Acute lymphoblastic leukemia: current status of therapy in children

Long-term results of four consecutive trials in childhood ALL performed by the ALL-BFM study group from 1981 to 1995. Berlin-Frankfurt-Münster

Four thousand, four hundred and forty eligible children of up to 18 years of age were treated in four consecutive trials between 1981 and 1995 with the treatment protocols of the Berlin-Frankfurt-Münster (BFM) study group for childhood acute lymphoblastic leukemia (ALL). The probability for event-free survival (pEFS) at 8 years improved from 65.8% in study ALL-BFM 81 to 75.9% in study ALL-BFM 90. The cumulative incidence of recurrences with CNS involvement was 10.1% and 9.3% in studies ALL-BFM 81 and 83, but was reduced to less than 5% in study ALL-BFM 90 (for isolated CNS relapses from 5.3% in study ALL-BFM 81 to 1.1% in study ALL-BFM 90). Four major findings were derived from this series of trials performed by 37 to 96 centers in Germany, Austria, and Switzerland: (1) Reintensification is a crucial part of treatment, even in low risk patients; (2) presymptomatic cranial radiotherapy can be safely reduced to 12 Gy, or even be eliminated if it is replaced by early intensive systemic and intrathecal methotrexate applied; (3) maintenance therapy given a total of 24 months from diagnosis provides a lower rate of systemic relapses than treatment for 18 months; (4) inadequate response to an initial 7-day prednisone window (combined with one intrathecal injection of methotrexate on day 1) defines about 10% of the patients with a very high risk of relapse. For patients with adequate early response (90% of all) an 8-year pEFS of 80% has been achieved in the most recent trial ALL-BFM 90. While it has proven so far to be impossible to improve the outcome for the small group of high risk patients, the number of recurrences could be effectively reduced for the large group of patients responding adequately to the prednisone in vivo sensitivity test. Apart from inadequate prednisone response, patients with hyperleukocytosis, age <1 year, or the presence of the Philadelphia-chromosome (Ph+ ALL) are at a particularly high risk of failure.

Treatment of patients with acute lymphoblastic leukemia with bulky extramedullary disease and T-cell phenotype or other poor prognostic features: randomized controlled trial from the Children's Cancer Group

BACKGROUND

Children with acute lymphoblastic leukemia with multiple poor prognostic factors and who have a lymphomatous mass at diagnosis, whether of T- or non-T-immunophenotype, are at increased risk of short term remission and extramedullary recurrence, and are in need of better therapies.

METHODS

Six hundred and ninety-four eligible patients ranging in age from 1-20 years were entered on the study. Sixty-five percent of the patients had T-cell immunophenotype. Of these, 678 were randomized to one of four regimens: Regimen A: Berlin-Frankfurt-Munster (BFM) 76/79; Regimen B: LSA2-L2 with cranial irradiation; Regimen C: LSA2-L2 without cranial irradiation; and Regimen D: the New York (NY) regimen.

RESULTS

Complete remission was induced in 97% of patients. The overall event free survival (EFS) +/- the standard deviation was 60 +/- 4% 6 years after diagnosis, in contrast to 36 +/- 6% in a comparable historic group. The EFS of the 371 T-cell patients was 62 +/- 7%. EFS was best on the NY (67 +/- 7%) and the BFM (67 +/- 6%) arms. These were significantly better than the EFS on the 2 LSA-L2 regimens, with an EFS of 53 +/- 8% (Regimen B) and 42 +/- 11% (Regimen C) (P = 0.03 and 0.0003 for NY vs. Regimen B and NY vs. Regimen C; P = 0.01 and 0.0001 for BFM vs. Regimen B and BFM vs. Regimen C). Regimen C had a 3-fold greater central nervous system (CNS) recurrence rate than the identical chemotherapy Regimen B (16 +/- 5% vs. 6 +/- 4%; P = 0.02), although the difference in overall EFS did not reach the required level for significance. Testicular recurrence varied from 2-8% in comparison with 20% in the historic group. EFS was not influenced by age, gender, CNS disease at diagnosis, morphology, or immunophenotype. In addition to treatment regimen and early response rate, initial leukocyte count, hemoglobin level, liver, spleen, and lymph node enlargement, and the presence of a mediastinal mass had univariate prognostic influence on EFS. In multivariate analysis, only the kinetics of response, leukocyte count (unfavorably, P < 0.0001), and mediastinal mass status (favorably, P = 0.01) were prognostic.

CONCLUSIONS

The adverse prognostic implications of lymphomatous ALL can be minimized by the NY and BFM regimens. Cranial irradiation resulted in better CNS disease control when added to the LSA2-L2 regimen, but did not improve the overall disease free survival. With improved systemic chemotherapy, there was no excess of lymph node, testicular, or other local recurrence without prophylactic irradiation to sites of initial bulk disease or to the testes.

Overview of clinical studies of childhood acute lymphoblastic leukemia for more than ten years by the Japanese Children's Cancer and Leukemia Study Group

Since 1981, the Children's Cancer and Leukemia Study Group (CCLSG) has developed a series of protocols for treatment of acute lymphoblastic leukemia (ALL) in childhood. In the first randomized controlled study of the 811 protocol (1981-1983) a comparison of conventional daily 6-mercaptopurine and methotrexate with a pulsed regimen of the two drugs was performed. The superiority of the pulsed regimen was shown. In the next 841 protocol (1984-1987) a comparison of two drugs and three drugs during induction therapy was conducted. The three-drug regimen resulted in a significantly higher event-free survival (EFS) rate. In the 874 protocol (1987-1990) two regimens with or without cranial irradiation were randomly compared, and there was no significant difference between the two regimens for the standard-risk group. To further improve the EFS rate a risk group-directed protocol 911 was conducted starting in January 1991. Life-table analysis of serial CCLSG protocols revealed that the outcome of overall ALL has gradually improved with an increase of the EFS rate; 41.4% +/- 3.6% at 14 years for the 811 protocol, 51.3% +/- 3.5% at 11 years for the 841 protocol, 56.7% +/- 3.1% at 8 years for the 874 protocol, and 78.2% +/- 3.1% at 4 years for the more recent 911 protocol.

Active immunization of children with leukemias and lymphomas against infection by hepatitis B virus

Engerix B vaccine was administered to 54 children with leukemias and lymphomas aged from 2 to 15 years. In 36 cases chemotherapy was completely stopped, and 18 cases were receiving maintenance treatment. Engerix B was given at 0, 1, 2 and 6 months in a dose of 20 micrograms to children < 10 years, and 40 micrograms to older patients. The effectiveness of active immunization was demonstrated after complete therapy cessation in 88% of cases. The levels of antibodies determined 1 year after primary vaccination remained high, and in most of the vaccinated children they were > 1000 mIU/mL. In children vaccinated in the course of maintenance treatment the levels of antibodies did not give sufficient protection against infection.

Outcome after cessation of therapy in childhood acute lymphoblastic leukaemia. The Associazione Italiana Ematologia ed Oncologia Pediatrica (AIEOP)

A total of 2192 children with acute lymphoblastic leukaemia who had reached cessation of therapy in complete remission were followed for a median time of 52 months after treatment suspension. Of the 485 relapses observed, 62.3% occurred in the first year off therapy and 68.9% involved the bone marrow. Eight relapses were reported more than 5 years (62-143 months) after treatment withdrawal. Males fared worse than females consistently, experiencing 1.5 times more relapses (P < 0.0001). Thirteen patients died in continuous complete remission, 5 because of non-neoplastic central nervous system complications. There were 11 second solid malignancies, 8 of them in the central nervous system; 9 subjects presented an haematopoietic malignancy after ALL. The projected event-free survival at 8 years is 73%. Twenty-two of the 171 young adults (age > 20 years) were married and 16 have had 21 healthy children. Twenty-four per cent of patients experienced an unfavourable event. Relapses accounted for 93% of failures. Central nervous system late effects and second malignancies were the major causes of non-leukaemic morbidity and mortality.

CD7+, CD4-/CD8- acute leukemia with t(11;14)(p15;q11) in a child

A t(11;14)(p15;q11) was the sole chromosome abnormality observed in the malignant cells of a 10-year-old boy with acute leukemia. Morphologically, these cells were classified as L1 by the criteria of the French-American-British Working Group. Cytochemical analysis revealed that the leukemic cells were negative for Sudan Black B, periodic acid Schiff, and esterases, and positive for acid phosphatase. Immunophenotyping disclosed that the cells expressed a very immature antigenic profile [CD34+, CD7+, cytoplasmic CD3+, membrane CD3-, CD4-, and CD8-]. In spite of very intensive chemotherapy, complete remission was never induced, and the child died of progressive disease. The relationship of this case to other reported cases of acute leukemia arising from immature pluripotent hematopoietic cells is discussed.

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

One hundred six children with newly diagnosed non-T-, non-B-cell acute lymphoblastic leukemia (ALL) were treated in a Pediatric Oncology Group (POG) pilot study in which six courses of intermediate-dose methotrexate (MTX) and cytosine arabinoside (Ara-C) (1 g/m2 each) were added to a "backbone" of standard continuation therapy. The dose and sequence of MTX/Ara-C administration were based on a preclinical model that demonstrated synergism between MTX and Ara-C. Poor-risk patients (n = 49) were assigned to "up-front" therapy, in which the MTX/Ara-C courses were administered during the initial 15 weeks of remission. Standard-risk patients (n = 57) were assigned to "spread-out" therapy, in which the MTX/Ara-C courses were interspersed at 12-week intervals within continuation treatment. Toxicity after intermediate-dose MTX/Ara-C, principally neutropenia and fever, was judged significant but manageable. Unexpectedly, the incidence of fever and neutropenia less than 500/mm3 was greater after "spread-out" therapy (38%) than after "up-front" therapy (6%). At 4 years, the Kaplan-Meier estimate of event-free survival (EFS) is 71% (+/- 7%) for standard-risk patients and 53% (+/- 8%) for poor-risk patients. The results of this pilot study support the use of intermediate-dose MTX/Ara-C in additional studies.

Late effects of antileukemic treatment

Increasing numbers of childhood ALL survivors have increased the need to assess the physical and psychosocial functioning of this group in a careful manner. This article reviews data on the frequency and types of second malignancies, structural and functional changes in the central nervous system, endocrine effects on growth and reproduction, and psychosocial aspects of development. Most long-term survivors of ALL do not have serious or life-threatening medical problems; however, medical and psychosocial problems may not be insignificant and may require coordinated management over prolonged periods.

Comparison of intermittent or continuous methotrexate plus 6-mercaptopurine in regimens for standard-risk acute lymphoblastic leukemia in childhood (JCCLSG-S811). The Japanese Children's Cancer and Leukemia Study Group

From 1981 to 1983, 131 previously untreated patients with acute lymphoblastic leukemia (ALL) standard-risk group were entered to the protocol JCCLSG-S811. Of 119 eligible patients, 115 (96.6%) attained complete remission by treatment with prednisone (PRD) plus vincristine (VCR) or vindesine (VDS). After preventive central nervous system (CNS) therapy including 18 Gy cranial irradiation and three doses of intrathecal methotrexate (MTX), the patients were assigned randomly to the two maintenance chemotherapies, Regimen A and Regimen B. Regimen A (intermittent regimen) consisted of PRD (120 mg/m2/day by mouth for 5 days) plus 6-mercaptopurine (6MP) (175 mg/m2/day by mouth for 5 days) plus VCR (2.0 mg/m2 intravenously) alternating biweekly with MTX (225 mg/m2 intravenously). Regimen B (continuous regimen) consisted of 6MP (50 mg/m2/day by mouth) plus MTX (20 mg/m2/week by mouth) combined with pulses of PRD and VCR (the same dosages as Regimen A) every 4 weeks. As the late intensification therapy (LIT), five courses of high-dose MTX (2000 mg/m2 per dose per week intravenously for three doses every 12 weeks) with leucovorin rescue were administered to all patients who were in continuous complete remission (CCR) for more than 2 years. Sixty and 55 patients, respectively, were registered in Regimen A and B. The CCR rates in Regimen A and B were 75.1% +/- 5.8% (mean +/- 1 SE) and 49.7% +/- 7.3% (P less than 0.01) at 4 years, and 72.1% +/- 6.3% and 49.7% +/- 7.3% (P less than 0.05) at 5 years, respectively. In Regimen B, CNS and testicular relapses increased after 3 years of CCR. In addition, the patients in Regimen B had a much higher incidence of infections than Regimen A. The LIT did not seem to have important effects on the duration of CCR. From these data we conclude that the intermittent cyclic regimen of 6MP and MTX may be more effective as compared to the continuous administration of these drugs in the maintenance chemotherapy.

No adverse prognostic influence of hepatitis B virus infection in acute childhood lymphoblastic leukemia

In the years 1980-1985 72 children with acute lymphoblastic leukemia were diagnosed and treated by intensive combination chemotherapy (BFM protocols 79, 81, 83). Of these children 33 acquired a Hepatitis B-virus-carrier state with 1983 as the peak year of incidence. Both groups of patients, the infected and the uninfected ones, were comparable as to prognostic factors. All except 8 patients are off chemotherapy after a total duration of treatment of 1 1/2 or 2 years. Probability for event-free survival (life table analysis, maximum observation time 82 months, minimum 12 months) is equal (0.77 vs. 0.75) in both groups. With 3 exceptions, all HBV-infected patients still carry the HBs-antigen in the serum; 22 of the 30 living patients in the infected group developed anti-HBc.

High risk lymphoblastic leukemia in children: prognostic factors and management

Most of the presenting clinical and biological features that have prognostic significance in childhood acute lymphoblastic leukemia are closely related, although they are not equally important. The predictive value of these factors can vary with the efficacy of the therapy delivered. Although there are no uniform criteria to define a high-risk group, an initially high leukocyte count and an age less than 1 or greater than 10 years at diagnosis are universally accepted as the most powerful indicators of a poor outcome. With advances in immunology and genetics, blast cell immunophenotypes and karyotypic abnormalities have emerged as independently significant prognostic factors. With this information, therapy can be tailored for patients at various risks of treatment failure. Using early aggressive therapy, more than 60% of patients are expected to be long-term survivors, but better therapy is still needed for those at high risk of relapse. Innovative approaches, such as bone marrow transplantation, phenotype-specific treatment, or pharmacokinetic-directed therapy, are being tested.

Intensive consolidation chemotherapy for acute lymphoblastic leukaemia (UKALL X pilot study)

Eighty two children with acute lymphoblastic leukaemia presenting at this hospital received one or two modules of intensive chemotherapy to consolidate remission. Modules were given after four and roughly 19 weeks on treatment. Each included two doses of daunorubicin (45 mg/m2/day), cytosine arabinoside (100 mg/m2 twice daily X 5), etoposide (100 mg/m2/day X 5), and 6-thioguanine (80 mg/m2/day X 5). A total of 132 courses were given. This study included all new patients except girls aged 1-14 years with presenting leucocyte count less than 20 X 10(9)/l. Twenty patients with recurrent disease were also included. The first 32 patients were given cytosine as a 24 hour infusion, but combined with the other agents this was associated with severe intestinal toxicity, which necessitated a change to a less toxic 12 hourly bolus regimen. The complications of the module are reviewed in terms of myelosuppression, enterotoxicity, infection, and other clinical problems encountered. All patients became profoundly neutropenic and thrombocytopenic. The latter was significantly more severe after cytosine infusion. Overall, 64% received platelet transfusions and 85% were re-admitted with fevers requiring intravenous antibiotics for between four and 56 days. Gastrointestinal toxicity with the modified module occurred in 38% of patients and was severe in 13%. This intensification module has been adopted by the Medical Research Council Working Party on Childhood Leukaemia for use in a multicentre study (UKALL X) and the details of the problems encountered in the pilot study may be of value to other centres now using this protocol.

The role of massive therapy with autologous bone marrow transplantation in Burkitt's lymphoma

Burkitt's lymphoma has proved to be a very useful model for the evaluation of both massive therapy regimens and purging techniques. Results from several centres now confirm a number of general principles in relation to the use of ABMT procedures in this tumour. Patients in whom conventional chemotherapy has failed can be cured by massive therapy but this should be limited to those who have responded to salvage regimens or have only achieved first PR. Chemoresistant relapse is unlikely to be cured and the high probability of a transient response does not justify the procedure in such cases. Important ongoing clinical studies include the use of ABMT in first CR for CNS disease or B-cell ALL. Results in allogeneic grafts suggest that current massive therapy regimens are curative in only 20-50% of patients (Appelbaum and Thomas, 1983) and new combinations are, therefore, still required. Phase I and II studies in patients with 'resistant relapse' are investigating the use of sequential high-dose alkylating agents and role of TBI. It is of particular importance to develop effective conventional 'salvage' regimens. Recent experience indicates that the combination of high-dose cisplatin and VP 16 is useful; other possibilities include high-dose interferon and high-dose cytarabine. Purging techniques in BL are now at an advanced stage and the combination of immunological and chemical treatments, once of proven efficacy in individual patients at a laboratory level, should be the subject of randomized studies.

Adult acute lymphoblastic leukaemia: a study of prognostic features and response to treatment over a ten year period

Between 1974 and 1984 69 adults with acute lymphoblastic leukaemia (ALL) were treated with two different protocols. Fifty-four (78%) of the patients entered complete remission (CR); 27 of these then received a consolidation protocol consisting of daunorubicin, cytosine arabinoside and 6-thioguanine, followed by two courses of intravenous methotrexate 500 mg m-2 with folinic acid rescue. All patients received intrathecal methotrexate and cranial irradiation (24 Gy) followed by maintenance therapy with 6-mercaptopurine and methotrexate for at least 2 years. The median survival for all patients was 23 months from the time of presentation with an actuarial 5-year survival of 21%. The actuarial chance of surviving 5 years in CR for patients receiving the consolidation protocol was 38% compared to 19% for patients receiving no consolidation (P = NS). Only patient age and white cell count at presentation were found to influence the chance of achieving CR and the chance of overall survival. The presence or absence of c-ALL antigen did not influence prognosis. Patients younger than 35 years with low white cell counts at presentation (less than 10 X 10(9)1(-1] had a particularly good prognosis but no patient with T-ALL and no patient older than 50 years old at diagnosis survived more than 18 months.

The enigma of testicular leukemia: a critical review

Isolated testicular relapse (T.R.) in acute lymphoblastic leukemia (ALL) has an overall incidence of 10% and affects mainly patients off therapy. Multivariate analysis of pretreatment characteristics has shown that lymphadenopathy and splenomegaly are independently associated with increased risk of T.R. during maintenance and off therapy, respectively. Sequential biopsy studies have demonstrated that testicular biopsies are unable to detect scanty infiltrates and have no practical utility. Prophylactic gonadal irradiation produced equivocal results and should not be used because of its sterilizing effect. Intensive multi-drug regimens or prolonged maintenance were unable to substantially reduce T.R. rate. On the contrary, intermediate-dose methotrexate (IDM) early in remission has almost abolished T.R. These findings strongly support the hypothesis that testicular interstitium is a very peculiar site where blasts are partially protected from the drug action; high drug concentrations are required for the optimal cytocidal effect. There are sufficient clues of a link between the excess of late marrow relapse in male sex and the capacity of testes of harboring blasts. Therefore IDM early in remission should be routinely adopted for prevention of testicular leukemia and its potential of late spread.