The significance of an isolated central nervous system relapse, occurring as first relapse in children with acute lymphoblastic leukemia

Long-term outcome of initially homogenously treated and relapsed childhood acute lymphoblastic leukaemia in Austria--a population-based report of the Austrian Berlin-Frankfurt-Münster (BFM) Study Group

Relapsed acute lymphoblastic leukaemia (ALL) is the most common cause for a fatal outcome in paediatric oncology. Although initial ALL cure rates have improved up to 80%, the prognosis of recurrent ALL remains dismal with event-free-survival (EFS) rates about 35%. In order to analyse a population-based cohort with uniform treatment of initial disease, we examined the outcome of children suffering from relapsed ALL in Austria for the past 20 years and the validity of the currently used prognostic factors (e.g. time to and site of relapse, immunophenotype). Furthermore, we compared survival rates after chemotherapy alone with those after allogeneic stem cell transplantation (SCT). All 896 patients who suffered from ALL in Austria between 1981 and 1999 were registered in a prospectively designed database and treated according to trials ALL-Berlin-Frankfurt-Münster (BFM)-Austria (A) 81, ALL-A 84 and ALL-BFM-A 86, 90 and 95. Of these, 203 (23%) suffered from recurrent disease. One-hundred-and-seventy-two patients (85%) achieved second complete remission. The probability of 10-year EFS for the total group was 34 +/- 3%. Clinical prognostic markers that independently influenced survival were time to relapse, site of relapse and the immunophenotype. Additionally, a Cox regression model demonstrated that allogeneic SCT after first relapse was associated with a superior EFS compared with chemo/radiotherapy only (hazard ratio = 0.254; P = 0.0017).

Bone marrow leukemic progenitor cell content in pediatric T-lineage acute lymphoblastic leukemia patients with an isolated extramedullary first relapse

Isolated extramedullary relapse in childhood acute lymphoblastic leukemia (ALL) is associated frequently with the T-lineage immunophenotype and may be accompanied by occult bone marrow disease. We employed highly sensitive multiparameter flow cytometry and blast colony assays to quantify the leukemic progenitor cell (LPC) burden in the pretreatment bone marrows of 15 pediatric T-lineage ALL patients with an isolated extramedullary first relapse. Sites of extramedullary relapse were CNS (11 patients), testes (3 patients), and both CNS and testes (1 patient). Bone marrow LPC were detectable in 8 patients (53%) and undetectable in 7 patients (47%) at day 0 of post-relapse induction therapy, with LPC counts ranging from 0/10(6) mononuclear cells (MNC) to 518/10(6) MNC (mean +/- SEM, 50+/-34/10(6) MNC). Five of 9 patients with an early relapse (< 18 months after achieving a first complete remission [CR1]) and 3 of 6 patients with a late relapse (> or = 18 months from CR1) had detectable bone marrow LPC at day 0. Five of 8 patients with NCI-defined poor risk ALL and 3 of 7 patients with NCI-defined standard risk ALL had detectable LPC at day 0. Following post-relapse induction chemotherapy. LPC counts were detectable in bone marrows of 4 of 6 evaluated patients. Thus, approximately half of the extramedullary relapse T-lineage ALL patients studied had substantial occult involvement of the bone marrow. These findings may partly explain the previously observed poor prognosis of T-lineage patients following a CNS relapse.

Delayed craniospinal irradiation for a first isolated central nervous relapse of acute lymphoblastic leukemia: report on 14 cases

BACKGROUND

Children developing an isolated central nervous system (CNS) relapse as first recurrence of their acute lymphoblastic leukemia (ALL) are considered to have a systemic relapse as well. They are mostly treated with intensive chemotherapy and craniospinal irradiation. In most treatment schedules, irradiation is given early after induction treatment. Because craniospinal irradiation affects a large portion of hematopoietic bone marrow systemically, treatment is often delayed owing to aplasias. Also, dose reductions are frequently needed. Children receiving simultaneously irradiation and chemotherapy are prone to (often severe) neurotoxicity. This study reports on children with a first isolated CNS relapse of their ALL receiving chemotherapy for 40 weeks. Treatment ends with the administration of irradiation given after cessation of chemotherapy.

PROCEDURE

Fourteen children, with blasts and >5 cells/mm(3) in two consecutive samples of cerebrospinal fluid and a blast percentage <5% in their bone marrow were treated according to an intensive systemic and site-specific chemotherapy. Craniospinal irradiation was administered after cessation chemotherapy.

RESULTS

Event-free-survival was 57% (confidence interval 35-89%), freedom from relapse was 61.5%; follow-up ranges from 2.0 to 15.1 years (median 11.7 years). One child died from septicemia during induction. Five children experienced a second relapse and died from their malignancy. Two children [with a t(9;22) or a rearranged MLL gene] relapsed prior to radiotherapy. Outcome was related to duration of first remission, age at relapse, and identification as a high-risk patient at initial diagnosis. No neurologic complications were noted during and after treatment.

CONCLUSIONS

Delayed irradiation for isolated CNS relapse in children with ALL gives favorable survival rates, without significant toxicity. Neurotoxicity was absent.

Improved survival of children with isolated CNS relapse of acute lymphoblastic leukemia: a pediatric oncology group study

PURPOSE

Isolated meningeal relapse in children with acute lymphoblastic leukemia (ALL) usually has been followed by bone marrow relapse and limited survival. The purpose of this study was to prevent marrow relapse by administering intensive therapy before delayed craniospinal radiation.

PATIENTS AND METHODS

Eighty-three patients with ALL in first bone marrow remission with an isolated CNS relapse were treated with systemic chemotherapy known to enter into the CSF and intrathecal chemotherapy for 6 months. Craniospinal irradiation (24 Gy cranial/15 Gy spinal) was then administered, followed by 1.5 years of maintenance chemotherapy.

RESULTS

All 83 patients achieved a second remission. The 4-year event-free survival (EFS) rate was 71.1% +/- 5.3%. There was a fourfold increased risk of relapse for children whose initial remission was less than 18 months. The 4-year EFS rate for patients with a first complete remission >/= 18 months was 83.3% +/- 5.3%, and for those with a first complete remission less than 18 months, it was 46.2% +/- 10.2% (P =.0002.) There was a low incidence of neurologic toxicity and an unexpectedly high rate of allergic reactions to L-asparaginase. Five patients developed secondary malignancies: two with acute nonlymphoblastic leukemia during therapy, one with myelodysplasia after therapy, and two with brain tumors 1.5 to 2 years after cessation of therapy.

CONCLUSION

For children with ALL and an isolated CNS relapse, treatment that delays definitive craniospinal irradiation by 6 months to allow for more intensive systemic and intrathecal chemotherapy results in better EFS than has been previously reported. Using this approach, the long-term prognosis for children with first complete remission >/= 18 months is comparable to that at the time of original diagnosis of ALL.

Improving the diagnostic accuracy of cytologic cerebrospinal fluid examinations in acute lymphoblastic leukemia using high-power microscopy and terminal deoxynucleotidyl transferase determinations

In patients with acute lymphoblastic leukemia (ALL), cytologic examination of cerebrospinal fluid (CSF) is becoming increasingly important for clinical management. In order to enhance the diagnostic accuracy of CSF cytology results, the value of using terminal deoxynucleotidyl transferase (Tdt) and high-power (1,000x) light microscopy, together with conventional cytologic examination was assessed. In 33 CSF samples from ten multiply examined Tdt-positive ALL patients, original cytologic interpretations were compared to Tdt results. Cytology samples were reviewed by two pathologists (one with hematopathologic expertise). The cases in which cytologic interpretation did not correlate with Tdt result were first reviewed via 1,000x microscopy without knowledge of Tdt result, then re-reviewed with knowledge of Tdt result. Conventional cytology alone diagnosed 64% of cases accurately (Tdt representing the comparative standard). High-power microscopy increased the correlation to 82%. Use of high-power microscopy and knowledge of Tdt result together produced a total of 85% of cases with correlation of results. High-power microscopic examination therefore contributes significantly to the accurate diagnosis of ALL, and knowledge of the Tdt result at the time of cytologic examination produces an additional advantage in providing an objective measure for CSF involvement by leukemia. Using all three methods in conjunction is recommended in order to increase the overall accuracy of CSF examination for the detection of leukemic involvement in ALL patients.

Relapse of precursor B-cell acute lymphoblastic leukemia as an isolated central nervous system mass lesion 9 years after initial diagnosis

Seven years after completion of chemotherapy for acute lymphoblastic leukemia, diagnosed at the age of 5 years, a black female presented with signs of increased intracranial pressure. Neuroimaging showed a large enhancing extra-axial occipital tumor mass. The resection specimen showed morphologic, cytogenetic, and immunophenotypic features consistent with relapse of the primary leukemia. Bone marrow examination was negative for malignancy. The long duration of complete remission followed by the formation of a mass in the central nervous system are highly unusual features of recurrent acute lymphoblastic leukemia.

Outcome after first relapse in children with acute lymphoblastic leukemia: a population-based study of 315 patients from the Nordic Society of Pediatric Hematology and Oncology (NOPHO)

This study reports the outcome after relapse of acute lymphoblastic leukemia (ALL) in a population-based study of 809 children over 1 year of age diagnosed July 1981 through June 1986 and with non-B acute lymphoblastic leukemia in the five Nordic countries. By January 1994, 315 children had suffered at least one relapse. The bone marrow was involved in 216 cases. There were 69 isolated CNS relapses, 25 isolated testicular recurrences and five relapses in other extramedullary sites. Of the 315 children with relapse, 94 are still in a second complete remission 12-138 (median: 78) months after relapse. The overall probability of a second event free survival (P-2.EFS) and survival after relapse was 0.28 and 0.33 respectively. The probability of remaining in second remission at 11 years was significantly correlated to the duration of first remission (P < 0.001), the site of relapse (P < 0.001) and gender (P = 0.004). The P-2.EFS for early, intermediate, and late bone marrow involved relapses were 0.08, 0.19, and 0.50 respectively. For early, intermediate and late isolated CNS relapses the P-2.EFS were 0.21, 0.38 and 0.61, respectively. The P-2.EFS for boys with isolated testicular relapses was 0.69. Girls with isolated CNS relapse (P < 0.001) and with bone marrow involved relapse (P = 0.04) had a significantly better prognosis than boys. Children with initial high risk criteria, especially T-ALL and mediastinal mass who relapsed, had a very poor prognosis.

CONCLUSION

In this population-based study, about 30% of children with ALL obtained a long second remission and possible cure.

Significance of lymphoblasts in cerebrospinal fluid in newly diagnosed pediatric acute lymphoblastic malignancies with bone marrow involvement: possible benefit of dexamethasone

We analyzed retrospectively the data on 135 children treated since 1983 for acute lymphoblastic leukaemia and non-Hodgkin's lymphoma with bone marrow involvement with respect to the presence of lymphoblasts in cerebrospinal fluid (CSF) and the number of cells in CSF, both at initial diagnosis and during follow-up. Of these children 96, 11, and 28 suffered from B-progenitor, mature B cell, and T-cell malignancies respectively. In two patients initial central nervous system involvement was documented by the presence of lymphoblasts with high CSF cell counts (B+C+ patients); 19 patients had CSF lymphoblasts with normal CSF cell counts (B+C- patients); the others had no CSF blasts and normal CSF cell counts (B-C- patients). In B+C- and B-C- patients 5-year-leukaemia-free survival was 66 and 70%, respectively (i.e., not significantly different). None of the B+C- patients experienced a first relapse in the central nervous system. Differences in outcome by comparing with reports of others may be related to the use of dexamethasone instead of prednisone in almost all of our patients.

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.

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.

Central nervous system treatment in childhood acute lymphoblastic leukemia. Long-term follow-up of patients diagnosed between 1973 and 1985

BACKGROUND

Despite advances in the treatment of childhood acute lymphoblastic leukemia (ALL), optimal therapy of the central nervous system (CNS) remains controversial.

METHODS

Between 1973 and 1985, 540 children with ALL (199 standard risk and 341 high risk) were treated on four protocols.

RESULTS

The 7-year event-free survival rate (+/- standard error) was 62.1% (+/- 2.1) for the entire group: 71.8% (+/- 3.2) for standard-risk and 56.4% (+/- 2.7) for high-risk patients. Five hundred eighteen of the children entered complete remission and received cranial irradiation with intrathecal methotrexate for CNS treatment; 197 had standard-risk ALL and 321 had high-risk ALL. Thirty-one patients (5 standard risk and 26 high risk) had a CNS relapse with or without concurrent bone marrow relapse as an initial event, the latest of which was observed 49 months after complete remission. The cumulative incidence of CNS relapse was 6.0% (+/- 1.1) for the entire group: 2.5% (+/- 1.1) for standard-risk and 8.2% (+/- 1.5) for high-risk patients (P = 0.01). CNS recurrence of leukemia, whether as an "isolated" site or a "combined" site of relapse, was a major adverse event. Only 4 of 31 patients were alive for 25+, 28+, 54+, and 71+ months after a CNS relapse. The median survival time after CNS relapse was 22 months: 21 months for the 20 patients who had an isolated CNS relapse, and 23 months for the 11 patients who had a CNS relapse concurrent with a recurrence in other sites.

CONCLUSIONS

Although attempts to diminish CNS treatment-related morbidity are warranted for standard-risk patients, the authors recommend that intensive CNS treatment be enhanced for the high-risk patients because CNS relapses continue to occur in this population. Furthermore, CNS relapse after cranial irradiation was associated with a very poor prognosis and needs to be treated as intensively as a bone marrow relapse.

Intra-thecal treatment of leptomeningeal lymphoma with immunotoxin

An animal model has been established to investigate the effect of intra-thecal (i.t.) immunotoxins in the treatment of leptomeningeal metastases of acute lymphoblastic leukaemia (ALL). Direct inoculation of L2C lymphoma cells into the cisterna magna of guinea-pigs gives rise to a leptomeningeal pattern of growth, similar to that of human ALL, and to a systemic leukaemia which develops in approximately 14 days. In our model the systemic disease could be controlled with cyclophosphamide while the meningeal disease progressed and provided a target for i.t. immunotoxin. The immunotoxin used consisted of an anti-idiotypic antibody disulphide-bonded to the ribosome-inactivating protein saporin. It was highly cytotoxic to L2C cells in vitro, being around 30,000 times more potent than a control immunotoxin at inhibiting protein synthesis. In vivo, the maximum tolerated dose of i.t. immunotoxin was 10 micrograms. From the rate at which radiolabelled immunotoxins appeared in the plasma following i.t. injection, we were able to estimate that its half-life in the cerebrospinal fluid (CSF) was between 1 1/2 and 2 hr. Intrathecal treatment of guinea-pigs with immunotoxin 1 day after inoculation of L2C cells into the cisterna magna had a remarkable therapeutic effect. All guinea-pigs treated with 0.5 or 5 micrograms of immunotoxin survived, and remained tumour-free for more than 100 days after treatment, while control animals given cyclophosphamide alone or an irrelevant immunotoxin had a mean survival time of 28 days. Provided concerns over toxicity can be overcome, these results indicate that i.t. immunotoxins offer an alternative, highly specific form of treatment in leptomeningeal neoplasia.