous system directed therapy with cranial irradiation and intrathecal methotrexate, and continuing treatment for 2 years. 1171 children were randomised to receive additional intensification therapy at 5 weeks, 20 weeks, both, or neither. At follow-up of at least 3 years disease-free survival for all children at 5 years was 62% (95% confidence interval [Cl] 60.0-64.4), a significant improvement over the 56% (53.0-59.6) found in the preceding MRC UKALL trial. The 5-year disease-free survival was 71% (65.5-76.1) for children randomised to two blocks of intensification therapy, this being significantly better than the 62% (56.6-68.0), 61% (55.7-67.1), and 57% (50.9-62.7) rates for the groups randomised to one intensification block at 5 weeks, one at 20 weeks, and no intensification, respectively. The benefits of intensification therapy were seen irrespective of clinical factors known to influence outcome such as age, sex, and initial leucocyte count. We conclude that the addition of two courses of intensification therapy has produced a 14% improvement in disease-free survival and an 11% improvement in overall survival for the randomised patients. This additional treatment is of benefit to all children with acute lymphoblastic leukaemia, even those traditionally deemed at lower risk of relapse.

An odyssey in search of a cure: the evolution of treatment of childhood acute lymphoblastic leukemia in the United Kingdom

This review charts the evolution of therapy for childhood acute lymphoblastic leukaemia (ALL) in the United Kingdom. The present chemotherapeutic regimen is the result of experience gained from carefully planned randomised cooperative studies carried out during the last two decades. In common with the experience of the West German and American groups, the best results have been in those treated with post remission intensification blocks. With current chemotherapy protocols, almost 70% of children with ALL in U.K. can be cured but there may be a medical cost of such a cure, in terms of both acute and long term toxicity. This was especially true when central nervous system (CNS) therapy with cranial irradiation was used. Therefore present regimens are examining chemotherapeutic options for CNS disease control and the efficacy of additional post remission intensification. Failure of chemotherapy is most often seen in those children with a presenting white cell count of more than 50 x 10(9)/l, very young children and/or the presence of certain chromosomal rearrangements (e.g. t4: 11, t9: 22). At present the optimum therapeutic option for such high risk patients and for the majority of those in second remission, is an allogenic bone marrow transplant if an HLA-matched sibling is available. Modern day therapy is both complicated and costly and will be beyond the resources available for most children with ALL in developing countries. A significant decrease in worldwide mortality due to ALL will only occur if either the disease can be prevented or a simpler cure devised.

Intensive alternating drug pairs for treatment of high-risk childhood acute lymphoblastic leukemia. A Pediatric Oncology Group pilot study

BACKGROUND

To prevent drug resistance, the authors designed a protocol that featured early intensive rotating drug pairs as part of the therapy for acute lymphoblastic leukemia (ALL).

METHODS

After prednisone, vincristine, asparaginase, and daunorubicin induction, 12 intensive treatments (ABACABACABAC) were given in 30 weeks: A--intermediate-dose methotrexate (IDMTX) plus intermediate-dose mercaptopurine (MP); B--cytosine arabinoside (AC) plus daunorubicin (DNR); C--AC plus teniposide (VM-26). Triple intrathecal chemotherapy (AC, MTX, and hydrocortisone) was given for central nervous system (CNS) prophylaxis. Continuation therapy consisted of weekly MTX and daily MP until 2.5 years of continuous complete remission had been achieved.

RESULTS

Seventy-four children (age range, 1-19 years) at high risk of relapse were treated. Of 55 with B-lineage (early pre-B, pre-B) ALL, 24 have failed (2 induction failures, 2 deaths from infection, and 20 relapses). The event-free survival (EFS) rate at 4 years was 55.5% (standard error [SE] +/- 7.7%). Of 19 patients with T-cell ALL, 12 have failed (2 induction failures and 10 relapses). The EFS rate at 4 years was 32.6% (SE +/- 26.8%). Toxicities were significantly more common after AC and DNR or AC and VM-26 than IDMTX and MP. There were no toxicity-related deaths during intensive treatments.

CONCLUSION

Early intensive rotating therapy is tolerable and warrants consideration for additional trials of patients with high-risk, B-lineage ALL.

Lessons from 20 years of curative therapy of childhood acute leukaemia

The past 20 years of curative therapeutics of childhood acute leukaemia has been largely a period of consolidation of gains, refinement of techniques and dissemination of expertise and technology. However, certain lessons have been learned. First, cure can be permanent but the complexity and cost of curative treatment currently restricts its accessibility; prevention or simple curative treatment is needed. Secondly, cure of the child demands that the risk of adverse sequelae of treatments be carefully balanced with known therapeutic benefits. Thirdly, preventive meningeal irradiation is no longer required. Fourth, treatment intensification is self-limiting. Adverse reactions can cancel out or exceed therapeutic benefits, resulting in a lower cure rate or a similar cure rate with lower quality of cure. Finally, morphology, immunophenotype and genotype of acute leukaemia are important criteria for selecting and scheduling drug therapy. Genotype may be the most important since leukaemia is a genetic disorder for which morphology and immunophenotype are mere reflections. However, none of these features, individually or together, are sufficient to explain all the difference in outcome among children on a given treatment plan or to completely fulfill the need of criteria for selection of treatment. Acute leukaemia remains an unsolved problem demanding considerably more basic and clinical research to meet the need for prevention and simple dependable curative treatment.