Abstract 3633: Disparities in relapse among a large multi-ethnic population of children diagnosed with acute lymphoblastic leukemia (ALL): A report from the Reducing Ethnic Disparities in Acute Leukemia (REDIAL) Consortium

Introduction: While end-induction minimal residual disease (MRD) is the strongest prognostic factor for relapsed ALL, approximately half of all relapses occur in children who are MRD negative. Latino ethnicity is also a risk factor for relapse. To further explore these associations, we conducted an interim analysis of risk factors for relapse in a large multi-ethnic population of children diagnosed with ALL.

Methods: The REDIAL Consortium includes patients diagnosed with ALL at six major pediatric cancer centers in the Southwestern U.S. The study period was 2004 to 2018, and we included individuals who were 1-23 years of age when diagnosed with ALL. Time to relapse was defined as time from ALL diagnosis to the initial relapse event, with individuals censored at date of death, last follow-up, or bone marrow transplant. Demographic and clinical factors evaluated included race/ethnicity (Latino, non-Latino Black, non-Latino White, non-Latino other), sex, age at diagnosis (1-5, 6-10, 11-15, >15 years), ALL immunophenotype (B-cell, T-cell), National Cancer Institute (NCI) risk group, central nervous system involvement, enrollment on a Children’s Oncology Group clinical trial, end-induction disease failure, and end-induction bone marrow flow cytometric MRD. Cox proportional hazards models were used to calculate adjusted hazards ratios (HRs) and 95% confidence intervals (CIs). Analyses were further stratified based on end-induction MRD status (positive ≥0.01%, negative <0.01%).

Results: Overall, there were 1,710 ALL patients with a median age at diagnosis of 5 years (interquartile range: 3-11 years). The majority of patients were Latino (60.1%) and male (56.9%). Of the 379 MRD-positive patients, 74 (19.5%) relapsed, compared to 138 of 1,233 (11.2%) MRD-negative patients (p<0.0001). In adjusted models, factors associated with a greater risk of relapse included MRD positivity (HR=1.72, 95% CI: 1.26-2.36), older age at diagnosis (>15 vs. 1-5 years, HR=1.98, 95% CI: 1.19-3.29), and NCI high-risk group (HR=1.74, 95% CI: 1.20-2.52), while patients enrolled on a clinical trial were less likely to relapse (HR=0.76, 95% CI: 0.57-0.99). Among MRD-positive patients, Latinos were less likely to relapse (HR=0.60, 95% CI: 0.33-0.99) compared to non-Latino Whites, whereas Latinos who were MRD negative were more likely to relapse (HR=1.68, 95% CI: 1.09-2.59).

Conclusion: In a large contemporary multi-ethnic cohort of >1,700 children with ALL, we observed significant disparities in relapse by MRD status, age at diagnosis, NCI risk group, clinical trial enrollment, and race/ethnicity. Notably, nearly 65% of relapse events occurred in MRD-negative patients. Further analyses are ongoing in REDIAL to evaluate the impact of other factors including cytogenetics and novel biomarkers of relapse.

Citation Format: Pagna Sok, Austin L. Brown, Olga A. Taylor, M. Brooke Bernhardt, Juan C. Bernini, Rodrigo A. Erana, Timothy Griffin, Kenneth Heym, Van T. Huynh, Laura Klesse, Kathleen Ludwig, Sandi L. Pruitt, Karen R. Rabin, Michael E. Scheurer, Philip J. Lupo. Disparities in relapse among a large multi-ethnic population of children diagnosed with acute lymphoblastic leukemia (ALL): A report from the Reducing Ethnic Disparities in Acute Leukemia (REDIAL) Consortium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3633.

Abstract 3636: Ethnic disparities in methotrexate neurotoxicity during pediatric acute lymphoblastic leukemia therapy: A report from the Reducing Ethnic Disparities in Acute Leukemia (REDIAL) Consortium

Introduction: Methotrexate (MTX) is a key component of curative chemotherapy for pediatric acute lymphoblastic leukemia (ALL). However, delivery of MTX is often interrupted by dose-limiting acute neurotoxicity, which manifests as seizures, stroke-like symptoms, or altered mental status. Because incidence and risk factors for MTX neurotoxicity are poorly defined, we evaluated clinical and demographic predictors of MTX neurotoxicity using the multi-ethnic REDIAL Consortium.

Methods: The REDIAL cohort includes pediatric patients diagnosed with ALL at six treatment centers in the southwestern U.S. This interim analysis evaluated 756 patients age 1-21 years diagnosed with B-ALL (2005-2018). Electronic health records were reviewed to determine race/ethnicity (Latino, non-Latino White, non-Latino Black, or Other), body mass index, sex, age, and intravenous (IV) MTX dose. Applying Ponte di Legno criteria, acute MTX neurotoxicity was defined as neurologic episodes occurring <21 days from intrathecal or IV MTX, which resulted in MTX treatment modifications. The proportion of patients who experienced MTX neurotoxicity and corresponding 95% confidence interval (CI) was calculated overall and within the induction, post-induction, and maintenance treatment phases. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR) for the association between clinical factors and MTX neurotoxicity.

Results: The study population was 56.6% Latino, 52.8% male, 41.4% treated with >5g/m2 IV MTX, and diagnosed at a median age of 5 years. Overall, 15.5% (95% CI: 12.9-18.3%) of patients experienced neurotoxic events (n=117), including 1.9% (n=14, 95% CI: 1.0-3.1%) during induction, 13.0% (n=98, 95% CI: 10.7-15.6%) during post-induction, and 0.7% (n=5, 95% CI: 0.2-1.5%) during maintenance therapy. Ethnic differences were not statistically significant during induction or maintenance phases. Compared to non-Latinos, post-induction neurotoxicity was significantly more frequent among Latinos (aOR = 2.87, 95% CI: 1.68-5.10), with disparities observed during consolidation, interim maintenance and delayed intensification phases. Exposure to >5g/m2 IV MTX (aOR = 2.16, 95% CI: 1.08-3.24) and older age at diagnosis (aOR = 1.16, 95% CI: 1.08-1.24) were also associated with a significantly more post-induction neurotoxicity. No factors evaluated were significantly associated with neurotoxicity during induction and maintenance therapy.

Conclusions: MTX neurotoxicity disproportionally affects Latino children during ALL post-induction therapy. Additional work is warranted to identify risk factors for neurotoxicity during induction and maintenance therapy as well as the specific clinical and host biological factors responsible for post-induction ethnic differences in MTX neurotoxicity.

Citation Format: Austin L. Brown, Rachel D. Harris, Olga A. Taylor, Melanie B. Bernhardt, Juan C. Bernini, Rodrigo A. Erana, Timothy Griffin, Kenneth Heym, Van T. Huynh, Kathleen Ludwig, Avner Meoded, Sandi L. Pruitt, Philip J. Lupo, Karen R. Rabin, Michael E. Scheurer. Ethnic disparities in methotrexate neurotoxicity during pediatric acute lymphoblastic leukemia therapy: A report from the Reducing Ethnic Disparities in Acute Leukemia (REDIAL) Consortium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3636.

Infantile cytomegalovirus-associated autoimmune hemolytic anemia

Autoimmune hemolytic anemia (AIHA) is a hematologic disorder that is rarely seen in infants and young children. Most cases are associated with viral or bacterial infection, but the immunologic events leading to hemolysis are poorly understood. We describe two infants with severe cytomegalovirus (CMV)-associated warm antibody AIHA. One case was immunohematologically analyzed and showed suggestive evidence that endogenous anti-CMV IgG antibodies were the pathogenic antibodies leading to hemolysis, implicating a possible causal relationship between AIHA and CMV infection. Both patients were ultimately treated with intravenous CMV immune globulin, with subsequent improvement. These cases suggest that investigation for the presence of CMV in infantile AIHA is warranted and that CMV immune globulin should be considered as a therapeutic option.

Beneficial effect of intravenous dexamethasone in children with mild to moderately severe acute chest syndrome complicating sickle cell disease

Acute chest syndrome (ACS) in patients with sickle cell disease (SCD) has historically been managed with oxygen, antibiotics, and blood transfusions. Recently high-dose corticosteroid therapy was shown to reduce the duration of hospitalization in children with SCD and vaso-occlusive crisis. Therefore, we chose to assess the use of glucocorticoids in ACS. We conducted a randomized, double-blind placebo-controlled trial to evaluate the efficacy and toxicity of intravenous dexamethasone (0.3 mg/kg every 12 hours x 4 doses) in children with SCD hospitalized with mild to moderately severe ACS. Forty-three evaluable episodes of ACS occurred in 38 children (median age, 6.7 years). Twenty-two patients received dexamethasone and 21 patients received placebo. There were no statistically significant differences in demographic, clinical, or laboratory characteristics between the two groups. Mean hospital stay was shorter in the dexamethasone-treated group (47 hours v 80 hours; P = .005). Dexamethasone therapy prevented clinical deterioration and reduced the need for blood transfusions (P < .001 and = .013, respectively). Mean duration of oxygen and analgesic therapy, number of opioid doses, and the duration of fever was also significantly reduced in the dexamethasone-treated patients. Of seven patients readmitted within 72 hours after discharge (six after dexamethasone; P = .095), only one had respiratory complications (P = 1.00). No side effects clearly related to dexamethasone were observed. In a stepwise multiple linear regression analysis, gender and previous episodes of ACS were the only variables that appeared to predict response to dexamethasone, as measured by lengh of hospital stay. Intravenous dexamethasone has a beneficial effect in children with SCD hospitalized with mild to moderately severe acute chest syndrome. Further study of this therapeutic modality is indicated.

Low-dose recombinant human granulocyte colony-stimulating factor therapy in children with symptomatic chronic idiopathic neutropenia

OBJECTIVES

To prospectively define the lowest possible doses of recombinant human granulocyte colony-stimulating factor (rhG-CSF) that would benefit selected children with chronic idiopathic neutropenia whose disease was severe enough to interfere appreciably with quality of life.

STUDY DESIGN

The efficacy of low-dose rhG-CSF therapy was investigated in six children with symptomatic chronic idiopathic neutropenia. All patients received rhG-CSF, 5 micrograms/kg subcutaneously, as a single daily dose until an absolute neutrophil count (ANC) above 1.5 x 10(9)/L was observed. The rhG-CSF dosage interval and amount were then increased and decreased, respectively, in an alternating fashion until the lowest rhG-CSF dose that would maintain the ANC above 1.0 x 10(9)/L (1000/mm3) was reached.

RESULTS

Although the minimal dose requirements varied, all patients were able to maintain a mean ANC > 1.0 x 10(9)/L during a mean follow-up period of 14 months at doses ranging from 1.0 microgram/kg once weekly to 5.0 micrograms/kg every other day. Administration of rhG-CSF resulted in resolution of all preexisting chronic infections, reduction in the frequency of new infectious episodes, and discontinuation of prophylactic antibiotics. In all patients the ANC decreased to pretreatment values when further reduction or discontinuation of rhG-CSF therapy was attempted. By identifying the minimal effective dose in each patient, we were able to reduce the treatment cost by a mean of 81% compared with daily dosage at 5 micrograms/kg.

CONCLUSIONS

Recombinant human granulocyte colony-stimulating factor therapy at low doses (< or = 5 micrograms/kg) every 2 to 7 days to symptomatic children with chronic idiopathic neutropenia is effective and no more costly than supportive treatment with antibiotics.

Diagnosis and management of chronic neutropenia during childhood

The approach to the diagnostic evaluation of a patient with neutropenia can be guided largely by clinical history and physical examination and does not always require an extensive laboratory evaluation. Based on the history and bone marrow morphology, most children with chronic neutropenia can be classified and managed. Most patients with chronic neutropenia are free of infections and are able to maintain a normal lifestyle with no or minimal medical intervention. On the other hand, for patients with recurrent or severe infections, careful follow-up and institution of treatment are mandatory. The Food and Drug Administration has approved the use of rhG-CSF in patients with chronic neutropenia. As mentioned previously, the use of colony-stimulating factors has dramatically improved the outcome for many patients with the more severe neutropenia; however, this cytokine is expensive, so treatment should be reserved for more severely affected patients and not given just because the ANC is low. Although concerns exist regarding leukemogenic effects or eventual loss of the progenitor cell compartment driven by the continuous stimulation of rhG-CSF, at this moment, the long-term data available suggest that the chronic administration of rhG-CSF is safe.

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.

High-dose intravenous methylprednisolone therapy for patients with Diamond-Blackfan anemia refractory to conventional doses of prednisone

OBJECTIVES

To assess the efficacy and toxicity of very high doses of glucocorticoids in patients with congenital pure red cell aplasia (Diamond-Blackfan anemia) who did not respond to standard doses of prednisone.

STUDY DESIGNS

We prospectively treated eight patients with transfusion-dependent Diamond-Blackfan anemia with high intravenous doses of methylprednisolone. All patients had previously not responded to one or more oral courses of prednisone in standard doses and were dependent on erythrocyte transfusions. Every patient initially received methylprednisolone at a dose of 30 mg/kg per day, followed by slow tapering for 4 weeks, but none responded. All patients then received a second treatment course starting at 100 mg of methylprednisolone per kilogram per day, again followed by slow tapering of the dosage.

RESULTS

Three patients had a complete response that has been sustained for 21+, 31+, and 41+ months, respectively. One patient had a partial response. Toxic effects included a rise in serum alanine aminotransferase activity in all patients, transient diabetes mellitus in one child, and three episodes of bacteremia in two patients with intravenous access devices.

CONCLUSIONS

We conclude that very high doses of methylprednisolone may induce sustained remission in some patients with transfusion-dependent Diamond-Blackfan anemia refractory to standard-dose prednisone therapy.

Fatal hemolysis induced by ceftriaxone in a child with sickle cell anemia

A 2-year-old boy with sickle cell anemia had a massive, fatal hemolytic reaction after administration of an intravenous dose of ceftriaxone. Laboratory studies demonstrated the presence of an IgM antibody against ceftriaxone, binding to and destroying the patient's erythrocytes by an immune complex mechanism. This rare complication should be considered in the differential diagnosis when hemoglobinuria develops in a child after administration of ceftriaxone or a similar agent.

Aminophylline for methotrexate-induced neurotoxicity

Methotrexate, a mainstay treatment for children with acute lymphoblastic leukaemia, can cause neurotoxicity, with paralysis, seizures, somnolence, anorexia, and headaches. The pathophysiology of this reaction is unknown. It has been suggested that the anti-inflammatory effect of methotrexate in patients with arthritis is due to adenosine release brought on by inhibition of purine synthesis. Since adenosine is a central nervous system depressant, we wondered whether adenosine release in the central nervous system could account for some of the neurotoxicity due to methotrexate, and whether that toxicity could be lessened by displacement of adenosine from its receptor by aminophylline. 6 patients (age 3-16 years) who had methotrexate-induced neurotoxicity unresponsive to standard treatment received 2.5 mg/kg aminophylline. In addition, the concentration of adenosine in the cerebrospinal fluid (CSF) from 11 children completing a 24-h systemic methotrexate protocol was compared with that in 8 newly diagnosed patients and 12 who had not received any treatment for at least a week. 4 of 6 patients with toxic signs and symptoms attributed to methotrexate and unrelieved by steroids, epidural blood patch, promethazine, 5-hydroytryptamine antagonists, paracetamol, and narcotics, had complete resolution of neurotoxicity after or during a 1-h infusion of aminophylline; 2 others had a pronounced improvement but persistent nausea. CSF adenosine concentrations of patients receiving methotrexate, even when there was very slight or no toxicity, were greatly increased compared with control subjects (mean values of 217 and 51 nmol/L, median 175 and 52 nmol/L). Subacute methotrexate neurotoxicity may be mediated by adenosine and relieved by aminophylline.

Acute basophilic leukemia in a child. Anaphylactoid reaction and coagulopathy secondary to vincristine-mediated degranulation

BACKGROUND

Acute de novo basophilic leukemia (ABL) is uncommon in adults, and extremely rare in children. To the authors' knowledge, there have been no previous reports of anaphylactoid reactions from basophilic degranulation in children with this condition.

METHODS

This report describes the clinicopathologic profile and complications of a patient with de novo ABL.

RESULTS

Immediately after the first induction dose of intravenous vincristine, the patient developed an anaphylactoid reaction and disseminated intravascular coagulation with massive pulmonary hemorrhage. A normal serum tryptase level suggested that this life-threatening event was secondary to tumor lysis (basophilic degranulation), rather than to a mast-cell mediated anaphylactic reaction to vincristine. This interpretation is supported by the coagulation studies, which suggested release of heparin from the blast granules.

CONCLUSIONS

Although de novo ABL is rare, it should be considered when cytoplasmic basophilic granules are seen in the leukemic cells of patients with what otherwise appears to be undifferentiated leukemia, and the pertinent diagnostic procedures should be undertaken. During the treatment of ABL, potential complications related to basophilic degranulation should be anticipated, and antihistamine prophylaxis may be of value.

Adjuvant chemotherapy for treatment of unresectable and metastatic angiomatoid malignant fibrous histiocytoma

Angiomatoid malignant fibrous histiocytoma (AMFH) is a low grade soft tissue sarcoma usually treated with surgery alone. Only one adult patient has been treated with systemic chemotherapy. The authors report a case of unresectable, metastatic AMFH treated initially with vincristine, doxorubicin, dactinomycin, and cyclophosphamide. A complete response at the metastatic site and a marked reduction in the size of the primary tumor allowed complete surgical excision 7 months after treatment was initiated. The patient remains disease free 19 months after being diagnosed. It was concluded that systemic chemotherapy may be effective in patients with AMFH.

Splenic rupture in hemophilia

PURPOSE

Little information is available regarding splenic injury in patients with hemophilia. We describe here the management of splenic rupture in five of our patients with hemophilia and summarize the literature describing this complication.

PATIENTS AND METHODS

Two human immunodeficiency virus-seropositive patients were managed medically and did not require splenectomy. A third patient had a high titer inhibitor to both porcine and human factor VIII and required emergency splenectomy. Two boys had not been previously diagnosed with hemophilia until they underwent splenectomy after abdominal trauma.

RESULTS

All five patients survived.

CONCLUSIONS

These cases demonstrate that nonsurgical management of splenic injury in patients with hemophilia can be performed safely and that splenectomy can be successfully performed despite a high titer of factor VIII inhibitor.

Hypoprothrombinemia and severe hemorrhage associated with a lupus anticoagulant

We recently encountered a previously healthy 3-year-old girl who had severe bleeding resulting from a severe deficiency of prothrombin. A lupus anticoagulant was identified by several different methods. The patient was successfully treated with glucocorticoids. This rare complication of a lupus anticoagulant should be considered in the differential diagnosis of a previously well child who suddenly has hemorrhage.