Augmented post-induction therapy for children with high-risk acute lymphoblastic leukemia and a slow response to initial therapy

Intensive care in patients with newly diagnosed malignancies and a need for cancer chemotherapy

OBJECTIVE

Patients with newly diagnosed cancer responsible for organ failures may require intensive care unit (ICU) admission and immediate chemotherapy. Outcomes in this population have not been studied.

DESIGN

Prospective observational cohort study.

SETTING

Teaching hospital.

SUBJECTS

All patients admitted to the ICU, from January 1997 to June 2003, for organ failures due to newly diagnosed, untreated cancer and deemed necessary to receive immediate cancer chemotherapy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

For the period of 6.5 yrs, 100 patients met the study criteria: 43 had acute leukemia, 37 lymphoma, and 12 solid tumors. Median Simplified Acute Physiology Score II was 39 (30-48) points, and median Logistic Organ Dysfunction score was 5 (3-7) points. Three variables were independently associated with 30-day mortality: need for vasopressor therapy (odds ratio, 6.01; 95% confidence interval, 1.86-19.4), mechanical ventilation (odds ratio, 6.36; 95% confidence interval, 1.76-22.94); and hepatic failure (odds ratio, 7.76; 95% confidence interval, 1.25-48.27). Overall survival was 60% after 30 days and 49% after 180 days.

CONCLUSIONS

Mortality was chiefly dependent on the nature and number of organ failures, not on the nature or stage of the malignancy. The 30-day and 180-day survival rates indicate that, in this selected group of patients, advanced disease at cancer diagnosis should not lead to refusal of ICU admission. Moreover, administration of chemotherapy in the intensive care unit is feasible, and although the mortality rate is high, routine ICU admission of patients with newly diagnosed cancer, specific organ failure, and the need for administration of chemotherapy in the ICU deserves evaluation.

Individualized therapy for childhood acute lymphoblastic leukemia

In the field of oncology, a growing emphasis is now being placed on individualizing treatment in a way that maximizes chance for cure while minimizing unwanted side effects. In childhood acute lymphoblastic leukemia (ALL), several well-established clinical and biologic prognostic variables have traditionally been used to risk stratify therapy for individual patients. While this approach has been very successful, many relapses still occur unpredictably in patients characterized as having favorable features of their disease at diagnosis. Furthermore, it is likely that other children are overtreated. Therefore, current initiatives in childhood leukemia have focused on identifying new prognostic markers to refine treatment decision-making. Recent advances, which include the sequencing of the human genome, and technical developments in high-throughput genomics and proteomics, have facilitated these efforts. This review will chart the evolution of individualized therapy for ALL, the most common malignancy of children.

Early response to induction is predictive of survival in childhood Philadelphia chromosome positive acute lymphoblastic leukaemia: results of the Medical Research Council ALL 97 trial

We report on the outcome of children with Philadelphia positive acute lymphoblastic leukaemia (Ph+ ALL) treated on the UK Medical Research Council (MRC) trial for childhood ALL, MRC ALL 97, between January 1997 and June 2002. Forty-two (2.3%) patients were Ph+. Nineteen (45%) had <25% blasts in bone marrow (BM) within the first 2 weeks of treatment and were defined as a good response group (GRG), the others as a poor response group (PRG). Thirty-six (86%) achieved first complete remission (CR1) at the end of induction, of which 28 underwent BM transplantation (BMT). The median follow-up was 42 months (range, 21-84). The 3-year event-free survival (EFS; 52%, 95% CI, 36-66%) was a considerable improvement on the previous MRC UKALL XI trial (27%). EFS for the GRG and PRG were 68% (43-84%) and 39% (18-59%), respectively (P = 0.03); presenting white cell count <50 x 10(9)/l (P = 0.02) was predictive for overall survival. Changes in the MRC ALL97 trial within the study period resulted in some Ph+ ALL receiving daunorubicin and either prednisolone or dexamethasone during induction. Though the use of daunorubicin during induction was not a prospective study question, EFS was significantly better for those whose induction included this drug (P = 0.02). Steroid randomization was not stratified for Ph+ ALL patients and was not predictive for EFS. BMT in CR1 appeared to reduce the risk of a subsequent BM relapse. These results show significant improvement on previous MRC trials; future therapeutic strategies should include early intensive therapy and BMT in CR1.

Leptomeningeal metastases from leukemias and lymphomas

Leptomeningeal dissemination of lymphoma and leukemia differs from that of solid tumors in a number of clinically important aspects. Specific histologic variants of lymphoma and leukemia have such a high incidence of cerebrospinal fluid (CSF) dissemination that assessing CSF cytology at diagnosis is crucial and prophylactic therapy of the CSF compartment is required. Furthermore, while the overall prognosis for patients with leptomeningeal metastases from leukemia and lymphoma is similar to solid tumors, selected patients have excellent response to therapy and attain durable remission. Therefore, aggressive treatment is warranted.

The seventh international childhood acute lymphoblastic leukemia workshop report: Palermo, Italy, January 29--30, 2005

Between 1995 and 2004, six International Childhood Acute Lymphoblastic Leukemia (ALL) Workshop have been held, and the completion of several collaborative projects has established the clinical relevance and treatment options for several specific genetic subtypes of ALL. This meeting report summarizes the data presented in the seventh meeting and the discussion.

Chemotherapy versus allogeneic transplantation for very-high-risk childhood acute lymphoblastic leukaemia in first complete remission: comparison by genetic randomisation in an international prospective study

BACKGROUND

The dismal prognosis of very-high-risk childhood acute lymphoblastic leukaemia could be improved by allogeneic haemopoietic cell transplantation. We compared this strategy with intensified chemotherapy protocols, with the aim to improve the outcome of children with very-high-risk acute lymphoblastic leukaemia in first complete remission.

METHODS

A cooperative prospective study was set up in seven countries. Very-high-risk acute lymphoblastic leukaemia in first complete remission was defined by the presence of at least one of the following criteria: (1) failure to achieve complete remission after the first four-drug induction phase; (2) t(9;22) or t(4;11) clonal abnormalities; and (3) poor response to prednisone associated with T immunophenotype, white-blood-cell count of 100x10(9)/L or greater, or both. Children were allocated treatment by genetic chance, according to the availability of a compatible related donor, and assigned chemotherapy or haemopoietic-cell transplantation. The primary outcome was disease-free survival and analysis was by intention to treat.

FINDINGS

Between April, 1995, and December, 2000, 357 children entered the study, of whom 280 were assigned chemotherapy and 77 related-donor haemopoietic-cell transplantation. 5-year disease-free survival was 40.6% (SE 3.1) in children allocated chemotherapy and 56.7% (5.7) in those assigned transplantation (hazard ratio 0.67 [95% CI 0.46-0.99]; p=0.02); 5-year survival was 50.1% (3.1) and 56.4% (5.9), respectively (0.73 [0.49-1.09]; p=0.12).

INTERPRETATION

Children with very-high-risk acute lymphoblastic leukaemia benefit from related-donor haemopoietic-cell transplantation compared with chemotherapy. The gap between the two strategies increases as the risk profile of the patient worsens.

Pharmacokinetic/pharmacodynamic relationships of asparaginase formulations: the past, the present and recommendations for the future

The discovery of the tumour-inhibitory properties of asparaginase began 50 years ago with the observation that guinea-pig serum-treated lymphoma-bearing mice underwent rapid and often complete regression. Soon afterwards, the asparaginase of bacterial origin was isolated. The asparaginases of bacterial origin induce anti-asparaginase neutralising antibodies in a large proportion of patients (44-60%), thus negating the specific enzymatic activity and resulting in failure of the target amino acid deamination in serum. There is immunological cross-reaction between the antibodies against various formulations of native Escherichia coli-asparaginase and polyethylene glycol (PEG)-asparaginases, but not to Erwinia asparaginase, as suggested by laboratory preclinical findings. This evidence was strongly inferred from the interim analyses in the Children's Cancer Group (CCG)-1961 study. Thus, anti-E. coli or PEG-asparaginase antibodies seropositive patients may benefit from the Erwinia asparaginase. The inter-relationships between asparaginase activity, asparagine (ASN) and glutamine deamination remain largely unexplored in patients. Studies have shown that ASN depletion is insufficient to induce apoptosis in T lymphoblasts in vitro and that the inhibitory concentration of CEM T-cell line is correlated with the asparaginase concentration responsible for 50% glutamine deamination. The optimal catalysis of ASN and glutamine deamination in serum by asparaginase induces apoptosis of leukaemic lymphoblasts. The percentage of ASN and glutamine deamination was predicted by asparaginase activity. Asparaginase activity of 0.1 IU/mL provided insufficient depletion of both amino acids in high-risk acute lymphoblastic leukaemia (ALL) patients. With increasing glutamine deamination, mean asparaginase activities and percentages of post-treatment samples with effective ASN depletion (<3 micromol/L) increase. Both glutamine and ASN deamination are predicted by asparaginase activity. Further population analyses resulted in identification of sigmoid relationships between asparaginase levels and post-treatment glutamine and ASN deamination.Furthermore, pharmacodynamic analyses strongly suggested that >/=90% deamination of glutamine must occur before optimal ASN deamination takes place, due to the de novo ASN biosynthesis by the liver. These pharmacodynamic results from the best-fit population pharmacokinetic/pharmacodynamic model obtained from nonlinear mixed effects model pharmacodynamic analyses for standard-risk ALL patients are similar. These analyses produced the following results: (i) asparaginase activity </=0.4 IU/mL provided insufficient deamination of ASN, whereas >0.4-0.7 IU/mL was required for optimal (90%) ASN and glutamine deamination; and (ii) deamination of glutamine is dependent on asparaginase activity and it correlates with enhanced serum ASN deamination. Thus, glutamine deamination enhances asparaginase efficacy in ALL patients. Deamination of ASN >/=90% of control or ASN concentration <3 micromol/L may be associated with improved survival in this subset of patients. Our findings support the pharmacodynamic mechanism of PEG-asparaginase for disease control in ALL patients. These results taken together strongly support new experimental approaches for application of population pharmacokinetic/pharmacodynamic analyses to further enhance survival of leukaemia patients.

Outcome of cancer patients considered for intensive care unit admission: a hospital-wide prospective study

PURPOSE

To evaluate the outcome of cancer patients considered for admission to the intensive care unit (ICU).

PATIENTS AND METHODS

Prospective, one-year hospital-wide study of all cancer and hematology patients, including bone marrow transplantation patients, for whom admission to the ICU was requested.

RESULTS

Of the 206 patients considered for ICU admission, 105 patients (51%) were admitted. Of the 101 patients who were not admitted, 54 patients (26.2%) were considered too sick to benefit, and 47 patients (22.8%) were considered to be too well to benefit from the ICU. Of these 47 patients, 13 patients were admitted later. Survival rates after 30 and 180 days were significantly associated with admission status (P < .0001). Remission of the malignancy (odds ratio [OR], 3.37; 95% CI, 1.25 to 9.07) was independently associated with ICU admission, whereas poor chronic health status (OR, 0.38; 95% CI, 0.16 to 0.74) and solid tumor (OR, 0.43; 95% CI, 0.24 to 0.78) were associated with ICU refusal. In admitted patients, 30-day and 6-month survival rates were 54.3% and 32.4%, respectively. Of the patients considered too sick to benefit from ICU admission, 26% were alive on day 30 and 16.7% on day 180. Among patients considered too well to benefit, the 30-day survival rate was a worrisome 78.7%. Calibration of the Mortality Probability Model (the only score available at triage) was of limited value for predicting 30-day survival (area under the curve, 0.62).

CONCLUSION

Both the excess mortality in too-well patients later admitted to the ICU and the relatively good survival in too-sick patients suggest the need for a broader admission policy.

Pharmacogenetics of outcome in children with acute lymphoblastic leukemia

Acquired genetic characteristics of acute lymphoblastic leukemia (ALL) cells are used to individualize therapy, whereas germ line genetic characteristics generally are not. We determined whether ALL outcome was related to 16 genetic polymorphisms affecting the pharmacodynamics of antileukemic agents. Of 246 children, 116 were treated on the lower-risk (LR) and 130 on the higher-risk (HR) arms of a St Jude protocol. Patients in the HR group with the glutathione S-transferase (GSTM1) non-null genotype had greater risk of hematologic relapse (P = .03), which was further increased by the thymidylate synthetase (TYMS) 3/3 genotype (P = .03). These genotypes remained predictive in multivariate analyses (P < .001 and .003, respectively). No genotypes were predictive in the LR arm. Expression of these 2 genes in ALL blasts was lower in those with low-activity genotypes. For central nervous system relapse, among the HR group, the vitamin D receptor start site (P = .02) and intron 8 genotypes (P = .04) predisposed, whereas for LR patients the TYMS 3/3 genotype predisposed (P = .04). The GSTM1 non-null and TYMS 3/3 genotypes are plausibly linked to drug resistance. Polymorphisms interact to influence antileukemic outcome and represent determinants of response that can be used to optimize therapy.

Immunodeficiency in children with acute lymphoblastic leukemia after completion of modern aggressive chemotherapeutic regimens

OBJECTIVE

To determine the prevalence, duration, and a potential cause of humoral defect(s) in children with acute lymphoblastic leukemia (ALL) at least 1 year after completion of chemotherapy.

STUDY DESIGN

Antibody titers for mumps, rubeola, rubella, tetanus and diphtheria toxoid, poliovirus serotypes 1, 2,and 3, Haemophilus influenzae type b, varicella, and hepatitis B were obtained from 100 children with ALL. Children with non-protective titers to these microbial antigens were re-vaccinated and re-studied after anamnestic vaccine challenge.

RESULTS

The percent of children with ALL who had protective titers was markedly less than that anticipated for immunized control subjects. Longitudinally, many titers fluctuate between protective and non-protective antibody responses after re-immunization. The chemotherapy protocol used did not affect the ability of these children to express protective antibody responses. T-, B-, and NK-cell numbers and proliferative responses to mitogens were all normal. Age correlated with titer results for certain vaccines.

CONCLUSIONS

Children in remission from ALL have a high prevalence of humoral immune defects that are not related to any specific chemotherapy regimen. This antibody deficiency may place children with ALL at risk for the development of these bacterial and viral diseases, even after completion of chemotherapy. Pediatricians, oncologists, or both should periodically monitor humoral immunity after chemotherapy and re-vaccinate these children, as needed, to ensure prolonged immunoprotection.

Prognostic Value of Early Response to Treatment Combined with Conventional Risk Factors in Pediatric Acute Lymphoblastic Leukemia

To determine useful prognostic factors in treating childhood acute lymphoblastic leukemia (ALL), we correlated conventional risk factors and bone marrow response 14 days after induction chemotherapy. Our study included 116 precursor B-cell (n = 104) and T-cell (n = 12) ALL patients treated with our protocol between 1988 and 1999. The patients were classified into 3 initial risk groups on the basis of conventional risk factors (56 in the low-risk, 33 in the high-risk, and 27 in the very high-risk groups). All patients received similar systemic chemotherapy regimens before the evaluation of their bone marrow on day 14. We evaluated the marrow of 69 patients as M1 (less than 5% blasts), 25 as M2 (5%-25% blasts), and 22 as M3 (more than 25% blasts). Although all patients attained an initial complete remission (CR), relapse was noted in 33 of the 116 patients, and 15 patients died. All of the M1 marrow patients, irrespective of the initial risk group, showed the best event-free survival rate (85.1% +/- 3 4.4%), the lowest relapse rate (14.5%), and the highest attainment of a second CR (100%); they were defined as the new R1 prognostic group. The low-risk patients with M2 or M3 marrow (R2 group) had a relatively high relapse rate, but all of these relapsed patients were treated successfully with subsequent therapy. High- or very high-risk patients with M2 or M3 marrow (R3 group) had the worst prognosis. Our new prognostic definition (R1, R2, R3) incorporating day 14 marrow findings is useful to tailor early-phase treatments for better therapeutic results in childhood ALL.

Antioxidant status decreases in children with acute lymphoblastic leukemia during the first six months of chemotherapy treatment

BACKGROUND

Children undergoing treatment for acute lymphoblastic leukemia (ALL) receive combination chemotherapy and many of the components are associated with free radical production.

PROCEDURE

Among 103 children newly diagnosed with ALL, plasma concentrations of antioxidants, total antioxidant capacity (ORAC), and DNA oxidized base 8-oxodeoxyguanosine (8-oxo-dG) were analyzed at baseline and 3 and 6 months after diagnosis.

RESULTS

Plasma vitamin A, antioxidants, 8-oxo-dG, and ORAC changed from diagnosis through the first 6 months of ALL therapy. In patients with higher plasma concentrations of vitamin A, E, total carotenoids, ORAC, and 8-oxo-dG there was a beneficial association with fewer dose reductions, fewer infections, improved quality of life, less delay in chemotherapy treatment schedule, reduced toxicity, and fewer days spent in the hospital. There were also adverse relationships demonstrated.

CONCLUSIONS

Among children with ALL, antioxidant levels and oxidative stress appear to be associated with duration and complications of treatment.

Building better therapy for children with acute lymphoblastic leukemia

Childhood acute lymphoblastic leukemia is one of the most curable of all human cancers, but new approaches are urgently needed for children who relapse and to avoid severe side effects of curative therapy. Work from the laboratories of Rob Pieters and William Evans, including a paper in this issue of Cancer Cell, has led to the identification of genes whose expression correlates with drug crossresistance and long term outcome. The goal is now to integrate these and other findings using gene expression technology into the care of children with the most common pediatric malignancy.

Accumulation of methotrexate and methotrexate polyglutamates in lymphoblasts and treatment outcome in children with B-progenitor-cell acute lymphoblastic leukemia: a Pediatric Oncology Group study

We reported that children with B-progenitor-cell acute lymphoblastic leukemia (BpALL) treated in the early 1980s whose lymphoblasts accumulated high levels of methotrexate (MTX) and of methotrexate polyglutamates (MTXPGs) in vitro had an improved 5-year event-free survival (EFS) (65% (standard error (s.e.) 12%) vs 22% (s.e. 9%)). We repeated this study in children with BpALL treated in the early 1990s. The major change in treatment was the addition of 12 24-h infusions of 1 g/M2 MTX with leucovorin rescue (IDMTX). In 87 children treated on Pediatric Oncology Group (POG) study 9005 and POG 9006, the 5-year EFS for those whose lymphoblasts accumulated high levels of MTX and MTXPGs (79.2%, s.e. 8.3%) was not significantly different from that of patients with lesser accumulation of MTX and MTXPGs (77.7%, s.e. 5.4%). These findings support the notion that higher dose MTX therapy has contributed to increased cure, particularly for patients whose lymphoblasts accumulate the drug less well.

Bone marrow recurrence after initial intensive treatment for childhood acute lymphoblastic leukemia

BACKGROUND

The authors studied the clinical outcome of 106 children with acute lymphoblastic leukemia (ALL) who developed a bone marrow recurrence as the first adverse event after contemporary intensified therapy.

METHODS

Endpoints were the rates and lengths of second remission, the cumulative incidence of second hematologic recurrence, second event-free survival (EFS), and survival.

RESULTS

Bone marrow recurrences were isolated in 79 patients, and combined with an extramedullary site in 27 patients. The median time to recurrence was 2.6 years (range, 0.3-11.6 years). Seventy-six patients (71.7%) attained a second remission (median length, 0.7 year; range, 0.03-13.3 years). The 5-year survival probability among all patients was 24.2% +/- 4.2% (standard error). On multivariate analysis, time to first disease recurrence and blast cell lineage were found to be independent predictors of a second EFS (P = 0.008 and P = 0.028, respectively). The 5-year EFS estimate in patients with an initial disease remission of >/= 36 months was 42.6% +/- 7.8% but was only 12.5% +/- 3.9% among children with a short duration of disease remission (< 36 months). These estimates were 28.7% +/- 4.9% and 5.0% +/- 3.4%, respectively, for B blast and T blast cell lineages.

CONCLUSIONS

Despite acceptable long-term second EFS rates for certain subgroups, overall bone marrow recurrence after intensified first-line therapy for childhood ALL signals a poor outcome.

Long-term follow-up results of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (Hyper-CVAD), a dose-intensive regimen, in adult acute lymphocytic leukemia

BACKGROUND

Modern intensive chemotherapy regimens have improved the prognosis for patients with adult acute lymphocytic leukemia (ALL). With these regimens, the complete response rates are now reported to be > 80%, and the long-term survival rates range from 30% to 45%. The current analysis updated the long-term results with the original hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (Hyper-CVAD) program, with a median follow-up time of 63 months.

METHODS

Between 1992 and 2000, 288 patients were treated with Hyper-CVAD. The median age of the patients was 40 years, and 59 patients (20%) were > or = age 60 years. The incidence of Philadelphia chromosome (Ph)-positive ALL was 17%, and the incidence of of T-cell ALL was 13%.

RESULTS

A complete response (CR) was achieved in 92% of patients. The induction mortality rate was 5% (2% if the patient's age was < 60 years, and 15% if the patient's age was > or = 60 years). With a median follow-up time of 63 months, the 5-year survival rate was 38% and the 5-year CR duration rate was 38%. Multivariate analysis of prognostic factors for CR duration identified the following adverse factors: age > or = 45 years, leukocytosis > or = 50 x 10(9)/L, poor performance status (an Eastern Cooperative Oncology Group score of 3-4), Ph-positive disease, French-American-British L2 morphology, > 1 course to achieve CR, and Day 14 bone marrow blasts > 5%. Patients were divided into low-risk (risk score 0-1; 37%), intermediate risk (risk score 2-3; 36%), and poor-risk groups (risk score > or = 4; 27%) with 5-year CR duration rates of 52%, 37%, and 10%, respectively.

CONCLUSIONS

Compared with the previous VAD regimens, Hyper-CVAD was associated with significantly better CR rates, CR duration, and survival. The long-term follow-up results of Hyper-CVAD were favorable. Comparison of Hyper-CVAD with other established adult ALL regimens is warranted.

Pharmacogenetics of acute lymphoblastic leukemia

PURPOSE OF REVIEW

The outcome in children with acute lymphoblastic leukemia has improved significantly over the past four decades. Current therapy results in event-free survival exceeding 80% for most patients. The development of risk-adapted therapy based on characteristics of the child (age), leukemia (leukocyte count, acquired genetic characteristics) and early response to therapy allows dose intensification for children with higher-risk disease. Much less attention has been given to the role of host variability (pharmacogenetic polymorphism) in determining outcome. This review discusses literature reports in this area and describes some of the challenges facing the field as it moves forward.

RECENT FINDINGS

Polymorphisms in many different metabolic pathways have been demonstrated in single gene studies to influence the outcome of acute lymphoblastic leukemia. Challenges arise in establishing the generalizability of observations and interpreting complex gene-gene interactions in multigene pathways. Recent studies also illustrate the importance of correlation of clinical associations with biological mechanisms.

SUMMARY

Despite significant progress in the treatment of childhood acute lymphoblastic leukemia, therapy is still unsuccessful in 20% of patients. Further knowledge of and insight into the role of host genetic polymorphisms will improve the results by integrating pharmacodynamic and pharmacogenomic studies in individualizing therapy for children with acute lymphoblastic leukemia.

A case of infantile acute lymphoblastic leukemia presenting with rearrangement of MLL at 11q23 and apparent insertion or translocation at 10p12

We report the case of an 11-month-old patient with a clinical diagnosis of infantile acute lymphoblastic leukemia and an MLL (11q23) rearrangement in 69% of nuclei, revealed with interphase fluorescence in situ hybridization (FISH). Routine chromosome analysis of the bone marrow showed a very subtle rearrangement involving the short arm of chromosome 10 and the long arm of chromosome 11 in the abnormal cells. To clarify the nature of this rearrangement, we hybridized the MLL break-apart probe to previously G-banded slides. The rearrangement was interpreted as a small inversion within the band 11q23, separating the 5' MLL from the 3' MLL region. This segment on the long arm of chromosome 11 containing the rearranged MLL locus was either inserted in or translocated to the short arm of chromosome 10 at approximately band 10p12. The inversion affecting MLL may have followed insertion or preceded it. Molecular characterization of this rearrangement was not possible, due to limited sample material. There have been previous reports of rearrangements of MLL with the MLLT10 (alias AF10) gene locus at 10p12, including an interstitial inverted insertion of 11q13q23 in one case and insertion of 11q14q23 at 10p12 in another. These both resulted in a large derivative chromosome 10 and transcription of an MLL/MLLT10 fusion product. To our knowledge, the novel and cryptic rearrangement detected in our patient has not been described previously. A follow-up study of the patient's bone marrow at the end of induction therapy showed no morphologic evidence of residual leukemia and both FISH and chromosome analyses were normal.

Toxicity and efficacy of intensive chemotherapy for children with acute lymphoblastic leukemia (ALL) after first bone marrow or extramedullary relapse

BACKGROUND

Approximately 25% of children newly diagnosed with acute lymphoblastic leukemia (ALL) will eventually experience leukemic relapse, with bone marrow being the most common site of recurrence. The ability to achieve a durable second remission is complicated by toxicity and resistant disease. We report a novel combination of chemotherapy for relapsed pediatric ALL.

PROCEDURE

Thirty pediatric patients with relapsed medullary (n = 18) and extra-medullary (n = 12) ALL were enrolled at three pediatric institutions. Following receipt of induction and the first Block A and Block B of intensification, each patient was evaluated for toxicity, efficacy in achieving remission, and long-term survival. Additionally, minimal residual disease (MRD) detection by multidimensional flow cytometry (MDF) was performed.

RESULTS

During induction, the major non-hematopoeitic toxicities were mucositis (30% of patients) and bacteremia (50% of patients). Two patients (7%) died of toxicity during induction. Toxicity during intensification Block 1A and 1B was markedly reduced. Eight-nine percent of patients with marrow disease achieved a remission following induction and intensification. The event-free survival (EFS) for all patients at 2 and 4 years were 60% (95% CI: 42-78%) and 49% (95% CI: 30-68%), respectively.

CONCLUSIONS

This regimen for patients with relapsed ALL was successful in achieving a second remission for the majority of patients with acceptable toxicity.

Asparaginase Pharmacokinetics After Intensive Polyethylene Glycol-Conjugated L-Asparaginase Therapy for Children with Relapsed Acute Lymphoblastic Leukemia

PURPOSE

Asparaginase therapy is an important component in the treatment of children with acute lymphoblastic leukemia. Polyethylene glycol-conjugated asparaginase (PEG-ASNase) has significant pharmacological advantages over native Escherichia coli asparaginase. We investigated the pharmacokinetics of PEG-ASNase, presence of antibodies to PEG-ASNase, and concentrations of asparagine in serum and cerebrospinal fluid (CSF) in combination chemotherapy for relapsed pediatric acute lymphoblastic leukemia.

EXPERIMENTAL DESIGN

Twenty-eight pediatric patients with relapsed medullary (n = 16) and extramedullary (n = 11) acute lymphoblastic leukemia were enrolled at three pediatric institutions and had at least two serum and CSF samples obtained for analysis. Patients received induction therapy (including PEG-ASNase 2500 IU/m2 intramuscularly weekly on days 2, 9, 16, and 23) and intensification therapy (including PEG-ASNase 2500 IU/m2 intramuscularly once on day 7). Serum samples were obtained weekly during induction and intensification. CSF samples were obtained during therapeutic lumbar punctures during induction and intensification.

RESULTS

Weekly PEG-ASNase therapy resulted in PEG-ASNase activity of >0.1 IU/ml in 91-100% of patients throughout induction. During intensification, PEG-ASNase on day 7 resulted in PEG-ASNase activity >0.1 IU/ml in 94% and 80% of patients on days 14 and 21, respectively. Serum and CSF asparagine depletion was observed and maintained during induction and intensification in the majority of samples. PEG-ASNase antibody was observed in only 3 patients.

CONCLUSIONS

Intensive PEG-ASNase therapy in the treatment of relapsed acute lymphoblastic leukemia reliably results in high-level serum PEG-ASNase activity, and asparagine depletion in serum and CSF is usually achieved. Incorporation of intensive PEG-ASNase in future trials for recurrent acute lymphoblastic leukemia is warranted.

RAS oncogene mutations and outcome of therapy for childhood acute lymphoblastic leukemia

Activating mutations in the RAS oncogenes are among the most common genetic alterations in human cancers, including patients with acute lymphoblastic leukemia (ALL). We sought to define the frequency and spectrum, and possible prognostic importance, of N- and K-RAS mutations in children with ALL treated with contemporary therapy. Leukemic blast DNA from 870 children was analyzed for the presence of activating mutations in the N- or K-RAS oncogenes using a sensitive mutation detection algorithm. RAS mutations were present in the blasts of 131 (15.1%) pediatric ALL patients. The spectrum of mutations included 81 (9.3%) mutations of codons 12/13 of N-RAS, 12 (1.4%) mutations of codon 61 of N-RAS, 39 (4.5%) mutations of codons 12/13 of K-RAS, and 2 (0.2%) mutations of codon 61 of K-RAS. The presence of N- or K-RAS mutations was not associated with white blood cell count at diagnosis, sex, race, extramedullary testicular involvement, central nervous system disease, or NCI/CTEP ALL Risk Group. Patients with an exon 1 K-RAS mutation (codons 12/13) were significantly younger at diagnosis (P=0.001) and less frequently B-lineage phenotype (P=0.01). RAS mutation status did not predict overall survival, event-free survival and disease-free survival. While N- and K-RAS mutations can be identified in 15% of children with newly diagnosed ALL, they do not represent a significant risk factor for outcome using contemporary chemotherapy regimens.

Asparaginase antibody and asparaginase activity in children with higher-risk acute lymphoblastic leukemia: Children's Cancer Group Study CCG-1961

We investigated the anti-asparaginase antibody (Ab) and asparaginase enzymatic activity in the sera of 1,001 patients (CCG-1961) with high-risk acute lymphoblastic leukemia (HR-ALL). Patients received nine doses of native Escherichia coli asparaginase during induction. Half of rapid early responders (RER) were randomly assigned to standard intensity arms and continued to receive native asparaginase. The other RER patients and all slow early responders received 6 or 10 doses of PEG-asparaginase. Serum samples (n = 3,193) were assayed for determination of asparaginase Ab titers and enzymatic activity. Three hundred ninety of 1,001 patients (39%) had no elevation of Ab among multiple evaluations-that is, were Ab-negative (<1.1 over negative control)-and 611 patients (61%) had an elevated Ab titer (>1.1). Among these 611 patients, 447 had no measurable asparaginase activity during therapy. Patients who were Ab-positive but had no clinical allergies continued to receive E. coli asparaginase, the activity of which declined precipitately. No detectable asparaginase activity was found in 81 of 88 Ab-positive patients shortly after asparaginase injections (94% neutralizing Ab). The Ab-positive patients with clinical allergies subsequently were given Erwinase and achieved substantial activity (0.1-0.4 IU/ml). An interim analysis of 280 patients who were followed for 30 months from induction demonstrated that the Ab-positive titers during interim maintenance-1 and in delayed intensification-1 were associated with an increased rate of events. The CCG-1961 treatment schedule was very immunogenic, plausibly due to initially administrated native asparaginase. Anti-asparaginase Ab was associated with undetectable asparaginase activity and may be correlated with adverse outcomes in HR ALL.

Deletion of 7p or monosomy 7 in pediatric acute lymphoblastic leukemia is an adverse prognostic factor: a report from the Children's Cancer Group

Monosomy 7 or deletions of 7q are associated with many myeloid disorders; however, the significance of such abnormalities in childhood acute lymphoblastic leukemia (ALL) is unknown. Among 1880 children with ALL, 75 (4%) had losses involving chromosome 7, 16 (21%) with monosomy 7, 41 (55%) with losses of 7p (del(7p)), 16 (21%) with losses of 7q (del(7q)), and two (3%) with losses involving both arms. Patients with losses involving chromosome 7 were more likely to be > or =10 years old, National Cancer Institute (NCI) poor risk, and hypodiploid than patients lacking this abnormality. Patients with or without these abnormalities had similar early response to induction therapy. Event-free survival (EFS) and survival for patients with monosomy 7 (P<0.0001 and P=0.0007, respectively) or del(7p) (P<0.0001 and P=0.0001, respectively), but not of patients with del(7q), were significantly worse than those of patients lacking these abnormalities. The poorer EFS was maintained after adjustment for a Philadelphia (Ph) chromosome, NCI risk status, ploidy, or an abnormal 9p. However, the impact on survival was not maintained for monosomy 7 after adjustment for a Ph. These results indicate that the critical region of loss of chromosome 7 in pediatric ALL may be on the p-arm.

CNS-directed therapy in young children with T-lineage acute lymphoblastic leukemia: High-dose methotrexate versus cranial irradiation

BACKGROUND

Prophylactic use of cranial radiation therapy (CRT) in young children with acute lymphoblastic leukemia (ALL) is associated with significant long-term morbidity. Therefore, current treatment protocols for pediatric B-precursor ALL have abandoned prophylactic CRT in favor of intrathecal chemotherapy, combined with either high-dose methotrexate infusions (HD-MTX) or intensive systemic chemotherapy. In contrast, prophylactic CRT continues to be used in children with T-lineage ALL (T-ALL), who historically have had an inferior prognosis. We conducted a retrospective cohort study to determine the effect on survival of substituting HD-MTX for CRT in young children with T-ALL, a group that faces a high risk of long-term sequelae from CRT.

PROCEDURE

Twenty-six children, diagnosed with T-ALL between the ages of 1 and 5 years, were treated on the same high-risk leukemia protocol. Central nervous system (CNS) directed therapy consisted of either CRT (1,800 cGy) or HD-MTX (three doses of 8 g/m2), depending on the treatment era in which patients were diagnosed.

RESULTS

Of the 24 patients who entered remission, 12 received CRT and 12 received HD-MTX. Five-year event-free survival (EFS) (+/-SE) was 92 +/- 8% in the HD-MTX group versus 75 +/- 13% in the CRT group (P=0.23). Five-year overall survival (OS) was 100% in the HD-MTX group versus 75 +/- 13% in the CRT group (P=0.07). There were no CNS recurrences in the HD-MTX group. One patient treated with CRT developed a brain tumor.

CONCLUSIONS

The use of HD-MTX instead of CRT as CNS-directed therapy in very young children with T-ALL does not compromise survival, while avoiding the adverse long-term effects of cranial irradiation.

Evaluation of early marrow response in childhood aneuploid acute lymphoblastic leukemia: flow cytometric DNA analysis versus standard morphology

Despite improved survival rates for childhood acute lymphoblastic leukemia (ALL), the relapse rate remains at 20-30%. Early peripheral blood and bone marrow (BM) responses have been associated with more favorable outcomes; all current children's cancer group (CCG) protocols for ALL require BM evaluation at days 7 and 14 with subsequent therapy based on the results. Morphologic interpretation of aspirate smears during induction chemotherapy is challenging, as the samples are often hypocellular, excessively friable, and cytologically altered by drugs. We have shown discordancy of day 7 and 14 BM lymphoblast counts using morphologic and flow cytometric immunophenotypic analyses (FC). The aim of our study was to determine the utility, reliability, and cost effectiveness of lymphoblast enumeration using DNA content analysis by flow cytometry (DNA-FC) and to further demonstrate the subjectivity of morphologic review. All new cases of ALL had DNA-FC and FC analyses. The percentage of lymphoblasts as determined by both methods was compared for 82 aneuploid cases. Three pathologists independently reviewed aspirate smears from 39 bone marrow samples of aneuploid ALL that were obtained during early induction. These results were compared among themselves and with the results obtained by DNA-FC. We found excellent correlation between the percentage of lymphoblasts as determined by DNA-FC and FC (R2 = 0.97) over a range of 0 to 99%. Pathologic review agreed with the DNA-FC, on average, 68%. The sensitivity, specificity, and positive and negative predictive values of morphologic review, averaged 53, 84, 78, and 63%, respectively, when using DNA-FC as the "gold standard." All three pathologists achieved agreement of lymphoblast percentage by morphology in 72%. In our laboratory, the use of DNA-FC equates to one-sixth the time and one-half the price of FC per exam. We have shown a strong correlation between blast counts determined by DNA-FC and FC. DNA-FC is an objective, economical, and reliable method to assess early response in induction marrows from aneuploid ALL where morphology is often uninterpretable. This test is highly reproducible and available at most pediatric institutions. Prospective studies need to be employed to evaluate the effect of more definitive methods (DNA-FC and FC) of assessing the early response in bone marrows on prognosis.

Outcome of children with high-risk acute lymphoblastic leukemia (HR-ALL): Nordic results on an intensive regimen with restricted central nervous system irradiation

BACKGROUND

Improvement in outcome of childhood high-risk (HR) ALL was sought with a very intensive Nordic protocol leaving most patients without CNS-RT.

METHODS

A total of 426 consecutive children entered the NOPHO-92 HR-ALL program. HR criteria included WBC > or =50 x 10(9)/L, CNS or testicular involvement, T-cell, lymphomatous features, t(9;22), t(4;11), or slow response. Of these, 152 children had very high risk (VHR) with special definitions. CNS consolidation was based on high-dose MTX (8 g/m2) and ARA-C (12 g/m2) alternating. VHR patients also received cranial RT.

RESULTS

The 9-year EFS was 61 +/- 3%, OS 74 +/- 2%, and EFS for T-ALL 62 +/- 4%. Cumulative incidence of isolated CNS relapse was 4.7 +/- 1%, and CNS relapse in total 9.9 +/- 2%. Poor prognostic factors were WBC > or =200 x 10(9)/L and a very slow response.

CONCLUSIONS

HR-ALL was successfully treated on the NOPHO-92 regimen, with a relatively low CNS relapse rate for non-irradiated children. WBC > or =200 x 10(9)/L and very slow response emerged as strong poor prognostic factors.

Childhood and adolescent lymphoid and myeloid leukemia

Remarkable progress has been made in the past decade in the treatment and in the understanding of the biology of childhood lymphoid and myeloid leukemias. With contemporary improved risk assessment, chemotherapy, hematopoietic stem cell transplantation and supportive care, approximately 80% of children with newly diagnosed acute lymphoblastic leukemia and 50% of those with myeloid neoplasm can be cured to date. Current emphasis is placed not only on increased cure rate but also on improved quality of life. In Section I, Dr. Ching-Hon Pui describes certain clinical and biologic features that still have prognostic and therapeutic relevance in the context of contemporary treatment programs. He emphasizes that treatment failure in some patients is not due to intrinsic drug resistance of leukemic cells but is rather caused by suboptimal drug dosing due to host compliance, pharmacodynamics, and pharmacogenetics. Hence, measurement of minimal residual disease, which accounts for both the genetic (primary and secondary) features of leukemic lymphoblasts and pharmacogenomic variables of the host, is the most reliable prognostic indicator. Finally, he contends that with optimal risk-directed systemic and intrathecal therapy, cranial irradiation may be omitted in all patients, regardless of the presenting features. In Section II, Dr. Martin Schrappe performs detailed analyses of the prognostic impact of presenting age, leukocyte count, sex, immunophenotype, genetic abnormality, early treatment response, and in vitro drug sensitivity/resistance in childhood acute lymphoblastic leukemia, based on the large database of the Berlin-Frankfurt-Münster consortium. He also succinctly summarizes the important treatment components resulting in the improved outcome of children and young adolescents with this disease. He describes the treatment approach that led to the improved outcome of adolescent patients, a finding that may be applied to young adults in the second and third decade of life. Finally, he believes that treatment reduction under well-controlled clinical trials is feasible in a subgroup of patients with excellent early treatment response as evidenced by minimal residual disease measurement during induction and consolidation therapy. In Section III, Dr. Raul Ribeiro describes distinct morphologic and genetic subtypes of acute myeloid leukemia. The finding of essentially identical gene expression profiling by DNA microarray in certain specific genetic subtypes of childhood and adult acute myeloid leukemia suggests a shared leukemogenesis. He then describes the principles of treatment as well as the efficacy and toxicity of various forms of postremission therapy, emphasizing the need of tailoring therapy to both the disease and the age of the patient. Early results suggest that minimal residual disease measurement can also improve the risk assessment in acute myeloid leukemia, and that cranial irradiation can be omitted even in those with central-nervous-system leukemia at diagnosis. In Section IV, Dr. Charlotte Niemeyer describes a new classification of myelodysplastic and myeloproliferative diseases in childhood, which has greatly facilitated the diagnosis of myelodysplastic syndromes and juvenile myelomonocytic leukemia. The recent discovery of somatic mutations in PTPN11 has improved the understanding of the pathobiology and the diagnosis of juvenile myelomonocytic leukemia. Together with the findings of mutations in RAS and NF1 in the other patients, she suggests that pathological activation of RAS-dependent pathways plays a central role in the leukemogenesis of this disease. She then describes the various treatment approaches for both juvenile myelomonocytic leukemia and myelodysplastic syndromes in the US and Europe, emphasizing the differences between childhood and adult cases for the latter group of diseases. She also raises some controversial issues regarding treatment that will require well-controlled international clinical trials to address.

Fatal pulmonary hemorrhage associated with micrococcal infection in two children with acute lymphoblastic leukemia

Pulmonary hemorrhage is a rare cause of death in patients with acute leukemia. Within a 2-month period the authors observed two fatal pediatric cases, which were associated with opportunistic organisms of the genus Micrococcus. Both patients were receiving consolidation treatment for acute lymphoblastic leukemia. The authors discuss the causes of pulmonary hemorrhage in patients with leukemia and review the relevant literature. Micrococci have previously been considered as non-pathogenic, but there is considerable evidence for morbidity and mortality occurring, particularly in immunocompromised patients. The authors propose that micrococcal infection may have been a major predisposing factor for pulmonary hemorrhage in these thrombocytopenic patients.

Prognostic factors in childhood acute lymphoblastic leukemia

Approximately 80% of children and adolsecents with acute lymphoblastic leukemia (ALL) can be cured. To reduce the rate of relapses, but also to limit treatment toxicity, risk-adapted treatment has been attempted after identifying the most specific prognostic factors. In addition to clinical factors such as age and WBC, or factors of the leukemic cell such as the immunphenotype and the cytogenetics, the in vivo response to therapy has evolved as the most important predictor for relapse. The lack of specificity of most prognostic factors stimulated the search for more relevant parameters. Detection of residual disease at defined timepoints by cytomorphology can provide specific prognostic information, which allows to define new risk groups. Detection of minimal residual disease (MRD) by identifying clone-specific T-cell receptor- (TCR) or immunglobuline (Ig) gene rearrangements is currently being evaluated to extend this approach of testing the individual's sucsceptibility to therapy. The high sensitivity of the method when indicating fast clearance of leukemia might eventually spare some patients of inadequately toxic therapy. Persistent disease is an indication for treatment modification and intensification. If standardized tools are used for treatment response evaluation, logistics and quality controls are demanding but essential for the reliable conduct of such clinical studies.

Risk classification at the time of diagnosis differentially affects the level of residual disease in children with B-precursor acute lymphoblastic leukemia after completion of therapy

We have previously reported that children with B-precursor acute lymphoblastic leukemia (ALL) who remained in remission after successfully completing therapy had leukemia cells detectable by polymerase chain reaction (PCR) (N Engl J Med 1997;336(5):317-23). These patients were treated by an institutional protocol (P89-04) that lacked the post-remission intensification features of the contemporary Berlin-Frankfurt-Münster (BFM) based ALL protocols. In this report, we compared residual leukemia levels for patients on the P89-04 (n=15) and BFM-based Children's Cancer Group (CCG) studies (n=23) and for patients stratified according to risk group. Our goal was to establish which risk factors correlated with level of residual disease. Patients enrolled on the CCG protocols had lower levels of residual disease after completion of therapy than the P89-04 patients (P<0.019). Patients with high-risk disease also had lower levels of residual disease than patients with low risk disease (P<0.0001). Three-way analysis including time off treatment, risk group determined by features at presentation, and treatment protocol showed that risk group was the only significant independent variable (P<0.001).

Clinical and cellular pharmacology in relation to solid tumours of childhood

Our understanding of the clinical and cellular pharmacology of drugs commonly used in the treatment of childhood cancer have increased greatly over the past two decades. However, with the exception of childhood acute lymphoblastic leukaemia (ALL), our current knowledge of factors such as inter-patient pharmacokinetic variability and cellular determinants of chemosensitivity has not been utilized in the design of integrated clinical studies. Recent pre-clinical and clinical evaluation of the topoisomerase I inhibitors topotecan and irinotecan has highlighted the potential importance of pharmacological factors in their effectiveness as cytotoxics. In this review, the clinical and cellular pharmacology of vincristine, actinomycin D, doxorubicin, cyclophosphamide, ifosfamide, cisplatin, carboplatin and etoposide will be discussed in relation to the major paediatric solid tumours. For each disease type, knowledge of the clinical and cellular pharmacology of a candidate drug will be related to pharmacodynamic responses such as response, toxicity and prognosis. For diseases such as Wilms' tumour, osteogenic sarcoma and Ewing's tumour, histological response to initial induction chemotherapy is of prognostic significance, and the depth of response is increasingly recognised as an important determinant of prognosis for high-risk neuroblastoma. For several of these tumour types, the dose-intensity of chemotherapy may be an important variable in determining prognosis. However the relationship between pharmacokinetic variability, cellular pharmacology and the major determinants of chemosensitivity to those drugs employed in first line therapy is unknown. The study of these relationships, by means of up front window studies in children who present with high-risk disease, may be as important as the introduction of new agents. Indeed, the optimisation of current therapies may be required to allow a fully informed selection of those children for whom novel therapies are truly needed. Funding and international collaboration at the clinical and scientific level would be required to achieve these aims.

Newly diagnosed childhood acute lymphoblastic leukemia: update on prognostic factors and treatment

The development of effective therapy for children with acute lymphoblastic leukemia is one of the great successes of clinical hematology andoncology. Fifty years ago, childhood acute lymphoblastic leukemia was universally fatal, but current long-term event-free survival rates are nearly 80%. Despite this improved outcome, there are still many challenges facing investigators today. In some recent clinical trials, the outcome of "high-risk" patients has approached that of "lower risk" patients, suggesting that currently applied clinical factors, such as age and presenting leukocyte count, no longer identify the 20% of newly diagnosed patients who ultimately will relapse. Additionally, therapy remains nonspecific, toxic, and sometimes lethal. As more children with acute lymphoblastic leukemia survive into adolescence and adulthood, there is a need to address the late sequelae of current therapy and to develop more leukemia-specific treatments. Promising avenues of research, which may identify biologically distinctive subsets of acute lymphoblastic leukemia and potential targets for novel therapies, include studies of minimal residual disease, lymphoblast genetics (including genetic profiling studies), and host-related pharmacogenomics.

Economic evaluation of recombinant human granulocyte colony-stimulating factor in very high-risk childhood acute lymphoblastic leukemia

PURPOSE

In a previous randomized study, the authors reported that granulocyte colony-stimulating factor (G-CSF) increased the chemotherapy dose-intensity delivered during the consolidation therapy of high-risk childhood acute lymphoblastic leukemia (ALL). The aim of the current study was to perform an economic evaluation in the same cohort.

METHODS

In this open-label multicenter randomized trial, prophylactic G-CSF was administered after consolidation therapy courses. Economic data were retrospectively quantified for each patient: hospital stays, drugs, and blood products.

RESULTS

Sixty-seven children were enrolled in the very high-risk branch of the FRALLE 93 protocol. Chemotherapy dose-intensity was significantly increased (105 +/- 5% in the G-CSF group vs. 91 +/- 4% in the non-G-CSF group, P < 0.001). The mean total costs per child were not statistically different: 32,309 dollars in the G-CSF group versus 31,569 dollars in the non-G-CSF group. Further analysis per child and per course (R3 or COPADM) demonstrated that the mean cost of hospitalization and the mean cost of intravenous antibiotics were significantly decreased in the G-CSF group after R3 courses (3,857 dollars vs. 4,993.80 dollars, P < 0.001; 171.40 dollars vs. 306.20 dollars, P = 0.029, respectively), but the cost of platelet transfusion was significantly increased (P = 0.03). Conversely, post-COPADM costs were similar. Finally, mean costs per course in the two randomized groups were not significantly different: 5,848.80 dollars versus 6,181 dollars and 7,388.10 dollars versus 6,475.70 dollars for R3 and COPADM, respectively. The 3-year probability of event-free survival between the two groups was not different.

CONCLUSIONS

G-CSF can increase chemotherapy dose-intensity in very high-risk ALL without raising costs, but event-free survival was not improved. The cost benefit of prophylactic treatment by G-CSF relies on the chemotherapeutic regimen given prior to G-CSF administration.

Intensification of therapy for children with lower-risk acute lymphoblastic leukemia: long-term follow-up of patients treated on Children's Cancer Group Trial 1881

PURPOSE

From December 1988 through December 1992, the Children's Cancer Group (CCG) conducted a randomized trial (CCG-1881) designed to evaluate the impact of adding a single delayed intensification phase of therapy to standard therapy for patients with newly diagnosed low-risk acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

Patients (n = 778) with newly diagnosed ALL, 2 to 9 years of age at diagnosis with an initial WBC count less than 10,000/microL, were eligible for this protocol. All patients received induction, consolidation, and interim maintenance phases of therapy over the first 16 weeks. At week 16, patients remaining in remission were randomly assigned to receive or not receive a single 7-week delayed intensification (DI) phase of therapy. Maintenance therapy was given in lieu of or after DI, with total duration of therapy approximately 3 years for boys and 2 years for girls.

RESULTS

Patients randomized to receive DI experienced fewer relapse events in all categories. Kaplan-Meier life-table estimates for continuous complete remission (CCR) at 7 years for the randomized regimens were 77% (SE, 2.4%) for the standard regimen and 83% (SE, 2.7%) for the DI regimen (P =.072). The only prognostic factor of significance post-randomization in this selected low-risk population was the day 14 marrow response (P =.0001).

CONCLUSION

The addition of a single DI phase of therapy was well tolerated and augmented 7-year CCR by 6% (SE of the difference, 3.3%), resulting in 26% fewer adverse events. Overall survival for eligible patients at 7 years is 90% (SE, 1.2%).

Prognostic significance of the TEL-AML1 fusion gene in pediatric acute lymphoblastic leukemia in Turkey

PURPOSE

The t(12;21) translocation is the most common reciprocal chromosomal rearrangement in pediatric acute lymphoblastic leukemia (ALL). This translocation fuses two genes, TEL and AML1, and results in the production of the TEL-AML1 fusion protein. The authors investigated the incidence and prognostic significance of the TEL-AML1 fusion gene in patients with ALL in Turkey.

METHODS

The authors analyzed 219 children with ALL using the reverse transcription-polymerase chain reaction.

RESULTS

The TEL-AML1 fusion transcript was detected in 20.1% (44/219) of newly diagnosed children with ALL. -positive patients had precursor B-cell ALL and were 3 to 10 years old at diagnosis. -positive patients had a significantly lower rate of relapse compared with -negative patients. -positive patients have a higher overall survival rate than -negative patients.

CONCLUSIONS

These data support that the presence of at diagnosis is an independent favorable prognostic indicator in patients with ALL in Turkey.

Treatment of acute lymphoblastic leukemia in Hong Kong children: HKALL 93 study

A population-based multicentre study for childhood acute lymphoblastic leukemia (ALL) was conducted in Hong Kong from 1993 to 1997. One hundred and forty-five newly diagnosed ALL patients were treated by the HKALL 93 protocol. Patients were stratified into three risk groups according to age, presenting white cell count, immunophenotyping and cytogenetic study. The patients received the same induction and early and late intensification at week 5 and week 20. Fifty-eight standard risk (SR) patients received regular intrathecal methotrexate as CNS preventive therapy, while 49 intermediate risk (IR) patients received high dose intravenous methotrexate and regular intrathecal methotrexate. Thirty-eight high risk (HR) patients were treated with prophylactic cranial irradiation and an additional intensification block at week 35. The induction remission rate was 97.2% with 2% induction death. Two patients died during first complete remission. Relapse occurred in 20.7, 42.9 and 42.1% of SR, IR and HR patients respectively. By multivariate logistic regression, age> or =10 years and white cell count> or =100 x 10(9)/l were the two significant variables accounting for mortality. The 5-year overall and event-free survival of the whole group was 81.3 and 62.6% respectively. According to risk groups, the event-free survival was 79, 49 and 61% for SR, IR and HR patients respectively, while the overall survival was 96, 73 and 68% for SR, IR and HR patients respectively. In conclusion, the treatment protocol had low treatment-related mortality but was associated with a rather high relapse rate, especially in IR patients. Salvage therapy achieved sustained second remission in some patients. More intensive treatment especially a late intensification is required to improve the outcome.

Should adolescents with acute lymphoblastic leukemia be treated as old children or young adults? Comparison of the French FRALLE-93 and LALA-94 trials

PURPOSE

To compare pediatric and adult therapeutic practices in the treatment of acute lymphoblastic leukemia (ALL) in adolescents.

PATIENTS AND METHODS

From June 1993 to September 1994, 77 and 100 adolescents (15 to 20 years of age) were enrolled in the pediatric FRALLE-93 and adult LALA-94 protocols, respectively. Among the different prognostic factors, we retrospectively analyzed the effect of the trial on achieving complete remission (CR) and event-free survival (EFS).

RESULTS

Patients were younger in the FRALLE-93 than in the LALA-94 protocol (median age, 15.9 v 17.9 years, respectively), but other characteristics were similar, including median WBC count (18 x 10(9) cells/L v 16 x 10(9) cells/L), B/T-lineage (54 of 23 v 72 of 28 patients), CD10-negative ALL (13% v 15%), and poor-risk cytogenetics (t(9;22), t(4;11), or hypodiploidy less than 45 chromosomes: 6% v 5%). The CR rate depended on WBC count (P =.005) and trial (94% v 83% in FRALLE-93 and LALA-94, respectively; P =.04). Univariate analysis showed that unfavorable prognostic factors for EFS were as follows: the trial (estimated 5-year EFS, 67% v 41% for FRALLE-93 and LALA-94, respectively; P <.0001), an increasing WBC count (P <.0001), poor-risk cytogenetics (P =.005), and T-lineage (P =.01). The trial and WBC count remained significant parameters for EFS in multivariate analysis (P <.0001 and P =.0004). Lineage subgroup analysis showed an advantage for the FRALLE-93 trial for CR achievement (98% v 81%; P =.002) and EFS (P =.0002) in B-lineage ALL and for EFS (P =.05) in T-lineage ALL. Age was not a significant prognostic factor in this population of adolescents.

CONCLUSION

This study's findings indicate that adolescents should be included in intensive pediatric protocols and that new trials should be designed, inspired by pediatric protocols, for the treatment of young adults with ALL.

Importance of minimal residual disease testing during the second year of therapy for children with acute lymphoblastic leukemia

PURPOSE

A high level of minimal residual disease (MRD) after induction chemotherapy in children with acute lymphoblastic leukemia (ALL) is an indicator of relative chemotherapy resistance and a risk factor for relapse. However, the significance of MRD in the second year of therapy is unclear. Moreover, it is unknown whether treatment intervention can alter outcome in patients with detectable MRD.

PATIENTS AND METHODS

We assessed the prognostic value of MRD testing in bone marrow samples from 85 children at 1, 12, and 24 months from diagnosis using clone-specific polymerase chain reaction primers designed to detect clonal antigen receptor gene rearrangements. These children were part of a multicenter, randomized clinical trial, which, in the second year of treatment, compared a 2-month reinduction-reintensification followed by maintenance chemotherapy with standard maintenance chemotherapy alone.

RESULTS

MRD was detected in 69% of patients at 1 month, 25% at 12 months, and 28% at 24 months from diagnosis. By univariate analysis, high levels of MRD at 1 month, or the presence of any detectable MRD at 12 or 24 months from diagnosis, were highly predictive of relapse. Multivariate analysis showed that MRD testing at 1 and 24 months each had independent prognostic significance. Intensified therapy at 12 months from diagnosis did not improve prognosis in those patients who were MRD positive at 12 months from diagnosis.

CONCLUSION

Clinical outcome in childhood ALL can be predicted with high accuracy by combining the results of MRD testing at 1 and 24 months from diagnosis.

Pediatric acute lymphoblastic leukemia

The outcome for children with acute lymphoblastic leukemia (ALL) has improved dramatically with current therapy resulting in an event free survival exceeding 75% for most patients. However significant challenges remain including developing better methods to predict which patients can be cured with less toxic treatment and which ones will benefit from augmented therapy. In addition, 25% of patients fail therapy and novel treatments that are focused on undermining specifically the leukemic process are needed urgently. In Section I, Dr. Carroll reviews current approaches to risk classification and proposes a system that incorporates well-established clinical parameters, genetic lesions of the blast as well as early response parameters. He then provides an overview of emerging technologies in genomics and proteomics and how they might lead to more rational, biologically based classification systems. In Section II, Drs. Mary Relling and Stella Davies describe emerging findings that relate to host features that influence outcome, the role of inherited germline variation. They highlight technical breakthroughs in assessing germline differences among patients. Polymorphisms of drug metabolizing genes have been shown to influence toxicity and the best example is the gene thiopurine methyltransferase (TPMT) a key enzyme in the metabolism of 6-mercaptopurine. Polymorphisms are associated with decreased activity that is also associated with increased toxicity. The role of polymorphisms in other genes whose products play an important role in drug metabolism as well as cytokine genes are discussed. In Sections III and IV, Drs. James Downing and Cheryl Willman review their findings using gene expression profiling to classify ALL. Both authors outline challenges in applying this methodology to analysis of clinical samples. Dr. Willman describes her laboratory's examination of infant leukemia and precursor B-ALL where unsupervised approaches have led to the identification of inherent biologic groups not predicted by conventional morphologic, immunophenotypic and cytogenetic variables. Dr. Downing describes his results from a pediatric ALL expression database using over 327 diagnostic samples, with 80% of the dataset consisting of samples from patients treated on a single institutional protocol. Seven distinct leukemia subtypes were identified representing known leukemia subtypes including: BCR-ABL, E2A-PBX1, TEL-AML1, rearrangements in the MLL gene, hyperdiploid karyotype (i.e., > 50 chromosomes), and T-ALL as well as a new leukemia subtype. A subset of genes have been identified whose expression appears to be predictive of outcome but independent verification is needed before this type of analysis can be integrated into treatment assignment. Chemotherapeutic agents kill cancer cells by activating apoptosis, or programmed cell death. In Section V, Dr. John Reed describes major apoptotic pathways and the specific role of key proteins in this response. The expression level of some of these proteins, such as BCL2, BAX, and caspase 3, has been shown to be predictive of ultimate outcome in hematopoietic tumors. New therapeutic approaches that modulate the apoptotic pathway are now available and Dr. Reed highlights those that may be applicable to the treatment of childhood ALL.

New treatment strategies in childhood acute lymphoblastic leukaemia

Today, 80% of paediatric patients with acute lymphoblastic leukaemia (ALL) can be cured. To reduce the rate of relapses, but also to limit treatment morbidity, risk-adapted treatment has been attempted after identifying the most specific prognostic factors. In addition to clinical factors (e.g. age, WBC), the immunophenotype and cytogenetic results, the early in vivo treatment response as determined by cytology had evolved as the most important predictor for relapse. The lack of specificity of most prognostic factors stimulated the search for more relevant parameters. Detection of minimal residual disease (MRD) at defined time points by identifying clone-specific T-cell receptor- (TCR) or immunoglobulin (Ig) gene rearrangements can provide new, highly specific prognostic information which allows definition of new risk groups. The high sensitivity of the method is a prerequisite for applying treatment reduction in patients with fast clearance of leukaemia. Persistent disease is an indication for treatment modification and intensification. Logistics and quality control are demanding but are essential for the introduction of this new technology into clinical practice.

Methotrexate polyglutamation may lack prognostic significance in children with B-cell precursor acute lymphoblastic leukemia treated with intensive oral methotrexate

BACKGROUND

The purpose of this study was to determine if a correlation exists between clinical outcome and accumulation and polyglutamation of methotrexate by lymphoblasts in vitro in children with B-cell precursor acute lymphoblastic leukemia (BCP-ALL).

PATIENTS AND METHODS

The amount of accumulated methotrexate and of long-chain methotrexate polyglutamates (MTXPG(3-7)) by lymphoblasts was determined in 52 children newly diagnosed with BCP-ALL after incubation with 1 micromol/L [(3)H]MTX for 24 hours in vitro. All patients then received intensive multiagent chemotherapy that used divided-dose oral methotrexate during consolidation and intensive continuation and standard oral weekly methotrexate during maintenance.

RESULTS

Eight patients had a bone marrow relapse at a median of 40.4 months (range 18.5-48.3 months) after diagnosis. The median follow-up for the remaining 44 patients is 69.0 months (range 22-92.8 months). There was no significant difference in the amount of accumulated methotrexate (1450.0 +/- 896.3 vs. 640 +/- 472.5 pmol/10 cells) or of accumulated MTXPG (1450.0 +/- 919.4 vs. 617.4 +/- 482.7 pmol/10(9) cells) (median +/- semi-interquartile ranges) between patients who relapsed and those who remained in continuous complete remission. The estimated 5-year event-free survival rate for patients whose lymphoblasts accumulated more than 500 pmol MTXPG(3-7)/10(9) cells was 80.0% +/- 7.3% versus 90.5% +/- 6.4% for those whose lymphoblasts accumulated less than 500 pmol MTXPG(3-7)/10(9) cells.

CONCLUSIONS

In the context of effective prolonged divided-dose oral methotrexate-based therapy in the treatment of BCP-ALL, methotrexate accumulation and polyglutamation no longer seem to have prognostic significance.

Racial and ethnic differences in survival of children with acute lymphoblastic leukemia

Black children with acute lymphoblastic leukemia (ALL) have poor outcomes, but limited information is available for children from other racial and ethnic backgrounds, such as Hispanic and Asian. We undertook a retrospective cohort study of children with ALL treated on Children's Cancer Group therapeutic protocols to determine outcomes by racial and ethnic backgrounds of patients treated with contemporary risk-based therapy. In total, 8447 children (white, n = 6703; Hispanic, n = 1071; black, n = 506; and Asian, n = 167) with newly diagnosed ALL between 1983 and 1995 were observed for a median of 6.5 years. Analysis of disease outcome was measured as overall survival (OS) and event-free survival (EFS) and was adjusted for known predictors of outcome including clinical features, disease biology, socioeconomic status, and treatment era (1983-1989 vs 1989-1995). There was a statistically significant difference in survival by ethnicity (P <.001). Five-year EFS rates were: Asian, 75.1% +/- 3.5%; white, 72.8% +/- 0.6%; Hispanic, 65.9% +/- 1.5%; and black, 61.5% +/- 2.2%. Multivariate analysis revealed that when compared with white children, black and Hispanic children had worse outcomes and Asian children had better outcomes after adjusting for known risk factors. The poorer outcomes among black children were most apparent among patients with standard-risk features (relative risk [RR], 2.0; 95% confidence interval [CI], 1.6-2.5), whereas poorer outcomes in Hispanic children (RR, 1.4; 95% CI, 1.2-1.6) were most evident among patients with high-risk features. Asian children had better outcomes than all racial and ethnic groups among high-risk patients, particularly in the recent era (5-year EFS, 90.9% +/- 6.1%). Racial and ethnic differences in OS and EFS persist among children with ALL who receive contemporary risk-based therapy. Future studies should focus on reasons-perhaps compliance or pharmacogenetics-for those differences.

Treatment of unresectable and metastatic hepatoblastoma: a pediatric oncology group phase II study

PURPOSE

To estimate the disease-response rate, proportion of patients whose tumors can be made resectable, event-free survival (EFS), and toxicity in children with unresectable or metastatic hepatoblastoma (HB) after sequential treatment with the following: (1) carboplatin (CARBO); (2) CARBO, vincristine, and fluorouracil (CARBO-VCR-5-FU); and (3) high-dose cisplatin and etoposide (HDDP-ETOP).

PATIENTS AND METHODS

Thirty-three assessable patients with stage III (n = 22) and stage IV (n = 11) HB were treated sequentially with one course of CARBO (700 mg/m(2)), followed by three courses of CARBO (700 mg/m(2)), day 0; 5-FU (1,000 mg/m(2)/d), by continuous infusion days 0 to 2; and VCR (1.5 mg/m(2)), days 0, 7, and 14. After that therapy, patients whose tumors were resectable underwent surgery and then received two additional courses of CARBO-VCR-5-FU. Children whose tumors remained unresectable after CARBO-VCR-5-FU or who demonstrated no response or progressive disease during this therapy received two courses of HDDP (40 mg/m(2)/d), days 1 to 5; and ETOP (100 mg/m(2)/d), days 2 to 4.

RESULTS

Five-year EFS estimates were 59% +/- 11% for stage III disease (n = 22) and 27% +/- 16% for stage IV disease (n = 11), respectively (P =.037). Twenty-seven (82%) of 33 patients had at least a partial response to chemotherapy; 18 (55%) of 33 responded to CARBO; 24 (80%) of 30 responded to CARBO and CARBO-VCR-5-FU; and nine (75%) of 12 responded to HDDP-ETOP. Surgical resection was achieved in 19 (58%) of 33 patients, including 15 (68%) of 22 stage III patients and four (36%) of 11 stage IV patients. Five-year EFS for patients whose tumors were completely resected was 79% +/- 10%.

CONCLUSION

Patients treated sequentially with CARBO, CARBO-VCR-5-FU, and HDDP-ETOP had response rates and EFS comparable to other therapeutic regimens. This regimen is effective in treating localized, unresectable HB and potentially has less toxicity than other regimens. Novel approaches are needed for patients with metastatic disease.