Practice Preferences for Consolidative Hematopoietic Stem Cell Transplantation Following Tisagenlecleucel in Children and Young Adults with B Cell Acute Lymphoblastic Leukemia

Treatment with tisagenlecleucel (tisa-cel) achieves excellent complete remission rates in children and young adults with relapsed or refractory B cell acute lymphoblastic leukemia (B-ALL), but approximately 50% maintain long-term remission. Consolidative hematopoietic stem cell transplantation (cHSCT) is a potential strategy to reduce relapse risk, but it carries substantial short- and long-term toxicities. Additionally, several strategies for management of B cell recovery (BCR) and next-generation sequencing (NGS) positivity post-tisa-cel exist, without an accepted standard. We hypothesized that practice preferences surrounding cHSCT, as well as management of BCR and NGS positivity, varies across tisa-cel-prescribing physicians and sought to characterize current practice preferences. A survey focusing on preferences regarding the use of cHSCT, management of BCR, and NGS positivity was distributed to physicians who prescribe tisa-cel for children and young adults with B-ALL. Responses were collected from August 2022 to April 2023. Fifty-nine unique responses were collected across 43 institutions. All respondents prescribed tisa-cel for children and young adults. The clinical focus of respondents was HSCT in 71%, followed by leukemia/lymphoma in 24%. For HSCT-naive patients receiving tisa-cel, 57% of respondents indicated they made individualized decisions for cHSCT based on patient factors, whereas 22% indicated they would avoid cHSCT and 21% indicated they would pursue cHSCT when feasible. Certain factors influenced >50% of respondents towards recommending cHSCT (either an increased likelihood of recommending or always recommending), including preinfusion disease burden >25%, primary refractory B-ALL, M3 bone marrow following reinduction for relapse, KMT2A-rearranged B-ALL, history of blinatumomab nonresponse, and HSCT-naive status. Most respondents indicated they would pursue HSCT for HSCT-naive, total body irradiation (TBI) recipients with BCR before 6 months post-tisa-cel or with NGS positivity at 1 or 3 months post-tisa-cel, although there was variability in responses regarding whether to proceed to HSCT directly or provide intervening therapy prior to HSCT. Fewer respondents recommended HSCT for BCR or NGS positivity in patients with a history of HSCT, in noncandidates for TBI, and in patients with trisomy 21. The results of this survey indicate there exists significant practice variability regarding the use of cHSCT, as well as interventions for post-tisa-cel BCR or NGS positivity. These results highlight areas in which ongoing clinical trials could inform more standardized practice.

Mediport use as an acceptable standard for CAR T cell infusion

Introduction

Mediport use as a clinical option for the administration of chimeric antigen receptor T cell (CAR T cell) therapy in patients with B-cell malignancies has yet to be standardized. Concern for mediport dislodgement, cell infiltration, and ineffective therapy delivery to systemic circulation has resulted in variable practice with intravenous administration of CAR T cell therapy. With CAR T cell commercialization, it is important to establish practice standards for CAR T cell delivery. We conducted a study to establish usage patterns of mediports in the clinical setting and provide a standard of care recommendation for mediport use as an acceptable form of access for CAR T cell infusions.

Methods

In this retrospective cohort study, data on mediport use and infiltration rate was collected from a survey across 34 medical centers in the Pediatric Real-World CAR Consortium, capturing 504 CAR T cell infusion routes across 489 patients. Data represents the largest, and to our knowledge sole, report on clinical CAR T cell infusion practice patterns since FDA approval and CAR T cell commercialization in 2017.

Results

Across 34 sites, all reported tunneled central venous catheters, including Broviac® and Hickman® catheters, as accepted standard venous options for CAR T cell infusion. Use of mediports as a standard clinical practice was reported in 29 of 34 sites (85%). Of 489 evaluable patients with reported route of CAR T cell infusion, 184 patients were infused using mediports, with no reported incidences of CAR T cell infiltration.

Discussion/Conclusion

Based on current clinical practice, mediports are a commonly utilized form of access for CAR T cell therapy administration. These findings support the safe practice of mediport usage as an accepted standard line option for CAR T cell infusion.

Chronic active Epstein-Barr virus and hydroa vacciniforme-like lymphoproliferative disorder in a pediatric patient complicated by fatal ruptured cerebral artery aneurysm

Hydroa vacciniforme-like lymphoproliferative disorder (HV-LPD) is a rare cutaneous form of chronic active Epstein-Barr virus (CAEBV) that presents with vesicular lesions induced by sun-exposure. Arterial aneurysm is a rare but potentially fatal complication of CAEBV and HV-LPD.

Response to sirolimus in capillary lymphatic venous malformations and associated syndromes: Impact on symptomatology, quality of life, and radiographic response

BACKGROUND

Capillary lymphatic venous malformations (CLVM) and associated syndromes, including Klippel-Trenaunay syndrome (KTS) and congenital lipomatous overgrowth, vascular malformation, epidermal nevi, skeletal, and spinal syndrome (CLOVES), are underrecognized disorders associated with high morbidity from chronic pain, recurrent infections, bleeding, and clotting complications. The rarity of these disorders and heterogeneity of clinical presentations make large-scale randomized clinical drug trials challenging. Identification of PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha [gene]) mutations in CLVM has made targeted medications, such as sirolimus, attractive treatment options. The aim of this study was to investigate the safety and efficacy of sirolimus therapy in CLVM.

PROCEDURE

A combined prospective and retrospective cohort of pediatric and young adult patients with CLVM treated with sirolimus was evaluated for disease response, including symptom improvement, quality of life (QOL), and radiologic response. Sirolimus dosing regimens and toxicities were also assessed.

RESULTS

Twenty-nine patients with CLVM, including KTS and CLOVES, were included. Ninety-three percent of patients reported improved QOL, and 86% had improvement in at least one symptom. Most significantly, improvement was noted in 100% of patients with bleeding and 89% with thrombotic complications with corresponding decreases in mean D-dimer (p = .008) and increases in mean fibrinogen (p = .016). No patients had progressive disease on sirolimus. Most common side effects included neutropenia, lymphopenia, infection, and aphthous ulcers/stomatitis. No toxicities were life-threatening, and none required long-term discontinuation of sirolimus.

CONCLUSION

Sirolimus appears to be effective at reducing complications and improving QOL in patients with CLVM and associated syndromes. In this patient cohort, sirolimus was well tolerated and resulted in few treatment-related toxicities.

Tumor Genomic Profiling and Ex Vivo Drug Sensitivity Testing for Pediatric Leukemia and Lymphoma Patients

OBJECTIVE

To describe the frequency of use of tumor genomic profiling and functional ex vivo drug sensitivity testing in pediatric patients with hematologic malignancies at our institution, and to determine how the results affected treatment selection.

METHODS

A retrospective chart review was conducted to analyze the frequency of tumor genomic profiling and functional drug sensitivity screening in our institution in pediatric patients with hematologic malignancies and to ask if the results were used to direct treatment. A case series of patients for whom these testing recommendations resulted in therapeutic interventions is reported.

RESULTS

Thirty-three patients underwent tumor genomic profiling assays, functional ex vivo testing, or both. Nineteen patients (58%) had genomic profiling assays performed alone, 3 (9%) had functional ex vivo testing performed alone, and 11 (33%) had both tests performed. Twenty-one (64%) patients had potentially actionable mutations detected by the genomic profiling assay. Seven (21%) patients received at least 1 chemotherapeutic agent in accordance with the tumor genomic profiling or functional ex vivo drug sensitivity testing results. Three (43%) of the 7 patients who were treated with testing directed therapy had a favorable treatment response (PR or CR) to treatments selected based upon results of genomic or functional ex vivo testing.

CONCLUSIONS

This retrospective case series demonstrates that precision medicine techniques such as genomic profiling and drug sensitivity testing can positively inform treatment selection in pediatric patients with relapsed or refractory leukemia and lymphoma.

Intracranial germ cell tumors in Adolescents and Young Adults: European and North American consensus review, current management and future development

The incidence of intracranial germ cell tumors (iGCT) is much lower in European and North American (E&NA) than in Asian population. However, E&NA cooperative groups have simultaneously developed with success treatment strategies with specific attention paid to long-term sequelae. Neurological sequelae may be reduced by establishing a diagnosis with an endoscopic biopsy and/or cerebrospinal fluid (CSF) and/or serum analysis, deferring the need to perform a radical surgery. Depending on markers and/or histological characteristics, patients are treated as either germinoma or non-germinomatous germ cell tumors (NGGCT). Metastatic disease is defined by a positive CSF cytology and/or distant drops in craniospinal MRI. The combination of surgery and/or chemotherapy and radiation therapy is tailored according to grouping and staging. With more than 90% 5-year event-free survival (EFS), localized germinomas can be managed without aggressive surgery, and benefit from chemotherapy followed by whole ventricular irradiation with local boost. Bifocal germinomas are treated as non-metastatic entities. Metastatic germinomas may be cured with craniospinal irradiation. With a 5-year EFS over 70%, NGGCT benefit from chemotherapy followed by delayed surgery in case of residual disease, and some form of radiotherapy. Future strategies will aim at decreasing long-term side effects while preserving high cure rates.

Irradiation-free RIC HSCT has a tolerable safety profile and is effective therapy for pediatric bone marrow failure syndromes

For patients with bone marrow failure syndromes (BMFS) who may tolerate gradual donor engraftment and achieve adequate disease control with stable mixed chimerism, RIC regimens may be preferable to myeloablative regimens. We performed a retrospective analysis of outcomes for patients who underwent HSCT at our institution between 2009 and 2017 for BMFS using an irradiation-free RIC regimen. Fourteen pediatric patients with BMFS received fludarabine (30 mg/m² IV daily × 3), thiotepa (5 mg/kg IV every 12 hours × 2), and melphalan (70 mg/m² IV daily × 2) prior to HSCT. Our cohort included the following diagnoses: SAA (n = 7), CAMT (n = 4), SCN (n = 1), DBA (n = 1), and non-Fanconi congenital BMF (n = 1). Seven patients underwent a MSD transplant; seven underwent an unrelated donor transplant. All patients are alive with median follow-up of 1112 days (range 455-2549 days). The median time to neutrophil engraftment was 16 days (range 10-26 days). All were transfusion independent by day + 100. The highest grade of aGVHD was grade 2; 8 (57%) did not develop aGVHD. Four (28.5%) developed extensive cGVHD, 4 (28.5%) developed limited cGVHD, and 6 (43%) did not develop cGVHD. No patients developed SOS. None died from GVHD or infectious complications. HSCT with RIC with fludarabine, thiotepa, and melphalan for BMFS was effective with a tolerable safety profile. Probability of OS at 100 days and 1 year was 100%.

Prognostic Value of Preoperative MRI Metrics for Diffuse Lower-Grade Glioma Molecular Subtypes

BACKGROUND AND PURPOSE

Despite the improved prognostic relevance of the 2016 WHO molecular-based classification of lower-grade gliomas, variability in clinical outcome persists within existing molecular subtypes. Our aim was to determine prognostically significant metrics on preoperative MR imaging for lower-grade gliomas within currently defined molecular categories.

MATERIALS AND METHODS

We undertook a retrospective analysis of 306 patients with lower-grade gliomas accrued from an institutional data base and The Cancer Genome Atlas. Two neuroradiologists in consensus analyzed preoperative MRIs of each lower-grade glioma to determine the following: tumor size, tumor location, number of involved lobes, corpus callosum involvement, hydrocephalus, midline shift, eloquent cortex involvement, ependymal extension, margins, contrast enhancement, and necrosis. Adjusted hazard ratios determined the association between MR imaging metrics and overall survival per molecular subtype, after adjustment for patient age, patient sex, World Health Organization grade, and surgical resection status.

RESULTS

For isocitrate dehydrogenase (IDH) wild-type lower-grade gliomas, tumor size (hazard ratio, 3.82; 95% CI, 1.94-7.75; P < .001), number of involved lobes (hazard ratio, 1.70; 95% CI, 1.28-2.27; P < .001), hydrocephalus (hazard ratio, 4.43; 95% CI, 1.12-17.54; P = .034), midline shift (hazard ratio, 1.16; 95% CI, 1.03-1.30; P = .013), margins (P = .031), and contrast enhancement (hazard ratio, 0.34; 95% CI, 0.13-0.90; P = .030) were associated with overall survival. For IDH-mutant 1p/19q-codeleted lower-grade gliomas, tumor size (hazard ratio, 2.85; 95% CI, 1.06-7.70; P = .039) and ependymal extension (hazard ratio, 6.34; 95% CI, 1.07-37.59; P = .042) were associated with overall survival.

CONCLUSIONS

MR imaging metrics offers prognostic information for patients with lower-grade gliomas within molecularly defined classes, with the greatest prognostic value for IDH wild-type lower-grade gliomas.

Molecular Subtype Classification in Lower-Grade Glioma with Accelerated DTI

BACKGROUND AND PURPOSE

Image-based classification of lower-grade glioma molecular subtypes has substantial prognostic value. Diffusion tensor imaging has shown promise in lower-grade glioma subtyping but currently requires lengthy, nonstandard acquisitions. Our goal was to investigate lower-grade glioma classification using a machine learning technique that estimates fractional anisotropy from accelerated diffusion MR imaging scans containing only 3 diffusion-encoding directions.

MATERIALS AND METHODS

Patients with lower-grade gliomas (n = 41) (World Health Organization grades II and III) with known isocitrate dehydrogenase (IDH) mutation and 1p/19q codeletion status were imaged preoperatively with DTI. Whole-tumor volumes were autodelineated using conventional anatomic MR imaging sequences. In addition to conventional ADC and fractional anisotropy reconstructions, fractional anisotropy estimates were computed from 3-direction DTI subsets using DiffNet, a neural network that directly computes fractional anisotropy from raw DTI data. Differences in whole-tumor ADC, fractional anisotropy, and estimated fractional anisotropy were assessed between IDH-wild-type and IDH-mutant lower-grade gliomas with and without 1p/19q codeletion. Multivariate classification models were developed using whole-tumor histogram and texture features from ADC, ADC + fractional anisotropy, and ADC + estimated fractional anisotropy to identify the added value provided by fractional anisotropy and estimated fractional anisotropy.

RESULTS

ADC (P = .008), fractional anisotropy (P < .001), and estimated fractional anisotropy (P < .001) significantly differed between IDH-wild-type and IDH-mutant lower-grade gliomas. ADC (P < .001) significantly differed between IDH-mutant gliomas with and without codeletion. ADC-only multivariate classification predicted IDH mutation status with an area under the curve of 0.81 and codeletion status with an area under the curve of 0.83. Performance improved to area under the curve = 0.90/0.94 for the ADC + fractional anisotropy classification and to area under the curve = 0.89/0.89 for the ADC + estimated fractional anisotropy classification.

CONCLUSIONS

Fractional anisotropy estimates made from accelerated 3-direction DTI scans add value in classifying lower-grade glioma molecular status.

Cost-Effectiveness of Chimeric Antigen Receptor T-Cell Therapy in Pediatric Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia

BACKGROUND

Chimeric antigen receptor T-cell (CAR-T) therapy is a promising new class of cancer therapy but has a high up-front cost. We evaluated the cost-effectiveness of CAR-T therapy among pediatric patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL).

METHODS

We built a microsimulation model for pediatric patients with relapsed/refractory B-ALL receiving either CAR-T therapy or standard of care. Outcomes included costs, quality of life (health utility), complications, and survival. We measured cost-effectiveness with the incremental cost-effectiveness ratio (ICER), with ICERs under $100 000 per quality-adjusted life-year (QALY) considered cost effective. One-way and probabilistic sensitivity analyses were used to test model uncertainty.

RESULTS

Compared to standard of care, CAR-T therapy increased overall cost by $528 200 and improved effectiveness by 8.18 QALYs, resulting in an ICER of $64 600/QALY. The model was sensitive to assumptions about long-term CAR-T survival, the complete remission rate of CAR-T patients, and the health utility of long-term survivors. The base model assumed a 76.0% one-year survival with CAR-T, although if this decreased to 57.8%, then CAR-T was no longer cost effective. If the complete remission rate of CAR-T recipients decreased from 81% to 56.2%, or if the health utility of disease-free survivors decreased from 0.94 to 0.66, then CAR-T was no longer cost effective. Probabilistic sensitivity analysis found that CAR-T was cost effective in 94.8% of iterations at a willingness to pay of $100 000/QALY.

CONCLUSION

CAR-T therapy may represent a cost-effective option for pediatric relapsed/refractory B-ALL, although longer follow-up of CAR-T survivors is required to confirm validity of these findings.

Clofarabine Can Replace Anthracyclines and Etoposide in Remission Induction Therapy for Childhood Acute Myeloid Leukemia: The AML08 Multicenter, Randomized Phase III Trial

PURPOSE

To identify effective and less toxic therapy for children with acute myeloid leukemia, we introduced clofarabine into the first course of remission induction to reduce exposure to daunorubicin and etoposide.

PATIENTS AND METHODS

From 2008 through 2017, 285 patients were enrolled at eight centers; 262 were randomly assigned to receive clofarabine and cytarabine (Clo+AraC, n = 129) or high-dose cytarabine, daunorubicin, and etoposide (HD-ADE, n = 133) as induction I. Induction II consisted of low-dose ADE given alone or combined with sorafenib or vorinostat. Consolidation therapy comprised two or three additional courses of chemotherapy or hematopoietic cell transplantation. Genetic abnormalities and the level of minimal residual disease (MRD) at day 22 of initial remission induction determined final risk classification. The primary end point was MRD at day 22.

RESULTS

Complete remission was induced after two courses of therapy in 263 (92.3%) of the 285 patients; induction failures included four early deaths and 15 cases of resistant leukemia. Day 22 MRD was positive in 57 of 121 randomly assigned evaluable patients (47%) who received Clo+AraC and 42 of 121 patients (35%) who received HD-ADE (odds ratio, 1.86; 95% CI, 1.03 to 3.41; P = .04). Despite this result, the 3-year event-free survival rate (52.9% [44.6% to 62.8%] for Clo+AraC v 52.4% [44.0% to 62.4%] for HD-ADE, P = .94) and overall survival rate (74.8% [67.1% to 83.3%] for Clo+AraC v 64.6% [56.2% to 74.2%] for HD-ADE, P = .1) did not differ significantly across the two arms.

CONCLUSION

Our findings suggest that the use of clofarabine with cytarabine during remission induction might reduce the need for anthracycline and etoposide in pediatric patients with acute myeloid leukemia and may reduce rates of cardiomyopathy and treatment-related cancer.

Extent of Surgical Resection in Lower-Grade Gliomas: Differential Impact Based on Molecular Subtype

BACKGROUND AND PURPOSE

Diffuse lower-grade gliomas are classified into prognostically meaningful molecular subtypes. We aimed to determine the impact of surgical resection on overall survival in lower-grade glioma molecular subtypes.

MATERIALS AND METHODS

For 172 patients with lower-grade gliomas (World Health Organization grade II or III), pre- and postsurgical glioma volumes were determined using a semiautomated segmentation software based on FLAIR or T2-weighted MR imaging sequences. The association of pre- and postsurgical glioma volume and the percentage of glioma resection with overall survival was determined for the entire cohort and separately for lower-grade glioma molecular subtypes based on isocitrate dehydrogenase (IDH) and 1p/19q status, after adjustment for age, sex, World Health Organization grade, chemotherapy administration, and radiation therapy administration.

RESULTS

For the entire cohort, postsurgical glioma volume (hazard ratio, 1.80; 95% CI, 1.18-2.75; P = .006) and the percentage of resection (hazard ratio, 3.22; 95% CI, 1.79-5.82; P < .001) were associated with overall survival. For IDH-mutant 1p/19q-codeleted oligodendrogliomas, the percentage of resection (hazard ratio, 6.69; 95% CI, 1.57-28.46; P = .01) was associated with overall survival. For IDH-mutant 1p/19q-noncodeleted astrocytomas, presurgical glioma volume (hazard ratio, 3.20; 95% CI, 1.22-8.39; P = .018), postsurgical glioma volume (hazard ratio, 2.33; 95% CI, 1.32-4.12; P = .004), and percentage of resection (hazard ratio, 4.34; 95% CI, 1.74-10.81; P = .002) were associated with overall survival. For IDH-wild-type lower-grade gliomas, pre-/postsurgical glioma volume and percentage of resection were not associated with overall survival.

CONCLUSIONS

The extent of surgical resection has a differential survival impact in patients with lower-grade gliomas based on their molecular subtype. IDH-mutant lower-grade gliomas benefit from a greater extent of surgical resection, with the strongest impact observed for IDH-mutant 1p/19q-noncodeleted astrocytomas.

A phase II clinical trial of adoptive transfer of haploidentical natural killer cells for consolidation therapy of pediatric acute myeloid leukemia

Abstract

Consolidation therapies for children with intermediate- or high-risk acute myeloid leukemia (AML) are urgently needed to achieve higher cure rates while limiting therapy-related toxicities. We determined if adoptive transfer of natural killer (NK) cells from haploidentical killer immunoglobulin–like receptor (KIR)–human leukocyte antigen (HLA)-mismatched donors may prolong event-free survival in children with intermediate-risk AML who were in first complete remission after chemotherapy. Patients received cyclophosphamide (Day − 7), fludarabine (Days − 6 through − 2), and subcutaneous interleukin-2 (Days − 1, 1, 3, 5, 7, and 9). Purified, unmanipulated NK cells were infused on Day 0, and NK cell chimerism and phenotyping from peripheral blood were performed on Days 7, 14, 21, and 28. As primary endpoint, the event-free survival was compared to a cohort of 55 patients who completed chemotherapy and were in first complete remission but did not receive NK cells. Donor NK cell kinetics were determined as secondary endpoints. Twenty-one patients (median age at diagnosis, 6.0 years [range, 0.1–15.3 years]) received a median of 12.5 × 10⁶ NK cells/kg (range, 3.6–62.2 × 10⁶ cells/kg) without major side effects. All but 3 demonstrated transient engraftment with donor NK cells (median peak donor chimerism, 4% [range, 0–43%]). KIR–HLA-mismatched NK cells expanded in 17 patients (81%) and contracted in 4 (19%). However, adoptive transfer of NK cells did not decrease the cumulative incidence of relapse (0.393 [95% confidence interval: 0.182–0.599] vs. 0.35 [0.209–0.495]; P = .556) and did not improve event-free (60.7 ± 10.9% vs. 69.1 ± 6.8%; P = .553) or overall survival (84.2 ± 8.5% vs. 79.1 ± 6.6%; P = .663) over chemotherapy alone. The lack of benefit may result from insufficient numbers and limited persistence of alloreactive donor NK cells but does not preclude its potential usefulness during other phases of therapy, or in combination with other immunotherapeutic agents.

Trial registration

www.clinicaltrials.gov, NCT00703820. Registered 24 June 2008.

Neuroimaging-Based Classification Algorithm for Predicting 1p/19q-Codeletion Status in IDH-Mutant Lower Grade Gliomas

BACKGROUND AND PURPOSE

Isocitrate dehydrogenase (IDH)-mutant lower grade gliomas are classified as oligodendrogliomas or diffuse astrocytomas based on 1p/19q-codeletion status. We aimed to test and validate neuroradiologists' performances in predicting the codeletion status of IDH-mutant lower grade gliomas based on simple neuroimaging metrics.

MATERIALS AND METHODS

One hundred two IDH-mutant lower grade gliomas with preoperative MR imaging and known 1p/19q status from The Cancer Genome Atlas composed a training dataset. Two neuroradiologists in consensus analyzed the training dataset for various imaging features: tumor texture, margins, cortical infiltration, T2-FLAIR mismatch, tumor cyst, T2* susceptibility, hydrocephalus, midline shift, maximum dimension, primary lobe, necrosis, enhancement, edema, and gliomatosis. Statistical analysis of the training data produced a multivariate classification model for codeletion prediction based on a subset of MR imaging features and patient age. To validate the classification model, 2 different independent neuroradiologists analyzed a separate cohort of 106 institutional IDH-mutant lower grade gliomas.

RESULTS

Training dataset analysis produced a 2-step classification algorithm with 86.3% codeletion prediction accuracy, based on the following: 1) the presence of the T2-FLAIR mismatch sign, which was 100% predictive of noncodeleted lower grade gliomas, (n = 21); and 2) a logistic regression model based on texture, patient age, T2* susceptibility, primary lobe, and hydrocephalus. Independent validation of the classification algorithm rendered codeletion prediction accuracies of 81.1% and 79.2% in 2 independent readers. The metrics used in the algorithm were associated with moderate-substantial interreader agreement (κ = 0.56-0.79).

CONCLUSIONS

We have validated a classification algorithm based on simple, reproducible neuroimaging metrics and patient age that demonstrates a moderate prediction accuracy of 1p/19q-codeletion status among IDH-mutant lower grade gliomas.

Features of diffuse gliomas that are misdiagnosed on initial neuroimaging: a case control study

PURPOSE

The neuroimaging diagnosis of diffuse gliomas can be challenging owing to their variable clinical and radiologic presentation. The purpose of this study was to identify factors that are associated with imaging errors in the diagnosis of diffuse gliomas.

METHODS

A retrospective case-control analysis was undertaken. 18 misdiagnosed diffuse gliomas on initial neuroimaging (cases) and 108 accurately diagnosed diffuse gliomas on initial neuroimaging (controls) were collected. Clinical, pathological, and imaging metrics were tabulated for each patient. The tabulated metrics were compared between cases and controls to determine factors associated with misdiagnosis.

RESULTS

Cases of misdiagnosed diffuse glioma (vs controls) were more likely to undergo initial triage as a stroke workup [OR 14.429 (95% CI 4.345, 47.915), p < 0.0001], were less likely to enhance [OR 0.283 (95% CI 0.098, 0.812), p = 0.02], were smaller (mean diameter 4.4 vs 6.0 cm, p = 0.0008), produced less midline shift (median midline shift 0.0 vs 2.0 mm, p = 0.003), were less likely to demonstrate necrosis [OR 0.156 (95% CI 0.034-0.713), p = 0.008], and were less likely to have IV contrast administered on the initial MRI [OR 0.100 (95% CI 0.020, 0.494), p = 0.008].

CONCLUSION

Several clinical and radiologic metrics are associated with diffuse gliomas that are missed or misdiagnosed on the initial neuroimaging study. Knowledge of these associations may aid in avoiding misinterpretation and accurately diagnosing such cases in clinical practice.

CNS Langerhans cell histiocytosis: Common hematopoietic origin for LCH-associated neurodegeneration and mass lesions

BACKGROUND

Central nervous system Langerhans cell histiocytosis (CNS-LCH) brain involvement may include mass lesions and/or a neurodegenerative disease (LCH-ND) of unknown etiology. The goal of this study was to define the mechanisms of pathogenesis that drive CNS-LCH.

METHODS

Cerebrospinal fluid (CSF) biomarkers including CSF proteins and extracellular BRAFV600E DNA were analyzed in CSF from patients with CNS-LCH lesions compared with patients with brain tumors and other neurodegenerative conditions. Additionally, the presence of BRAFV600E was tested in peripheral mononuclear blood cells (PBMCs) as well as brain biopsies from LCH-ND patients, and the response to BRAF-V600E inhibitor was evaluated in 4 patients with progressive disease.

RESULTS

Osteopontin was the only consistently elevated CSF protein in patients with CNS-LCH compared with patients with other brain pathologies. BRAFV600E DNA was detected in CSF of only 2/20 (10%) cases, both with LCH-ND and active lesions outside the CNS. However, BRAFV600E+ PBMCs were detected with significantly higher frequency at all stages of therapy in LCH patients who developed LCH-ND. Brain biopsies of patients with LCH-ND demonstrated diffuse perivascular infiltration by BRAFV600E+ cells with monocyte phenotype (CD14+ CD33+ CD163+ P2RY12- ) and associated osteopontin expression. Three of 4 patients with LCH-ND treated with BRAF-V600E inhibitor experienced significant clinical and radiologic improvement.

CONCLUSION

In LCH-ND patients, BRAFV600E+ cells in PBMCs and infiltrating myeloid/monocytic cells in the brain is consistent with LCH-ND as an active demyelinating process arising from a mutated hematopoietic precursor from which LCH lesion CD207+ cells are also derived. Therapy directed against myeloid precursors with activated MAPK signaling may be effective for LCH-ND. Cancer 2018;124:2607-20. © 2018 American Cancer Society.

Management of neuro-oncologic emergencies

Patients with brain tumors and systemic malignancies are subject to diverse neurologic complications that require urgent evaluation and treatment. These neurologic conditions are commonly due to the tumor's direct effects on the nervous system, such as cerebral edema, increased intracranial pressure, seizures, spinal cord compression, and leptomeningeal metastases. In addition, neurologic complications can develop as a result of thrombocytopenia, coagulopathy, hyperviscosity syndromes, infection, immune-related disorders, and adverse effects of treatment. Patients may present with typical disease syndromes. However, it is not uncommon for patients to have more subtle, nonlocalizing manifestations, such as alteration of mental status, that could be attributed to other systemic, nonneurologic complications. Furthermore, neurologic complications are at times the initial manifestations of an undiagnosed malignancy. Therefore a high index of suspicion is essential for rapid assessment and management. Timely intervention may prolong survival and improve quality of life. In this chapter, we will discuss the common neuro-oncologic emergencies, including epidemiology, pathophysiology, clinical presentation, diagnosis, and treatment.

Feasibility of Pegylated Interferon in Children and Young Adults With Resected High-Risk Melanoma

BACKGROUND

Pegylated interferon α-2b (IFN α-2b) improves disease-free survival in adults with resected stage III melanoma. We conducted a study to determine the feasibility and safety of incorporating pegylated IFN α-2b as adjuvant therapy in the treatment of children and adolescents with high-risk melanoma. Pharmacokinetic studies of IFN α-2b and neuropsychological and quality of life (OL) assessments were performed.

PATIENT AND METHODS

Eligible patients with resected American Joint Committee on Cancer Stage IIC, IIIA, and IIIB cutaneous melanoma received nonpegylated IFN α-2b 20 million units/m(2) /day intravenously 5 days per week for 4 weeks (induction) followed by pegylated IFN α-2b 1 μg/kg/dose weekly subcutaneously (SQ) for 48 weeks (maintenance).

RESULTS

Twenty-three patients (15 females, median age 10 years) were enrolled. All patients completed induction therapy; five patients did not complete maintenance therapy either because of recurrent disease (n = 2) or toxicity (n = 3). The most common grade 3 and 4 toxicities of pegylated IFN α-2b were neutropenia (35%) and elevated liver transaminases (17%). The median nonpegylated IFN α-2b AUC0-∞ (5,026 pcg⋅hr/ml) was similar to adults. The median pegylated IFN α-2b exposure (48,480 pcg⋅hr/ml) was greater than the cumulative weekly exposure for nonpegylated IFN α-2b administered SQ three times per week (TIW). Validated measures demonstrated an improvement in QOL scores and no decline in psychological functioning over the course of therapy.

CONCLUSIONS

Pegylated IFN α-2b 1 μg/kg/dose SQ weekly as maintenance therapy in children and adolescents with high-risk melanoma is feasible with tolerable toxicity and appears to yield higher exposures than nonpegylated IFN α-2b administered SQ TIW.

Abstract 5048: Racial/ethnic diversity in pediatric oncology clinical trial enrollment at Rady Children's Hospital San Diego

Background: In the United States, more than 12,000 children ages 0-21 are diagnosed with cancer each year. Over the past few decades, survival rates in pediatric oncology have improved dramatically, as a result of the successful enrollment of approximately 70% of the cases in clinical trials. However, cancer is still the leading cause of death by disease in children, ages 1-14. Little work has been done to assess disparities in clinical trials enrollment in pediatric oncology.

Purpose: To assess disparities in clinical trial participation for childhood cancer by age, sex, cancer type, insurance, language, and Hispanic ethnicity at RCHSD.

Methods: Data including enrollment onto any clinical trial at RCHSD for newly diagnosed patients in 2008-2012 was collected. We sub-grouped and analyzed by race/ethnicity, age, sex, cancer type (solid or liquid), insurance, and language. Protocols were divided into 3 groups: Biology, Treatment and Registry. Basic descriptive statistics were calculated using SPSS statistical software. Significant differences were tested using a chi-square analysis and 95% confidence intervals. (Significance = p &lt; 0.05).Rates of enrollment among different sub-groups were obtained and compared.

Results: There were 594 cases included in the analysis. The overall rate of enrollment for all race/ethnicities on any protocol was 59.3%. When analyzing by race/ethnicity, only comparisons between Hispanics and Non-Hispanic whites (NHWs) were assessed. Our analysis revealed significant underrepresentation among Hispanics (55.3 %) when compared to NHWs (65.0 %) enrolled in any protocol (p=0.044) and in enrollment onto Biology protocols (77.0% vs. 86.6%) (p=0.036), among males (54.5%) when compared to females (65.7%) enrolled in any protocol (p=0.008), enrollment onto solid cancer (53.8%) compared to liquid cancer (65.4%) (p=0.006), and among 15-21 year olds (47.2%) when compared to all other age groups in any protocol (p&lt;0.001). No disparities were found among different languages or insurance coverage.

Conclusion: Significant underrepresentation in clinical trial participation was observed for Hispanics, 15-21 year olds, males, and those with a solid cancer type. Equality in clinical accrual across underrepresented groups, including minorities is crucial to ensuring equivalent treatment and survival outcomes for all pediatric cancer patients. More research is needed to better understand barriers to participation from the patient, family, and physician's perspectives and to formulate targeted interventions.

Citation Format: Paula Aristizabal, Jenelle Singer, Renee Cooper, Mehrzad Milburn, Deborah Schiff, M. Elena Martinez. Racial/ethnic diversity in pediatric oncology clinical trial enrollment at Rady Children's Hospital San Diego. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5048. doi:10.1158/1538-7445.AM2014-5048

Outcome of indwelling tunneled PleurX® catheter placement in pediatric and young adult patients with malignant effusions

Malignant effusions may cause significant morbidity and mortality for cancer patients. Indwelling tunneled PleurX® catheter placement for intermittent drainage of malignant effusions has been shown to be efficacious in adults but has not been studied in children. We performed a retrospective review of nine children and young adults who underwent PleurX® catheter placement for the palliation of symptoms associated with malignant effusions. Eight of nine demonstrated symptomatic improvement and seven of nine were discharged from the hospital after catheter placement. No patients experienced catheter-associated complications. PleurX® catheter placement should be considered for palliation of symptoms due to malignant effusions in pediatric oncology patients.

Multiple receptor tyrosine kinases converge on microRNA-134 to control KRAS, STAT5B, and glioblastoma

Receptor tyrosine kinases (RTKs) are co-deregulated in a majority of glioblastoma (GBM), the most common and most deadly brain tumor. We show that the RTKs MET, EGFR, and PDGFR regulate microRNA-134 (miR-134) in GBM. We find that miR-134 is downregulated in human tumors and cancer stem cells and that its expression inversely correlates with the activation of MET, EGFR, and PDGFR. We demonstrate that miR-134 inhibits cancer cell and stem-cell proliferation, survival, and xenograft growth, as well as cancer stem-cell self-renewal and stemness. We identify KRAS and STAT5B as targets of miR-134, and establish molecular and functional links between RTKs, miR-134, KRAS/STAT5B and malignancy in vitro and in vivo. We show that miR-134 induction is required for the anti-tumor effects of RTK inhibitors. We also uncover the molecular pathways through which RTKs regulate miR-134 expression and demonstrate the involvement of MAPK signaling and the KLF4 transcription factor. We therefore identify miR-134 as a novel RTK-regulated tumor-suppressive hub that mediates RTK and RTK-inhibitor effects on GBM malignancy by controlling KRAS and STAT5B.

Primary CNS posttransplant lymphoproliferative disease (PTLD): an international report of 84 cases in the modern era

We performed a multicenter, International analysis of solid organ transplant (SOT)-related primary central nervous system (PCNS) posttransplant lymphoproliferative disease (PTLD). Among 84 PCNS PTLD patients, median time of SOT-to-PTLD was 54 months, 79% had kidney SOT, histology was monomorphic in 83% and tumor was EBV+ in 94%. Further, 33% had deep brain involvement, 10% had CSF involvement, while none had ocular disease. Immunosuppression was reduced in 93%; additional first-line therapy included high-dose methotrexate (48%), high-dose cytarabine (33%), brain radiation (24%) and/or rituximab (44%). The overall response rate was 60%, while treatment-related mortality was 13%. With 42-month median follow-up, three-year progression-free survival (PFS) and overall survival (OS) were 32% and 43%, respectively. There was a trend on univariable analysis for improved PFS for patients who received rituximab and/or high-dose cytarabine. On multivariable Cox regression, poor performance status predicted inferior PFS (HR 2.61, 95% CI 1.32-5.17, p = 0.006), while increased LDH portended inferior OS (HR 4.16, 95% CI 1.29-13.46, p = 0.02). Moreover, lack of response to first-line therapy was the most dominant prognostic factor on multivariable analysis (HR 8.70, 95% CI 2.56-29.57, p = 0.0005). Altogether, PCNS PTLD appears to represent a distinct clinicopathologic entity within the PTLD spectrum that is associated with renal SOT, occurs late, is monomorphic and retains EBV positivity.