Early response to induction therapy as a predictor of disease-free survival and late recurrence of childhood acute lymphoblastic leukemia: a report from the Childrens Cancer Study Group

Treatment of high-risk acute lymphoblastic leukemia in children using the AL851 and ALHR88 protocols: a report from the Kyushu-Yamaguchi Children's Cancer Study Group in Japan

A total of 125 children, who were diagnosed as having high-risk acute lymphoblastic leukemia (ALL), were treated with two consecutive protocols designated as AL851 (1985-1988) and ALHR88 (1988-1990). All patients received induction therapy consisting of vincristine (VCR), prednisolone (PSL), daunorubicin (DNR), and I-asparaginase (I-Asp). In the ALHR88 protocol, the patients whose blasts in the bone marrow (BM) were > or = 25% on day 14 of induction therapy and who were classified into T-cell type received additional cytosine arabinoside (AraC). After consolidation with intermediate-dose methotrexate (MTX), reinduction therapy including VCR, dexamethasone, and adriamycin followed by high-dose AraC was done for all patients. Intrathecal MTX and 24Gy of cranial irradiation were used to prevent central nervous system leukemia. A maintenance therapy consisting of 6-mercaptopurine, cyclophosphamide, MTX, DNR, VCR, and AraC was administered for 3 years after achieving a complete remission (CR). CR was achieved in 51/55 (92.7%) for AL851 and 68/70 (97.1%) for ALHR88. The 5-year event-free survival rates were 49.1 +/- 6.7% in AL851 and 62.5 +/- 6.1% in ALHR88. The factors related to a poor prognosis were a high initial leukocyte count of greater than 50 x 10(9)/L (P < 0.001), an L2 morphology of leukemic cells by FAB classification (P = 0.009), the chromosomal abnormality (P = 0.004) and high residual leukemic cells in BM (> or = 25%) on day 14 of induction therapy (P < 0.001). Taking these factors into consideration, more intensive protocols were started in 1990 for the patients with high-risk ALL.

Accumulation of methotrexate polyglutamates in lymphoblasts is a determinant of antileukemic effects in vivo. A rationale for high-dose methotrexate

Methotrexate (MTX) is one of the most widely used drugs for the treatment of childhood acute lymphoblastic leukemia (ALL) and is commonly given in high doses. However, the rationale for high-dose MTX (HDMTX) has been challenged recently. To determine whether higher MTX polyglutamate (MTXPG) concentrations in ALL blasts translate into greater antileukemic effects, 150 children with newly diagnosed ALL were randomized to initial treatment with either HDMTX (1,000 mg/m2 intravenously over 24 h) or lower-dose MTX (30 mg/m2 by mouth every 6 h x 6). ALL blasts accumulated higher concentrations of MTXPG and long-chain MTXPG (MTXPGLC) after HDMTX (P < 0.00001). Of 101 patients evaluable for peripheral blast cytoreduction, MTXPG concentrations were higher in patients whose blast count decreased within 24 h (P = 0.005) and in those who had no detectable circulating blasts within 4 days (P = 0.004). The extent of inhibition of de novo purine synthesis in ALL blasts was significantly related to the blast concentration of MTXPGLC (IC95% = 483 pmol/10(9) blasts). The percentage of patients with 44-h MTXPGLC exceeding the IC95% was greater after HDMTX (81%) than LDMTX (46%, P < 0.0001). These data indicate that higher blast concentrations of MTXPG are associated with greater antileukemic effects, establishing a strong rationale for HD-MTX in the treatment of childhood ALL.

Acute lymphoblastic leukemia. A comprehensive review with emphasis on biology and therapy

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children. It is now curable in 60-70% of children. Most of the current understanding of the biology and treatment of ALL originates from studies of children. In adults, although much progress has been achieved, ALL is curable in only 20-35% of patients.

METHODS

A review of the biology and treatment of ALL from the English literature was performed.

RESULTS

Immunophenotypic and cytogenetic analyses of ALL have contributed to a more rational classification of ALL. These analyses have identified subgroups with poor prognosis or with different therapeutic requirements. Overall, 60-70% of adults with ALL have poor prognostic features, including older age, a high leukocyte count, non-T-cell immunophenotype, Ph-positive genotype, and longer time to achieve a complete remission. These patients have a cure rate of 20-25%, whereas those without these risk factors, have a 60-70% probability of survival. The use of more intensive induction regimens with growth factor support may improve survival rates. Also, intensive consolidation-intensification may improve survival rates. Most patients benefit from maintenance therapy, but the dose schedule must be optimized. Central nervous system (CNS) prophylaxis is beneficial, particularly for patients with a high risk for CNS relapse and when introduced early during induction of remission. Patients with high risk characteristics may benefit from allogeneic bone marrow transplantation (BMT) during first remission, and all other patients may benefit from it during first or subsequent relapse. Autologous BMT may be a valuable option for poor compliant patients.

CONCLUSIONS

Although the prognosis of patients with ALL has improved markedly during the past decades, newer strategies, including more dose-intensive therapy, the search for new drugs, and more target-specific therapy, are needed to improve the current cure rates.

Prognostic value of early response to chemotherapy assessed by the day 15 bone marrow aspiration in adult acute lymphoblastic leukemia: a prospective analysis of 437 cases and its application for designing induction chemotherapy trials

The early response to induction chemotherapy assessed by the percentage of residual blast cells in the D15 bone marrow aspiration was prospectively evaluated in 437 patients included in the same multicentric trial of newly diagnosed adult acute lymphoblastic leukemia (LALA87). Among them, 286 patients (65.4%) had < or = 5% residual blasts and their complete remission (CR) rate at D28 was 91% while the CR rate at D28 was only 34% for the 151 patients (34.6%) with more than 5% blasts at D15 of the induction chemotherapy. The persistence of more than 5% of blasts was associated with a significantly worse overall survival (P < 0.0001) and worse disease-free survival (P = 0.02). These data are used as a support for simulating different strategies in order to improve CR rates in future clinical trials. Results are consistent with the fact that D15 marrow evaluation might be a relevant test allowing an early intensification of a subgroup of patients predicted to fail with conventional induction chemotherapy.

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.

Induction toxicity in childhood acute lymphoblastic leukemia: a comparison of two schedules of daunorubicin administration

The haematological toxicity of the induction phase of chemotherapy for acute lymphoblastic leukaemia (ALL) was compared in two cohorts of patients. The principal difference between these two cohorts was the mode of administration of the anthracycline, daunorubicin (DNR). Both groups received four-drug induction chemotherapy, which produced a high remission rate. Those receiving DNR on days 1 and 2 experienced a profound but shorter period of neutropenia and more severe thrombocytopenia than those who received the DNR weekly. The pattern of hospitalisation and support facilities in the individual unit may determine which regimen is to be preferred. These observations are relevant for the newly diagnosed patient in whom an anthracycline is retained in the induction therapy for ALL.

Early cytoreduction: a major prognostic factor in adult acute lymphoblastic leukemia

Prognostic factors in acute lymphoblastic leukemia (ALL) are used for treatment stratification of ALL. Definition of simple parameters such as the presence or absence of peripheral leukemic cells after one week of treatment could help for stratification. A retrospective study was conducted on 79 previously untreated adult patients with ALL followed in the Hematology department of Hotel Dieu from 1981 to 1991. 84% of patients achieved complete remission (CR), 7% were refractory to induction treatment, and 7 patients (9%) died during the first month after diagnosis. After multivariate analysis the only independent statistically significant factors for achieving CR were the absence of peripheral blast cells at day 7 (PBC D7) (p = 0.009) and age (< 50 years) (p = 0.03). For CR duration the same independent statistically significant factors were found (PBC D7 = 0 versus > 0, p = 0.008; and age < or > or = 30 years, p = 0.045). The PBC D7 value was more significant when circulating blast cells were present at diagnosis. In patients with more than 50,000 PBC at diagnosis, the 10- years event free disease was 62% +/- 20% when PBC were absent at day 7 versus 0% when PBC were present (p < 0.002). All 20 patients with prolonged DFS had PBC D7 = 0 achieving CR by 28 days. The persistence of PBC at Day 7 could be used as a factor to identify a subgroup of poor prognosis adults with ALL.

Applications of cytometry to study acute leukemia: in vitro determination of drug sensitivity and detection of minimal residual disease

Modern clinical applications of cytometry include the determination of the most powerful antileukemic drugs in each patient at the time of diagnosis and the monitoring of residual disease during and off treatment. The precision of in vitro assays to test the susceptibility of cancer cells to cytotoxic drugs depends on the ability to maintain the cells' viability in culture. We found that bone marrow-derived allogeneic stromal cells are critical to prevent death by apoptosis of acute lymphoblastic leukemia (ALL) cells. Thus, we devised an in vitro drug sensitivity assay in which ALL cells are seeded onto stromal cells and viable leukemic cells are counted at the end of cultures by flow cytometry. Our preliminary results indicate that this assay is suitable for evaluating the drug sensitivity of leukemic lymphoblasts and testing the antileukemic activity of potentially effective compounds which have not yet been administered to patients with ALL. The identification of immunophenotypes expressed on leukemic cells but absent or extremely rare among normal hematopoietic progenitors allows close monitoring of the effects of drug treatment in vivo. Phenotypes that afford a detection level of 1 leukemic cell among 10,000 normal bone marrow cells have been identified in 90% of cases of T-ALL, 25% of B-lineage ALL, and 40% of acute myeloid leukemia (AML). In several studies, residual disease emerging during continuation therapy or off treatment almost invariably anticipated overt relapse by 1-7 months. These data indicate the reliability of immunologic techniques to detect occult leukemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of a new intensive therapy for acute lymphoblastic leukemia in children at increased risk of early relapse. The Memorial Sloan-Kettering-New York-II protocol

BACKGROUND

Improved survival of children with acute lymphoblastic leukemia (ALL) has made it more difficult to develop new protocols to further improve results. The authors report the pilot experience with the Memorial Sloan-Kettering-New York-II (MSK-NY-II) protocol, based on the New York regimen with changes made in an attempt to improve efficacy while reducing toxicity.

METHODS

Forty-four of 46 consecutive patients were randomized to one of four regimens varying only in the sequence and mode of administration of the drugs during the first 48 hours of therapy, while the kinetics of the disappearance of the leukemic cells from the bone marrow was monitored with bone marrow aspirates and biopsies on days 0, 2, 7, and 14.

RESULTS

Thirty-two high-risk and 12 average-risk patients were randomized. The marrow contained less than 25% blasts in 74.4% and 92.9% by day 7 and 14, respectively. Ninety-three percent achieved remission. Regimens beginning with daunorubicin achieved a greater and more rapid reduction in leukemic cells than those starting with cyclophosphamide. Daunorubicin infusion produced a more rapid cytoreduction than daunorubicin bolus. Two of 41 patients who achieved remission relapsed, and there was one death in remission. With a median follow-up of 54+ months, the event-free survival (EFS) rate was 86% +/- 10%. Disease-free survival (DFS) rate at 48 months was 93%. The estimated 4-year EFS rate for the high-risk and average-risk patients were 83 +/- 14% and 93 +/- 10%, respectively. Four of 18 patients given daunorubicin bolus and 0 of 18 patients given daunorubicin infusion who were monitored with serial echocardiograms had significant decrease in cardiac function (P = 0.10). The major toxicity of the therapy was infections, with 35% of patients developing serious infections during induction and consolidation. Half the patients had an episode of bacteremia from the venous catheter during the 2 years of maintenance.

CONCLUSIONS

Close monitoring of kinetics of cytoreduction can rapidly distinguish between similar therapies, and the surrogate end-point may reduce the need for the long follow-up periods that may still be required to demonstrate differences in EFS. Continuous infusion of daunorubicin had less cardiotoxicity with faster antileukemic activity than bolus infusion. The MSK-NY-II protocol with a 86% 4-year EFS rate and a 95% DFS rate was a promising new regimen for the treatment of average-risk and high-risk ALL.

Childhood acute lymphoblastic leukemia immunophenotypes and their prognostic significance: experience of the IGCI-study in 389 children. International Society for Chemo-immunotherapy (IGCI-Vienna) Cooperative Group

The prognostic significance of immunophenotype and other features including sex, age, anaemia, WBC, FAB type, and PAS staining were analysed in a group of 389 children newly diagnosed as acute lymphoblastic leukemia (ALL) and treated according to the BFM 1981/1983 protocol. The CR rate was higher (82-94%) in immunophenotypic subgroups defined as 'non-B' compared with B-ALL (54%). The probability of being in CCR at the end of follow up was 0.68 (median. observation, 3 years). Using the stepwise Cox regression analysis the following independent factors predictive of duration of CCR were selected (relative risk in brackets): 1. WBC (> 25G/1:< 25G/1 = 2.0, P = 0.0008), 2. age (> 10y:2-10y = 1.3, P = 0.04), 3. CALLA positivity (neg.:posit. = 2.4, P = 0.04), 4. CALLA within B-cell progenitor ALL (pre;preB,Calla-:Calla+ = 1.7, P = 0.007). T-ALL appeared to have a worse prognosis than U-ALL and B-progenitor derived ALL but it did not retain independent prognostic significance in multivariate analysis.

Cytomorphology of childhood lymphoblastic leukaemia: a prospective study of 2000 patients. United Kingdom Medical Research Council's Working Party on Childhood Leukaemia

Blast cell morphology of children with lymphoblastic leukaemia (ALL) entering two national multicentre trials was prospectively reviewed by three haematologists to define the clinical importance of (a) French-American-British (FAB) classification, (b) the presence of cytoplasmic vacuoles, and (c) the presence of 'hand-mirror' cells. Of 2135 evaluable children, 1907 (89%) had FAB L1 morphology and 228 (11%) L2. (L3 patients were not eligible for the trials in question). L2 patients more frequently had residual disease 14 d after starting treatment and had a significantly inferior disease-free survival, but not if the analysis was stratified for age, sex and diagnostic white cell count (WBC). 627 (29%) had blast cells with cytoplasmic vacuoles, and showed a significant survival advantage over the remainder. Vacuoles were positively associated with a low WBC, age range 1-6 years and blast cell positivity for CD10, but their benign influence was apparent even when these variables were taken into account. 'Hand-mirror' (HM) cells were only studied in UKALL X, and were noted in 316/1402 (23%) children. There appeared to be an inverse correlation between HM cells and cytoplasmic vacuoles and a weak association with T-cell immunophenotype, but no prognostic significance was evident. FAB classification appears to be of less prognostic importance than has previously been supposed, though L2 disease is more resistant to current remission induction regimens. Hand-mirror cells may be more common in T-ALL, but are seen in all types and are not related to prognosis. Cytoplasmic vacuoles are predictive of a good response to current therapeutic schedules even allowing for other prognostic variables, and are the single most important morphological feature relating to prognosis in childhood ALL.

Detection and quantitation of neoplastic cells in acute lymphoblastic leukaemia, by use of the polymerase chain reaction

We report a simple and robust method for sensitive quantitation of leukaemic cells in acute lymphocytic leukaemia. Chain determining region 3 (CDR3) of the immunoglobulin heavy chain gene is a precise genetic marker for a patient's leukaemic clone. Quantitation of the leukaemic lymphocytes was achieved by use of the polymerase chain reaction to detect CDR3 at limiting dilution of DNA samples. Five patients were studied and high levels (1 in 1 to 1 in 10) of leukaemic cells were detected at diagnosis or relapse. Leukaemic cells were detected in remission marrows from three patients, at levels of 1 in 1000 to 1 in 100,000. All five patients showed a 1000 to 100,000-fold reduction in the levels of leukaemic cells after induction therapy. This technique should prove useful for monitoring therapy and may help predict outcome.

The value of the immunological subtypes and individual markers compared to classical parameters in the prognosis of acute lymphoblastic leukemia

The value of the immunophenotypical subtypes and individual markers was compared with classical parameters in the prognosis of 150 patients with acute lymphoblastic leukemia (ALL). Regarding the immunophenotype, common-ALL had a better prognosis than T-ALL in the children's group. However, in adults the situation was different since both null and T-ALL patients had longer survival rates than the common pre-B group. Moreover, several individual markers add interesting prognostic information, either in ALL as a whole group or within the different immunophenotypes. Thus, the expression of CD10 and TdT had a significantly favourable influence in the outcome of the whole series of patients; within the T-ALL, those cases positive for CD10 also had a longer median survival (33 versus 17 months). In addition, in the common ALL patients group the expression of a relatively mature B marker--CD20--appeared to have a favourable prognosis (27 versus 13 months). Other non lineage specific markers, such as CD9 and CD38 did not seem to influence survival. Regarding the more conventional parameters, our data suggest that the classical age prognostic classification in children (less than 15 years) and adults can be improved using two cut-off points at 11 and 35 years. Moreover, the multivariate analysis showed that this variable, together with FAB morphology and WBC counts were the best combination of parameters for predicting survival. The present study shows that although the immunophenotype helps us in understanding the biological heterogeneity of ALL, having also prognostic implications, there are other clinical and hematological features that yield stronger prognostic information.

Day 7 marrow response and outcome for children with acute lymphoblastic leukemia and unfavorable presenting features

The percent of marrow blasts on day 7 of therapy was determined for 128 children with previously untreated acute lymphoblastic leukemia and white blood count (WBC) greater than or equal to 50,000/microliters and/or lymphomatous features enrolled in the Childrens Cancer Study Group trial of the Berlin Frankfurt Munster 76/79 regimen (CCG-193P). Patients received four-drug induction therapy including vincristine, prednisone, l-asparaginase, and daunomycin. Ninety-seven patients had fewer than 25% marrow blasts on day 7. Of these, 94 survived and maintained remission through day 28 and were designated early responders. Thirty-one patients had greater than 25% marrow blasts on day 7. Of these, 28 survived and achieved remission on day 28 and were designated late responders. The outcome of patients who underwent a day 7 marrow aspiration was similar to those who did not. Early responders had a 77.4% +/- 4.5% (standard deviation) 3-year estimated disease free survival, while late responders had 47.3% +/- 9.8% (P less than 0.001). Early responders had a superior outcome both in the subset with an initial WBC less than 50,000/microliters (P = 0.025) and in the subset with a WBC greater than or equal to 50,000/microliters (P = 0.01). The day 7 marrow response had prognostic value in this population of children with unfavorable presenting features who received four-drug remission induction therapy.