Successful Multimodal Treatment of Intracranial Growing Teratoma Syndrome with Malignant Features.

Molecular analysis of the growing teratoma syndrome has not been extensively studied. Here, we report a 14-year-old boy with a growing mass during treatment for a mixed germ cell tumor of the pineal region. Tumor markers were negative; thus, growing teratoma syndrome was suspected. A radical resection via the occipital transtentorial approach was performed, and histopathological examination revealed a teratoma with malignant features. Methylation classifier analysis confirmed the diagnosis of teratoma, and DMRT1 loss and 12p gain were identified by copy number variation analysis, potentially elucidating the cause of growth and malignant transformation of the teratoma. The patient remains in remission after intense chemoradiation treatment as a high-risk germ cell tumor.

Landscape of driver mutations and their clinical effects on Down syndrome-related myeloid neoplasms.

Transient abnormal myelopoiesis (TAM) is a common complication in newborns with Down syndrome (DS). It commonly progresses to myeloid leukemia (ML-DS) after spontaneous regression. In contrast to the favorable prognosis of primary ML-DS, patients with refractory/relapsed ML-DS have poor outcomes. However, the molecular basis for refractoriness and relapse, and the full spectrum of driver mutations in ML-DS remain largely unknown. We conducted a genomic profiling study of 143 TAM, 204 ML-DS, and 34 non-DS acute megakaryoblastic leukemia cases, including 39 ML-DS cases analyzed by exome sequencing. Sixteen novel mutational targets were identified in ML-DS samples. Of these, inactivations of IRX1 (16.2%) and ZBTB7A (13.2%) were commonly implicated in the upregulation of the MYC pathway and were potential targets for ML-DS treatment with bromodomain-containing protein 4 inhibitors. Partial tandem duplications of RUNX1 on chromosome 21 were also found, specifically in ML-DS samples (13.7%), presenting its essential role in DS leukemia progression. Finally, in 177 patients with ML-DS treated following the same ML-DS protocol (the Japanese Pediatric Leukemia and Lymphoma Study Group AML-D05/D11), CDKN2A, TP53, ZBTB7A, and JAK2 alterations were associated with a poor prognosis. Patients with CDKN2A deletions (n = 7) or TP53 mutations (n = 4) had substantially lower 3-year event-free survival [28.6% vs. 90.5%, P < 0.001; 25.0% vs. 89.5%, P < 0.001] than those without these mutations. These findings considerably change the mutational landscape of ML-DS, provide new insights into the mechanisms of progression from TAM to ML-DS, and help identify new therapeutic targets and strategies for ML-DS.

Multi-omics analyses of choroid plexus carcinoma cell lines reveal potential targetable pathways and alterations.

PURPOSE: Choroid plexus carcinomas (CPCs) are extremely rare brain tumors and carry a dismal prognosis. Treatment options are limited and there is an urgent need to develop models to further research. In the present study, we established two CPC cell lines and performed multi-omics analyses. These cell lines serve as valuable models to propose new treatments in these rare but deadly brain tumors. METHODS: Multi-omic profiling including, (i) methylation array (EPIC 850 K), (ii) whole genome sequencing (WGS), (iii) CANCERPLEX cancer genome panel testing, (iv) RNA sequencing (RNA-seq), and (v) proteomics analyses were performed in CCHE-45 and NGT131 cell lines. RESULTS: Both cell lines were classified as methylation class B. Both harbored pathogenic TP53 point mutations; CCHE-45 additionally displayed TP53 loss. Furthermore, alterations of the NOTCH and WNT pathways were also detected in both cell lines. Two protein-coding gene fusions, BZW2-URGCP, and CTTNBP2-ERBB4, mutations of two oncodrivers, GBP-4 and KRTAP-12-2, and several copy number alterations were observed in CCHE-45, but not NGT131. Transcriptome and proteome analysis identified shared and unique signatures, suggesting that variability in choroid plexus carcinoma tumors may exist. The discovered difference's importance and implications highlight the possible diversity of choroid plexus carcinoma and call for additional research to fully understand disease pathogenesis. CONCLUSION: Multi-omics analyses revealed that the two choroid plexus carcinoma cell lines shared TP53 mutations and other common pathway alterations and activation of NOTCH and WNT pathways. Noticeable differences were also observed. These cell lines can serve as valuable models to propose new treatments in these rare but deadly brain tumors.

Outcome for Children and Young Adults With T-Cell ALL and Induction Failure in Contemporary Trials.

PURPOSE: Historically, patients with T-cell acute lymphoblastic leukemia (T-ALL) who fail to achieve remission at the end of induction (EOI) have had poor long-term survival. The goal of this study was to examine the efficacy of contemporary therapy, including allogeneic hematopoietic stem cell transplantation (HSCT) in first remission (CR1). METHODS: Induction failure (IF) was defined as the persistence of at least 5% bone marrow (BM) lymphoblasts and/or extramedullary disease after 4-6 weeks of induction chemotherapy. Disease features and clinical outcomes were reported in 325 of 6,167 (5%) patients age 21 years and younger treated in 14 cooperative study groups between 2000 and 2018. RESULTS: With a median follow-up period of 6.4 years (range, 0.3-17.9 years), the 10-year overall survival (OS) was 54.7% (SE = 2.9), which is significantly higher than the 27.6% (SE = 2.9) observed in the historical cohort from 1985 to 2000. There was no significant impact of sex, age, white blood cell count, central nervous system disease status, T-cell maturity, or BM disease burden at EOI on OS. Postinduction complete remission (CR) was achieved in 93% of patients with 10-year OS of 59.6% (SE = 3.1%) and disease-free survival (DFS) of 56.3% (SE = 3.1%). Among the patients who achieved CR, 72% underwent HSCT and their 10-year DFS (with a 190-day landmark) was significantly better than nontransplanted patients (63.8% [SE = 3.6] v 45.5% [SE = 7.1]; P = .005), with OS of 66.2% (SE = 3.6) versus 50.8% (SE = 6.8); P = .10, respectively. CONCLUSION: Outcomes for patients age 21 years and younger with T-ALL and IF have improved in the contemporary treatment era with a DFS benefit among those undergoing HSCT in CR1. However, outcomes still lag considerably behind those who achieve remission at EOI, warranting investigation of new treatment approaches.

Nelarabine, intensive L-asparaginase, and protracted intrathecal therapy for newly diagnosed T-cell acute lymphoblastic leukaemia in children and young adults (ALL-T11): a nationwide, multicenter, phase 2 trial including randomisation in the very high-risk group.

BACKGROUND: T-cell acute lymphoblastic leukaemia has distinct biological characteristics and a poorer prognosis than B-cell precursor acute lymphoblastic leukaemia. This trial aimed to reduce the rate of radiation and haematopoietic stem-cell transplantation (HSCT) while improving outcomes by adding nelarabine, intensified L-asparaginase, and protracted intrathecal therapy in the Berlin-Frankfurt-Münster (BFM)-type treatment. METHODS: In this nationwide, multicenter, phase 2 trial, we enrolled patients with newly diagnosed T-cell acute lymphoblastic leukaemia (age <25 years at diagnosis) conducted by Japan Children's Cancer Group and Japan Adult Leukemia Study Group. Patients were stratified into standard-risk, high-risk, and very-high-risk groups according to prednisolone response, CNS status, and end-of-consolidation minimal residual disease. We used the Associazione Italiana di Ematologia Oncologia Pediatrica (AIEOP)-BFM-ALL 2000-backbone chemotherapy. Nelarabine (650 mg/m2 per day for 5 days) was given to high-risk and very high-risk patients. All patients received, until the measurement of end-of-consolidation minimal residual disease, an identical therapy schedule, which included the prednisolone pre-phase remission induction therapy with dexamethasone (10 mg/m2 per day, for 3 weeks [for patients <10 years] or for 2 weeks including a 7-day off interval [for patients ≥10 years]) instead of prednisolone, and consolidation therapy added with Escherichia coli-derived L-asparaginase. On the basis of the stratification, patients received different intensities of treatment; L-asparaginase-intensified standard BFM-type therapy for standard risk and nelarabine-added high risk BFM-type therapy for high risk. In the very high-risk group, patients were randomly assigned (1:1) to group A (BFM-based block therapy) and group B (another block therapy, including high-dose dexamethasone) stratified by hospital, age (≥18 years or <18 years), and end-of-induction bone marrow blast percentage of M1 (<5%) or M2 (≥5%, <25%)+M3 (≥25%). Cranial radiotherapy was limited to patients with overt CNS disease at diagnosis (CNS3; >5 white blood cells per µL with blasts) and patients with no evidence of CNS disease received protracted triple intrathecal therapy. Only very high-risk patients were scheduled to receive HSCT. The primary endpoint was 3-year event-free survival for the entire cohort and the proportion of patients with disappearance of minimal residual disease between randomly assigned groups A and B in the very high-risk group. Secondary endpoints were overall survival, remission induction rate, and occurrence of adverse events. 3 years after the completion of patient accrual, a primary efficacy analysis was performed in the full analysis set and the per-protocol set. This study is registered with the Japan Registry of Clinical Trials, jRCTs041180145. FINDINGS: Between Dec 1, 2011, and Nov 30, 2017, of 349 eligible patients (median age 9 years [IQR 6-13]), 238 (68%) were male, and 28 (8%) patients had CNS3 status. 168 (48%) patients were stratified as standard risk, 103 (30%) as high risk, 39 (11%) as very high risk, and 39 (11%) as no risk (patients who had off protocol treatment before risk assessment. The composite complete remission (complete remission plus complete remission in suppression) rate after remission induction therapy was 89% (298 of 335 patients). HSCT was performed in 35 (10%) of 333 patients. With a median follow-up of 5·2 years (IQR 3·6-6·7), 3-year event-free survival was 86·4% (95% CI 82·3-89·7%) and 3-year overall survival was 91·3% (87·7-93·8%). The proportion of minimal residual disease disappearance was 0·86 (12 of 14 patients; 95% CI 0·57-0·98) in group A and 0·50 (6 of 12 patients, 0·21-0·79) in group B. Grade 3 peripheral motor neuropathy was seen in 11 (3%) of 349 patients and sensory neuropathy was seen in 6 (2%) patients. The most common grade 3 or worse adverse event was febrile neutropenia (294 [84%] of 349 patients). Treatment-related death occurred in three patients due to sepsis, gastric perforation, or intracranial haemorrhage during remission induction. INTERPRETATION: The ALL-T11 protocol produced encouraging outcomes with acceptable toxicities despite limited cranial radiotherapy and HSCT use. FUNDING: Ministry of Health, Labor and Welfare of Japan, and Japan Agency for Medical Research and Development. TRANSLATION: For the Japanese translation of the abstract see Supplementary Materials section.

Outcomes following induction failure in Japanese children with acute lymphoblastic leukemia.

The characteristics and prognosis of Japanese children with acute lymphoblastic leukemia (ALL) who fail to achieve complete remission after remission induction chemotherapy (i.e., experience induction failure) are poorly understood. Therefore, we retrospectively analyzed data of patients enrolled in Japanese clinical trials for newly diagnosed ALL between 1996 and 2009. Among 4956 participants, 89 (1.8%) experienced induction failure. With a 6.0-year median follow-up, the 5-year overall survival rate of the entire cohort was 43.0% ± 5.5%. Survival rates did not differ between patients with B-cell precursor ALL (BCP-ALL) and T-cell ALL (T-ALL). In multivariate analysis, day 15 M3 marrow (bone marrow blast count ≥ 25%) was significantly correlated with poorer survival in the whole or BCP-ALL cohorts. In T-ALL, age < 6 years was significantly associated with poor survival. However, due to the small sample size, this correlation must be further investigated. Most T-ALL and BCR-ABL-positive BCP-ALL patients underwent allogeneic stem cell transplantation (allo-SCT). Survival rates did not differ between BCR-ABL-negative BCP-ALL patients who did and did not undergo allo-SCT, possibly due to the inclusion of lower-risk patients in the latter group. In conclusion, the induction failure rate and survival after diagnosis of induction failure in our study were comparable to previously reported figures.

Short stature as an initial presenting presentation of unicentric Castleman disease in a child: A case report with long-term follow-up and a literature review.

Short stature is a common clinical condition in paediatric outpatient clinics and is associated with various clinical conditions, ranging from normal variants to severe diseases. Short stature is known to be caused by chronic inflammatory conditions, in which over-produced inflammatory cytokines are reported to be involved in growth suppression. Castleman disease is a rare lymphoproliferative disorder known as a chronic inflammatory disease with overproduction of interleukin 6, which often causes systemic symptoms such as fever, fatigue, weight loss, and night sweats. Here, we report the case of a 10-year-old female diagnosed with unicentric Castleman disease, who presented with short stature as the sole clinical sign but lacked typical systemic symptoms of Castleman disease. An elevated serum C-reactive protein level led us to suspect a chronic inflammatory condition, and we found an intra-abdominal tumour that was histopathologically confirmed as Castleman disease. The tumour removal resulted in a steady catch-up in her height in the six years following the surgery. We also present a brief review of relevant literature on paediatric cases of Castleman disease associated with growth impairment. Clinicians should be aware that chronic inflammatory conditions can cause growth impairment, which may be a key clinical manifestation of such conditions.

Epigenetic upregulation of Schlafen11 renders WNT- and SHH-activated medulloblastomas sensitive to cisplatin.

BACKGROUND: Intensive chemotherapeutic regimens with craniospinal irradiation have greatly improved survival in medulloblastoma patients. However, survival markedly differs among molecular subgroups and their biomarkers are unknown. Through unbiased screening, we found Schlafen family member 11 (SLFN11), which is known to improve response to DNA damaging agents in various cancers, to be one of the top prognostic markers in medulloblastomas. Hence, we explored the expression and functions of SLFN11 in medulloblastoma. METHODS: SLFN11 expression for each subgroup was assessed by immunohistochemistry in 98 medulloblastoma patient samples and by analyzing transcriptomic databases. We genetically or epigenetically modulated SLFN11 expression in medulloblastoma cell lines and determined cytotoxic response to the DNA damaging agents cisplatin and topoisomerase I inhibitor SN-38 in vitro and in vivo. RESULTS: High SLFN11 expressing cases exhibited significantly longer survival than low expressing cases. SLFN11 was highly expressed in the WNT-activated subgroup and in a proportion of the SHH-activated subgroup. While WNT activation was not a direct cause of the high expression of SLFN11, a specific hypomethylation locus on the SLFN11 promoter was significantly correlated with high SLFN11 expression. Overexpression or deletion of SLFN11 made medulloblastoma cells sensitive and resistant to cisplatin and SN-38, respectively. Pharmacological upregulation of SLFN11 by the brain-penetrant histone deacetylase-inhibitor RG2833 markedly increased sensitivity to cisplatin and SN-38 in SLFN11-negative medulloblastoma cells. Intracranial xenograft studies also showed marked sensitivity to cisplatin by SLFN11-overexpression in medulloblastoma cells. CONCLUSIONS: High SLFN11 expression is one factor which renders favorable outcomes in WNT-activated and a subset of SHH-activated medulloblastoma possibly through enhancing response to cisplatin.

NKp44-based chimeric antigen receptor effectively redirects primary T cells against synovial sarcoma.

BACKGROUND: T-cell receptor-engineered T-cell therapies have achieved promising response rates against synovial sarcoma in clinical trials, but their applicability is limited owing to the HLA matching requirement. Chimeric antigen receptor (CAR) can redirect primary T cells to tumor-associated antigens without requiring HLA matching. However, various obstacles, including the paucity of targetable antigens, must be addressed for synovial sarcoma. Ligands for natural killer (NK) cell-activating receptors are highly expressed by tumor cells. METHODS: The surface expression of ligands for NK cell-activating receptors in synovial sarcoma cell lines was analyzed. We analyzed RNA sequencing data deposited in a public database to evaluate NKp44-ligand expression. Primary T cells retrovirally transduced with CAR targeting NKp44 ligands were evaluated for their functions in synovial sarcoma cells. Alterations induced by various stimuli, including a histone deacetylase inhibitor, a hypomethylating agent, inflammatory cytokines, and ionizing radiation, in the expression levels of NKp44 ligands were investigated. RESULTS: Ligands for NKp44 and NKp30 were expressed in all cell lines. NKG2D ligands were barely expressed in a single cell line. None of the cell lines expressed NKp46 ligand. Primary synovial sarcoma cells expressed the mRNA of the truncated isoform of MLL5, a known cellular ligand for NKp44. NKp44-based CAR T cells specifically recognize synovial sarcoma cells, secrete interferon-γ, and exert suppressive effects on tumor cell growth. No stimulus altered the expression of NKp44 ligands. CONCLUSION: NKp44-based CAR T cells can redirect primary human T cells to synovial sarcoma cells. CAR-based cell therapies may be an option for treating synovial sarcomas.

Disease Progression of WHIM Syndrome in an International Cohort of 66 Pediatric and Adult Patients.

Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome (WS) is a combined immunodeficiency caused by gain-of-function mutations in the C-X-C chemokine receptor type 4 (CXCR4) gene. We characterize a unique international cohort of 66 patients, including 57 (86%) cases previously unreported, with variable clinical phenotypes. Of 17 distinct CXCR4 genetic variants within our cohort, 11 were novel pathogenic variants affecting 15 individuals (23%). All variants affect the same CXCR4 region and impair CXCR4 internalization resulting in hyperactive signaling. The median age of diagnosis in our cohort (5.5 years) indicates WHIM syndrome can commonly present in childhood, although some patients are not diagnosed until adulthood. The prevalence and mean age of recognition and/or onset of clinical manifestations within our cohort were infections 88%/1.6 years, neutropenia 98%/3.8 years, lymphopenia 88%/5.0 years, and warts 40%/12.1 years. However, we report greater prevalence and variety of autoimmune complications of WHIM syndrome (21.2%) than reported previously. Patients with versus without family history of WHIM syndrome were diagnosed earlier (22%, average age 1.3 years versus 78%, average age 5 years, respectively). Patients with a family history of WHIM syndrome also received earlier treatment, experienced less hospitalization, and had less end-organ damage. This observation reinforces previous reports that early treatment for WHIM syndrome improves outcomes. Only one patient died; death was attributed to complications of hematopoietic stem cell transplantation. The variable expressivity of WHIM syndrome in pediatric patients delays their diagnosis and therapy. Early-onset bacterial infections with severe neutropenia and/or lymphopenia should prompt genetic testing for WHIM syndrome, even in the absence of warts.

Discontinuation of tyrosine kinase inhibitors in pediatric chronic myeloid leukemia.

BACKGROUND: The feasibility of tyrosine kinase inhibitor (TKI) discontinuation in pediatric chronic myeloid leukemia (CML) remains to be fully elucidated. PROCEDURES: TKI was prospectively discontinued in patients who were diagnosed with CML at <20 years of age, treated with TKI for ≥3 years, and sustained molecular response 4.0 (MR4.0) for ≥2 years. Molecular relapse was defined as a single loss of major molecular response (MMR) (BCR-ABL1IS >0.1%). Relapsed patients resumed the same TKI therapy administered before discontinuation. RESULTS: Twenty-two patients with chronic-phase CML were enrolled, and the median ages at diagnosis and at TKI discontinuation were 9 (range: 1-14) years and 16 (5-26) years, respectively. The median follow-up time after TKI discontinuation was 37 months (range: 24-41 months). The median duration of TKI treatment before discontinuation was 100 (42-178) months, and that of MR4.0 was 53.5 (25-148) months. The treatment-free remission (TFR) rate at 12 months was 50.0% (90% confidence interval: 31.7%-65.8%). Eleven patients experienced loss of MMR within 4 months after TKI discontinuation and resumed TKI as originally prescribed. No progression was observed, and all 11 patients regained MR4.0 after TKI resumption. No patient had a withdrawal syndrome. The quality-of-life analysis suggested that successful TFR may improve academic performance in some patients. In patients who discontinued TKI therapy before puberty, the possibility of improvement in growth velocity upon TKI discontinuation was observed. CONCLUSIONS: TKI could be discontinued safely in patients with pediatric CML showing a sustained deep MR.

Resolution of Pediococcus acidilactici bacteremia without antibiotic therapy in a 16-year-old adolescent with leukemia receiving maintenance chemotherapy.

Pediococcus spp. have been reported to cause infections in patients with underlying conditions. However, the pathogenicity of this bacteria is unclear. Herein, we describe the first case of Pediococcus acidilactici bacteremia, which occurred in a 16-year-old male with dasatinib-induced hemorrhagic colitis during maintenance therapy for leukemia and resolved without antibiotic treatment. P. acidilactici bacteremia might be self-limiting, even in immunocompromised patients receiving chemotherapy.

Dual-antigen targeted iPSC-derived chimeric antigen receptor-T cell therapy for refractory lymphoma.

We generated dual-antigen receptor (DR) T cells from induced pluripotent stem cells (iPSCs) to mitigate tumor antigen escape. These cells were engineered to express a chimeric antigen receptor (CAR) for the antigen cell surface latent membrane protein 1 (LMP1; LMP1-CAR) and a T cell receptor directed to cell surface latent membrane protein 2 (LMP2), in association with human leucocyte antigen A24, to treat therapy-refractory Epstein-Barr virus-associated lymphomas. We introduced LMP1-CAR into iPSCs derived from LMP2-specific cytotoxic T lymphocytes (CTLs) to generate rejuvenated CTLs (rejTs) active against LMP1 and LMP2, or DRrejTs. All DRrejT-treated mice survived >100 days. Furthermore, DRrejTs rejected follow-up inocula of lymphoma cells, demonstrating that DRrejTs persisted long-term. We also demonstrated that DRrejTs targeting CD19 and LMP2 antigens exhibited a robust tumor suppressive effect and conferred a clear survival advantage. Co-operative antitumor effect and in vivo persistence, with unlimited availability of DRrejT therapy, will provide powerful and sustainable T cell immunotherapy.

Effectiveness of 4-1BB-costimulated HER2-targeted chimeric antigen receptor T cell therapy for synovial sarcoma.

BACKGROUND: Synovial sarcoma is a rare malignant soft-tissue tumor that is prevalent in adolescents and young adults, and poor prognosis has been reported in patients with metastatic lesions. Chimeric antigen receptor (CAR) T-cell therapy is an emerging novel therapy for solid tumors; however, its application in synovial sarcoma has not yet been explored. METHODS: A novel human epidermal growth factor receptor 2 (HER2)-targeted CAR containing scFv-FRP5, CD8α hinge and transmembrane domains as well as 4-1BB costimulatory and CD3ζ signaling domains was developed. Three synovial sarcoma cell lines that expressed the fusion transcript SS18-SSX1/2/4 were used in the study. Cytokine secretion assay, cytotoxicity assay, and real-time cell analysis experiments were conducted to confirm the function of T cells transduced with the CAR gene. RESULTS: High cell-surface expression of HER2 was observed in all the cell lines. HER2-targeted/4-1BB-costimulated CAR T cells specifically recognized the synovial sarcoma cells, secreted interferon gamma and tumor necrosis factor alpha, and exerted cytotoxic effects in these cells. CONCLUSION: To the best of our knowledge, this is the first study to indicate that HER2-targeted CAR T cells are directly effective against molecularly defined synovial sarcoma cells. Furthermore, our findings might set the basis for developing improved CAR T cell-based therapies for chemo-refractory or relapsed synovial sarcoma.