Philadelphia chromosome-positive acute lymphoblastic leukemia in children: durable responses to chemotherapy associated with low initial white blood cell counts

To substantiate the reported sensitivity of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) to St Jude-type multiagent chemotherapy and to identify means of selecting patients most likely to benefit from such treatment, we analyzed the clinical and biologic characteristics of 12 patients with classic Ph+ ALL who were treated in either of two total therapy programs at St Jude Children's Research Hospital (1989-1994). Event-free survival estimates for this cohort were compared with historical data on 11 patients from an earlier total therapy study (Lancet 1994; 343: 331-332). The prognostic importance of age, white blood cell count and other presenting features was assessed by the logrank test in all 23 patients. Complete remissions were induced in 92% of the patients treated since 1989, compared with 82% of the historical control group (P > 0.05). There was essentially no difference in event-free survival between the study group and historical controls (4-year Kaplan-Meier estimates, 33 +/- 19% s.e. vs 36 +/- 13%). Further analysis of potentially informative risk factors identified a good-prognosis subgroup defined by an initial white blood cell count of < or =25 x 10(9)/l and a 4-year event-free survival of 73 +/- 19%. In conclusion, intensive multiagent chemotherapy offers an attractive therapeutic option for children and adolescents with Ph+ ALL and low presenting leukocyte count.

Human granulocyte colony-stimulating factor after induction chemotherapy in children with acute lymphoblastic leukemia

BACKGROUND

Recombinant human granulocyte colony-stimulating factor PO1 CA-20180ilgrastim) hastens the recovery from neutropenia after P30 CA-21765emotherapy, but its role in the management of childhood leukemia is unclear.

METHODS

We randomly assigned 164 patients with acute lymphoblastic leukemia (age range, 2 months to 17 years) to receive placebo or G-CSF (10 microg per kilogram of body weight per day subcutaneously), beginning one day after the completion of remission-induction therapy and continuing until the neutrophil count was greater than or equal to 1000 per cubic millimeter for two days. The clinical and laboratory effects of this therapy were documented for 21 days. The area under the plasma G-CSF concentration-time curve was measured on days 1 and 7 in both groups.

RESULTS

Responses to the growth factor could be assessed in 148 patients (73 in the G-CSF group and 75 in the placebo group). G-CSF treatment did not significantly lower the rate of hospitalization for febrile neutropenia (58 percent in the G-CSF group vs. 68 percent in the placebo group; relative risk, 0.85; 95 percent confidence interval, 0.59 to 1.16), increase the likelihood of event-free survival at three years (83 percent in both groups), or decrease the number of severe infections (five in the G-CSF group vs. six in the placebo group). Patients treated with G-CSF had shorter median hospital stays (6 days vs. 10 days, P=0.011) and fewer documented infections (12 vs. 27, P=0.009). The median total costs of supportive care were similar in the G-CSF and placebo groups ($8,768 and $8,616, respectively). Among patients who did not have febrile neutropenia during the first week of G-CSF or placebo injections, higher systemic exposure to the growth factor on day 7 was significantly related to a lower probability of subsequent hospitalization (P=0.049).

CONCLUSIONS

G-CSF treatment had some clinical benefit in children who received induction chemotherapy for acute lymphoblastic leukemia, but it did not reduce the rate of hospitalization for febrile neutropenia, prolong survival, or reduce the cost of supportive care.

Higher frequency of glutathione S-transferase deletions in black children with acute lymphoblastic leukemia

The genetic polymorphisms in human glutathione S-transferases (GST) M1 and T1 have been associated with race, disease risk, and outcome of some adult cancers. Also, there are racial differences in the incidence and characteristics of childhood acute lymphoblastic leukemia (ALL). Our objectives were to compare the frequency of the null genotype for GSTM1, GSTT1, or both in children with ALL to that in healthy controls, and to determine whether GST genotype was associated with treatment outcome and prognostic factors. We studied GSTM1 and GSTT1 genotypes in somatic cell DNA from black children and white children with ALL and in 416 healthy controls, using a polymerase chain reaction technique. Ninety of 163 (55.2%) white ALL patients and 14 of 34 (41.2%) black patients were GSTM1 null, frequencies not significantly different (P = .19) than healthy controls (53.5% in whites and 27.6% in blacks), although there was a trend toward more null genotypes in black ALL patients. Twenty-three of 163 (14.1%) white ALL patients and 12 of 34 (35.3%) black ALL patients were GSTT1 null, not different (P = .34) than the frequencies in healthy controls (15.0% in whites and 24.1% in blacks). However, the frequency of the "double-null" genotype, lacking both GSTM1 and GSTT1, was higher in black patients with ALL (8 of 34 or 23.5%) than in black controls (3.9%) (P = .0005), but this was not the case in white patients with ALL (10 of 163 or 6.1%) compared to white controls (8.0%) (P = .68). In stratified analyses, the GST double-null genotype was not associated with other characteristics that might differ between whites and blacks with ALL, such as age, T-lineage immunophenotype, presenting white blood cell count, DNA index, or insurance status. The null genotype for GSTM1, GSTT1, or both was not found to be a prognostic factor for disease-free survival or probability of hematologic remission; central nervous system relapse tended to be less common in those with the GSTM1 null genotype (P = .054). The double-null genotype for GSTM1 and GSTT1 is more common among blacks but not whites with childhood ALL. These data suggest that GST genotype, coupled with unidentified additional risk factors, may play a role in risk of childhood ALL in American blacks.

TEL gene rearrangement in acute lymphoblastic leukemia: a new genetic marker with prognostic significance

PURPOSE

TEL gene rearrangements due to the 12;21 chromosomal translocation are the most common molecular genetic abnormality in childhood acute lymphoblastic leukemia (ALL), occurring in approximately 25% of cases with a B-precursor immunophenotype. The limited number of clinically useful genetic markers in this leukemia subtype prompted us to assess TEL status as a predictor of treatment outcome.

PATIENTS AND METHODS

We determined the status of the TEL gene (rearranged or germline) in 188 cases of B-precursor acute leukemia using Southern blot analysis and related the findings to event-free survival. All comparisons of outcome were stratified by treatment regimen, risk classification, age, and leukocyte count.

RESULTS

Forty-eight patients (26%) had a rearranged TEL gene. At 5 years of follow-up, an estimated 91% +/- 5% (SE) of this group were event-free survivors, compared with only 65% +/- 5% of the group with germline TEL (stratified log-rank P = .011). For nonhyperdiploid patients, the odds ratio of an adverse event in the germline TEL group to that for the rearranged TEL group was 4.06 (95% confidence interval, 1.86 to 8.84). The relationship of TEL rearrangement to a favorable prognosis was independent of recognized good-risk features in B-precursor leukemia, including age, initial leukocyte count, and hyperdiploidy.

CONCLUSION

Rearrangement of the TEL gene distinguishes a large subset of children with favorable-prognosis B-precursor leukemia who cannot be identified by standard prognostic features. It may be possible to treat these patients less aggressively without loss of therapeutic efficacy.

Overt testicular disease at diagnosis is associated with high risk features and a poor prognosis in patients with childhood acute lymphoblastic leukemia

BACKGROUND

The impact of overt testicular disease on survival was assessed among patients treated at the study institution for childhood acute lymphoblastic leukemia (ALL) over a 15-year period. To the authors' knowledge, the frequency of overt testicular involvement at diagnosis of ALL and its impact on treatment outcome have not been reported previously.

METHODS

The medical records of all 651 boys with ALL enrolled on St. Jude Total Therapy Studies X-XIIIA (May 1979 to December 1993) were reviewed to determine the frequency of overt testicular involvement at diagnosis. The log rank test and sequential Cox regression analyses, adjusted for known adverse features, were used to compare event free and overall survival for patients with and without testicular leukemia. A matched-pairs analysis was then conducted for both outcome measures.

RESULTS

Thirteen of the 651 male patients (1.9%) presented with overt testicular leukemia. Compared with the other patients, these 13 boys had a significantly higher frequency of infant or adolescent age at diagnosis, hyperleukocytosis, splenomegaly, and mediastinal mass; a poorer 5-year event free survival (38% [95% confidence interval (CI), 15.4-61.4%] vs. 58% [95% CI, 53.6-61.7%], P = 0.06, log rank test); and a significantly poorer 5-year overall survival (37% [95% CI, 14-60.4%] vs. 75% [95% CI, 71.3-78.4%], P = 0.002). The difference in overall, but not event free, survival was supported by sequential Cox regression analyses and by the matched-pairs analysis (P = 0.04).

CONCLUSIONS

Overt testicular involvement with leukemia at diagnosis was associated with an adverse survival in boys with ALL. Testicular irradiation may not be necessary in those patients who present with overt testicular involvement. This finding merits prospective evaluation in a larger sample of similarly treated patients.

Effectiveness of intensified rotational combination chemotherapy for late hematologic relapse of childhood acute lymphoblastic leukemia

Relapsed acute lymphoblastic leukemia (ALL) usually carries a dire prognosis. We evaluated the effectiveness and long-term complications of intensive rotational combination chemotherapy for late hematologic relapse (median, 16 months after elective cessation of therapy) among 34 children and young adults (ages 4 to 23 years). Concurrent central nervous system (CNS) relapse was present in 3 cases and testicular relapse in 4. Secondary therapy comprised an intensive five-drug reinduction (6 weeks) followed by continuation treatment with four drug pairs, rotated weekly in 4-week cycles over 120 weeks. Intrathecal chemotherapy (methotrexate, hydrocortisone, cytarabine) was given three times during reinduction and every 8 weeks during continuation. Treatment was electively discontinued at week 120 in the absence of detectable disease. Thirty-three patients (97%) attained a second complete remission. At a median follow-up of 9.3 years (range, 4.5 to 11.4), estimates of 5-year second event-free and overall survival (+/- SE) are 65% +/- 8% and 79% +/- 7%, respectively. Eleven patients had a second relapse (9 marrow, 2 testicular) and one developed secondary myeloid leukemia. There have been no CNS relapses or deaths in remission. Treatment was well-tolerated and was given largely on an outpatient basis. Late effects are primarily endocrinologic; one child had a second malignant solid tumor (presumed related to initial radiation therapy) that was treated successfully. Intensive treatment with alternating non-cross-resistant drug pairs for late hematologic relapses of ALL is effective and well-tolerated, and produces results similar to those achieved in patients with newly diagnosed ALL. Event-free survival compares favorably with reports of other relapse regimens, including those incorporating bone marrow transplantation.

A subtle deletion of 12p by routine cytogenetics is found to be a translocation to 21q by fluorescence in situ hybridization: t(12;21)(p13;q22)

A 4-year-old boy with acute lymphoblastic leukemia (ALL) whose leukemic cells contained at diagnosis a del(6q) had a different clone at relapse, characterized by an abnormal short arm of chromosome 12 (12p). Fluorescence in situ hybridization (FISH) analysis using a cosmid probe from the 12p12-13 region indicated a translocation of the 12p to another unknown chromosome of "G-group" size. Further analysis by dual chromosome painting confirmed the presence of a translocation, identified as t(12;21)(p13;q22). Previously reported cases showed this translocation at diagnosis of ALL, whereas this is the first case showing the specific t(12;21)(p13;q22) at relapse. This case study illustrates the value of FISH in resolving subtle recurrent chromosomal rearrangements that escape detection by routine cytogenetic analysis. Subsequent molecular evaluation of the patient's leukemic cells with the t(12;21) demonstrated a TEL/AML1 fusion protein.

Prognostic factors in the acute lymphoid and myeloid leukemias of infants

The age boundaries and prognostic factors that define the infant leukemias are still controversial. We therefore analyzed event-free survival according to age group in 96 children treated for acute lymphoblastic leukemia (ALL) and 51 treated for acute myeloid leukemia (AML) before the age of 2 years. The study population was registered in consecutive institutional trials of multiagent chemotherapy conducted between 1980 and 1994. Among infants with ALL, event-free survival was significantly poorer in the 0- to 6-month-old group than in patients treated between 6 and 12 months of age (P = 0.03), whose outcome was in turn inferior to that in the 12- to 18-month and 18- to 24-month age groups (P = 0.013). Leukemic cells from ALL patients younger than 12 months had a significantly higher frequency of 11q23/MLL abnormalities, as well as better growth in stromal cell culture, compared to lymphoblasts from the older groups (P < 0.01). The only independent predictor of adverse prognosis among infants diagnosed with ALL before age 12 months was the presence of an 11q23/MLL rearrangement (P = 0.03). These findings contrast sharply with results for the AML cohort, whose event-free survival did not vary significantly by age group (P = 0.58). Male sex (P = 0.01) and leukocyte count > or = 50 x 10(9/l) (P = 0.04), but not 11q23 abnormalities, were independently associated with a poorer outcome for children with AML younger than 12 months at diagnosis. Thus, in very young children with ALL (but not AML), the rearrangement status of the 11q23/MLL region supersedes age group as a determinant of treatment outcome.

Escalating systemic exposure of continuous infusion topotecan in children with recurrent acute leukemia

PURPOSE

To determine the maximum-tolerated systemic exposure (MTSE) and exposure-limiting toxicity of continuous infusion topotecan in children with recurrent acute leukemia.

PATIENTS AND METHODS

Patients received escalating levels of topotecan systemic exposure as measured by steady-state topotecan lactone concentration (Css). Samples obtained within the first 24 hours were measured by high-pressure liquid chromatography (HPLC) for topotecan. A two-compartment model was fit to the data using a Bayesian algorithm. Css was calculated for each patient; if it differed by more than 20% of target, a new dosage was begun within 6 hours. Follow-up concentrations were obtained as well as serial plasma samples postinfusion. Toxicity and evidence of activity were assessed after each course.

RESULTS

Thirteen boys and five girls received 23 courses of topotecan. Target Css ranged from 1.0 to 5.3 ng/mL (topotecan doses, 0.5 to 3.3 mg/m2/d). Nineteen of 23 courses were within +/- 20% of target after adjustment (range, 77% to 139%). The MTSE was 4.0 ng/mL, and mucositis was exposure-limiting at 5.3 ng/mL. A significant relation between topotecan lactone Css and the severity of mucositis was observed. Myelosuppression was experienced but was not considered exposure-limiting. One complete response and one partial response were noted.

CONCLUSION

The MTSE for continuous infusion topotecan was 4.0 ng/mL. Responses were noted at Css comparable to those producing responses in a severe combined immunodeficiency (SCID) mouse model. Further studies of topotecan are warranted.

Rearrangement of the MLL gene confers a poor prognosis in childhood acute lymphoblastic leukemia, regardless of presenting age

MLL gene rearrangements are associated with an extremely poor prognosis in infants with acute lymphoblastic leukemia (ALL), but little is known about their clinical significance in older children. Therefore, we studied 45 cases of childhood ALL with abnormalities of chromosome 11q23 for rearrangement of the MLL gene to determine if this feature confers a uniformly poor prognosis. MLL gene rearrangements were detected in all 18 cases with the common t(4;11), t(9;11) or t(11;19) translocations, whereas only 5 of 12 patients with either unbalanced or uncommon balanced translocations demonstrated a rearrangement. Abnormalities of the MLL gene were not detected in any of the 15 cases with a deletion or inversion of the chromosomes 11q23 region. The presence of an MLL rearrangement was significantly associated with age less than 1 year (P < .001), leukocyte count >50 x 10(9)/L (P = .003), and the absence of leukemic cell CD10 expression (P < .001). In a stratified statistical analysis adjusted for age and treatment protocol, MLL gene rearrangement was correlated with an inferior treatment outcome (P = .028). The 4-year event-free survival estimate (+/- SE) was 10% +/- 6.5% for cases with a rearranged MLL gene and 64% +/- 19.2% for other cases. When infants were excluded from the analysis, MLL rearrangement was still significantly associated with a poor outcome (P = .02), and remained so with the exclusion of t(4;11)-positive cases (P = .05). Thus, regardless of presenting age, MLL gene rearrangement identifies a high-risk subgroup of patients who are not likely to be cured with conventional treatment.

Heterogeneity of hyperdiploid (51-67) childhood acute lymphoblastic leukemia

We studied the fully banded chromosomes of 182 children with hyperdiploid (51-67) acute lymphoblastic leukemia (ALL) to better delineate the heterogeneity of this disease subtype. Forty-six percent of the cases had numerical changes exclusively, while the remainder had structural as well as numerical changes. Chromosome 21 was added most often (97% of cases), followed by chromosomes 6 (86%), X (81%), 14 (80%), 4 (76%), 18 (68%), 17 (68%), 10 (56%), 8 (34%) and 5 (26%). Chromosomal translocations, including the t(1;19)(q23;p13) and t(9;22)(q34;q11), were detected in only 20% of the cases, as compared with 50% in ALL in general. The most common structural alterations were duplication of the 1q arm and isochromosome of 17q, present in 25 (14%) and nine (5%) cases, respectively. The presence of absence of structural abnormalities in these cases did not influence event-free survival, as assessed in 168 patients enrolled in three successive protocols for children with newly diagnosed ALL. By contrast, patients with 51-55 chromosomes per leukemic cell (n=105) appeared to fare worse than the 56-67 subgroup (n=63) (5-year probability of event-free survival = 72 +/- 5% (s.e.) vs 86 +/- 5%; P=0.04 by the stratified log-rank test). The poorer prognosis of the 51-55 subgroup was partly due to the higher frequency of isochromosome of 17q; 6/7 patients with the isochromosome in this group have had an adverse event. Other unfavorable features within the hyperdiploid (51-55) ALL subgroup include a low prevalence of trisomies of chromosomes 4 and 10 and a higher proportion of patients with leukocyte counts greater than 50 X 10(9)/l when compared to hyperdiploid (56-67). Thus, ALL defined by 51-55 chromosomes appears to be a clinicobiologic entity quite distinct from cases with higher modal numbers.

Etoposide achieves potentially cytotoxic concentrations in CSF of children with acute lymphoblastic leukemia

PURPOSE

Although epipodophyllotoxins are commonly used in contemporary treatment regimens for acute lymphoblastic leukemia (ALL), their potential role in CNS-directed therapy has received little attention. We prospectively studied 20 children during initial remission of ALL and 16 children at relapse to assess CSF penetration of etoposide.

METHODS

Simultaneous plasma and CSF concentrations were assessed at a median of 2.8 hours (range, 0.4 to 5.3) after an intravenous (i.v.) or oral dose in 41 paired samples.

RESULTS

Etoposide given at 300 mg/m2 i.v. to patients during first remission and at 50 or 25 mg/m2 orally to those in relapse resulted in median CSF levels of 0.175 mumol/L (range, .066 to 2.12), 0.011 mumol/L (range, .004 to .032), and 0.007 mumol/L (range, .003 to .014), respectively. The CSF etoposide concentration was > or = 10 nmol/L in 20 of 20, five of 10, and two of 11 courses following 300 mg/m2 i.v., 50 mg/m2 orally, and 25 mg/m2 orally, respectively, and was positively related to both the concurrent etoposide plasma concentration (R2 = .64) and to dose (R2 = .73). The median ratio of CSF to plasma concentration was 0.30% (range, 0.09% to 3.12%), which was not related to dose, plasma concentration, or time postdose at which samples were obtained, but was positively correlated with the CSF protein concentration (R2 = 0.43, P = .006). Both the absolute etoposide CSF concentrations (P = .008) and the ratio of CSF to plasma concentrations (P = .023) were higher among first-remission patients who had CSF leukemic blasts at diagnosis compared with those without CSF blasts.

CONCLUSION

Because etoposide concentrations as low as 10 nmol/L may be cytotoxic in vitro, prolonged daily oral low-dose (50 mg/m2) or conventional i.v. doses of etoposide may contribute to successful CNS-directed therapy in children with ALL.

Epipodophyllotoxin-related acute myeloid leukemia: a study of 35 cases

To define better the risk of epipodophyllotoxin-related acute myeloid leukemia (AML) after extended follow-up and to assess responses to intensive salvage therapy, all patients who developed this complication after treatment for acute lymphoblastic leukemia (ALL) or non-Hodgkin lymphoma (NHL) in consecutive clinical trials at St Jude Children's Research Hospital from 1979 to 1994 were studied. Cases with 'lineage switch' or 'clonal selection' were excluded. Epipodophyllotoxin-related AML developed in 32 of 1140 patients treated for ALL and in three of 332 treated for NHL; it was a first adverse event in 25 and two cases, respectively. The complication was diagnosed at 12-130 months (median 34 months) after the initiation of treatment with epipodophyllotoxins; all but one of the cases occurred within 73 months, indicating that the risk is negligible after 6 years. The predominant karyotypic feature was 11q23 translocations (71% of cases); 21q22 rearrangements were rare. In a stepwise Cox regression analysis, two factors increased the risk of this complication: weekly or twice weekly administration of epipodophyllotoxins (P < 0.001); and the administration of asparaginase immediately before epipodophyllotoxin therapy (P < 0.001). Initial responses to salvage therapy were comparable to those reported for de novo AML: 92% of the evaluable patients entered complete remission after combination treatment. Single-agent therapy with 2-chlorodeoxyadenosine induced complete or partial remissions in one-half of the patients treated. The long-term survival rate was dismal. Of the 17 evaluable patients treated exclusively with chemotherapy, only one is alive at 84 months, compared to three of 16 patients who underwent bone marrow transplantation (alive at 10, 23 and 73 months). Cases of epipodophyllotoxin-related AML constitute a unique clinical syndrome that will require innovative strategies for cure.

Persistence of circulating blasts after 1 week of multiagent chemotherapy confers a poor prognosis in childhood acute lymphoblastic leukemia

Early response to therapy, typically assessed by bone marrow status, is predictive of outcome in childhood acute lymphoblastic leukemia (ALL). Less is known about the significance of early clearance of blast cells in peripheral blood. We reviewed medical records of all patients with ALL enrolled on St Jude Total Therapy Study XI (February 1984 to September 1988) to determine the presence of blast cells in peripheral blood at diagnosis and after 1 week of intensive induction therapy. Of the 358 patients, 59 lacked evidence of circulating blast cells at diagnosis, and data were unavailable for 2 patients. The prognostic significance of persistent circulating blast cells in the remaining 297 patients was assessed in a multivariate analysis that included known adverse prognostic factors. Persistent circulating leukemic blasts were present at day 8 in 41 patients (14%). Compared with the "blast-negative" group, these patients had a significantly higher frequency of several adverse clinical features (leukocyte count > 50 x 10(9)/L, mediastinal mass, central nervous system leukemia, T-cell phenotype, lack of CD10 expression, and L2 morphology) and a significantly poorer 5-year event-free survival (34% +/- 8% [SE] v 77% +/- 3%, P < .01). By multivariate analysis, blast cell persistence at week 1 was the most significant adverse feature in the overall cohort (relative risk, 2.9; 95% confidence interval, 1.8 to 4.8) and in an analysis limited to B-lineage cases (relative risk, 3.6; 95% confidence interval, 1.9 to 7.1). Patients identified by this simple, noninvasive measure may benefit from early modification of therapy.

Vincristine neuropathy in type I and type II Charcot-Marie-Tooth disease (hereditary motor sensory neuropathy)

A patient with Ewing's sarcoma and demyelinating type Charcot-Marie-Tooth disease (CMT) developed severe neuropathy after receiving a total vincristine dose of 6 mg. Recovery was slow and incomplete. A second patient with axonal type CMT developed moderate neuropathy but tolerated extended vincristine administration and recovered quickly. Possible underlying neuropathy should be excluded before vincristine treatment is begun by careful examination including inspection of the feet, followed by electrophysiologic studies as indicated. In demyelinating CMT, vincristine should be avoided; in axonal form cautious use may be considered.

An intensive re-treatment protocol for children with an isolated CNS relapse of acute lymphoblastic leukemia

PURPOSE

To assess the salvage rate and long-term complications among children treated with an intensive regimen for isolated CNS relapse during first remission of acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

Twelve boys and eight girls, diagnosed at a median age of 4 years, had CNS relapse at a median age of 7 years. Five had CNS leukemia at presentation, while five completed treatment before relapse. First complete remission lasted a median of 22.5 months. Ten patients had received cranial irradiation plus intrathecal (IT) therapy, and the remainder had received high-dose intravenous and/or IT methotrexate (MTX) as CNS-directed treatment. Retrieval therapy consisted of a five-agent intensive reinduction regimen followed by continuation therapy with four rotating drug pairs. Triple-IT therapy was administered weekly for 4 to 5 weeks, then every 6 weeks until craniospinal radiation (cranium, 24 Gy; spine, 15 Gy; both sites, 1.5 Gy per fraction) was administered.

RESULTS

All 20 children achieved a second complete remission. The 5-year estimate of disease-free survival (mean +/- SE) was 70% +/- 11%. Thirteen patients remain in remission at 71+ to 126+ months (median, 104+), and 10 of 13 patients tested have normal IQ scores. Four patients have had a second relapse (one CNS and three non-CNS), and three have developed other malignancies. Prior cranial irradiation was associated with subsequent failure; only three of 10 patients who previously received radiotherapy, compared with all of the other 10 patients, remained in second remission.

CONCLUSION

This intensive retrieval therapy is effective and well tolerated by children with an isolated CNS relapse of ALL, especially those who have not received prior cranial irradiation. Most patients have no significant neuropsychologic impairment.

Survival outcome following isolated central nervous system relapse treated with additional chemotherapy and craniospinal irradiation in childhood acute lymphoblastic leukemia

PURPOSE

An analysis of survival outcome following isolated central nervous system (CNS) relapse treated with craniospinal irradiation (CSI) and additional chemotherapy in children with acute lymphoblastic leukemia (ALL) was conducted.

METHODS AND MATERIALS

Eighteen of 344 pediatric patients with ALL who attained initial complete remission on the St. Jude Children's Research Hospital "Study XI" prospective protocol (1984-1988) developed a CNS relapse as first adverse event. Median interval to isolated CNS relapse was 7.5 months (range = 2-40 months) after achieving initial complete remission. At diagnosis, 14 of the 18 children were categorized as "high risk" for subsequent leukemic relapse. Preventive cranial irradiation [PCI (18 Gy)] was delivered as planned to one of the 14 "high-risk" children. The other 13 "high-risk" patients experienced a CNS relapse during the first year of continuation therapy prior to week 52 of planned PCI. All four "low-risk" patients experienced a CNS relapse beyond the first year of continuation therapy; none were scheduled to receive PCI. Following isolated CNS relapse, all 18 patients were treated on a prospective contingency of "Study XI" trial consisting of intensified reinduction chemotherapy, weekly intrathecal methotrexate/hydrocortisone/Ara-C x 4-6 injections, craniospinal irradiation (cranium to 24.0 Gy and spine to 15.0 Gy at 1.5 Gy/fraction) and maintenance systemic therapy for a minimum of 1 year.

RESULTS

Ten of 18 patients remain in continuous complete secondary remission at 17 to 50 months post-CNS relapse. Second sites of relapse in the remaining eight children were as follows: CNS in four, bone marrow in three, and bilateral testicular in one patient. Each of these eight patients died of progressive leukemia. At a median followup of 40 months post-initial CNS relapse, the 3-year secondary Kaplan-Meier survival and event-free survival are 72% and 56%, respectively. Minimal long-term neurotoxicity was associated with the treatment regimen. The most important prognostic factors predicting continuous secondary remission included white blood cell count at diagnosis (p = 0.05), and duration of initial remission (p = 0.04).

CONCLUSION

This trial demonstrates that more than one-half of patients may be successfully salvaged with intensified chemotherapy and craniospinal irradiation without significant morbidity following an isolated CNS relapse, despite previous multiagent chemotherapy though virtually no prior PCI in childhood ALL.

A prospective neurocognitive evaluation of children treated with additional chemotherapy and craniospinal irradiation following isolated central nervous system relapse in acute lymphoblastic leukemia

PURPOSE

A prospective assessment of neurocognitive performance was conducted in children with acute lymphoblastic leukemia (ALL) following isolated central nervous system (CNS) relapse to evaluate the impact of additional systemic/intrathecal (IT) chemotherapy and craniospinal irradiation (CSI) upon long-term intellectual function.

METHODS AND MATERIALS

Twenty-one children with ALL manifesting an isolated CNS relapse between 1984 through 1989 underwent serial evaluations of intellectual function. Neurocognitive function was measured by the full-scale intelligence quotient (FSIQ) as determined by the age-appropriate Wechsler Intelligence Scale and by achievement in reading, math, and spelling as assessed by the Wide Range Achievement Test (WRAT). Intelligence testing was initiated following isolated CNS relapse after clearance of cerebrospinal fluid (CSF) cytology but prior to CSI and continued at annual intervals for a minimum of 4 years postmeningeal failure. Protocol treatment for isolated CNS relapse consisted of reinduction and maintenance systemic therapy, intrathecal (IT) triple-agent chemotherapy, and early CSI (cranium to 24 Gy and spine to 15 Gy at 1.5 Gy/fraction) as outlined on the institutional "Total XI" trial.

RESULTS

All 21 children attained secondary CNS remission and underwent the planned additional systemic/IT chemotherapy and CSI. Fourteen of the 21 children remain in secondary continuous remission, while the remaining 7 experienced a second relapse and were removed from further neurocognitive assessment. For the eight female and six male long-term survivors, mean ages at original diagnosis and at CSI were 5.7 years (range = 0.6-16.2) and 7.0 years (range = 1.8-17.0), respectively. At a median follow-up interval of 4.6 years (ranges 1.7-6.8) post-CNS relapse, comparison of group mean initial to final FSIQs revealed no statistically significant difference between the two measures (94.5 vs. 95.9, respectively, n = 11, p = 0.52). None of the children are functioning in the mentally retarded range. Final FSIQ outcome directly correlated with initial FSIQ (p = 0.00005, n = 11), age at diagnosis (p = 0.009, n = 14), and age at CSI (p = 0.011, n = 14). In addition, change between initial and final FSIQ scores inversely correlated with age at diagnosis (p = 0.009) and age at CSI (p = 0.018) but not with baseline IQ score (p = 0.41). Initial FSIQ scores were not influenced by either age at diagnosis (p = 0.12) or age at CSI (p = 0.14). Final group mean (range) WRAT scores in reading, math, and spelling were measured to be 94.7 (68-132), 95.6 (69-126), and 93.7 (77-122), respectively (n = 13). Final reading and math scores directly correlated with both age at diagnosis (p = 0.01) and age at CSI (p = 0.009). Spelling outcome did not correlate with either age at diagnosis (p = 0.25) or age at CSI (p = 0.24). Nine children are placed in regular classrooms, while the remaining five require a mixed classroom environment.

CONCLUSION

In our study, children with ALL experiencing an isolated CNS relapse tolerated additional systemic/IT chemotherapy and CSI without apparent deterioration of group serial intellectual scores. However, longitudinal analyses of group intellectual measures obscured the independent impact of initial FSIQ, age at original diagnosis, and age at CSI upon individual neurocognitive outcome. Early and more intensive psychoeducational stimulation may be needed in very young children presenting with low initial FSIQ scores who are treated with CSI and additional chemotherapy following isolated CNS relapse in ALL.

Immunologic, cytogenetic, and clinical characterization of childhood acute lymphoblastic leukemia with the t(1;19) (q23; p13) or its derivative

PURPOSE

To evaluate the immunophenotypes, karyotypes, and clinical features, including treatment responses, of patients with childhood acute lymphoblastic leukemia (ALL) and either a t(1;19)(q23;p13) or a der(19)t(1;19)(q23;p13) translocation.

PATIENTS AND METHODS

The lymphoblasts of 45 patients with a balanced translocation, t(1;19) or its derivative form, der(19)t(1;19), were analyzed by cytogenetic and immunologic methods for differences that might suggest distinct subtypes of ALL. This cohort was treated in four consecutive clinical trials with a median overall follow-up duration of 7 years.

RESULTS

A pre-B immunophenotype was found in 10 cases with the balanced t(1;19) and 31 with the unbalanced der(19)t(1;19). The four remaining cases, each with a derivative t(1;19), were classified as early pre-B ALL. The characteristic surface antigen profile of the 41 pre-B cases was CD19+/CD10+/CD22+/CD34-/CD20+/-, whether the translocation was balanced or derivative. In contrast to the four early pre-B cases, which had hyperdiploid karyotypes (> 50 chromosomes), the pre-B cases were primarily pseudodiploid. Comparison of presenting clinical and laboratory features, as well as event-free survival, failed to disclose any differences that would warrant separation of pre-B cases with a balanced or derivative translocation. However, neither subgroup responded to therapy as well as patients with early pre-B ALL, each of whom remains in complete remission for > or = 3 years.

CONCLUSION

The t(1;19) and the der(19)t(1;19) identify a relatively homogeneous group of patients with pre-B ALL, who can be expected to respond similarly to intensive chemotherapy. The exceptional cases have an early pre-B phenotype with hyperdiploid karyotypes and appear to have favorable prognosis.

Blast cell methotrexate-polyglutamate accumulation in vivo differs by lineage, ploidy, and methotrexate dose in acute lymphoblastic leukemia

High-dose methotrexate (HDMTX) is a component of most treatment protocols for childhood acute lymphoblastic leukemia (ALL), yet recent studies of receptor-mediated transport and saturable polyglutamylation have questioned its rationale. To investigate this in vivo, methotrexate and its active polyglutamated metabolites (MTX-PG) were measured in bone marrow blasts obtained from 101 children randomized to single-agent therapy with either HDMTX (1 g/m2 per 24 h i.v., n = 47) or low-dose MTX (LDMTX, 30 mg/m2 by mouth every 6 h x 6, n = 54), before remission induction therapy. Blast concentrations of total MTX-PGs (median 460 vs 1380 pmol/10(9) cells) and of long-chain MTX-glu4-6 were both significantly higher after HDMTX (P < 0.001). With either treatment, MTX-PGs were significantly higher in B-lineage blasts than in T-lineage blasts (LDMTX P = 0.001, HDMTX P = 0.03). In a multiple regression analysis of B-lineage ALL, blast MTX-PG was significantly related to MTX dose (or plasma MTX concentration), lymphoblast ploidy (hyperdiploid > nonhyperdiploid), and percentage S-phase. This is the first evidence that HDMTX achieves higher MTX-PG concentrations in ALL blasts in vivo, establishing a rationale for HDMTX in the treatment of childhood ALL, especially T-lineage or nonhyperdiploid B-lineage ALL, disease characteristics associated with a poor prognosis on conventional therapy.

Transfusions and risk of failure in childhood acute lymphoblastic leukemia

To examine the relationship of blood product support to treatment outcome in childhood ALL, we reviewed records of all 358 patients with newly diagnosed ALL treated on St Jude Total Therapy Study XI (February 1984 to September 1988). All but six patients received blood products (median 7 units, range 0-246), with approximately 90% given during the 6-week induction period. Because all 16 patients who received > or = 50 units failed, the number of units transfused was predictive of treatment failure in multivariate analysis (relative risk = 1.8, p = 0.02), although the number of units transfused was also associated with initial leukocyte count and age. Among the remaining 342 patients who received < 50 units, the number of units transfused was associated with reduced event-free survival in univariate analysis only, with maximal significance at > 7 units (p = 0.006). Because exclusion of the 16 patients who received the most blood eliminates the independent effect of transfusions on patient outcome, we believe that the number of transfusions is largely an epiphenomenon which reflects the effects of two risk factors not included in traditional outcome analysis in childhood ALL. These are acuity of illness during induction, and reduction of chemotherapy doses during induction therapy, due to the severity of illness. Immunomodulation caused by exposure to blood products appears unlikely to contribute strongly to outcome in childhood ALL.

Advances in therapy for childhood non-B-lymphoblastic leukaemia

The majority of therapeutic gains for patients with ALL have come from prospectively planned clinical trials. Beginning in the 1970s, series of well-designed protocols have produced valuable information that has permitted the development of curative therapy for more than two-thirds of patients. This success emphasizes the importance of controlled, carefully analysed therapeutic studies, which pay dividends for many years by providing a sound basis for future developments. Experienced biostatisticians should be involved early in the development of clinical trials to ensure that research questions can be reliably answered in terms of the size and composition of the patient sample and in terms of accrual time. Despite extensive pre-planning, a protocol may require early termination due to unexpected results that compromise the integrity of the initial design (Rivera et al, 1985). Thus, periodic treatment assessment of the trial is crucial to a successful outcome. Extended follow-up of patients is a requirement in every leukaemia study since relapses may occur many years after diagnosis, especially if patients have a lower risk of treatment failure (Rivera et al, 1979). The quality of long-term survival must also be well documented because all protocols include toxic therapy (Ochs and Mulhern 1988). Every physician treating children with ALL would like to select therapy that is both effective and well tolerated. Unfortunately, this is not always possible when patients have high-risk features. Secondary AML, deaths in remission and fatal organ toxicity (Steinherz, 1991c) are equally devastating complications of current chemotherapy for ALL, and no single protocol can be recommended over any other. Patients with ALL may be equally well served by any of several different protocols. The practice of administering 6MP + MTX alone and usually orally as continuation treatment has been virtually abandoned. Today, most children receive intensified chemotherapy in one schedule or another, including good-risk patients on POG protocols who, although treated largely with antimetabolite-based programmes, receive high-dose chemotherapy during the initial 6 months of treatment. In view of the more favourable results attained with reinduction therapy in recent CCG studies, these investigators also recommend such an approach for children with better-risk ALL. We fully agree. Regrettably, with the success of current regimens for higher-risk ALL, it has not been possible to exclude all toxic agents that may induce serious late complications.(ABSTRACT TRUNCATED AT 400 WORDS)

Molecular evidence for minimal residual bone marrow disease in children with 'isolated' extra-medullary relapse of T-cell acute lymphoblastic leukemia

Central nervous system (CNS) relapse confers a poor prognosis in children with acute lymphoblastic leukemia (ALL). It is uncertain whether morphologically undetectable leukemia is present in the bone marrow at the time of CNS relapse, or whether the CNS acts as a 'sanctuary' site to allow reseeding of the marrow at a later time. We examined DNA from bone marrow samples from six patients with T-cell ALL with isolated CNS relapse using sensitive polymerase chain reaction (PCR) assays to detect minimal residual disease. One of these PCR assays was based on amplification of leukemia-specific TCR-delta gene rearrangements, while the other assay relied upon detection of the c-tal deletion. In four patients, where bone marrow samples were taken at the time of CNS relapse, residual disease was detectable in every sample at a level below morphological detection. In addition, three patients had residual disease detected in their subsequent bone marrow when CNS disease was not evident. Our findings, although preliminary, suggest that relapse of leukemia in the CNS reflects resurgence of the disease in the bone marrow that is first detected clinically in the CNS. The concomitant molecular detection of bone marrow leukemia at time of 'isolated' CNS relapse in children with T-cell ALL explains subsequent bone marrow relapse in some of these children, and argues for intensive systemic therapy of these patients.