Intensive chemotherapy for Philadelphia-chromosome-positive acute lymphoblastic leukaemia

Childhood acute lymphoblastic leukaemia with the classic Philadelphia chromosome translocation is fatal in patients treated with chemotherapy alone. We report probable cures in three adolescents and one child who received extensively reinforced, early chemotherapy followed by rotational treatment with pairs of non-cross-resistant drugs. The median duration of leukaemia-free survival in this subgroup is 6.5 years (range 6-8 years). The two patients with long-term bone marrow surveillance for residual disease showed no evidence of the Philadelphia chromosome at 31 and 53 months post-remission. Such intensive chemotherapy is a reasonable option for patients who are not able to undergo bone marrow transplantation.

Epipodophyllotoxins in the treatment of childhood cancer

We reported marked biologic activity with the epipodophyllotoxins in phase I/II studies of childhood cancer conducted in the 1970s. We have since extensively used the combination of teniposide and ara-C in the treatment of acute lymphoblastic leukemia (ALL). Initially we treated patients with refractory disease and found that the combination lacked clinical cross-resistance with standard antileukemic drugs. This formed a rationale to move teniposide and/or etoposide to front-line therapy of childhood ALL. The superior results projected for our last trial, an overall cure rate of about 75%, are attributable in part to early use of epipodophyllotoxins. This class of agents is also used extensively in the treatment of newly diagnosed childhood solid tumors, including neuroblastoma, medulloblastoma, rhabdomyosarcoma, and germ-cell tumors. Secondary leukemias following treatment with epipodophyllotoxins have been reported in a small subset of patients. Current data show that the most important risk factor is the schedule of drug delivery, which has led to appropriate protocol modifications.

Treatment of acute lymphoblastic leukemia. 30 years' experience at St. Jude Children's Research Hospital

BACKGROUND

Therapy for childhood lymphoblastic leukemia has evolved during the past three decades, but key questions about what are the least toxic, most effective forms of treatment remain unanswered because of the lack of comprehensive follow-up information.

METHODS

To assess long-term outcome in the series of clinical trials conducted at St. Jude Hospital, we compared the results of treatment typical of four eras: exploratory combination chemotherapy (era 1, 1962 to 1966; 91 patients), regimens for the control of meningeal leukemia (era 2, 1967 to 1979; 825 patients), limited intensification of therapy (era 3, 1979 to 1983; 428 patients), and extended intensification of therapy (era 4, 1984 to 1988; 358 patients). ("Intensification" refers to strategies of systemic chemotherapy that are more aggressive than conventional ones.) The major end points were survival and event-free survival; we also calculated the relative risk of treatment failure and the rate of relapse or death after treatment ended (post-treatment failure rate).

RESULTS

The probability of event-free survival improved significantly in each successive era (P < 0.001 by the log-rank test), reaching 71 percent in era 4. There was a decrease of approximately 50 percent in the risk of treatment failure from one era to the next in each subgroup of patients defined according to different combinations of the leukocyte count, race, age, and sex. Leukemia appeared to be eradicated in patients who remained in complete remission for three years or more after treatment in era 4. The incidence of death due to nonleukemic causes remained 4 to 6 percent despite the trend toward more intensive treatment. An estimated 765 patients (45 percent) are long-term survivors; most of them (80 percent) have no health problems related to leukemia or its treatment.

CONCLUSIONS

The development and successful application of preventive therapy for meningeal leukemia, followed by the intensification of systemic chemotherapy, has progressively improved the rate of cure of childhood lymphoblastic leukemia, with relatively few adverse sequelae.

Clinical significance of CD34 expression in childhood acute lymphoblastic leukemia

The CD34 antigen was detected on > or = 10% of the blast cells in 235 (70%) of 335 cases of newly diagnosed childhood acute lymphoblastic leukemia (ALL) treated in two consecutive chemotherapy trials. By immunophenotype, the distribution of positive cases favored early pre-B ALL (83%; n = 180) followed by pre-B ALL (61%; n = 89) and then T-cell ALL (46%; n = 61) (P < .001). Among the B-lineage cases, CD34 expression was significantly associated with favorable presenting features: age 1 to 10 years, white race, absence of central nervous system (CNS) leukemia, low serum lactate dehydrogenase level, CD10 expression, and leukemic cell hyperdiploidy (> 50 chromosomes or DNA index > or = 1.16). Event-free survival was clearly superior for patients with CD34+ leukemia (P = .01), with an estimated 83% +/- 6% (SE) of the cohort remaining free of adverse events at 5 years post diagnosis, as compared to 63% +/- 10% of the group without this feature. Multivariate analysis showed that the prognostic influence of the antigen was independent of age, leukocyte count, and other well-recognized factors, suggesting that it would add discriminatory power to current systems of risk assignment. Findings in T-cell ALL were the reverse: CD34 expression showed positive correlations with initial CNS leukemia and CD10 negativity but not with any good-risk presenting characteristics. Log-rank analysis indicated no adverse effect on treatment outcome by CD34 antigen expression, although additional patients with need to be studied to obtain a definitive answer. The opposed clinical associations of CD34 expression in B- and T-lineage ALL may reflect fundamental biologic differences between these leukemia species.

Low leukocyte counts with blast cells in cerebrospinal fluid of children with newly diagnosed acute lymphoblastic leukemia

BACKGROUND

Treatment of the central nervous system is crucial to the successful treatment of acute lymphoblastic leukemia in children. The intensity and timing of the therapy are based on the presence or predicted risk of central nervous system leukemia as assessed according to criteria that remain controversial.

METHODS

The clinical importance of leukemic blast cells detected in cerebrospinal fluid at the time of diagnosis was evaluated in 351 children with acute lymphoblastic leukemia in a randomized trial of intensive chemotherapy. All patients received intrathecal chemotherapy during the first year. Patients considered to be at high risk of relapse because of their clinical and cytogenetic features also received cranial irradiation and intrathecal chemotherapy one year after remission. Patients were considered to have central nervous system leukemia at diagnosis if they had at least 5 leukocytes per microliter of cerebrospinal fluid, with leukemic blast cells apparent in cytocentrifuged preparations, or cranial-nerve palsy; they received additional intrathecal injections of chemotherapeutic agents and cranial irradiation. Patients were retrospectively classified on the basis of cerebrospinal fluid findings: 291 patients had no detectable blast cells, 42 had fewer than 5 leukocytes per microliter and blast cells, and 18 had central nervous system leukemia as defined above. The clinical characteristics and outcomes of treatment in these groups were analyzed.

RESULTS

The five-year probability of survival free of relapses confined to the central nervous system in patients with detectable blast cells and fewer than 5 leukocytes per microliter of cerebrospinal fluid was lower than in patients without blast cells (mean [+/- SE], 87 +/- 13 vs. 96 +/- 2 percent), but was not different from the probability in patients with central nervous system leukemia at diagnosis. All such isolated relapses of leukemia in patients with detectable blast cells occurred during the first year of treatment, before scheduled cranial irradiation. In a multivariate analysis, the presence of cerebrospinal fluid blast cells with fewer than 5 leukocytes per microliter was independently related to the risk of relapse confined to the central nervous system.

CONCLUSIONS

Patients with leukemic blast cells in their cerebrospinal fluid are at increased risk for central nervous system relapse when cranial irradiation is delayed. Such patients require intensified central nervous system treatment early in the course of therapy.

Cytogenetically different leukemic clones at relapse of childhood acute lymphoblastic leukemia

Sequential analysis of blast cell chromosomes in 98 cases of acute lymphoblastic leukemia (ALL) disclosed entirely different karyotypes for nine patients at the time of relapse. The presenting clinical, immunophenotypic, and cytogenetic features of this subgroup were similar to those of the 89 patients without major karyotypic shifts. The median length of initial remissions in these nine patients, all of whom received intensive multiagent therapy, was 24 months (range, 6 to 35); responses to subsequent treatment have been uniformly poor. Prominent cytogenetic changes included a gain of modal chromosome numbers in five cases, a loss of chromosomes in two, and the acquisition of an 11q23 rearrangement in three. We propose several different mechanisms to account for these findings. In one, the presence of an entirely different ALL karyotype at relapse may represent induction of secondary leukemia analogous to the well-described entity of epipodophyllotoxin-related secondary acute myeloid leukemia (AML).

Candida tropicalis infections in children with leukemia

The Candida species account for approximately three-fourths of fungal infections in patients with cancer. Although Candida albicans is the most frequent cause, C. tropicalis is increasingly implicated as an important pathogen. Over a 12 year period 19 children treated for leukemia at our institution developed C. tropicalis infections. We describe their clinical presentation, extent of fungal infection, treatment, and outcome. Fungemia without meningitis in 11 children was treated successfully, whereas C. tropicalis meningitis in 7 children was uniformly fatal. An additional patient had unsuspected, widespread infection detected at autopsy. Multiple sites, including the cerebrospinal fluid yielded C. tropicalis. Previously reported risk factors including neutropenia, broad-spectrum antibiotic usage, corticosteroid therapy, and total parenteral nutrition were observed in our cases. A high index of suspicion and the early use of aggressive antifungal therapy are critical to the successful management of C. tropicalis infections in children with leukemia.

N-CAM (CD56) expression by CD34+ malignant myeloblasts has implications for minimal residual disease detection in acute myeloid leukemia

The molecules detected by CD34 and CD56 monoclonal antibodies are simultaneously expressed in approximately 20% of childhood acute myeloid leukemia (AML) cases, and this phenotype is associated with t(8;21)(q22;q22) karyotype. By contrast, bone marrow samples from normal donors (n = 5) and patients with CD56- malignancies in remission (n = 8) contained fewer than 1 in 10,000 CD34+/CD56+ cells. CD34+/CD56+ cells were readily identified when leukemic blasts were admixed with normal bone marrow cells at a 1:10(4) ratio. Cells expressing both markers (0.01-0.8% of mononuclear cells) were also found in bone marrow samples from two of three children with CD34+/CD56+ AML studied, who were in remission by morphologic criteria. In one of these patients, detection of residual disease by flow cytometry anticipated overt hematologic relapse. A second patient, in whom minimal residual disease was detected prior to and following autografting, died of unrelated causes while in morphologic remission. The third patient had no detectable residual disease prior to and following autografting, and is still in morphologic and immunologic remission 100+ days post-transplant. The expression of CD56 on CD34+ cells is leukemia-associated and offers a means of identifying extremely small numbers of these cells by flow cytometry. This sensitive approach can now be used to assess the efficacy of treatment and detect early relapse in patients with CD34+/CD56+ AML.

Progress in the treatment of adolescents with acute lymphoblastic leukemia

BACKGROUND AND METHODS. The authors studied the clinical and biologic features and treatment response of 358 children with acute lymphoblastic leukemia (ALL), including 90 adolescents, treated on a single multiagent protocol (St. Jude Total Study XI, 1984-1988). This was done to clarify whether the disease differed in adolescents and to determine the degree of improvement in treatment outcome produced by this modern intense chemotherapy.

RESULTS

Compared with the younger children (1-9 years of age; infants 1 year old or younger excluded; n = 257), adolescents (10-18 years of age; n = 90) were significantly more likely to have adverse prognostic features, including T-cell phenotype, L2 blast cell morphologic characteristics, blasts with negative findings for common ALL antigen, and ploidy other than hyperdiploidy greater than 50. Eighty-six of the 90 (96%) adolescents achieved a complete remission, a rate similar to that of the children (97%). Although the event-free survival (EFS) of adolescents was shorter than that of younger children (5-year EFS of 66 +/- 8% versus 75 +/- 5%, respectively; P = 0.04), in this analysis of consecutively treated patients with ALL it showed a significant statistical and clinical improvement as compared with that in our previous study (St. Jude Total Study X, 1979-1983; 5-year EFS rate of 66 +/- 8% versus 37 +/- 5%, respectively; P < 0.001). Within the adolescent group treated on Total Study XI, the EFS was worse for those older than 15 years of age than for those 10-14 years old (46 +/- 15% versus 75 +/- 8%, respectively; P = 0.007). Toxic effects primarily included myelosuppression without severe sequelae. Approximately 96% of the therapy was administered in the outpatient setting.

CONCLUSIONS

The increased frequency of unfavorable clinical and biologic features undoubtedly accounts for the poorer prognosis of adolescents with ALL, a conclusion supported by the lack of independent prognostic importance of age in this study. The authors conclude that approximately two-thirds of adolescents can be cured when treated with this intensive but tolerable therapy, showing that this form of treatment significantly has changed the prognosis of adolescents with ALL.

Treatment of late bone marrow relapse in children with acute lymphoblastic leukemia: a Pediatric Oncology Group study

Children with acute lymphoblastic leukemia (ALL) who have completed 2.5 to 3 years of initial chemotherapy have an off-therapy relapse rate of approximately 20%. In an attempt to improve the survival of children with a late bone marrow (BM) relapse (ie, occurring greater than 6 months after cessation of primary therapy), the Pediatric Oncology Group designed a randomized study to compare the efficacy of doxorubicin/prednisone and cytarabine/teniposide in a multidrug retreatment chemotherapy program. Treatment consisted of remission reinduction with vincristine, prednisone, and doxorubicin, central nervous system prophylaxis with triple intrathecal chemotherapy, and continuation therapy (for 132 weeks) with alternating cycles of oral 6-mercaptopurine/methotrexate and intravenous vincristine/cyclophosphamide. Patients received intermittent courses of either prednisone/doxorubicin (regimen 1) or teniposide/cytarabine (regimen 2) during continuation therapy and a late intensification phase with either vincristine, prednisone, and doxorubicin (regimen 1) or teniposide and cytarabine (regimen 2). One hundred two of 105 evaluable patients (97%) achieved a second complete remission. Twenty-eight of 50 patients on regimen 1 have failed compared with 28 or 52 patients on regimen 2 (log-rank analysis, P = .68), indicating that this trial was inconclusive as to which treatment regimen was superior. The overall 4-year event-free survival for children with a late BM relapse was 37% +/- 6%. Age less than 10 years at initial diagnosis (P < or = .001), white blood cell count less than 5,000/microL at relapse (P = .036) and duration of first remission greater than 54 months (P = .039) were independently associated with a more favorable outcome. While the randomized trial was inconclusive, prolonged second complete remissions were secured in more than one-third of children with a late BM relapse of ALL. The prognostic factors identified may help select children with a late BM relapse who can be successfully retreated with chemotherapy alone.

Clinical significance of CD10 expression in childhood acute lymphoblastic leukemia

The independent significance of CD10 expression in childhood acute lymphoblastic leukemia (ALL) is uncertain because most studies have not adjusted for other risk features, such as age and immunophenotype, or for treatment effects. We reassessed the clinical importance of CD10 expression in patients who received highly effective contemporary treatment. CD10 antigen was detected in blast cells from 384 of 408 patients (94%) with B-lineage ALL and 36 of 90 (40%) with T-cell ALL. In the B-lineage subgroup, CD10 expression was associated with favorable presenting features: age > or = 1 year, lower leukocyte count (< 50 x 10(9)/l), and leukemic cell DNA index > or = 1.16 or hyperdiploidy > 50 chromosomes. One-half of the patients with CD10- B-lineage ALL had 11q23 chromosomal abnormalities. Separate analysis of the marker in T-cell ALL revealed no differences between CD10+ and CD10- cases in clinical features or karyotypic patterns, with the exception of a lower frequency of central nervous system leukemia and a higher frequency of 9p abnormalities in the former subgroup. CD10+ T-cell cases were also significantly more likely than CD10- cases to coexpress CD21, CD1, CD4, or CD8. Lack of CD10 expression was independently associated with an adverse prognosis in T-cell ALL (p = 0.02). However, for the larger subgroup of patients with B-lineage ALL, CD10 expression has no independent prognostic significance.

Disposition of antineoplastic agents in the very young child

Maturation of physiologic process which govern the disposition of pharmacologic agents can yield significant changes in absorption, distribution, metabolism, and elimination of drugs in neonates, infants and children. However, there are very little data concerning the disposition of anticancer drugs in young children. Pharmacokinetic data for six anticancer agents were compared in infants less than 1 year of age and children greater than 1 year of age treated at St Jude Children's Research Hospital. No pharmacokinetic data were available for infants less than 2 months of age. Median methotrexate clearance tended to be lower in four infants (0.26-0.99 years) vs 108 children (1-19 years): 80 vs 103 ml min-1 m-2, respectively (P = 0.01). There was no difference in the median 42 h methotrexate concentration. Teniposide systemic clearance and terminal half-life and cytarabine systemic clearance were not different between the two groups. There was no significant difference in etoposide systemic clearance when normalised to body surface area (ml min-1 m-2), however a significantly lower systemic clearance relative to body weight (ml min-1 kg-1) was observed in two infants, 0.5 to 1 year of age, vs 23 children, 3-18 years of age. Doxorubicin systemic clearance was not significantly different between the two groups when systemic clearance was expressed in ml min-1 kg-1. However, there was a trend toward a lower rate of systemic clearance in ml min-1 m-2 in infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyperdiploid (47-50) acute lymphoblastic leukemia in children

Among ploidy groups in childhood acute lymphoblastic leukemia (ALL), hyperdiploidy 47 to 50 is perhaps the least well known. From December 1979 to December 1990, we successfully studied banded karyotypes in 598 cases of newly diagnosed ALL, of which 86 (14.4%) had modal chromosome numbers of 47 to 50. In this group, the most frequently acquired numerical abnormalities were +21 (n = 34), +X (18), +8 (8), and +10 (7). The chromosomal regions most often affected by structural abnormalities were 1q (n = 13), 6q (12), 12p (18), and 19p (9). Analysis of event-free survival (EFS) for Studies X and XI among patients with hyperdiploid (47 to 50) ALL showed no significant differences in outcome according to the presence (n = 36) or absence (n = 35) of chromosomal translocations (P = .81) or the gain of specific chromosomes (P = .40). Patients with hyperdiploid (47 to 50) ALL treated in a contemporary program of multiagent chemotherapy had a significantly better outcome than did those in an earlier study using less intensive therapy (4-year EFS = 75% [95% confidence interval, 55% to 86%] v 41% [22% to 59%]; P = .006 by the logrank test). Our findings indicate that the adverse prognosis previously attributed to hyperdiploidy 47 to 50 improves significantly with more effective chemotherapy.

Clinical trials of teniposide (VM-26) in childhood acute lymphocytic leukemia

We describe the development of VM-26 (teniposide) as an effective agent in combination chemotherapy for childhood acute lymphocytic leukemia (ALL). Beginning with its paired use with cytarabine for patients relapsing on conventional therapy, teniposide has shown consistent ability to reduce leukemic cell populations not responsive to other agents. Encouraging results in the treatment of refractory ALL led to the decision to incorporate teniposide into combination chemotherapy for patients with newly diagnosed leukemia. This strategy has yielded higher cure rates for subsets of patients at high risk of treatment failure, including those with initial leukocyte counts of more than 100 x 10(9)/L, and may extend remission lengths for all patients, regardless of risk status. In view of the prolonged marrow aplasia seen with use of teniposide and cytarabine as inducing agents, the optimal role of this combination may be that of "remission reinforcement" therapy. Because of its novel mechanism of action, teniposide affords opportunities to develop new drug combinations that may increase the proportion of long-term ALL survivors still further.

Trisomy 21 as the sole acquired chromosomal abnormality in children with acute lymphoblastic leukemia

Most studies of cytogenetic abnormalities in leukemia patients have focused on structural chromosomal rearrangements. Less attention has been paid to the role of single numerical abnormalities in the complex mechanisms of leukemia pathogenesis. We therefore studied 11 cases of acute lymphoblastic leukemia (ALL) with trisomy 21 as the sole chromosomal abnormality, representing 1.8% of 601 completely banded cases of ALL seen during a 10-year period. Bone marrow cells from all but one of these cases also had normal karyotypes, representing 8 to 77% of the completely analyzed metaphases. Each of the five cases tested lacked evidence of trisomy 21 mosaicism of constitutional origin in peripheral blood samples. The presenting features of these five girls and six boys were heterogeneous but tended to reflect lower-risk ALL: median age, 3.3 years (range 1-18 years), median leukocyte count, 11.6 x 10(9)/l (range 1.8-82 x 10(9)/l), white race, and a B-cell precursor immunophenotype. Complete remissions were readily induced in all 11 patients. With follow-up ranging from 1+ months to 6.4+ years, the only relapses have been extramedullary (testis and central nervous system) in two patients, both of whom have since achieved second remissions of greater than 76 and greater than 65 months. Trisomy 21 as the sole chromosomal abnormality in childhood ALL appears related to favorable presenting risk features and may represent a good prognosis subset within the group of patients with 47-50 chromosomes.

Complications and outcome in childhood acute lymphoblastic leukemia with hyperleukocytosis

Hyperleukocytosis (greater than or equal to 100 x 10(9) leukocytes/L) was identified at diagnosis of acute lymphoblastic leukemia in 64 of 358 patients enrolled on St Jude Total Therapy Study XI from February 1984 to September 1988. These children received a seven-drug induction regimen followed by high-dose methotrexate, cranial irradiation at 1 year of remission, and 120 weeks of continuation therapy with rotational administration of four drug pairs. The 27 patients with leukocyte counts greater than or equal to 200 x 10(9)/L underwent initial cytoreduction via leukapheresis or exchange transfusions. The complete remission rate for patients with hyperleukocytosis (94%) was similar to that for the overall series (96%). Stepwise regression analysis showed that hyperleukocytosis was significantly associated with age less than 1 year at diagnosis, T-cell immunophenotype, leukemic cell ploidy less than or equal to 50 chromosomes, organomegaly, and elevated lactic dehydrogenase. The 27 patients with extreme hyperleukocytosis (greater than 200 x 10(9)/L) different from the other 37 children only in a higher frequency of French-American-British (FAB) L2 morphology. Estimated 4-year event-free survival (EFS) was 52% +/- 8% (SE) for patients with hyperleukocytosis versus 79% +/- 4% for patients with leukemic counts less than 100 x 10(9)/L (P less than .0001). Patients with leukocyte counts of 100 to 200 x 10(9)/L had a significantly better EFS than those with counts greater than 200 x 10(9)/L (64% +/- 10% v 34% +/- 14%; P = .04). Thus, the therapy in this trial proved satisfactory for children with leukocyte counts of 100 to 200 x 10(9)/L; further study is needed to improve the outlook for children with counts greater than 200 x 10(9)/L.

Lack of CD45 antigen on blast cells in childhood acute lymphoblastic leukemia is associated with chromosomal hyperdiploidy and other favorable prognostic features

The leukocyte common antigen (CD45) was detected on the surface of leukemic cells in 217 (87%) of 249 cases of newly diagnosed childhood acute lymphoblastic leukemia (ALL). All 55 cases of T-lineage ALL, compared with 159 of 191 B-lineage cases, expressed the CD45 antigen (P = .0005). The frequency of CD45 expression did not differ between cases of early pre-B (CD19+, cytoplasmic mu-) and pre-B (CD19+, cytoplasmic mu+) ALL. Cases of ALL lacking CD45 had significantly lower leukocyte counts (P = .002) and serum lactic dehydrogenase (LDH) levels (P = .007) and were more likely to have leukemic cell hyperdiploidy greater than 50 (P less than .0001) or a DNA index greater than 1.15 (P less than .0001), as compared with cases positive for the antigen. Of the 130 patients whose follow-up duration was sufficient for analysis of event-free survival, the 53 with the highest levels of CD45 expression (greater than or equal to 90%) were the most likely to have an adverse event on intensive multiagent chemotherapy. Patients without detectable CD45 had a negligible risk of failure. This study suggests a relationship between the expression of the CD45 antigen on leukemic lymphoblasts and other biologic factors that influence prognosis in ALL.

Recurrent cerebrovascular accident with L-asparaginase rechallenge

We report a 15-year-old boy diagnosed with acute lymphoblastic leukemia (ALL) in 1983. Induction therapy included L-asparaginase. After the second dose of L-asparaginase, he had a left sided focal seizure and computed tomography (CT) scan of the head showed a right frontal infarct. No further L-asparaginase was given. Complete remission was achieved and he successfully completed therapy in 1986. Eight months later he had an isolated bone marrow relapse. Reinduction therapy included L-asparaginase. After the fourth dose of L-asparaginase, he presented with severe headache and a CT scan showed a right temporal infarct. Repeat infarction on rechallenge with L-asparaginase has not been previously reported. Prophylactic therapy, such as fresh frozen plasma, should be considered before patients, with a previous cerebral insult, are rechallenged with L-asparaginase. However the effectiveness of such therapy has not been established.

Differences in teniposide disposition and pharmacodynamics in patients with newly diagnosed and relapsed acute lymphocytic leukemia

Teniposide, a widely used investigational anticancer drug, is extensively bound to plasma proteins (greater than 95%). The present study evaluated the clearance and pharmacodynamics of total and unbound teniposide in patients with acute lymphocytic leukemia who were either in first complete remission or who had relapsed and achieved a subsequent complete remission. When compared to values of patients in first remission, the mean total systemic clearance of teniposide in relapsed patients was significantly lower at the time remission reinduction therapy was initiated, but increased to values greater than first remission patients after a subsequent remission was achieved. However, the mean clearance of unbound teniposide (ml/min/m2) was 3-fold lower in relapsed patients during reinduction therapy (1224 vs. 4261, P less than .0001), and improved but remained low after these patients achieved a subsequent remission (1965, P = .025). Changes in plasma protein binding accounted for the increase in total clearance when unbound clearance decreased. Continuous therapy with L-asparaginase was the major treatment difference in those patients with hypoalbuminemia and lower clearance of unbound teniposide. In 15 evaluable patients in complete remission, there was a statistically significant (P = .039) linear correlation between the percentage decrease in white blood cell count and the systemic exposure (AUC) to unbound teniposide, with higher exposure associated with a greater decrease in white blood cell count. There was not a significant correlation between the percent decrease in white blood cell count and the dosage given or the systemic exposure to total teniposide.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute myeloid leukemia in children treated with epipodophyllotoxins for acute lymphoblastic leukemia

BACKGROUND AND METHODS

Treatment of cancer with the epipodophyllotoxins (etoposide and teniposide) has been linked to the development of acute myeloid leukemia (AML) in children and adults, but the factors that might influence the risk of this complication of therapy are poorly defined. We therefore assessed the importance of potential risk factors for secondary AML in 734 consecutive children with acute lymphoblastic leukemia who attained complete remission and received continuation (maintenance) treatment according to different schedules of epipodophyllotoxin administration.

RESULTS

Secondary AML was diagnosed in 21 of the 734 patients, in 17 of whom this complication was the initial adverse event. Prolonged administration of epipodophyllotoxin (teniposide with or without etoposide) twice weekly or weekly was independently associated with the development of secondary AML (P less than 0.01 by Cox regression analysis). The overall cumulative risk of AML at six years was 3.8 percent (95 percent confidence interval, 2.3 percent to 6.1 percent); but within the subgroups treated twice weekly or weekly, the risks were 12.3 percent (95 percent confidence interval, 5.7 percent to 25.4 percent) and 12.4 percent (95 percent confidence interval, 6.1 percent to 24.4 percent), respectively. In the subgroups not treated with epipodophyllotoxins or treated with them only during remission induction or every two weeks during continuation treatment, the highest cumulative risk was 1.6 percent (95 percent confidence interval, 0.4 percent to 6.1 percent). After adjustment for treatment frequency, there was no apparent relation between the total dose of epipodophyllotoxins and the development of secondary AML. The relative hazard of etoposide as compared with teniposide could not be determined.

CONCLUSIONS

The risk of epipodophyllotoxin-related AML depends largely on the schedule of drug administration. Other factors, including the cumulative dose of epipodophyllotoxin, radiotherapy, and the initial biologic features of the leukemic blast cells, do not appear to have critical roles.

Characterization of childhood acute leukemia with multiple myeloid and lymphoid markers at diagnosis and at relapse

To define the clinical and biologic significance of childhood acute mixed-lineage leukemia diagnosed by stringent criteria, we studied 25 cases of acute lymphoblastic leukemia expressing greater than or equal to 2 myeloid-associated antigens (My+ ALL), and 16 cases of acute myeloid leukemia expressing greater than or equal to 2 lymphoid associated antigens (Ly+ AML). These cases represented 6.1% of 410 newly diagnosed ALLs (two treatment protocols) and 16.8% of 95 AMLs (two protocols). T-lineage--associated antigens were identified in 9 of the My+ ALL cases and in 14 of those classified as Ly+ AML; all but 1 of the 19 cases that could be subclassified had an early thymocyte stage of differentiation. The My+ ALL cases had an increased frequency of French-American-British (FAB) L2 morphology (36%); the Ly+ AML cases were characterized by FAB M1 or M2 morphology, low levels of myeloperoxidase reactivity and combined populations of myeloperoxidase-positive large blasts and small blasts generally of hand-mirror morphology. Karyotypic abnormalities included t(9;22)(q34;q11) in three cases of My+ ALL, 11q23 translocations in two cases of My+ ALL, and 14q32 translocations in three My+ ALL and five Ly+ AML cases. Mixed-lineage expression lacked prognostic significance in either ALL or AML; however, the findings indicate that some patients with Ly+ AML may respond to prednisone, vincristine, and L-asparaginase after failing on protocols for myeloid leukemia. At relapse, two My+ ALLs had converted to AML and two Ly+ AMLs to ALL; one case in each group showed complete replacement of the original karyotype. Acute mixed-lineage leukemia does not adequately describe the heterogeneity of the cases identified in this study and should be replaced by a set of more restrictive terms that indicate the unique biologic features of these leukemias.

Risk of adverse events in children completing treatment for acute lymphoblastic leukemia: St. Jude Total Therapy studies VIII, IX, and X

We studied the frequency, causes, and predictors of adverse events in 624 patients who had completed treatment for acute lymphoblastic leukemia (ALL) in three consecutive total therapy studies (VII, IX, and X, 1972 to 1983). Event-free survival in study X was significantly better overall than that in studies VIII and IX (P less than .0001 by the log-rank test). In study X, 75% of the patients were electively taken off therapy, compared with 54% in studies VIII and IX. However, the risks of having an adverse event during the first 5 years after completion of therapy were remarkably similar: 22% (95% confidence interval, 17% to 29%) in study X versus 24% (20% to 29%) in studies VIII and IX. Bone marrow, testicular, and CNS relapses accounted for the majority of failures in both groups (85% in study X and 92% in studies VIII and IX). Late adverse events consisted largely of hematologic relapses and the development of solid tumors. Black race (P = .001) and leukemia without an anterior mediastinal mass (P = .05) were associated with an increased risk of failure after completion of treatment in the two earlier clinical trials, whereas a lower leukemic cell DNA content (DNA index less than 1.16) was the only predictor of late treatment failure in the more recent trial (P = .019). None of the other presenting features that were examined (eg, age, leukocyte count, and sex) had value as predictors of late failure. Thus, improved treatment altered the impact of specific prognostic factors and the distribution of sites of relapse, but it did not significantly affect the risk of delayed failure.