Elevated c-myc expression in childhood medulloblastomas

Medulloblastoma is a rare brain tumor usually occurring in late childhood or early adolescence. Little is known regarding the cell of origin or cellular events leading to its malignant transformation. We have studied the expression of developmentally regulated mRNA in tumor samples by the Northern hybridization assay to determine a relative stage at which a block to further differentiation occurs. In a series of five medulloblastoma tumors analyzed, only one of eight markers for cellular differentiation, the glial fibrillary acidic protein mRNA, was expressed at significant levels. Interestingly, three of six medulloblastoma tumor samples were found to have elevated levels of c-myc mRNA. In one of these tumors, we have found evidence of mutation of the c-myc protooncogene. We discuss possible mechanisms of c-myc activation in medulloblastoma tumors.     

High-dose chemotherapy and autologous stem cell rescue in children with newly diagnosed high-risk or relapsed medulloblastoma or supratentorial primitive neuroectodermal tumor

BACKGROUND: Single or tandem double high-dose chemotherapy (HDCT) was used to treat children with newly diagnosed high-risk or relapsed medulloblastoma and supratentorial primitive neuroectodermal tumor (MB/sPNET) in order to defer or avoid radiotherapy in young children. PROCEDURE: Thirty-seven HDCTs were given to 25 children with newly diagnosed high-risk or relapsed MB/sPNET. Tandem double HDCT was used for 12 of 15 patients initially intended to receive double HDCT. RESULTS: Three-year EFS (+/-SE) in 6 newly diagnosed high-risk (>3 years old), 8 newly diagnosed (<3 years old), and 11 relapsed MB/sPNET was 83.3 +/- 15.2%, 62.5 +/- 20.5%, and 29.1 +/- 15.7%, respectively. Three-year EFS for patients in CR or PR and in less than PR at first HDCT was 67.4 +/- 11.0% and 16.7 +/- 15.2%, respectively (P = 0.001). Three-year EFS in patients initially intended to receive double HDCT and single HDCT was 66.0 +/- 12.4% and 40.0 +/- 15.5%, respectively. For 19 patients in CR or PR at first HDCT, 3-year EFS was 88.9 +/- 10.5% in tandem double HDCT group, and 44.4 +/- 16.6% in single HDCT group, respectively (P = 0.037). Although four treatment-related mortalities (TRMs) occurred during 25 first HDCTs, no TRM occurred during 12 second HDCTs. In four of eight young children, craniospinal radiotherapy was successfully withheld without subsequent relapse. CONCLUSIONS: High-dose chemotherapy may improve the survival of children with newly diagnosed high-risk MB/sPNET, and, to some extent, the survival of those with relapsed MB/sPNET. Further study is necessary to elucidate the efficacy of tandem double HDCT.     

Her-2/neu expression in osteosarcoma increases risk of lung metastasis and can be associated with gene amplification

The purpose of this study was to investigate whether Her-2/neu expression at diagnosis of osteosarcoma could provide biologic and prognostic information that predicts the risk of pulmonary metastases and outcome. Human epidermal growth factor (Her-2/neu) expression in 25 initial pretreatment osteosarcoma biopsies and 12 posttreatment pulmonary metastatic osteosarcoma resection specimens was assessed by standard immunohistochemical techniques on formalin-fixed paraffin-embedded tissue. As a screening analysis to determine if gene amplification may be a mechanism for increased Her-2/neu expression, FISH analysis was conducted on seven Her-2/neu immunostain-positive samples and five Her-2/neu immunostain-negative samples. Cytoplasmic Her-2/neu reactivity was identified in 11/25 (44%) of primary tumors and in 7/12 (58%) resection specimens from pulmonary metastases. Cytoplasmic Her-2/neu expression was associated with shorter overall metastasis-free survival. Her-2/neu gene amplification was identified by FISH analysis in six of the seven immunostain-positive samples but was also identified in two of the five immunostain-negative samples. Her-2/neu expression in patients with osteosarcoma is associated with an increased risk of metastasis and may define a subset of patients with a more aggressive tumor phenotype. Her-2/neu gene amplification may provide a mechanism for Her-2/neu overexpression in certain cases of osteosarcoma. Whether Her-2/neu expression influences outcome needs to be examined further in a prospective fashion. The hope is that Her-2/neu expression will identify patients who may benefit from the addition of directed biologic therapy.     

Neurotrophin receptor TrkC predicts good clinical outcome in medulloblastoma and other primitive neuroectodermal brain tumors

BACKGROUND: Neurotrophins and their cognate receptors TrkA, TrkB and TrkC regulate proliferation, differentiation and death of neuronal progenitor cells and may be implicated in the progression of medulloblastoma and other primitive neuroectodermal brain tumors (PNET). These common childhood brain tumors are composed of morphologically undifferentiated cells that have important similarities to neuroectodermal progenitor cells of the developing CNS. PATIENTS AND METHODS: To identify biologic prognostic factors in childhood PNET we determined expression levels of TrkC mRNA in tumor samples from 87 PNET patients by in situ hybridization. Comparison of TrkC mRNA expression levels with clinical variables was performed using univariate and multivariable Cox regression analysis. RESULTS: Cox regression analysis revealed that children with tumors expressing no or little TrkC mRNA had a 4.8-fold (p < 0.00005) greater risk of death than children with tumors with high TrkC mRNA expression. This hazard ratio remained consistent after adjusting for clinical variables. Five-year survival was 89% for patients with PNETs expressing high levels of TrkC mRNA and 47% for patients with PNETs expressing little or no levels of TrkC mRNA (log rank; p < 0.00005). CONCLUSIONS: The TrkC neurotrophin receptor appears to be a powerful independent prognostic factor in PNET and may have a role in patient assignment to risk-based treatment strategies.     

髓母细胞瘤组织bcl-XL mRNA和蛋白表达及临床意义

目的 研究bcl-XL基因在儿童髓母细胞瘤组织中的表达水平及意义。方法 应用免疫组织化学染色和原位杂交方法对41例儿童髓母细胞瘤（其中复发性肿瘤11例）和20例正常人脑组织中Bcl-XL蛋白和bcl-XL mRNA的表达水平进行检测，并与临床资料和预后进行比较。结果 儿童髓母细胞瘤组织免疫组织化学染色90．2％（37／41）表达Bcl-XL蛋白；原位杂交显示95．1％（39／41）表达bcl-XL mRNA。两者呈正相关。正常人脑组织Bcl-XL表达水平和强度显著低于髓母细胞瘤（P〈0．01）。复发性肿瘤Bel-XL表达水平和强度显著高于非复发肿瘤（P〈0．01），且98％复发性肿瘤在首次治疗时均有肿瘤在第四脑室底浸润。结论 凋亡抑制基因bcl-XL在儿童髓母细胞瘤的恶性进展中发挥重要作用。bcl-XL表达水平和强度和首次发病时肿瘤在第四脑室底的浸润是儿童髓母细胞瘤的重要预后因素。     

Prognostic factors and treatment outcome in childhood Hodgkin disease

BACKGROUND: The goals of this study included: (1) Identification of factors prognostic for event-free survival (EFS) and overall survival (OS), and (2) Definition of risk groups for risk adapted therapy in children with Hodgkin disease (HD). PROCEDURE: From 1991 to 2003, 69 children with newly diagnosed, untreated biopsy-proven stage I-IV HD were treated with chemotherapy (CT) and low-dose involved field radiotherapy (LD-IFRT). The relationship of pretreatment factors to EFS and OS was analyzed by univariate and multivariate analysis. RESULTS: The 5-year EFS and OS for all patients were 90.77% and 96.22%, respectively with a median follow-up of 73 months (3-137 months). Male to female ratio was 3:1 and 21 children (32.3%) were less than 7 years of age. Mixed cellularity was the predominant histologic subtype (38.5%). Factors associated with inferior EFS by univariate analysis were extranodal disease, hemoglobin level <11 g/dl, number of involved lymph node regions and stage. By multivariate analysis only stage IV disease was significant. CONCLUSION: Our study confirms that excellent results are achievable with combined modality therapy in childhood HD. In order to use risk-adapted therapy in children with HD, clinical prognostic factors should be validated with large, multicentered prospective clinical studies.     

Evaluation of prognostic factors in a tumor volume-adapted treatment strategy for localized Ewing sarcoma of bone: the CESS 86 experience. Cooperative Ewing Sarcoma Study

BACKGROUND: The Cooperative Ewing Sarcoma Study (CESS 86), conducted by the German Society of Pediatric Oncology and Hematology (GPOH), was planned on the basis of the results of the preceding CESS 81 study. The prognostic significance of tumor volume in localized Ewing sarcoma of bone was well documented in the CESS 81 trial. As a consequence, the treatment intensity was adapted to volume in the follow-up CESS 86 trial: the four-drug combination used in CESS 81 was amended for patients with large tumor volume (> or = 100 ml), where ifosfamide was substituted for cyclophosphamide. PROCEDURE: From January 1986 to June 1991, 177 protocol patients with localized Ewing sarcoma of bone were registered in CESS 86. The prognostic implication of tumor volume and several covariates was evaluated using Kaplan-Meier life table analysis and Cox's proportional hazard model. RESULTS: The estimated 5- and 8-year event-free survival (EFS) rates were both 59%. Age, gender, tumor site, and a tumor volume of 100 ml did not distinguish groups of patients with different prognosis. However, the prognosis of patients with tumors >200 ml (8-year EFS rate: 42%) was significantly inferior compared to patients with tumors both of 100 to 200 ml (70%) and of <100 ml (63%). In contrast to CESS 81, the histological response to chemotherapy was no longer a significant prognostic factor (EFS: 64% for good and 50% for poor responders, respectively). CONCLUSIONS: Despite risk-adapted treatment intensity, tumor volume retained its prognostic significance; the cut point, however, was shifted toward larger volumes.     

组蛋白去乙酰化酶7基因表达与儿童急性淋巴细胞白血病临床生物学特征及预后的相关性

目的：探讨组蛋白去乙酰化酶7（HDAC7）基因在急性淋巴细胞白血病（ALL）患儿骨髓标本中的表达及其与临床特征、早期治疗反应和长期预后的关系。 方法：纳入2010年1月1日至2012年12月30日首都医科大学附属北京儿童医院（我院）血液肿瘤中心收治的ALL患儿,排除入院前曾不规则使用激素和初诊骨髓样本中幼稚细胞比例＜70%的患儿。采用实时定量PCR（RT-qPCR）检测ALL患儿初诊骨髓标本中的HDAC7基因表达。以3例ALL患儿停药3年以上处于缓解状态的骨髓样本中的HDAC7表达水平作为对照,将ALL患儿分为高表达（≥1.0）组和低表达（＜1.0）组,分析组间临床生物学特征、微小残留病和无事件生存率（EFS）。 结果：共纳入236例ALL患儿,初诊骨髓标本中HDAC7基因表达水平为0.046~10.581,高表达组124例,低表达组112例。单因素分析显示HDAC7基因表达与初诊外周血WBC＜50×109·L-1 、免疫表型和融合基因类型相关,P均＜0.05;多因素分析显示WBC＜50×109·L-1 和融合基因类型是HDAC7表达的影响因素,P均＜0.05。中危ALL患儿中,HDAC7高表达组的预后好于低表达组,5年EFS分别为（91.0±3.5）%和（75.5±4.9）%,P=0.013,HDAC7表达是中危患儿的独立预后因素（P=0.013）,OR值和95%置信区间为1.26（1.31~9.51）。 结论：ALL患儿骨髓中HDAC7基因表达水平与临床和生物学特征相关;HDAC7基因低表达是中危患儿预后不良的独立危险因素。     

10岁以上儿童青少年急性淋巴细胞白血病的临床特点及预后分析

目的研究10岁以上儿童青少年初诊急性淋巴细胞白血病(ALL)患儿的临床特点及预后。方法对86例10岁以上ALL患儿(B-ALL 62例,T-ALL 24例)的临床特点、治疗疗效及预后因素进行回顾性分析,采用Kaplan-Meier分析评估患儿无事件生存率(EFS)和总生存率(OS),COX回归模型评估EFS、OS的影响因素。结果 86例患儿中,中危组和高危组患儿分别为62例和24例。首诊表现为肝肿大的53例(62%),脾肿大50例(58%),淋巴结肿大46例(54%)。初诊时外周血WBC≥50×109/L者29例(34%)。78例进行了染色体核型分析,21例(27%)染色体数目异常,其中15例为超二倍体(19%)、4例(5%)为亚二倍体,2例(3%)为假二倍体;11例(14%)染色体结构异常,其中Ph染色体阳性1例,t(1;19)1例。TEL-AML1融合基因3例(4%),E2A-PBX1融合基因3例(4%),BCR-ABL融合基因6例(7%),SIL-TAL1融合基因4例(5%)。1疗程完全缓解率为99%(85/86)。5年EFS率、OS率分别为64%±6%和75%±5%。中危组的5年EFS率、OS率均高于高危组(P0.05)。B-ALL患儿5年EFS率优于T-ALL组(P0.05)。COX多因素回归分析显示,初诊时白细胞计数、诱导缓解末微小残留病是EFS、OS的独立影响因素。结论 10岁以上ALL患儿具有不利预后的临床特征,初诊时白细胞计数、诱导缓解末MRD是决定远期疗效的重要因素。     

A multi-institutional retrospective study of intracranial ependymoma in children: identification of risk factors.

PURPOSE: The goal of this multi-institutional retrospective study of children with intracranial ependymoma was to identify risk factors associated with unfavorable overall survival (OS) and event-free survival (EFS). PATIENTS AND METHODS: Clinical data, including demographics, tumor location, spread, histology, details of surgery, radiation treatment, and chemotherapy were collected. Clinical characteristics and univariate and multivariate analyses of risk factors for OS and EFS are presented. RESULTS: Eleven U.S. institutions contributed 83 patients treated from 1987 to 1991. The OS at 5 and 7 years was 57% and 46%, and EFS at 5 and 7 years was 42% and 33%. Patients 3 years of age or younger differed from the older group by more common infratentorial location, less common gross total resection (GTR), and postoperative use of chemotherapy rather than radiation. This younger group of patients had worse survival (P < 0.01) than the older age group. Other than young age, less than GTR and World Health Organization (WHO) II grade 3 histology were significant adverse risk factors for EFS in univariate and multivariate analyses. OS shared the same adverse risk factors except for histology in multivariate analysis, which was only of borderline significance (P = 0.05). Progression at the original tumor location, present in 89% of patients, was the major pattern of tumor recurrence. Adjuvant chemotherapy in the group older than 3 years or craniospinal radiation in M0 patients did not significantly change EFS. CONCLUSIONS: Adverse outcome in childhood intracranial ependymoma is related to age (3 years or younger), histology (grade 3), and degree of surgical resection (less than GTR). New approaches, particularly for local tumor control in younger patients, are needed to improve survival.     

Biological stability of RNA isolated from RNAlater-treated brain tumor and neuroblastoma xenografts

BACKGROUND: Advances in molecular biological research have led to identification of prognostic factors such as Trk mRNA expression in primitive neuroectodermal tumors of the CNS and neuroblastoma. To study prospectively the importance of these prognostic factors in large groups of homogeneously treated patients, tumor specimens of good quality must be acquired, preserved, and stored at multiple institutions. Immediate freezing of tumor biopsy samples in liquid nitrogen and storage at -70 degrees C are the most commonly used method of tissue preservation for future RNA analysis. PROCEDURE: To evaluate alternative methods of preserving tissue samples for subsequent RNA analysis, we tested a new RNA stabilization solution. Using tumor tissue of two CNS tumor and one neuroblastoma human xenografts, we compared total RNA isolated from tumor tissue stored for 7 days at room temperature in stabilization solution to that of snap-frozen tissue. The quality of the RNA was studied by spectrophotometry, gel electrophoresis, RT-PCR, and gene expression profiling. RESULTS: No major differences were observed in the quality of RNA isolated from tumor samples stored at room temperature in the RNA stabilization solution compared to snap-frozen tumor samples stored at -70 degrees C. CONCLUSIONS: High-quality RNA can be prepared from tumor tissue stored at room temperature. Whenever snap freezing is not feasible, pieces of tumor tissue can be treated with RNAlater for subsequent RNA analysis. Short-term storage and shipment of well-preserved tumor tissue are clearly feasible for all institutions, thereby facilitating large multiinstitutional studies of biological prognostic factors.     

Metastatic Group 3 Medulloblastoma in a Patient With Tuberous Sclerosis Complex: Case Description and Molecular Characterization of the Tumor

Medulloblastoma is the most common pediatric brain tumor. We describe a child with tuberous sclerosis complex that developed a Group 3, myc overexpressed, metastatic medulloblastoma (MB). Considering the high risk of treatment‐induced malignancies, a tailored therapy, omitting radiation, was given. Based on the evidence of mammalian target of rapamycin mTORC, mTOR Complex; RAS, Rat sarcoma; RAF, rapidly accelerated fibrosarcoma (mTOR) pathway activation in the tumor, targeted therapy was applied resulting in complete remission of disease. Although the PI3K/AKT/mTOR signaling pathway plays a role in MB, we did not find TSC1/TSC2 (TSC, tuberous sclerosis complex) mutation in our patient. We speculate that a different pathway resulting in mTOR activation is the basis of both TSC and MB in this child; H&E, haematoxilin and eosin; Gd, gadolinium.     

Metastatic Ewing sarcoma/PNET of bone at diagnosis: prognostic factors--a report from Saudi Arabia

BACKGROUND: To evaluate outcome and prognostic factors in Saudi Arabian patients with metastatic Ewing sarcoma and PNET of bone (PMES) at diagnosis. PROCEDURE: Ninety-nine of 304 (33%) consecutive patients with Ewing sarcoma and PNET of bone registered at our centre from 1975 to 1998, had metastatic disease at registration and 93 were available for analysis. The maximum x-axis diameter of the primary tumor was used as the measure of primary tumor size. Usually a trial of systemic treatment was undertaken before a decision was made on local treatment. Standard chemotherapy regimens were used in all treated patients. Forty-one (44%) patients did not receive radical local treatment due to an inadequate response to chemotherapy, or a decision not to undertake more than palliative treatment. Radical treatment of the primary site was radiation alone 41 (79%), resection alone 7 (13%), and resection and radiation 4 (8%). RESULTS: The 5-year survival rates were 9% for all 93 evaluable patients, 16% for 52 patients who received chemotherapy and radical local treatment, 0% for 41 patients who received lesser treatment, 19% for 43 patients with lung metastases alone, and 0% (P = 0.002) for 50 patients with other sites involved. For 60 patients with imaging data, 5-year survivals were 34 and 0% when the maximum transverse diameter of the primary tumor was < 10 cm (N = 20) and > or = 10 cm (N = 40), respectively. CONCLUSIONS: Small primary tumor size and the presence of lung metastases alone were the only significant favorable prognostic factors. Earlier diagnosis will be the basis for better results.     

Metastatic sites in stage IV and IVS neuroblastoma correlate with age, tumor biology, and survival.

PURPOSE: The goal of this study was to determine the incidence of metastatic sites in neuroblastoma and the extent to which metastatic sites correlate with age, tumor biology, and survival. PATIENTS AND METHODS: All 648 patients with stage IV and IVS neuroblastoma registered on Children's Cancer Group protocols 3881 and 3891 were analyzed. Metastatic site data were provided by treating institutions and reviewed in patients with central nervous system (CNS), intracranial, lung, or "other" metastases. RESULTS: The incidence of metastatic sites at diagnosis was 70.5% in bone marrow, 55.7% in bone, 30.9% in lymph nodes, 29.6% in liver, 18.2% in intracranial and orbital sites, 3.3% in lung, and 0.6% in CNS. Event-free survival (EFS) was decreased in patients with bone, bone marrow, CNS, intracranial/ orbital, lung, and pleural metastases, and improved in those with liver and skin metastases. In infants, MYCN amplification and unfavorable Shimada histopathology correlated with increased frequencies of bone and intracranial or orbital metastases. In older patients, MYCN amplification correlated with increased frequencies of intracranial or orbital, liver, and lung metastases. Multivariate analysis revealed that metastatic site is not an independent prognostic factor. CONCLUSIONS: Metastatic pattern in neuroblastoma differs with age and correlates with tumor biological features and EFS. These correlations could reflect changes in host or tumor biological features with age resulting in differences in metastatic capacity or tumor affinity for specific sites.     

Natural history and biology of stage A neuroblastoma: a Pediatric Oncology Group Study

PURPOSE: To prospectively analyze the outcome of patients with Stage A neuroblastoma (NB) treated with surgery alone, especially with regard to the prognostic significance of age, tumor site, MYCN copy number, tumor cell ploidy, and histology. PATIENTS AND METHODS: The clinical course of 329 patients with Stage A disease registered on the POG NB Biology Study #9047 between February, 1990 and October, 1997 were evaluated. Age, tumor site, MYCN copy number, tumor cell ploidy, and histology were analyzed for their impact on event-free survival (EFS) and survival (S). RESULTS: The 5-year estimated EFS and S rates for the 329 patients were 91% (+/-3%) and 96% (+/-2%), respectively. The EFS rate was similar for infants younger than 12 months and children age 12 months or older, but age older than 12 months was predictive of lower S rates (P = 0.044). Patients with adrenal, abdominal non-adrenal, thoracic, and cervical tumors had similar S rates. The majority of patients had tumors with favorable biologic features, and only 3% had MYCN amplification. For infants with diploid tumors, the EFS rate was 82% (+/-16%), but effective therapy yielded an S rate of 100%. Rate of S was 80% (+/-26%) and 64% (+/-27%) for patients with unfavorable tumor histology and MYCN-amplified tumors, respectively. CONCLUSION: The outcome for patients with Stage A NB treated with surgery alone is excellent. Although EFS and S rates were significantly worse for patients with MYCN-amplified tumors, a subset achieved long-term remission after surgery alone. For patients with Stage A and MYCN amplification, additional factors are needed to distinguish the patients who will achieve long-term remission with surgery alone from those who will develop recurrent disease.     

INSS 4期神经母细胞瘤患儿3年无事件生存率的相关因素分析

目的 探讨影响INSS 4期神经母细胞瘤患儿3年无事件生存率(event-free survival,EFS)的相关因素.方法 回顾性分析2014年4月至2020年4月经上海市儿童医院确诊和完善评估的68例INSS 4期神经母细胞瘤患儿临床资料.收集患儿年龄、性别、神经元烯醇化酶(neuron specific eno...     

Medulloblastoma metastatic to the suprasellar region at diagnosis: a report of six cases with clinicopathologic correlation

The presence of metastatic disease in patients newly diagnosed with medulloblastoma remains one of the most important prognostic factors that determines event-free survival. In the present study, anatomic distribution and the signal characteristics and enhancement patterns of subtle anterior third ventricular recess metastases were compared with those of the original tumor; medical records were reviewed for clinical presentation, surgical stage, treatment and long-term outcomes. All foci were clinically occult; 5 out of 6 had negative cerebrospinal fluid cytology, and in 4 out of 6, the only evidence of metastatic disease was documented suprasellar disease that resolved or significantly improved following irradiation and chemotherapy. Histologically, 3 of the 6 patients had tumors with large cell/anaplastic features, a significant increase compared to the expected incidence of 4-8.8%. Patients with tumors that show large cell/anaplastic features may be at higher risk for early metastatic involvement of this unusual site.     

Risk stratification in medulloblastoma: screening for molecular markers

BACKGROUND: The present study evaluates molecular markers for patients at risk of poor or no response to medulloblastoma. The aim of the study is to optimize therapy stratification. PATIENTS AND METHODS: 69 snap-frozen medulloblastoma samples were examined. C-MYC amplification was determined by fluorescence in situ hybridisation (FISH) analysis. Methylation specific PCR revealed the level of promoter methylation status of the tumor suppressor genes CASP8 (Caspase 8), TIMP3, CDH1 (E-Cadherin), CDKN2A (p16) and MGMT. Expression of GAS7 was evaluated by RT-PCR. RESULTS: C-MYC amplification: 4/69 tumors displayed high level amplification; 53/69 tumors displayed low level (< 4 copies) or no amplification; 12/69 samples were not predictive. In patients with c-MYC amplification a tendency towards unfavorable outcome was observed (p = 0.3). Promoter methylation status: CASP8: in 36/40 tumors methylated; TIMP3: 1/38 methylated; MGMT 0/44 methylated; CDKN2A: 1/46 methylated; E-cadherin 3/36 methylated; no association between methylation status and clinical outcome. GAS7: Detection of specific RNA in 20/29 medulloblastoma samples. CONCLUSION: No significant association between amplification of c-MYC and clinical outcome was observed. Promoter methylation of tumor suppressor genes is non-randomly distributed with a high level of methylation of CASP8. Recent studies show that silencing of CASP8 by methylation could be overcome by interferon gamma providing a possible therapeutic mechanism. GAS7 was shown to be a marker of mature neuronal cells with potential antitumorigenic capacity in neuronal tumors. In medulloblastoma 20/29 of the tumors examined express GAS7. Therefore a tumor suppressing function of GAS7 is improbable.