Hsiu-Hao Chang

Long-term results of Taiwan Pediatric Oncology Group studies 1997 and 2002 for childhood acute lymphoblastic leukemia

The long-term outcome of 1390 children with acute lymphoblastic leukemia (ALL), treated in two successive clinical trials (Taiwan Pediatric Oncology Group (TPOG)-ALL-97 and TPOG-ALL-2002) between 1997 and 2007, is reported. The event-free survival improved significantly (P=0.0004) over this period, 69.3±1.9% in 1997–2001 to 77.4±1.7% in 2002–2007. A randomized trial in TPOG-97 testing L-asparaginase versus epidoxorubicin in combination with vincristine and prednisolone for remission induction in standard-risk (SR; low-risk) patients yielded similar outcomes. Another randomized trial, in TPOG-2002, showed that for SR patients, two reinduction courses did not improve long-term outcome over one course. Decreasing use of prophylactic cranial irradiation in the period 1997–2008 was not associated with increased rates of CNS relapse, prompting complete omission of prophylactic cranial irradiation from TPOG protocols, beginning in 2009. Decreased use of etoposide and cranial irradiation likely contributed to the low incidence of second cancers. High-risk B-lineage ALL, T-cell, CD10 negativity, t(9;22), infant, and higher leukocyte count were consistently adverse factors, whereas hyperdiploidy >50 was a consistently favorable factor. Higher leukocyte count and t(9;22) retained prognostic significance in both TPOG-97 and TPOG-2002 by multivariate analysis. Although long-term outcome in TPOG clinical trials is comparable with results being reported worldwide, the persistent strength of certain prognostic variables and the lower frequencies of favorable outcome predictors, such as ETV6-RUNX1 and hyperdiploidy >50, in Taiwanese children warrant renewed effort to cure a higher proportion of patients while preserving their quality of life.

IKZF1 deletions predict a poor prognosis in children with B‐cell progenitor acute lymphoblastic leukemia: A multicenter analysis in Taiwan

Despite current risk‐directed therapy, approximately 15–20% of pediatric patients with acute lymphoblastic leukemia (ALL) have relapses. Recent genome‐wide analyses have identified that an alteration of IKZF1 is associated with very poor outcomes in B‐cell progenitor ALL. In this study, we determined the prognostic significance of IKZF1 deletions in patients with childhood ALL. This study analyzed 242 pediatric B‐cell progenitor ALL patients in Taiwan. We developed a simple yet sensitive multiplex quantitative PCR coupled with capillary electrophoresis to accurately determine the allele dose of IKZF1, and high resolution melting was used for mutation screening for all coding exons of IKZF1. Twenty‐six (10.7%) pediatric B‐cell progenitor ALL patients were found to harbor these deletions. Most of the deletions were broader deletions that encompassed exon 3 to exon 6, consistent with previous reports. Genomic sequencing of IKZF1 was carried out in all cases and no point mutations were identified. Patients with IKZF1 deletions had inferior event‐free survival (P < 0.001), and overall survival (P = 0.0016). The association between IKZF1 deletions and event‐free survival was independent of age, leukocyte count at presentation, and cytogenetic subtype by multivariate Cox analysis (P = 0.003, hazard ratio = 2.45). This study indicates that detection of IKZF1 deletions upon diagnosis of B‐cell progenitor ALL may help to identify patients at risk of treatment failure. IKZF1 deletions could be incorporated as a new high‐risk prognostic factor in future treatment protocols. To the best of our knowledge, this is the first study to examine the poor prognosis of IKZF1 deletions in an Asian population. (Cancer Sci 2011; 102: 1874–1881)

Acquisition of JAK2, PTPN11, and RAS mutations during disease progression in primary myelodysplastic syndrome

Cytokines play an important role in the developmental programs of normal hematopoiesis and leukemia. Signaling through cytokines receptors is mediated in part by the activation of tyrosine kinases, particularly the Janus kinases (Jaks). Many of the effects of Jak2 are mediated through the recruitment of signal transducer and activator of transcription (Stat) to phosphotyrosyl residues on the erythropoietin, granulocyte macrophage colony-stimulating factor, and interleukin-3 receptors. Shp2, the nonreceptor tyrosine phosphatase encoded by PTPN11, also participates in signaling events downstream of the receptors of growth factors, cytokines, hormones, antigens, and extracellular matrixes. It has compound functions and is involved in a variety of signal transduction processes, such as the Ras-Raf-Map kinase, Jak-Stat, PI3 kinase, and nuclear factor-B (NF-B) pathways. Jak2 and Shp2 form a complex signaling network in hematopoietic progenitor cells. Perturbed Jak2 and Shp2 signalings may induce hematopoietic malignancies. Recently, a somatic point mutation of JAK2 (V617F), which results in constitutive activation of the tyrosine kinase and factor independent growth of hematopoietic cells, has been found in patients with myeloproliferative disorders.1 Dominant mutations in PTPN11, which result in gain of function of shp2, have also been demonstrated in juvenile myelomonocytic leukemia (JMML).2

Poor outcome in post transplant lymphoproliferative disorder with pulmonary involvement after allogeneic hematopoietic SCT: 13 years' experience in a single institute.

EBV-induced post transplant lymphoproliferative disorder (PTLD) continues to be a major complication after transplantation. Between January 1993 and April 2006, 12 cases of B-cell lymphoproliferative disorder were identified among 577 patients after allogeneic hematopoietic SCT (HSCT) with an overall incidence of 2.51% at 1 year. Grades II–IV acute GVHD, CMV antigenemia and the use of antithymocyte globulin (ATG) were independent risk factors for PTLD. At diagnosis, all of the tumors were CD20-positive and 11 (92%) were EBV-encoded RNA (EBER)-positive. Of the 12 patients with B-cell lymphoproliferative disorder, 8 had pulmonary involvement and 10 had extranodal involvement. Eleven patients received weekly rituximab therapy at a dose of 375 mg/m2; the median interval between the onset of symptoms and rituximab therapy was 6 days. The overall mortality rate was 92% and seven (64%) of the deaths were directly attributable to disseminated PTLD within days or weeks of presentation. In our series, pulmonary PTLD followed an extremely aggressive course and poor response to current therapy, even though rituximab was included in the therapeutic regimens.

Notch1 Expression Predicts an Unfavorable Prognosis and Serves as a Therapeutic Target of Patients with Neuroblastoma

Purpose: Notch signaling has been implicated to play a critical role in the tumorigenesis of neuroblastoma (NB) and can modulate calreticulin (CRT) expression that strongly correlates with tumor differentiation and favorable prognosis of NB. We thus sought to determine how Notch regulates CRT expression and affects NB tumor behavior. Experimental Design: The Notch-dependent regulation of CRT expression in cultured NB cells was analyzed by confocal microscopy and Western blotting. Notch1 protein expression in 85 NB tumors was examined by immunohistochemistry and correlated with the clinicopathologic/biological characters of NB patients. The progression of NB tumors in response to attenuated Notch signaling was examined by using a xenograft mouse model. Results: We showed that CRT is essential for the neuronal differentiation of NB cells elicited by inhibition of Notch signaling. This effect was mediated by a c-Jun-NH2-kinase–dependent pathway. Furthermore, NB tumors with elevated Notch1 protein expression were strongly correlated with advanced tumor stages, MYCN amplification, an undifferentiated histology, as well as a low CRT expression level. Most importantly, the opposing effect between Notch1 and CRT could reciprocally affect the survival of NB patients. The administration of a γ-secretase inhibitor into a xenograft mouse model of NB significantly suppressed the tumor progression. Conclusions: Our findings provide the first evidence that a c-Jun-NH2-kinase-CRT–dependent pathway is essential for the neuronal differentiation elicited by Notch signaling blockade and that Notch1 and CRT can synergistically predict the clinical outcomes of NB patients. The present data suggest that Notch signaling could be a therapeutic target for NB. Clin Cancer Res; 16(17); 4411–20. ©2010 AACR.

Characterization of Neuroblastic Tumors Using 18F-FDOPA PET

Neuroblastic tumors are childhood neoplasms that possess amino acid decarboxylase (AADC) activity and can theoretically be imaged by 18F-fluorodihydroxyphenylalanine (18F-FDOPA) PET, a new diagnostic tool for neuroendocrine tumors. In this study, we explored the accuracy and clinical role of 18F-FDOPA PET in neuroblastic tumors. Methods: From 2008 to 2011, patients with tissue-proven neuroblastic tumors receiving 18F-FDOPA PET at initial diagnosis or during follow-ups were enrolled. The sensitivity and specificity of 18F-FDOPA PET were compared with those of 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy and 18F-FDG PET, using tumor histology as the standard. The maximum standardized uptake value and tumor-to-liver uptake ratio on 18F-FDOPA PET were measured and correlated with AADC messenger RNA level in tumor tissue. Results: Fifty tumors from 34 patients, including 42 neuroblastic tumors and 8 lesions without viable tumor cells, were eligible for analysis. 18F-FDOPA PET successfully detected neuroblastic tumors of different histologic types in various anatomic sites, at a sensitivity of 97.6% (87.4%–99.9%) and a specificity of 87.5% (47.3%–99.7%). In tumors with concomitant studies, 18F-FDOPA PET demonstrated a higher sensitivity than 123I-MIBG scintigraphy (n = 18; P = 0.0455) or 18F-FDG PET (n = 46; P = 0.0455). Among the 18 tumors with concomitant 123I-MIBG scans, 4 tumors with viable cells were 123I-MIBG–negative but were successfully detected by 18F-FDOPA PET. The tumor uptake of 18F-FDOPA significantly correlated with AADC expression (n = 15 nonhepatic tumors; maximum standardized uptake value, P = 0.0002; tumor-to-liver uptake ratio, P < 0.0001). Conclusion: 18F-FDOPA PET showed high sensitivity and specificity in detecting and tracking neuroblastic tumors in this preliminary study with a small cohort of patients and might be complementary to 123I-MIBG scintigraphy and 18F-FDG PET. By correlating with AADC expression, 18F-FDOPA PET might serve as a useful imaging tool for the functional assessment of neuroblastic tumors.

Identification of GRP75 as an Independent Favorable Prognostic Marker of Neuroblastoma by a Proteomics Analysis

Purpose: Neuroblastoma (NB) is a heterogeneous neoplasm. Detailed biological discrimination is critical for the effective treatment of this disease. Because the tumor behavior of NB is closely associated with the histologic state of differentiation, we thus aimed to identify novel differentiation-associated markers of NB with prognostic implication. Experimental Design: A human NB cell line SH-SY5Y was used as a model system to explore potential biomarkers for the differentiation of NB by proteomic analyses. Seventy-two NB tumor tissues were subsequently investigated by immunohistochemistry to validate the correlations between the expression of a novel prognostic marker, various clinicopathologic and biological factors, and patient survival. Results: Using two-dimensional differential gel electrophoresis, we found a total of 24 spots of proteins in SH-SY5Y cells whose expression was enhanced following differentiation. Glucose-regulated protein 75 (GRP75) was unambiguously identified as one of the five proteins that were dramatically up-regulated following differentiation. Immunohistochemical analyses of 72 NB tumor tissues further revealed that positive GRP75 immunostaining is strongly correlated with differentiated histologies (P < 0.001), mass-screened tumors (P = 0.016), and early clinical stages (P < 0.001) but inversely correlated with MYCN amplification (P = 0.010). Univariate and multivariate survival analyses showed that GRP75 expression is an independent favorable prognostic factor. Conclusions: The present findings clearly showed that our proteomics-based novel experimental paradigm could be a powerful tool to uncover novel biomarkers associated with the differentiation of NB. Our data also substantiate an essential role of GRP75 in the differentiation of NB.

B4GALNT3 Expression Predicts a Favorable Prognosis and Suppresses Cell Migration and Invasion via β1 Integrin Signaling in Neuroblastoma

β1,4-N-acetylgalactosaminyltransferase III (B4GALNT3) promotes the formation of GalNAcβ1,4GlcNAc (LacdiNAc or LDN). Drosophila β1,4-N-acetylgalactosaminyltransferase A (B4GALNTA) contributes to the synthesis of LDN, which helps regulate neuronal development. In this study, we investigated the expression and role of B4GALNT3 in human neuroblastoma (NB). We used IHC analysis to examine 87 NB tumors, and we identified correlations between B4GALNT3 expression and clinicopathologic factors, including patient survival. Effects of recombinant B4GALNT3 on cell behavior and signaling were studied in SK-N-SH and SH-SY5Y NB cells. Increased expression of B4GALNT3 in NB tumors correlated with a favorable histologic profile (P < 0.001, χ² test) and early clinical staging (P = 0.041, χ² test) and was a favorable prognostic factor for survival as evaluated by univariate and multivariate analyses. Reexpression of B4GALNT3 in SK-N-SH and SH-SY5Y cells suppressed cell proliferation, colony formation, migration, and invasion. Moreover, B4GALNT3 increased the LacdiNAc modification of β₁ integrin, leading to decreased phosphorylation of focal adhesion kinase (FAK), Src, paxillin, Akt, and ERK1/2. B4GALNT3-mediated suppression of cell migration and invasion were substantially reversed by concomitant expression of constitutively active Akt or MEK. We conclude that B4GALNT3 predicts a favorable prognosis for NB and suppresses the malignant phenotype via decreasing β₁ integrin signaling.

Improved efficacy and tolerability of oral deferasirox by twice-daily dosing for patients with transfusion-dependent β-thalassemia†

Deferasirox is an oral iron‐chelating agent taken once‐daily by patients with transfusion‐dependent iron overload. However, some patients are unresponsive or unable to tolerate once‐daily deferasirox. The current study evaluated whether twice‐daily deferasirox treatment showed increased efficacy or tolerability in unresponsive or intolerant patients.

Expression and prognostic significance of the apoptotic genes BCL2L13, Livin, and CASP8AP2 in childhood acute lymphoblastic leukemia

Improved treatment of childhood acute lymphoblastic leukemia (ALL) depends on the identification of new molecular markers that are able to predict treatment response and clinical outcome. The development of impaired apoptosis in leukemic cells is one factor that may influence their response to treatment. We investigated the expression of three apoptosis related genes, BCL2L13, CASP8AP2, and Livin, as well as their prognostic significance, in a retrospective study of 90 pediatric ALL patients diagnosed between 1996 and 2007 in Taiwan. Univariant analysis revealed that high expression of BCL2L13 was associated with inferior event-free survival and overall survival (p<0.001 and 0.005, respectively). Multivariate analysis for EFS and OS demonstrated that high expression of BCL2L13 was an independent prognostic factor for childhood ALL in this ethnic group.