Healthcare professional perspectives following implementation of an infection management care pathway for pediatric patients with cancer: a qualitative study.

PURPOSE: The Pediatric Oncology Group of Ontario (POGO) supported an effort to implement infection management care pathways based on clinical practice guidelines, to improve the consistency of infection management in pediatric cancer patients. The objective of this qualitative study was to describe the perspective of healthcare professionals (HCPs) following implementation. METHODS: Four tertiary pediatric oncology centers in Ontario, Canada, implemented the pathways. We randomly identified three HCPs per group (clinical pharmacists; nurse case managers, educators or practitioners and physician assistants; pediatric oncology fellows; or pediatric oncology staff physicians) per site and invited them to participate in a qualitative interview. One-on-one interviews were conducted remotely, followed by thematic analysis of interview transcripts. RESULTS: A total of 66 invitations were extended and 42 HCPs participated. Identified themes were: (1) implementation approach, (2) access and navigation, (3) engagement, (4) concerns, (5) workplace benefits, (6) reception, and (7) provincial harmonization. HCPs preferred in-person implementation strategies over e-mail communication. They identified teaching/educational utility and benefits to non-oncology departments and non-tertiary centers participating in shared care of patients. Other positive aspects related to evidence-based practice, safety, supporting oncology HCPs, and benefits to patients and families. Concerns included need to ensure users applied clinical judgement and loss of autonomy. Provincial harmonization of practice was viewed positively, although potential logistical and institutional cultural barriers were raised. CONCLUSIONS: Following infection management care pathway implementation, HCPs described educational utility and benefits to non-oncology departments, oncology HCPs, patients, and families. Our findings may facilitate future infection management care pathway provincial harmonization.

Performance of the eHealth decision support tool, MIPOGG, for recognising children with Li-Fraumeni, DICER1, Constitutional mismatch repair deficiency and Gorlin syndromes.

BACKGROUND: Cancer predisposition syndromes (CPSs) are responsible for at least 10% of cancer diagnoses in children and adolescents, most of which are not clinically recognised prior to cancer diagnosis. A variety of clinical screening guidelines are used in healthcare settings to help clinicians detect patients who have a higher likelihood of having a CPS. The McGill Interactive Pediatric OncoGenetic Guidelines (MIPOGG) is an electronic health decision support tool that uses algorithms to help clinicians determine if a child/adolescent diagnosed with cancer should be referred to genetics for a CPS evaluation. METHODS: This study assessed MIPOGG's performance in identifying Li-Fraumeni, DICER1, Constitutional mismatch repair deficiency and Gorlin (nevoid basal cell carcinoma) syndromes in a retrospective series of 84 children diagnosed with cancer and one of these four CPSs in Canadian hospitals over an 18-year period. RESULTS: MIPOGG detected 82 of 83 (98.8%) evaluable patients with any one of these four genetic conditions and demonstrated an appropriate rationale for suggesting CPS evaluation. When compared with syndrome-specific clinical screening criteria, MIPOGG's ability to correctly identify children with any of the four CPSs was equivalent to, or outperformed, existing clinical criteria respective to each CPS. CONCLUSION: This study adds evidence that MIPOGG is an appropriate tool for CPS screening in clinical practice. MIPOGG's strength is that it starts with a specific cancer diagnosis and incorporates criteria relevant for associated CPSs, making MIPOGG a more universally accessible diagnostic adjunct that does not require in-depth knowledge of each CPS.

Quick, Effective Screening Tasks Identify Children With Medical Conditions or Disabilities Needing Physical Literacy Support.

PURPOSE: This study evaluated screening tasks able to identify children with medical conditions or disabilities who may benefit from physical literacy. METHOD: Children completed ≤20 screening tasks during their clinic visit and then the Canadian Assessment of Physical Literacy (2nd edition) at a separate visit. Total Canadian Assessment of Physical Literacy scores <30th percentile were categorized as potentially needing physical literacy support. Receiver operator characteristic curves identified assessment cut points with 80% sensitivity and 40% specificity relative to total physical literacy scores. RESULTS: 223 children (97 girls; 10.1 [2.6] y) participated. Physical activity adequacy, predilection, and physical competence achieved ≥80% sensitivity and ≥40% specificity in both data sets. Adequacy ≤ 6.5 had 86% to 100% sensitivity and 48% to 49% specificity. Daily screen time >4.9 hours combined with Adequacy ≤6.15 had 88% to 10% sensitivity and 53% to 56% specificity. CONCLUSIONS: Activity adequacy, alone or with screen time, most effectively identified children likely to benefit from physical literacy support. Adequacy and screen time questionnaires are suitable for clinical use. Similar results regardless of diagnosis suggest physical competence deficits are not primary determinants of active lifestyles. Research to enhance screening specificity is required.

Gemtuzumab Ozogamicin Monotherapy Is a Well-tolerated Palliative Chemotherapy Option in Pediatric Multiply Relapsed Acute Myeloid Leukemia: A Multicenter Case Series and Review of the Literature.

Gemtuzumab ozogamicin (GO) is an anti-CD33 antibody that is Food and Drug Administration approved in upfront acute myeloid leukemia (AML) for patients over 1-month old, and for relapsed or refractory AML in patients over 2 years old. GO is now integrated in upfront pediatric AML treatment, and often in CD33+ relapse treatment combined with intensive conventional chemotherapy. Although GO was initially tested as a monotherapeutic agent in relapsed or refractory AML, there are few data in pediatric patients supporting this indication. In this review, we report 4 cases of multiply relapsed pediatric AML patients who were treated with GO monotherapy with palliative intent. Three of 4 patients obtained a complete response with GO reinduction, either as monotherapy or paired with conventional chemotherapy. Three patients remained in remission respectively for 5, 17, and 9 months with GO continuation monotherapy. The literature was reviewed regarding the use of GO in pediatric AML relapse settings.

Reliability and validity of proxy-SSPedi and mini-SSPedi in pediatric patients 2-7 years receiving cancer treatments.

BACKGROUND: Symptom Screening in Pediatrics Tool (SSPedi) was developed for symptom screening by children 8-18 years. Objectives were to evaluate the reliability and validity of proxy-SSPedi and self-report mini-SSPedi for younger children. METHODS: This multi-center study enrolled guardians of children 2-7 years receiving cancer treatments (proxy-SSPedi) and their children 4-7 years (mini-SSPedi). The two populations were: (1) More symptomatic group where children were receiving active cancer treatment and were in hospital or clinic for four consecutive days; and (2) Less symptomatic group where children were receiving maintenance therapy for acute lymphoblastic leukemia or had completed cancer therapy. Proxy-SSPedi or mini-SSPedi were completed with measures of mucositis, nausea, pain, quality of life and overall symptoms. Respondents in the more symptomatic group repeated proxy-SSPedi/mini-SSPedi and a global symptom change scale 3 days later. RESULTS: There were 402 guardians and 326 children included in the analysis. Test re-test reliability of proxy-SSPedi showed intraclass correlation coefficient (ICC) 0.83 (95% confidence interval (CI) 0.72-0.90). Mean difference in proxy-SSPedi between more and less symptomatic groups was 9.7 (95% CI 8.3-11.1). Proxy-SSPedi was responsive to change and hypothesized relationships between measures were observed. With a priori threshold ≥0.6, inter-rater ICC among all dyads and those 6-7 years were 0.54 (95% CI 0.45-0.62) and 0.62 (95% CI 0.50-0.71) respectively. Among participating children, other hypothesized reliability and validity thresholds were generally met. CONCLUSIONS: Proxy-SSPedi is reliable, valid and responsive in children 2-7 years old receiving cancer treatments. Mini-SSPedi can be used for children 6-7 years of age.

The expense of sending cerebrospinal fluid for analysis on all lumbar punctures in pediatric acute lymphoblastic leukemia patients.

BACKGROUND: Central nervous system (CNS) relapse in pediatric acute lymphoblastic leukemia (ALL) patients is uncommon. The cerebrospinal fluid (CSF) of patients with ALL is routinely sampled at each intrathecal chemotherapy treatment to screen for CNS relapse. The analysis of CSF is both time consuming and resource intensive and must be completed approximately 20 times per patient throughout treatment. Our objective was to examine the expense of routine screening on all CSF samples for CNS relapse in ALL patients, and to identify if CNS relapse can be detected clinically. METHODS: We identified all patients diagnosed with ALL at the Children's Hospital of Eastern Ontario (CHEO) between January 2001 and June 2021. We collected the total number of CSF samples in these patients and the number of CSF samples positive for CNS relapse. An in-depth chart review on the patients who relapsed in the CNS was completed to identify symptoms at relapse. RESULTS: Over the study period, 351 patients were diagnosed with ALL and underwent a total of 6515 lumbar punctures (LPs), each of which examined the CSF. The cost of CSF sample analysis is $14.32 (Canadian dollars [CDN]); thus, the total cost for the study sample was $93,294.80 (CDN). There were 14 CNS relapses and although symptoms including headache, vomiting, and fatigue were common, two patients were asymptomatic at relapse. CONCLUSIONS: Given the marginal cost of routine CSF screening and the lack of specific and sensitive symptoms for CNS relapse, we conclude that the routine practice of sending all CSF samples for analysis of CNS relapse in ALL patients is relatively inexpensive and beneficial.

Treatment of Sinusoidal Obstruction Syndrome With Defibrotide in Pediatric Cancer Patients Following Nontransplant-associated Chemotherapy: A Case Report and Review of the Literature.

Sinusoidal obstruction syndrome (SOS), formerly veno-occlusive disease (VOD), in pediatric cancer patients often presents as a complication of hematopoietic stem cell transplantation, and less commonly secondary to nontransplant-associated chemotherapy. Therapy with defibrotide is well-described as standard care for transplant-associated SOS/VOD, but the treatment of nontransplant-associated SOS/VOD is less clear. We report a 3-year-old with relapsed Wilms tumor and recurrent SOS/VOD, with successful use of defibrotide during chemotherapy. A review of pediatric cancer patients with nontransplant-associated SOS/VOD treated with defibrotide revealed 83 patients, and 66 were in remission. This review supports early treatment with defibrotide in patients with nontransplant-associated SOS/VOD.

Feeling scared or worried self-report in children receiving cancer treatments using the Symptom Screening in Pediatrics Tool (SSPedi).

INTRODUCTION: The objectives of this study were to describe reports of bother for feeling scared or worried among children with cancer and pediatric hematopoietic stem cell transplant (HSCT) recipients, and to identify factors associated with it. METHODS: We included children receiving cancer treatments who were 8-18 years of age. Three patient types were enrolled: inpatients receiving active cancer treatment, outpatients receiving maintenance acute lymphoblastic leukemia chemotherapy, and outpatients in survivorship. Amount of bother due to feeling scared or worried yesterday or today was self-reported using the Symptom Screening in Pediatrics Tool (SSPedi) on a 0-4 scale. Risk factors were evaluated using logistic regression. RESULTS: Among the 502 children included, 225 (45.0%) reported any degree of bother (score ≥ 1) and 29 (5.8%) reported severe bother (score ≥ 3) for feeling scared or worried. In multiple regression evaluating any bother, boys were less likely to be bothered (odds ratio (OR) 0.60, 95% confidence interval (CI) 0.41-0.87) and inpatients receiving active cancer treatment were more likely to be bothered compared to outpatients in survivorship (OR 3.58, 95% CI 2.00-6.52). The only factor associated with being severely bothered by feeling scared or worried was clinic visit or admission due to fever (OR 4.57, 95% CI 1.24-13.60). DISCUSSION: We found 45% of children receiving cancer treatments reported being bothered by feeling scared or worried. Girls and inpatients receiving active treatment experienced more bother of any degree, while visiting the hospital due to fever was associated with being severely bothered. Future work should identify interventions to prevent or alleviate this symptom.

Pontine gliomas a 10-year population-based study: a report from The Canadian Paediatric Brain Tumour Consortium (CPBTC).

BACKGROUND: Diffuse intrinsic pontine gliomas (DIPG) are midline gliomas that arise from the pons and the majority are lethal within a few months after diagnosis. Due to the lack of histological diagnosis the epidemiology of DIPG is not completely understood. The aim of this report is to provide population-based data to characterize the descriptive epidemiology of this condition in Canadian children. PATIENTS AND METHODS: A national retrospective study of children and adolescents diagnosed with DIPG between 2000 and 2010 was undertaken. All cases underwent central review to determine clinical and radiological diagnostic characteristics. Crude incidence figures were calculated using age-adjusted (0-17 year) population data from Statistics Canada. Survival analyses were performed using the Kaplan-Meier method. RESULTS: A total of 163 patients with pontine lesions were identified. Central review determined one-hundred and forty-three patients who met clinical, radiological and/or histological criteria for diagnosis. We estimate an incidence rate of 1.9 DIPG/1,000,000 children/year in the Canadian population over a 10 years period. Median age at diagnosis was 6.8 years and 50.3% of patients were female. Most patients presented with cranial nerve palsies (76%) and ataxia (66%). Despite typical clinical and radiological characteristics, histological confirmation reported three lesions to be low-grade gliomas and three were diagnosed as CNS embryonal tumor not otherwise specified (NOS). CONCLUSIONS: Our study highlights the challenges associated with epidemiology studies on DIPG and the importance of central review for incidence rate estimations. It emphasizes that tissue biopsies are required for accurate histological and molecular diagnosis in patients presenting with pontine lesions and reinforces the limitations of radiological and clinical diagnosis in DIPG. Likewise, it underscores the urgent need to increase the availability and accessibility to clinical trials.

A Unique Case of a Pediatric Patient With Blastic Plasmacytoid Dendritic Cell Neoplasm, Guillain Barre Syndrome, and Hemophagocytic Lymphohistiocytosis.

Blastic plasmacytoid dendritic cell neoplasm is a rare hematopoietic malignancy with a poor prognosis that is seen primarily in the elderly population. We describe a pediatric patient with blastic plasmacytoid dendritic cell neoplasm who subsequently developed Guillain Barre syndrome followed by hemophagocytic lymphohistiocytosis. All 3 conditions are uncommon, particularly in the pediatric population. It is unclear whether this patient developed these disease states independently, whether they were due to a viral trigger or if she has an underlying immune dysfunction that could have contributed to the development of these conditions. The patient is currently in remission and awaiting further immune work-up.

Reduction of Extramedullary Complications in Patients With Acute Myeloid Leukemia/Myelodysplastic Syndrome Treated With Azacitidine.

The distinction between myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) often relies on an arbitrary marrow blast cutoff of 30% in pediatrics and 20% in adults. There is little data about the treatment of children with extramedullary myeloid malignancy that has features of both, MDS and AML. Herein, we report for the first time 2 patients MDS/AML (1 with Shwachman-Diamond syndrome and 1 with idiopathic MDS and monosomy 7) who presented with extramedullary complications, received treatment with azacitidine, achieved complete remission and subsequently underwent hematopoietic stem cell transplantation.

Phase I dose-finding study for melatonin in pediatric oncology patients with relapsed solid tumors.

BACKGROUND: Melatonin is a natural health product used for sleep disturbances. In preliminary studies of adults with advanced cancer, 20 mg of melatonin daily was associated with reduction in anorexia and weight loss-symptoms that also impact pediatric oncology patients. High doses of melatonin have not been studied in pediatrics. METHODS: This was a multicenter single-arm phase I dose-escalation study utilizing a 3 + 3 design to determine the safety and tolerability of escalating doses of melatonin in pediatric oncology patients with relapsed solid tumors. Melatonin was given for 8 weeks at three dose levels-0.075 mg/kg (maximum 5 mg), 0.15 mg/kg (maximum 10 mg), and 0.3 mg/kg (maximum 20 mg). RESULTS: Melatonin was well tolerated at all three dose levels with no significant adverse events or dose-limiting toxicities. The only grade 3/4 toxicities were myelosuppression, which was attributed to the concomitant chemotherapy and occurred at all dose levels. Weight gain occurred in seven of nine patients, with a median increase of 1.1 kg (range -3.3 to 4.5) or 3.4% (range -10.2 to 8.7), with two patients losing weight (one in dose level 1 and one level 3). CONCLUSIONS: Melatonin is well tolerated at a dose of 0.3 mg/kg (maximum 20 mg), in the pediatric population. This study provides the background for further study of high-dose melatonin in pediatric oncology patients.

Management of chronic myeloid leukemia in children and adolescents: Recommendations from the Children's Oncology Group CML Working Group.

Chronic myeloid leukemia (CML) accounts for 2-3% of leukemias in children under 15 and 9% in adolescents aged 15-19. The diagnosis and management of CML in children, adolescents, and young adults have several differences compared to that in adults. This review outlines the diagnosis and management of the underlying disease as well as challenges that can occur when dealing with CML in this patient population.

Taste changes in children with cancer and hematopoietic stem cell transplant recipients.

BACKGROUND: Objectives were to describe bothersome self-reported changes in taste in pediatric oncology and hematopoietic stem cell (HSCT) patients and to identify patient and treatment-related factors associated with bothersome taste changes. METHODS: We prospectively enrolled children and adolescents with cancer or pediatric HSCT recipients 8-18 years of age from three groups: inpatients receiving cancer treatments; outpatients in maintenance therapy for acute lymphoblastic leukemia (ALL); and outpatients in survivorship. Bothersome changes in taste was self-reported using the Symptom Screening in Pediatrics Tool (SSPedi); nausea was self-reported using the Pediatric Nausea Assessment Tool (PeNAT). RESULTS: Among the 502 children included, 226 (45.0%) reported bothersome taste changes and 48 (9.6%) reported severely bothersome taste changes. In multiple regression, factors independently associated with severely bothersome taste changes were: inpatients receiving cancer treatments vs outpatients in survivorship (odds ratio (OR) 12.28, 95% confidence interval (CI) 2.50-222.27), ALL in maintenance vs outpatients in survivorship (OR 7.43, 95% CI 1.06-147.77), current nausea (OR 1.59, 95% CI 1.04-2.42), vomiting (OR 2.18, 95% CI 1.06-4.38), and first language not English (OR 2.09, 95% CI 0.97-4.28). CONCLUSIONS: We found that 45% of children with cancer and pediatric HSCT recipients reported bothersome changes in taste and these were severely bothersome in 9.6% of children. Inpatients receiving cancer treatment, those experiencing more nausea and vomiting and children whose first language was not English were at greater risk of severely bothersome changes in taste. Future work should evaluate systematic symptom screening in clinical practice and identify interventions focused on addressing bothersome taste changes.

Severely bothersome fatigue in children and adolescents with cancer and hematopoietic stem cell transplant recipients.

BACKGROUND: Objectives were to describe bothersome fatigue in children with cancer and hematopoietic stem cell (HSCT) recipients and to identify factors associated with severely bothersome fatigue. METHODS: We included children ages 8-18 years treated for cancer or HSCT recipients from three groups: [1] receiving active cancer treatment and admitted to hospital for at least 3 days, [2] attending outpatient clinic for acute lymphoblastic leukemia maintenance therapy, and [3] attending outpatient clinic following treatment completion. Fatigue was measured using the Symptom Screening in Pediatrics Tool (SSPedi); severely bothersome fatigue was defined as a lot or extremely bothersome fatigue (score of 3-4 on 0-4 scale). Factors associated with severely bothersome fatigue were examined using univariate and multiple logistic regression. RESULTS: Of 502 children included, 414 (82.5%) reported some degree of bothersome fatigue (scores 1-4), and 123 (24.5%) reported severely bothersome fatigue (score 3 or 4). In multiple regression analysis, factors significantly associated with severely bothersome fatigue were child age 11-14 and 15-18 years vs 8-10 years (odds ratio (OR) 2.11, 95% confidence interval (CI) 1.21-3.77 and OR 2.96, 95% CI 1.66-5.44), and inpatients receiving cancer treatment vs outpatients who had completed therapy (OR 3.85, 95% CI 2.17-7.27). CONCLUSIONS: We found that 82.5% of children with cancer or HSCT recipients reported bothersome fatigue and 24.5% of children reported severely bothersome fatigue. Risk factors for severely bothersome fatigue were older age and inpatients receiving active cancer treatment. Future work should evaluate systematic symptom screening in clinical practice and apply interventions to reduce fatigue.

Autologous stem cell transplantation for refractory opsoclonus myoclonus ataxia syndrome.

Opsoclonus, myoclonus, ataxia syndrome (OMA) is a severe neurologic disorder often associated with neuroblastoma. It is challenging to treat and can have long-term neurologic sequelae. Current recommended therapies include intravenous immunoglobulin, corticosteroids, rituximab, and chemotherapy (cyclophosphamide). We present two cases who were refractory to conventional therapy and underwent autologous stem cell transplantation (ASCT). One patient had complete resolution of symptoms following ASCT and the other patient had minimal change in symptoms with this therapy. These findings support consideration of ASCT as a therapeutic option for patients with refractory OMA after failure of known effective therapies.

Reirradiation in patients with diffuse intrinsic pontine gliomas: The Canadian experience.

OBJECTIVE: Clinical trials have failed to demonstrate a survival benefit of adjuvant chemotherapy in diffuse intrinsic pontine gliomas (DIPG). Radiation therapy (RT) is the only effective treatment thus far and reirradiation (rRT) has become an option at the time of progression. The aim of this study was to review the Canadian experience of DIPG rRT with a focus on the safety and possible efficacy of this approach. METHOD: We retrospectively reviewed the demographic, clinical, and RT data of patients with DIPG treated in Canada with rRT. RESULTS: Since January 2011, we identified 16 patients with progressive DIPG who received rRT. Median time from diagnosis to progression was 10.5 months (range, 4-37 months). rRT was given focally in 14 patients at a dose ranging from 21.6 to 36 Gy. rRT was well tolerated by all children but one. All but three patients showed neurological improvement. With a median follow-up from original diagnosis of 19.2 months, all patients died, with a median time from rRT to death of 6.48 months (range, 3.83-13.26 months). When compared to a historic cohort of 46 consecutive patients, the median time from progression to death was 92 days in the non-reirradiated patients versus 218 days in the reirradiated ones (P = 0.0001). CONCLUSION: In this limited experience, rRT was safe and feasible in patients with progressive DIPG, providing neurological improvement and a prolonged life span in most patients. Prospective Canadian rRT protocols are ongoing to further assess the benefit of this approach, including quality of life assessment.

Survival Following Tumor Recurrence in Children With Medulloblastoma.

Medulloblastoma is the most common malignant brain tumor in children. Published survival rates for this tumor are ∼70%; however, there is limited published information on outcome after disease recurrence. This was an observational study which included all persons under the age of 18 years diagnosed with medulloblastoma from 1990 to 2009 inclusive in Canada. Data collected included date of diagnosis, age at diagnosis, sex, stage, pathology, treatment, recurrence, and current status. Survival rates were determined. In total, 550 cases were ascertained meeting the study criteria. The overall survival rate at 1 year was 83.6%±1.7%, at 3 years 77.2%±1.9%, and at 5 years 72.5%±20%. The progression-free survival rates were 78%±1.9%, 70%±2.1%, and 69±2.1% at 1, 3, and 5 years from initial diagnosis. In total, 173 (31.2%) were reported to have had tumor recurrence and 23 (11.4%) of them were alive at the time of survey with an overall survival rate at 1 year of 38.3%±4%, at 2 years of 16.9%±3.3%, and at 5 years of 12.4%±2.8%. Our data confirm that children with recurrent medulloblastoma have a poor prognosis, supporting the need for novel treatment approaches for this group.

Evaluation of treatment-related mortality among paediatric cancer deaths: a population based analysis.

BACKGROUND: Objectives were to describe the proportion of deaths due to treatment-related mortality (TRM) and to identify risk factors and probable causes of TRM among paediatric cancer deaths in a population-based cohort. METHODS: We included children with cancer ⩽18 years diagnosed and treated in Ontario who died between January 2003 and December 2012. Deaths were identified using a provincial registry, the Pediatric Oncology Group of Ontario Networked Information System. Probable causes of TRM were described. RESULTS: Among the 964 deaths identified, 821 were included. The median age at diagnosis was 6.6 years (range 0-18.8) and 51.8% had at least one relapse. Of the deaths examined, TRM occurred in 217/821 (26.4%) while 604/821 (73.6%) were due to progressive cancer. Deaths from TRM did not change over time. Using multiple regression, younger age, leukaemia diagnosis and absence of relapse were independently positively associated with TRM. The most common probable causes of TRM were respiratory, infection and haemorrhage. CONCLUSIONS: TRM was responsible for 26.4% of deaths in paediatric cancer. Underlying diagnosis, younger age and absence of relapse were associated with TRM and causes of TRM differed by diagnosis group. Future work should evaluate TRM rate and risk factors among newly diagnosed cancer patients.

Central nervous system disease in pediatric acute myeloid leukemia: A report from the Children's Oncology Group.

BACKGROUND: The prognostic impact of central nervous system (CNS) involvement in children with acute myeloid leukemia (AML) has varied in past trials, and controversy exists over the degree of involvement requiring intensified CNS therapy. Two recent Children's Oncology Group protocols, AAML03P1 and AAML0531, directed additional intrathecal (IT) therapy to patients with CNS2 (≤5 white blood cell [WBC] with blasts) or CNS3 (>5 WBC with blasts or CNS symptoms) disease at diagnosis. METHODS: We examined disease characteristics and outcomes of the 1,344 patients on these protocols, 949 with CNS1 (no blasts), 217 with CNS2, and 178 with CNS3, with the latter two receiving additional IT therapy. RESULTS: Young age (P = 0.003), hyperleukocytosis (P < 0.001), and the presence of inversion 16 (P < 0.001) were the only factors more prevalent in patients with CNS2 or CNS3 disease. Complete remission at the end of induction (EOI) 2 was achieved less often in patients with CNS involvement (P < 0.001). From diagnosis, event-free survival (EFS) for patients with CNS involvement was significantly worse (P < 0.001), whereas overall survival (OS) was not (P = 0.16). From the EOI1, there was a higher relapse rate (RR) and worse disease-free survival (DFS), but less impact on OS (CNS1:DFS 58.9%, RR 34.1%, OS 69.3%; CNS2:DFS 53.2%, RR 40.9%, OS 74.7%; CNS3:DFS 45.2%, RR 48.8%, OS 60.8%; P = 0.006, P < 0.001, P = 0.045, respectively). Multivariable analysis showed that independently CNS2 and CNS3 status adversely affected RR and DFS. Traumatic diagnostic lumbar puncture was not associated with worse outcome. CONCLUSIONS: CNS leukemia confers greater relapse risk despite more aggressive locally directed therapy. Novel approaches need to be investigated in this group of patients.