Analysis of infectious complications in infants with acute lymphoblastic leukemia treated on the Children's Cancer Group Protocol 1953: a report from the Children's Oncology Group

Evolution and optimization of therapies for acute lymphoblastic leukemia in infants

Acute lymphoblastic leukemia (ALL) in infants accounts for less than 5% of pediatric ALL and is biologically and clinically unique. Approximately 70% to 80% of cases present as an aggressive leukemia with KMT2A gene rearrangement (KMT2A-r), which is one of the most difficult-to-cure forms of pediatric leukemia. Owing to continuing global efforts through multicenter clinical trials since the mid-1990s, a standard of care for infant KMT2A-r ALL, including minimal residual disease-based risk stratifications, "hybrid chemotherapy" incorporating myeloid leukemia-like drugs (e.g., cytarabine) into the ALL chemotherapy backbone, and selective use of allogeneic hematopoietic stem cell transplantation, has now been established. However, there are still many concerns regarding treatment of infants with KMT2A-r ALL, including insufficient efficacy of the current standard therapies, limited pharmacokinetic/pharmacodynamic data on drugs in infants, and management of both acute and late toxicities. Refinements in risk stratification based on leukemia biology, as well as the introduction of emerging novel immunotherapies and molecular-targeted drugs to contemporary therapy, through international collaboration would provide key solutions for further improvement in outcomes.

Infectious events in pediatric patients with acute lymphoblastic leukemia/lymphoma undergoing evaluation for fever without severe neutropenia

BACKGROUND

Infections cause significant treatment-related morbidity during pediatric acute lymphoblastic leukemia/lymphoma (ALL/LLy) therapy. Fevers during periods without severe neutropenia are common, but etiologies are not well-described. This study sought to describe the bloodstream infection (BSI) and non-BSI risk in children undergoing therapy for ALL/LLy.

METHODS

Demographic and clinical data were abstracted for febrile episodes without severe neutropenia at two children's hospitals. Treatment courses were stratified by intensity. Multivariate logistic regression evaluated characteristics associated with infection.

RESULTS

There were 1591 febrile episodes experienced by 524 patients. Of these, 536 (34%) episodes had ≥1 infection; BSI occurred in 30 (1.9%) episodes. No BSIs occurred in episodes with a recent procedural sedation or cytarabine exposure. Presence of hypotension, chills/rigors, higher temperature, and infant phenotype were independently associated with BSI (p < .05). Of the 572 non-BSIs, the most common was upper respiratory infection (URI) (n = 381, 67%). Compared to episodes without infection, URI symptoms, higher temperature, absolute neutrophil count 500-999/μl, and evaluation during a low-intensity treatment course were more likely to be associated with a non-BSI (p < .05) and inpatient status was less likely to be associated with a non-BSI (p < .05).

CONCLUSIONS

The BSI rate in pediatric patients with ALL/LLy and fever without severe neutropenia is low, but one-third of the time, patients have a non-BSI. Future research should test if the need for empiric antibiotics can be tailored based on the associations identified in this study.

Viridans Group Streptococci in Pediatric Leukemia and Stem Cell Transplant: Review of a Risk-stratified Guideline for Empiric Vancomycin in Febrile Neutropenia

Viridans group streptococci (VGS) are an important cause of sepsis in immunosuppressed children. We reviewed the effectiveness of risk-stratified addition of vancomycin to empiric febrile neutropenia therapy among 107 children with leukemia or undergoing an allogeneic transplant. Of 19 VGS bacteremia episodes, 78.9% were susceptible to risk-stratified antibiotics including 100% from high-risk patients. All blood cultures were flagged positive within 24 hours.

Presentation acuity, induction mortality, and resource utilization in infants with acute leukemia

BACKGROUND

Treatment of infants with acute leukemia remains challenging, especially for acute lymphocytic leukemia (ALL). Infants have shown markedly higher rates of induction mortality compared with noninfants. There are limited data on presentation acuity and supportive care utilization in this age group.

METHODS

In retrospective analyses of patients treated for new onset ALL or acute myeloid leukemia (AML) at pediatric hospitals contributing to the Pediatric Health Information System, we compared presentation acuity, induction mortality, and resource utilization in infants relative to noninfants less than 10 years at diagnosis.

RESULTS

Analyses included 10 359 children with ALL (405 infants, 9954 noninfants) and 871 AML (189 infants, 682 noninfants). Infants were more likely to present with multisystem organ failure compared to noninfants for both ALL (12% and 1%, PR = 10.8, 95% CI: 7.4, 15.7) and AML (6% vs. 3%; PR = 2.0, 95% CI: 1.0, 3.7). Infants with ALL had higher induction mortality compared to noninfants, even after accounting for differences in anthracycline exposure and presentation acuity (2.7% vs. 0.5%, HR = 2.1, 95% CI: 1.0, 4.8). Conversely, infants and noninfants with AML had similar rates of induction mortality (3.2% vs. 2.1%, HR = 1.2, 95% CI: 0.3, 3.9), which were comparable to rates among infants with ALL. Infants with ALL and AML had greater requirements for blood products, diuretics, supplemental oxygen, and ventilation during induction relative to noninfants.

CONCLUSIONS

Infants with leukemia present with higher acuity compared with noninfants. Induction mortality and supportive care requirements for infants with ALL were similar to all children with AML, and significantly higher than those for noninfants with ALL.

Acute Leukemia in Infants

PURPOSE OF THE REVIEW

Infant leukemia is a rare, distinct subgroup of pediatric acute leukemias diagnosed in children under 1 year of age and characterized by unique, aggressive biology. Here, we review its clinical presentation, underlying molecular biology, current treatment strategies, and novel therapeutic approaches.

RECENT FINDINGS

Infant leukemias are associated with high-risk molecular features and high rates of chemotherapy resistance. International collaborative clinical trials have led to better understanding of the underlying molecular biology, refined risk-based stratification, and investigated the use of hematopoietic stem cell transplantation. However, intensification of chemotherapy has failed to improve outcomes, and current regimens are associated with significant treatment-related and long-term toxicities. Infants with leukemia remain a challenging group to treat. We must continue collaborative efforts to move beyond traditional cytotoxic chemotherapy, incorporate molecularly targeted strategies and immunotherapy, and increase access to clinical trials to improve outcomes for this high-risk group of patients.

Prognosis of haploidentical hematopoietic stem cell transplantation in non-infant children with t(v;11q23)/MLL-rearranged B-cell acute lymphoblastic leukemia

B-cell acute lymphoblastic leukemia (B-ALL) with MLL-rearrangements (MLL-r) is rare in pediatric patients (aged >1 year), and optimal treatment strategies remain unclear. This study aimed to retrospectively evaluate the clinical characteristics, outcomes, and effects of allogeneic hematopoietic stem cell transplantation (allo-HSCT) of 37 non-infant children with t(v;11q23)/MLL-r B-ALL. Their 4-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse (CIR) were 69.8 %, 58.2 %, and 39.1 %, respectively, and differed significantly between patients receiving allo-HSCT (18/19 cases received haploidentical [haplo]-HSCT) at the first complete remission (HSCT at CR1, n = 19; 87.4 %, 89.5 % and 5.3 %) and those continuing consolidation therapy (Non-HSCT at CR1, n = 18; 52.2 %, 25.9 %, and 74.1 %, respectively), and the p values were 0.022, <0.001 and <0.001, respectively. Of the 13 patients experiencing relapse during consolidation chemotherapy, the five continuing with chemotherapy only died within 44 months, and the eight patients opting for allo-HSCT after CR2 had a 4-year OS of 57.1 %. Multivariate analysis revealed HSCT at CR1 as the only independent protective factor for OS, EFS, and CIR. The present results indicate that allo-HSCT (especially haplo-HSCT) at CR1 may decrease the relapse rate and improve the prognosis of non-infant children with t(v;11q23)/MLL-r B-ALL.

Prevalence and characteristics of acute respiratory virus infections in pediatric cancer patients

Background

Patients with pediatric cancer have a higher risk of morbidity and mortality because of respiratory viral infections than other patient populations.

Objectives

To investigate the causative viruses of respiratory infections and their burden among patients with pediatric cancer in Lebanon.

Study design

Nasopharyngeal swabs along with clinical and demographic data were collected from patients with pediatric cancer presenting febrile episodes with upper respiratory tract symptoms. Total nucleic acid was extracted from specimens followed by the real‐time PCR analysis targeting 14 respiratory viruses to estimate the frequency of infections.

Results

We obtained 89 nasopharyngeal swabs from patients with pediatric cancer (mean age, 5.8 ± 4.2 years). Real‐time PCR confirmed viral infection in 77 swabs (86.5%). Among these, 151 respiratory viruses were detected. Several viruses cocirculated within the same period; respiratory syncytial virus (RSV) being the most common (45.45%), followed by parainfluenza virus (PIV; 26%), influenza type B (26%), human metapneumovirus (24.6%), and human coronavirus (HCoV; 24.6%). Coinfections were detected in 55% of the subjects, and most of them involved RSV with one or more other viruses. A strong correlation was found between PIV, Flu (influenza of any type), RSV, and HCoV with the incidence of coinfections. RSV was associated with lower respiratory tract infections, nasal congestion, bronchitis, and bacteremia. HCoV was associated with bronchiolitis; rhinovirus was associated with hospital admission.

Conclusion

Patients with pediatric cancer have a high burden of respiratory viral infections and a high incidence of coinfections. Molecular diagnostics can improve management of febrile episodes and reduce antibiotic use.

Respiratory viruses are leading cause of ARTI in pediatric cancer patients.

Coinfections are common among febrile pediatric cancer patients.

RSV was the most common in mono‐ and coinfections among pediatric cancer patients.

RSV, PIV, Flu, HCoV are associated with coinfections.

Molecular diagnostics permit rapid and sensitive diagnostics and limit antibiotic abuse.

Infectious complications in children with acute lymphoblastic leukemia treated with the Taiwan Pediatric Oncology Group protocol: A 16-year tertiary single-institution experience

BACKGROUND

Infection is a major complication in pediatric patients with acute lymphoblastic leukemia during chemotherapy. In this study, the infection characteristics were determined and risk factors analyzed based on the Taiwan Pediatric Oncology Group (TPOG) acute lymphoblastic leukemia (ALL) protocol.

PROCEDURE

We retrospectively reviewed fever events during chemotherapy in 252 patients treated during two consecutive clinical trials at a single institution between 1997 and 2012. Patients were classified as standard, high, and very high risk by treatment regimen according to the TPOG definitions. We analyzed the characteristics and risk factors for infection.

RESULTS

Fever occurred in 219 patients (86.9%) with a mean of 2.74 episodes per person. The fever events comprised 64% febrile neutropenia, 39% clinically documented infections, and 44% microbiologically documented infections. The microbiologically documented infections were mostly noted during the induction phase and increased in very high risk patients (89 vs. 24% and 46% in standard-risk and high-risk patients, respectively). Younger age and higher risk (high-risk and very high risk groups) were risk factors for fever and microbiologic and bloodstream infections. Female gender and obesity were additive risk factors for urinary tract infection (odds ratios = 3.52 and 3.24, P < 0.001 and P = 0.004, respectively).

CONCLUSIONS

Infections developed primarily during the induction phase, for which younger age and higher risk by treatment regimen were risk factors. Female gender and obesity were additive risk factors for urinary tract infection.

Infectious complications in children with acute lymphoblastic leukemia treated in low-middle-income countries

Infections are the most important cause of morbidity and mortality in children treated for acute lymphoblastic leukemia (ALL). The rates of infection-associated mortality are up to 10-times higher in low- and middle-income countries (LMIC) than in high-income countries. The prevention, early recognition and management of infectious complications is especially challenging in LMIC because of disease and poverty-related factors, as well as the shortage of trained personnel, supplies, diagnostic tools and adequate organizational infrastructure. Children in LMIC with ALL, who are frequently underweight, are at increased risk of community-acquired pathogens, nosocomial multidrug-resistant pathogens and opportunistic microorganisms. This review summarizes the challenges of managing the major categories of infections in children receiving treatment for ALL and provides updated practical recommendations for preventing and managing these infections in LMIC.

Fungal colonization of the respiratory tract in allogeneic and autologous hematopoietic stem cell transplant recipients: a study of 573 transplanted patients

Background

Fungal colonization and infections remain a major cause of infection morbidity and mortality following hematopoietic stem cell transplantation (HSCT) in patients with hematological malignancies. The aim of this study was to analyze the spectrum of fungal microflora of the respiratory tract (oral cavity, pharynx, epiglottis, and sputum) in patients undergoing HSCT and to evaluate the relationship between HSCT type and incidence of mycotic colonization and infections.

Material/Methods

Retrospective analysis of fungal isolates collected from the respiratory tract (oral cavity, pharynx, epiglottis, and sputum) of 573 patients undergoing HSCT was performed.

Results

The overall rate of fungal colonization in patients undergoing HSCT was 8.7%. Patients undergoing allogeneic HSCT were statistically significantly more often colonized (12.95%) compared to autologous HSCT recipients (4.7%). Colonizing cultures were mainly C. albicans and C. krusei, and sporadically C. glabrata, C. famata, Aspergillus spp. and Saccharomyces cerevisiae. C. albicans was the most frequent species found in isolates from the pharynx, sputum, and oral cavity collected from patients undergoing HSCT. Aspergillosis was more common after allogeneic than after autologous HSCT. The pharynx was the most frequently colonized site.

Conclusions

Allogeneic HSCT recipients are more susceptible to fungal infections compared to the autologous group. Selection of species during prophylaxis and antifungal therapy requires developing more effective prevention and treatment strategies based on new antifungal drugs and microbe-specific diagnoses.

Successful Treatment of Disseminated Adenovirus Infection in an Infant With Acute Lymphoblastic Leukemia

Systemic adenovirus infection in the immunocompromised host is often fatal and therapeutic options are limited. We report an infant with acute lymphoblastic leukemia who developed disseminated adenovirus infection while lymphopenic during maintenance chemotherapy 6 months following a bout of adenoviral diarrhea. His serum adenoviral load peaked at 35 million copies/mL and was associated with pancytopenia and hepatic injury. Treatment with cidofovir was effective although associated with mild renal injury. The patient recovered fully and completed chemotherapy for infant acute lymphoblastic leukemia.

Decreased induction morbidity and mortality following modification to induction therapy in infants with acute lymphoblastic leukemia enrolled on AALL0631: a report from the Children's Oncology Group

BACKGROUND

Infants with acute lymphoblastic leukemia (ALL) have a poor prognosis. Intensification of therapy has resulted in fewer relapses but increased early deaths, resulting in failure to improve survival.

PROCEDURE

AALL0631 is a Phase 3 study for infants (<366 days of age) with newly diagnosed ALL. Induction initially (Cohort 1) consisted of 3 weeks of therapy based on COG P9407. Due to excessive early mortality, induction was amended to a less intensive 5 weeks of therapy based on Interfant-99. Additionally, enhanced supportive care guidelines were incorporated with hospitalization during induction until evidence of marrow recovery and recommendations for prevention/treatment of infections (Cohort 2).

RESULTS

Induction mortality was significantly lower for patients in Cohort 2 (2/123, 1.6%) versus Cohort 1 (4/26, 15.4%; P = 0.009). All induction deaths were infection related except one due to progressive disease (Cohort 2). Sterile site infections were lower for patients in Cohort 2 (24/123, 19.5%) versus Cohort 1 (15/26, 57.7%; P = 0.0002), with a significantly lower rate of Gram positive infections during induction for patients in Cohort 2, P = 0.0002. No clinically significant differences in grades 3-5 non-infectious toxicities were observed between the two cohorts. Higher complete response rates were observed at end induction intensification for Cohort 2 (week 9, 94/100, 94%) versus Cohort 1 (week 7, 17/25, 68%; P = 0.0.0012).

CONCLUSION

De-intensification of induction therapy and enhanced supportive care guidelines significantly decreased induction mortality and sterile site infections, without decreasing complete remission rates.

The evolution of clinical trials for infant acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) in infants has a significantly inferior outcome in comparison with older children. Despite initial improvements in survival of infants with ALL since establishment of the first pediatric cooperative group ALL trials, the poor outcome has plateaued in recent years. Historically, infants were treated on risk-adapted childhood ALL protocols. These studies were pivotal in identifying the need for infant-specific protocols, delineating prognostic categories and the requirement for a more unified approach between study groups to overcome limitations in accrual because of low incidence. This subsequently led to the development of collaborative infant-specific studies. Landmark outcomes have included the elimination of cranial radiotherapy following the discovery of intrathecal and high-dose systemic therapy as a superior and effective treatment strategy for central nervous system disease prophylaxis, with improved neurodevelopmental outcome. Universal prospective identification of independent adverse prognostic factors, including presence of a mixed lineage leukemia rearrangement and young age, has established the basis for risk stratification within current trials. The infant-specific trials have defined limits to which conventional chemotherapeutic agents can be intensified to optimize the balance between treatment efficacy and toxicity. Despite variations in therapeutic intensity, there has been no recent improvement in survival due to the equilibrium between relapse and toxicity. Ultimately, to improve the outcome for infants with ALL, key areas still to be addressed include identification and adaptation of novel prognostic markers and innovative therapies, establishing the role of hematopoietic stem cell transplantation in first complete remission, treatment strategies for relapsed/refractory disease and monitoring and timely intervention of late effects in survivors. This would be best achieved through a single unified international trial.

Modifications to induction therapy decrease risk of early death in infants with acute lymphoblastic leukemia treated on Children's Oncology Group P9407

BACKGROUND

Infants (<366 days of age) with acute lymphoblastic leukemia (ALL) have a poor prognosis. Most treatment failures occur within 6-9 months of diagnosis, primarily from relapse.

PROCEDURE

The Children's Oncology Group P9407 study was designed to test if early intensified treatment would improve outcome for infants with ALL. Due to a significant number of early deaths (< 90 days from enrollment), Induction therapy was amended three times. Cohorts 1 + 2 (n = 68), received identical Induction therapy except for reduced daunorubicin dose in Cohort 2. Cohort 3 (n = 141) received prednisone (40 mg/m(2)/day) instead of dexamethasone (10 mg/m(2)/day) and short infusion daunorubicin (30 minutes) instead of continuous infusion (48 hours), as well as additional supportive care measures throughout therapy.

RESULTS

Early deaths occurred in 17/68 (25%) infants in Cohorts 1 + 2 and 8/141 (5.7%) infants in Cohort 3 (P < 0.0001). Among infants ≤90 days of age at diagnosis, early death occurred in 10/17 (58.8%) in Cohorts 1 + 2 and 4/27 (14.8%) in Cohort 3 (P = 0.006). Among infants >90 days of age at diagnosis, early death occurred in 7/51 (13.7%) in Cohorts 1 + 2 and 4/114 (3.5%) in Cohort 3 (P = 0.036). Bacterial, viral, and fungal infections were more common in Cohorts 1 + 2 versus Cohort 3.

CONCLUSIONS

Early morbidity and mortality for infants with ALL were reduced by substitution of prednisone (40 mg/m(2)/day) for dexamethasone (10 mg/m(2)/day), the delivery of daunorubicin over 30 minutes instead of a continuous infusion for 48 hours, and the provision of more specific supportive care measures.

Pediatric Acute Lymphoblastic Leukemia: Is There Still a Role for Transplant?

Constant questioning of the applicability of transplant for any diagnosis is appropriate. This is particularly necessary in fields such as pediatric leukemia, in which significant progress in therapy and risk classification is being made. Outcomes with chemotherapy are constantly improving, and donor availability and transplant outcomes are also better. It is important to be aware of likely outcomes when counseling families and recommending therapy, and to consider issues of likely late side effects. Biological studies that predict prognosis, for example, array-based studies, hold hope of identifying the children destined to relapse at the outset of disease. However, a rigorous approach must be taken in determining whether transplant does improve outcome whenever this strategy is applied.

Fungal infections in oncology patients: update on epidemiology, prevention, and treatment

PURPOSE OF REVIEW

Fungal infections that occur after hematopoietic stem cell transplant and therapies for hematologic malignancies contribute to poor outcomes. In the recent year, studies have focused on updating epidemiologic data, providing an understanding of immunogenetic risks for infection, and optimizing prevention and treatment strategies; these studies will be reviewed.

RECENT FINDINGS

Contributions to our understanding of epidemiology have come from multicenter studies. Results demonstrate variability in the numbers of diagnosed invasive aspergillosis cases in oncology centers, and a persistent, although relatively low rate of invasive candidiasis. Both multiple and single-center studies are demonstrating improved outcomes of treating invasive aspergillosis. Several important studies have outlined the importance of immunogenetics in conferring risks for invasive fungal infections. There have been numerous studies recently published that assist with our understanding of preventive strategies, questioning the utility of pretherapy screening computed tomography scans and masks. Several important randomized trials compared alternative strategies to standard 'empirical' therapies. Finally, several studies were performed that outline complexity in administering new azole antifungals, assisting in optimizing outcomes.

SUMMARY

Studies published in the most recent year outline several important advances in our understanding of epidemiology, prevention and treatment of invasive fungal infections.