胶质瘤MGMT启动子甲基化定量检测的MS-HRM方法建立及评估

目的建立甲基化特异高分辨率溶解曲线(Methylation sensitive high resolution melting curve,MS-HRM)定量检测胶质瘤MGMT基因启动子甲基化的方法,用于指导胶质瘤患者术后化疗及预后判断。方法从标本库随机选取胶质瘤组织37例,提取DNA进行甲基化修饰,应用MS-HRM方法和甲基化特异性PCR(methylation specific PCR,MSP)进行MGMT基因启动子区甲基化检测。结果 MSP方法检测显示部分甲基化标本29例(78.4%),较甲基化(13.5%)和未甲基化(8.1%)差异显著。MS-HRM发现MGMT基因启动子甲基化水平在10%~25%和25%~50%的标本分别有14例(37.8%)和17例(49.5%)。结论成功建立MS-HRM检测胶质瘤MGMT启动子甲基化的方法,该方法特异性高、灵敏度强和可重复性,有望应用于临床胶质瘤MGMT启动子甲基化高通量定量检测,以指导个体化治疗。     

Meningeal hemangiopericytomas: A clinicopathological study with emphasis on MGMT (O6‐methylguanine‐DNA methyltransferase) promoter methylation status

Meningeal hemangiopericytomas (HPCs) are aggressive dural‐based tumors, for which no prognostic or predictive marker has been identified. Gross total resection is treatment of choice, but not easily achieved; hence, alkylating agents like temozolomide (TMZ) are now being tried. O⁶‐methylguanine‐DNA methyltransferase (MGMT) promoter methylation has proven prognostic and predictive value in glioblastomas. This study evaluates MGMT promoter methylation in meningeal HPCs to determine its role in HPC oncogenesis and its association with patient outcome. Meningeal HPCs diagnosed between 2002 and 2011 were retrieved and clinicopathological features reviewed. MGMT promoter methylation status was assessed by methylation‐specific polymerase chain reaction (MSP) and immunohistochemistry (IHC) for MGMT protein. HPCs accounted for 1.1% of all CNS tumors. Forty cases were analyzed; the majority were adults (mean age = 41.4 years). Seventy percent were primary and 30% were recurrent tumors; 60% were grade II and 40% were grade III. MGMT promoter methylation was identified in 45% of cases, including Grade II (54.2%) and Grade III (31.3%) (P = 0.203). Promoter methylation was significantly (P = 0.035) more frequent in primary (57.1%) than in recurrent (16.7%) tumors. No correlation was noted between MGMT promoter methylation by MSP and MGMT protein expression by IHC, or with progression‐free survival. Thus, a significant proportion of HPCs demonstrate MGMT promoter methylation, suggesting possible susceptibility to TMZ. As promoter methylation is more frequent in primary tumors, TMZ may serve as a therapeutic option in residual primary tumors. Epigenetic inactivation of MGMT in HPCs necessitates the assessment of prognostic and predictive value of MGMT promoter methylation in HPCs in larger clinical trials.     

O6 -methylguanine DNA methyltransferase gene promoter methylation in high-grade gliomas: a review of current status

Assessment of promoter methylation of the O 6 -methylguanine DNA methyltransferase (MGMT) gene has recently gained importance in molecular profiling of high-grade gliomas. It has emerged not only as an important prognostic marker but also as a predictive marker for response to temozolomide in patients with newly diagnosed glioblastoma. Further, recent studies indicate that MGMT promoter methylation has strong prognostic relevance even in anaplastic (grade III) gliomas, irrespective of therapy (chemotherapy or radiotherapy). This article provides an overview of its use as a predictive and prognostic biomarker, as well as the methods employed for its assessment and use in therapeutic decision making.     

Expression and prognostic value of mRNAs in lower grade glioma with MGMT promoter methylated

Due to the varied overall survival (OS), limited studies focus on the factors that affect the prognosis for lower grade glioma patients (LGGs) with MGMT promoter methylated. A total of 579 samples (TCGA LGGs 456; CGGA LGGs 123) were included to identify potential genes for LGGs with MGMT promoter methylated. All bioinformatics analyses were conducted using SPSS software and GraphPad Prism 6. Based on COX regression analysis, we established a four-gene signature (ALDOC, APOBEC3C, ANXA1 and ARPP21) and divided LGGs into two groups based on median risk score. The OS of LGGs in high risk group was shorter than low risk group (P < 0.0001). Furthermore, the OS in high risk group were shorter than low risk group in Grade II and III, respectively (P = 0.0003; P = 0.0104). It showed that the signature was an independent prognosis factor on multivariate Cox regression analysis (P = 0.033). Patients in high group tended to displayed high grade (GIII), IDH1 wild type and mesenchymal subtype preference. Four-gene signature was discovered for LGGs with MGMT promoter methylated. Our findings suggested that the four genes could serve as prognostic biomarkers.     

Genetic alterations and biomarkers for glioma

Over the last decade, significant progress has been made in understanding glioma on a molecular level. However, optimal incorporation of molecular markers into clinical care is still controversial. Here, the potential utility of genetic alterations found in gliomas in refining histological diagnosis, prognosis, and predictive values for treatment selection is reviewed. Among all, O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, 1p/19q codeletion, and isocitrate dehydrogenase 1 (IDH1) mutations have been identified as favorable prognostic markers. MGMT promoter methylation is the only potential predictive marker for response to temozolomide and alkylating agents in glioblastoma (GBM), but it is not of assistance in diagnostics. IDH1 mutations and 1p/19q codeletion are also useful for classifying and grading gliomas, since 1p/19q codeletion is tightly linked to oligodendroglial lineage, and IDH1 mutations are restricted to grade II/III gliomas, while not to primary GBM. BRAF fusion is a good marker for pilocytic astrocytoma. High-throughput profiling techniques for gene expression and epigenetic modification have provided new subtype classifications for GBM as well as lower grade gliomas, which may be of prognostic and predictive values. Efforts to identify molecular markers that predict the benefits of novel molecularly targeted treatments will enable better patient stratification and individualization of treatment.     

lncRNA RGMB-AS1在脑胶质瘤预后评估中的价值

目的 探讨长链非编码RNA（lncRNA）RGMB-AS1在脑胶质瘤病人预后评估中的作用。方法 选取2014年9月~2017年6月经术后病理检查证实的脑胶质瘤140例（低级别64例,高级别76例）,另选取颅脑损伤内减压术中切取正常脑组织25例为对照。实时荧光定量PCR法检测lncRNA RGMB-AS1的表达水平,以RGMB-AS1表达量的中位数为截断值,分为高表达组和低表达组。用Kaplan-Meier法比较总体生存期（OS）和无进展生存期（PFS）,用Cox比例回归风险模型分析影响胶质瘤病人预后的因素。结果 140例胶质瘤中,lncRNA RGMB-AS1高表达70例,低表达70例。胶质瘤组织lncRNA RGMB-AS1的相对表达量明显高于对照组（P<0.05）。多因素Cox比例回归风险模型分析结果显示年龄≥50岁、术前KPS评分<80分、WHO分级Ⅲ~Ⅳ级、lncRNA RGMB-AS1高表达是胶质瘤病人PFS和OS的独立影响因素（P<0.05）。lncRNA RGMB-AS1高表达胶质瘤病人PFS和OS较低表达病人均明显缩短（P<0.05）。无论是高级别胶质瘤,还是低级别胶质瘤,lncRNA RGMB-AS1高表达病人PFS和OS较低表达病人均明显缩短（P<0.05）。结论 lncRNA RGMB-AS1表达水平与脑胶质瘤病例级别呈正相关,lncRNA RGMB-AS1高表达脑胶质瘤病人生存期较低表达病人明显缩短。这提示lncRNA RGMB-AS1表达水平可作为脑胶质瘤病人预后评估指标。     

CUX-1在胶质瘤中的表达及其对临床病理和预后的意义

目的探究转录因子CUX-1在胶质瘤中的表达及其对临床病理和患者预后的意义。方法在TCGA数据库中对CUX-1在肿瘤和正常脑组织中的差异性表达及其对患者总体生存期的影响进行生物信息学分析。运用蛋白印迹、免疫组化实验检测CUX-1在不同级别胶质瘤中的表达,同时分析其与临床病理指标及患者预后的关系。结果生信分析结果表明CUX-1在胶质瘤中表达显著上调,且CUX-1高表达明显缩短患者生存期。蛋白印迹、免疫组化结果证明CUX-1随肿瘤WHO分级的升高而上调(P 0. 05),且CUX-1与胶质瘤WHO分级及增殖指标Ki67、P53mut显著相关(P 0. 05)。Kaplan-Meir分析示CUX-1低表达患者生存期显著长于高表达者(P 0. 01)。结论 CUX-1在胶质瘤中显著上调,且与肿瘤增殖密切相关,同时CUX-1高表达提示患者预后较差。综上,CUX-1有望作为胶质瘤预后的分子标志物和治疗的潜在靶点。     

Immunohistochemical profiles of IDH1, MGMT and P53: Practical significance for prognostication of patients with diffuse gliomas

Genetic and epigenetic status, including mutations of isocitrate dehydrogenase (IDH) and TP53 and methylation of O⁶‐methylguanine‐DNA methyltransferase (MGMT), are associated with the development of various types of glioma and are useful for prognostication. Here, using routinely available histology sections from 312 patients with diffuse gliomas, we performed immunohistochemistry using antibodies specific for IDH1 mutation, MGMT methylation status, and aberrant p53 expression to evaluate the possible prognostic significance of these features. With regard to overall survival (OS), univariate analysis indicated that an IDH1‐positive profile in patients with glioblastoma (GBM), anaplastic astrocytoma (AA), anaplastic oligoastrocytoma and oligodendroglioma, or a MGMT‐negative profile in patients with GBM and AA were significantly associated with a favorable outcome. Multivariate analysis revealed that both profiles were independent factors influencing prognosis. The OS of patients with IDH1‐positive/MGMT‐negative profiles was significantly longer than that of patients with negative/negative and negative/positive profiles. A p53 profile was not an independent prognostic factor. However, for GBM/AA patients with IDH1‐negative/MGMT‐negative profiles, p53 overexpression was significantly associated with an unfavorable outcome. Thus, the immunohistochemical profiles of IDH1 and MGMT are of considerable significance in gliomas, and a combination of IDH1, MGMT and p53 profiles may be useful for prognostication of GBM/AA.     

复发胶质瘤的病理学特征及其预后分析

目的探讨复发胶质瘤的病理学特征及其与患者预后的关系。方法回顾性分析2002年8月到2016年12月中山大学肿瘤防治中心神经外科收治的54例复发胶质瘤患者的临床资料。所有患者均再次行肿瘤切除术治疗,术后行病理学检测,包括肿瘤的世界卫生组织(WHO)分级、Ki-67指数、O6-甲基鸟嘌呤-DNA-甲基转移酶(MGMT)表达状态、异柠檬酸脱氢酶1(IDH1)状态;同时根据组织坏死程度、是否存在肿瘤细胞及肿瘤细胞活性情况进行病理学分型。采用Kaplan-Meier法分析患者的总生存期(OS)。进一步采用单因素和多因素Cox回归分析法判断影响复发胶质瘤患者OS的临床因素。结果54例患者的病理学检测结果,(1)WHO分级:Ⅱ级6例(11.1%)、Ⅲ级14例(25.9%)、Ⅳ级30例(55.6%),另4例(7.4%)未见肿瘤细胞。与初次手术比较,32例患者(59.2%)的WHO分级无变化,7例(13.0%)降低,15例(27.8%)升高。(2)Ki-67指数:共32例两次均行相关检测,其中15例的Ki-67指数降低、14例升高,另3例无改变。(3)IDH1状态:共29例两次均行相关检测,其中9例为突变型,20例为野生型;两次检测均未发生变化。(4)MGMT表达状态:共8例两次均行相关检测,6例无变化,其中3例表达阳性、3例表达阴性;另2例结果改变,均为初次表达阳性,二次表达阴性。(5)病理学分型:4例为坏死型,20例为混合型,30例为活性型。54例患者的随访时间为(16.1±3.2)个月(1.3~160.3)个月。Kaplan-Meier法分析结果显示,54例患者的中位OS(范围)为14.4个月(9.2~19.5个月)。多因素Cox回归分析结果显示,复发肿瘤WHO分级高(HR=2.80,95%CI:1.42~5.53,P<0.01)和术后未行放疗(HR=4.05,95%CI:1.41~11.64,P=0.01)是影响复发胶质瘤患者OS的独立危险因素。结论初步提示复发胶质瘤再次手术后的组织病理学会发生变化;再次手术后WHO病理分级低和术后行放疗是复发胶质瘤患者预后较好的临床因素。     

岛叶胶质母细胞瘤的临床特征和预后影响因素分析

目的探讨岛叶胶质母细胞瘤的临床特征和影响预后的临床因素。方法回顾性分析2006年7月至2013年6月中国脑胶质瘤基因组图谱计划(CGGA)数据库中44例岛叶胶质母细胞瘤患者的临床资料。所有患者均行肿瘤切除术,术后27例接受放、化疗联合治疗,另17例未接受。总结所有患者的临床特征,包括是否存在癫痫发作史、异柠檬酸脱氢酶1(IDH1)突变、O6-甲基鸟嘌呤-DNA-甲基转移酶(MGMT)甲基化、肿瘤强化情况及临床分型等。采用Kaplan-Meier法分析所有患者的无进展生存期(PFS)和总生存期(OS)。进一步采用多因素Cox回归分析方法探讨影响患者PFS和OS的临床因素。结果44例患者中,33例(75.0%)存在癫痫发作史,11例(25.0%)为IDH1突变型,19例(43.2%)存在MGMT甲基化,42例(95.5%)存在肿瘤强化。Yasargil分型:2例为3A型,27例为3B型,15例为5A/B型;Saito分型:2例局限于岛叶皮质内,9例经前环岛沟向额叶侵袭,16例经下环岛沟向颞叶侵袭,17例经2个以上环岛沟向多方侵袭;Moshe分型:35例对豆纹动脉形成包绕或侵袭,余9例未侵袭;壳核分型:38例对壳核不同程度的侵袭,余6例未累及。Kaplan-Meier法分析结果显示,所有患者的中位PFS为278 d,中位OS为435 d。多因素Cox回归分析结果显示,肿瘤体积小于中位数(HR=0.390,95%CI:0.189~0.802,P=0.011)、IDH1突变(HR=0.391,95%CI:0.175~0.876,P=0.023)及术后放、化疗联合治疗(HR=0.346,95%CI:0.162~0.738,P=0.006)是影响患者PFS的独立保护因素;而MGMT甲基化(HR=0.371,95%CI:0.181~0.758,P=0.007)、肿瘤切除程度≥90%(HR=0.412,95%CI:0.194~0.875,P=0.021)及术后接受放、化疗联合治疗(HR=0.347,95%CI:0.170~0.708,P=0.004)是影响患者OS的独立保护因素。结论岛叶胶质母细胞瘤对脑深部重要的神经血管结构具有很强的侵袭性,手术切除难度大,预后差;最大程度切除肿瘤并规范放、化疗可改善患者的预后。     

Gliosarcoma in septuagenarians and octogenarians: What is the impact of adjuvant chemoradiation?

The objective of our study is to determine the impact of adjuvant chemoradiation on overall survival (OS) for gliosarcoma in septuagenarians and octogenarians. Data were extracted from the National Cancer Data Base (NCDB). Chi-square test, Kaplan-Meier method, and Cox regression models were employed in SPSS 23.0 (Armonk, NY: IBM Corp.) for data analyses. 210 patients with gliosarcoma who underwent resection were identified. 168 (80.0%) patients received adjuvant chemoradiation, and 42 (20.0%) received adjuvant RT alone. Patients were more likely to receive adjuvant chemoradiation if they were male vs. female (85.3% vs. 71.6%, p = 0.016). There was no significant difference in receipt of adjuvant therapy by year of diagnosis, age at diagnosis, race, Charlson/Deyo Score, treatment facility type, tumor size, or extent of surgery. Those who received adjuvant chemoradiation had significantly better one-year OS than those who received adjuvant radiation alone (35.3% vs. 16.2%, p < 0.001). On subset analysis, this significant one-year OS benefit was observed in septuagenarians, those with Charlson/Deyo Score of 0, and in those with tumor size ≤5 cm. On multivariate analysis, receipt of adjuvant chemoradiation and greater extent of resection were independent prognostic factors for improved OS. Our data suggests that adjuvant chemoradiation is an independent prognostic factor for improved OS in elderly patients with gliosarcoma, and the results of our study can serve as estimated benchmarks for outcome in this growing and important patient population. Its benefit, however, may be limited to septuagenarians and those with lower comorbidity burden.     

Methylation status of the MGMT gene promoter fails to predict the clinical outcome of glioblastoma patients treated with ACNU plus cisplatin

We analyzed the methylation status of the O6‐methylguanine‐DNA methyltransferase (MGMT) promoter using a methylation‐specific polymerase chain reaction (MSP) in glioblastoma patients treated with 1‐(4‐amino‐2‐methyl‐5‐pyrimidinyl)methyl‐3‐(2‐chloroethyl)‐3‐nitrosourea (ACNU) plus cisplatin followed by radiation therapy. Forty‐eight patients with interpretable MSP results were included in this study. The MGMT promoter was methylated in 26 patients (54.2%, methylated group) and unmethylated in 22 patients (45.8%, unmethylated group). Comparison of clinical outcomes between the two groups revealed that the methylation status of the MGMT gene promoter was not a prognostic factor for overall survival (P = 0.516) or a predictive factor for radiological response to ACNU plus cisplatin treatment (P = 0.529). The most noteworthy explanation for the result is that the synergistic antitumor effects of ACNU and cisplatin resulting from inactivation of MGMT by cisplatin in MGMT active tumors offset the drug resistance.     

When temozolomide alone fails: adding procarbazine in salvage therapy of glioma

BACKGROUND: Since temozolomide (TMZ) entry into routine practice in the first-line management of glial tumors, post-TMZ recurrences present a growing challenge. Without standard chemotherapy for TMZ failure, care in such palliative settings requires consideration not only of efficacy but of toxicity and convenience. METHODS: At our institution, a combination regimen has been used: oral alkylating agents procarbazine (PCB) (100-150 mg/m2/day) and TMZ (150-200 mg/m2/day) administered on days 1-5 of a 28-day cycle. This treatment has been initiated upon radiological and/or clinical disease progression, and continued until evidence of further progression or toxicity. We retrospectively reviewed our experence with this regimen. RESULTS: Since November 2004, 17 patients (median age 53) were treated for histologically confirmed glioma (glioblastoma multiforme (GBM), N = 12; Grade 3 glioma, N = 3; Grade 2 glioma, N = 2) after a median of 2 recurrences. TMZ was previously given either as adjuvant therapy (post-chemoradiotherapy maintenance in 8 of 13 cases) or as salvage monotherapy (4 cases). Of 16 evaluable cases, 14 (13 high grade tumors) showed O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation. Two patients achieved partial response and one had complete response by RECIST criteria. Disease progressed after a median of 4 cycles (range 1 to 11+), with an actuarial progression-free survival of 42% after 6 cycles. Grade 3/4 toxicity was rare, and no dose reductions were needed. One patient discontinued treatment due to procarbazine hypersensitivity. CONCLUSION: Combination PCB-TMZ is well-tolerated, with modest activity in TMZ-exposed glioma.     

BCL3基因表达:一个新的胶质瘤预后预测因子

目的研究B细胞淋巴瘤因子3(B-Cell CLL/Lymphoma 3,BCL3)基因表达与胶质瘤预后之间的关系。方法从公用数据库中国脑胶质瘤基因组图谱计划(Chinese Glioma Genome Atlas,CGGA)和癌症基因组图谱计划(The Cancer Genome Atlas,TCGA)中下载了包含BCL3基因表达和患者预后的胶质瘤数据集数据,采用Gene Spring GX 11.0软件进行归一化,使用Cox回归分析和Kaplan-Meier分析进行数据分析。结果在低级别胶质瘤(Low Grade Glioma,LGG)和胶质母细胞瘤(Glioblastoma,GBM)数据集中,BCL3基因的表达与胶质瘤患者的总生存期(Overall Survival,OS)和无病生存期(Disease-free Survival,DFS)均显著相关(P0.05),在Batch1和Bactch2两个数据集中,BCL3基因表达与胶质瘤患者的OS也均显著相关(P0.05)。以BCL3表达水平中位数为界,将各数据集分为BCL3高表达组和低表达组,分析发现BCL3高表达组的死亡风险均显著高于低表达组,而GBM数据集中BCL3高表达组的肿瘤复发风险显著高于低表达组。结论 BCL3基因表达与胶质瘤的预后显著相关,且BCL3基因的高表达预示着较差的预后。BCL3基因表达是一个新的胶质瘤预后预测因子。     

6-氧-甲基鸟嘌呤-DNA甲基转移酶和P53在人脑胶质瘤中的表达与病理级别和预后关系的研究

目的：探讨6-氧-甲基鸟嘌呤-DNA甲基转移酶（MGMT）和P53在脑胶质瘤中的表达及意义。方法：采用免疫组化法检测133例肿瘤组织中MGMT蛋白和P53蛋白的表达情况,分析MGMT和P53与胶质瘤临床病理特征、预后及两者之间的相互关系。结果：不同级别胶质瘤间MGMT阳性表达率差异无统计学意义（P=0.158）;MGMT阳性表达水平差异也无统计学意义（P=0.138）,但MGMT表达水平与患者生存时间密切相关（P=1.07×10-6）。不同级别胶质瘤间P53阳性表达率差异无统计学意义（P=0.306）,而表达水平则在胶质瘤不同级别间差异有显著统计学意义,且呈正相关关系（r=0.187,P=0.032）;P53表达水平与患者生存时间密切相关（P=2.08×10-14）;MGMT和P53间无相关性（P=0.065）。结论：MGMT蛋白表达与胶质瘤病理分级无明显关系,P53蛋白表达水平与胶质瘤病理分级有关,两者都与生存时间密切相关。     

非受体型蛋白酪氨酸磷酸酶12基因在脑胶质瘤中的表达及意义

目的基于中国脑胶质瘤基因组图谱计划(CGGA)和癌症基因组图谱计划(TCGA)数据库分析非受体型蛋白酪氨酸磷酸酶12基因(PTPN12)在脑胶质瘤中的表达和意义。方法回顾性分析CGGA数据库(325例)和TCGA数据库(636例)中脑胶质瘤患者的临床资料和RNA测序数据。分析不同世界卫生组织(WHO)肿瘤级别、四分型亚型、异柠檬酸脱氢酶(IDH)突变状态、O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)启动子甲基化状态的患者PTPN12表达量的差异。根据PTPN12的表达量将患者分为PTPN12高表达组和PTPN12低表达组,采用Kaplan-Meier法绘制生存曲线,比较两组患者的生存差异。采用单因素和多因素Cox回归分析法判断PTPN12对脑胶质瘤患者的预后作用。进一步通过基因本体(GO)功能富集分析及京都基因和基因组百科全书(KEGG)通路富集分析获得基因相关的功能以及有关的通路。结果两数据库中,PTPN12的表达量均随脑胶质瘤病理级别的升高而升高(均P<0.01);与IDH突变型比较,IDH野生型中PTPN12表达量升高(均P<0.01);MGMT启动子非甲基化者PTPN12表达量高于MGMT启动子甲基化者(均P<0.01);PTPN12在经典型、间质型、神经元型以及前神经元型中表达量的差异均具有统计学意义,间质型中表达量最高(均P<0.01)。两数据库中,PTPN12高表达者均比低表达者的生存期短(均P<0.01)。两个数据库中,多因素Cox回归分析结果均显示,PTPN12表达量为脑胶质瘤患者生存期的独立影响因素(CGGA数据库中,HR=1.433,95%CI:1.094~1.876,P=0.009;TCGA数据库中,HR=1.588,95%CI:1.018~2.477,P=0.042)。GO分析结果显示,PTPN12表达量正相关的基因更多地富集在增殖、凋亡、黏附、蛋白水解、免疫反应、血管生成、药物反应、缺氧反应、肿瘤细胞G2/M期的转化、肿瘤细胞G1/S期的转化等多个与脑胶质瘤恶性进展相关的功能上。KEGG分析结果显示,与PTPN12表达量呈正相关的基因更多地富集在肿瘤相关通路、PI3K-Akt通路、丝裂原活化蛋白激酶通路、肿瘤坏死因子通路、缺氧诱导因子1通路、p53通路、凋亡通路以及细胞周期通路上。结论不同WHO肿瘤级别的脑胶质瘤患者PTPN12表达量不同,PTPN12表达量可独立用于脑胶质瘤患者的预后判断,且与多个脑胶质瘤恶性进展相关的功能和通路有关。     

胶质母细胞瘤MGMT基因启动子甲基化、MGMT蛋白表达和预后相关性分析

目的探讨脑胶质母细胞瘤中O-6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)基因启动子甲基化状态和MGMT蛋白表达水平与临床预后的相关性。方法收集119例人脑胶质母细胞瘤石蜡包埋样本,提取基因组DNA并进行亚硫酸氢盐修饰,用MethyLight法检测MGMT基因启动子甲基化状态,用免疫组织化学染色法检测MGMT蛋白表达水平,对MGMT基因启动子甲基化状态和MGMT表达水平与患者预后行相关性分析。结果在119例胶质母细胞瘤样本中,有42例检测到MGMT基因启动子甲基化,甲基化发生率为35.3%(42/119例),MGMT基因启动子甲基化与无进展生存期(P=0.011)及总体生存期(P=0.036)延长相关。MGMT蛋白表达水平和临床预后无相关性(P0.05),与MGMT基因启动子甲基化状态之间也无相关性(P0.05)。结论 MGMT基因启动子甲基化与胶质母细胞瘤患者预后呈正相关,由免疫组化法测得的MGMT蛋白表达水平和预后及基因启动子甲基化之间无关联性,MGMT基因启动子甲基化状态可以作为评判预后的生物学指标之一。     

Prognostic significance of contrast-enhancing low-grade gliomas in adults and a review of the literature

Abstract

Objectives: Survival and tumor recurrence for patients with low-grade gliomas is heterogeneous, with reported survival and recurrence times varying by several months to years. The prognostic implications of a contrast-enhancing low-grade glioma remain less well understood.

Methods: We retrospectively reviewed all adult patients who underwent a craniotomy for a hemispheric low-grade glioma (WHO grade II) from 1996 to 2006 at a single institution. Multivariate proportional hazards regression analysis was used to identify independent associations with survival, recurrence and malignant degeneration. Furthermore, a review of the literature for all works on low-grade gliomas and contrast enhancement was conducted.

Results: One hundred eighty-nine patients (87 fibrillary astrocytomas, 89 oligodendrogliomas and 13 mixed gliomas) were available for analysis, with 64 (34%) and 125 (66%) contrast-enhancing and non-enhancing tumors, respectively. There were no significant differences in clinical and treatment-related variables between patients with and without contrast enhancement. After multivariate analysis, contrast enhancement was independently associated with decreased survival (p=0.006) and increased recurrence (p=0.04) and trended toward significance with malignant degeneration (p=0.15). Five-year overall survival, progression-free survival and malignancy-free survival rates for patients with enhancement versus patients without enhancement were 70 versus 85% (p=0.002), 32 versus 49% (p=0.008) and 74 versus 90% (p=0.002), respectively. The review of the literature identified 14 works that fit our criteria. The majority of these published works had design-related limitations including small population size as well as the inclusion of non-WHO grade II gliomas, pediatric patients and patient undergoing biopsy.

Discussion: This study may provide insights into risk stratifying patients with low-grade gliomas and most specifically those that contrast enhance.     

A pilot study of glioblastoma multiforme in elderly patients: Treatments,O-6-methylguanine-DNA methyltransferase (MGMT) methylation status and survival

Objectives

Elderly Glioblastoma multiforme (GBM) patients have a worse prognosis and receive variable treatments. MGMT gene promoter methylation is linked with improved survival in GBM. We examined treatments administered and survival including in relation to MGMT methylation status in elderly GBM patients.

Patients and methods

Patients ≥65 years with diagnosed GBM between 1/01/2007 and 30/04/2009 and undergoing either a biopsy, subtotal (STR) or gross total resection (GTR) were included. The collected information included MGMT status [methylated (ME) vs. unmethylated (UN)] and survival data. p < 0.05 was considered significant.

Results

59 patients were identified with median age at diagnosis being 72.68 years (65.72–85.04). Treatment included surgery (25 GTR, 8 STR, 26 biopsy), chemoradiation (22) and radiotherapy alone (20). Overall median overall survival (MOS) was 219 days. MOS with chemoradiation was 316 days vs. 143 days without it (p = 0.011). 47 patients had definite MGMT status (28 ME, 19 UN). In ME patients, 9/28 received temozolamide compared to 10/19 in UN category. Temozolamide administration in patients with definite MGMT status was based on WHO performance status (p = 0.007). MOS in UN group was 308 days vs. 167 days in ME group (p = 0.068). In a multivariate Cox model including use of temozolamide, WHO score and methylation status, only temozolamide use was significantly associated with a reduced risk for death (HR 0.443, 95% CI 0.200–0.982, p = 0.045).

Conclusions

In this small cohort of patients, chemoradiation in suitable elderly GBM patients seemed to afford a survival benefit. MGMT methylation was not associated with an improved survival with temozolamide being the only factor leading to a better survival. Temozolamide use should be considered irrespective of MGMT status in this population with future large prospective studies needed to elucidate this further.