胃癌组织中MLH1，MSH2，MSH6 和PMS2 表达及与临床病理特征和预后的相关性分析

目的 探讨胃癌组织中错配修复蛋白 MutL homologue 1（MLH1）,MutS homologue 2（MSH2）,MutS homologue 6（MSH6）和减数分裂后分离为 2（postmeiotic segregation increased 2 ,PMS2）的表达及与临床病理特征和预后的相关关系。方法 选取承德医学院附属医院病理科 2018年 11月～2021年 11月确诊的 474例胃癌组织为研究对象,采用免疫组织化学 SP法检测胃癌组织中 MLH1,MSH2,MSH6和 PMS2蛋白表达水平,根据此四种蛋白表达情况将胃癌组织分为高频微卫星不稳定（microsatellite instability-high, MSI-H）组和低频微卫星不稳定或微卫星稳定 (microsatellite instability - low/ microsatellite stability, MSI-L/MSS)组,比较两组的临床病理特点。采用 Kaplan-Meier 生存分析法比较两组患者的预后情况。结果 474例胃癌中,MSI-L/MSS型胃癌为 403例（85.02%）,MSI-H型胃癌共 71例（14.98%）。其中 4种错配修复蛋白 MLH1,MSH2,MSH6和 PMS2任一表达缺失共 42例,占 8.86% (42/474);两种及以上蛋白表达缺失共 29例,占 6.12%（29/474）;MLH1,MSH2和 PMS2同时表达缺失率 0.84%（4/474）;MLH1,MSH2, MSH6和 PMS2全部表达缺失率 0.21%(1/474)。MSI-H型胃癌患者淋巴结转移率和脉管侵犯率低于 MSI - L/MSS型胃癌,差异具有统计学意义（χ2=21.65,8.93,均 P＜ 0.05）。而两组患者在性别、年龄、 Borramn分型、Lauren分型、分化程度、浸润深度和远处转移等方面比较,差异均无统计学意义（χ2=0.03～2.79,均 P＞ 0.05）。MSI-H型与 MSI-L/MSS型胃癌患者相比,三年总生存率（overall survival,OS）为 87.52%和 62.68%,差异无统计学意义（χ2=3.64,P＞ 0.05）,三年无进展生存率（progression-free survival,PFS）为 75.00%和 57.84%,差异无统计学意义（χ2=3.21,P＞ 0.05）。结论 与 MSI-L/MSS型胃癌相比, MSI-H型胃癌患者淋巴结的转移率低和脉管的侵犯率低,三年 OS和 PFS偏高,提示 MSI-H型胃癌患者有较好的预后。     

程序性死亡配体-1表达与微卫星不稳定性胃癌患者预后的关系

目的 观察微卫星不稳定性(microsatellite instability, MSI)胃癌患者癌组织程序性死亡配体-1(programmed death-ligand 1, PD-L1)表达变化,探讨其与MSI胃癌患者临床病理特征及预后的关系。方法 108例胃癌患者均行胃癌根治术,采用免疫组织化学法检测胃癌组织PD-L1阳性表达及错配修复蛋白表达情况,根据错配修复蛋白表达情况分为MSI组28例和非MSI组80例,比较2组患者胃癌组织PD-L1阳性表达率及不同临床病理特征的MSI胃癌患者癌组织PD-L1阳性表达率。随访3年,采用Kaplan-Manier生存曲线分析PD-L1阳性与阴性表达的MSI胃癌患者术后3年总生存率;绘制ROC曲线,评估癌组织PD-L1表达预测MSI胃癌患者术后3年预后不良的效能。结果 108例胃癌患者癌组织PD-L1阳性表达率为43.52%;MSI胃癌患者28例,发生率为25.93%。MSI组PD-L1阳性表达率(60.71%)高于非MSI组(37.50%)(χ²=4.547,P=0.033);临床分期Ⅲ～Ⅳ期(81.25%)、有淋巴结转...     

食管癌的微卫星不稳定性研究

人类基因组中分布着一种短片断或重复的核苷酸序列，称为微卫星(microsatellite，MS)。肿瘤患者常发生丢失或获得1个或多个MS序列，称为微卫星不稳定性(microsatellite instability，MSI)。在许多散发性肿瘤中可检测到MSI，如子宫内膜癌、胃癌、肾癌、卵巢癌、胰腺癌、膀胱癌、乳腺癌和肺癌等，但出现的频率不等，常由于检测MSI的位点和数量不同     

术前增强CT在评估结直肠癌微卫星不稳定性中的价值

目的:分析结直肠癌(colorectal cancer,CRC)患者术前增强计算机体层成像(computed tomography,CT)影像学特征与微卫星不稳定性(microsatellite instability,MSI)及预后的关系.方法:收集2010年3月—2016年3月的CRC患者术前增强CT图像及临床病理...     

微卫星DNA的测定方法

目前 ,微卫星 DNA (microsatellite DNA )不稳定性 (mi-crosatellite instability,MSI)作为肿瘤细胞的基因标志物 ,在肿瘤研究中愈来愈被人们所重视。由于微卫星重复的单位较小 ,检测困难 ,从而限制了其多态性的应用。随着 PCR技术的不断完善和分子生物学技术的不断发展 ,对微卫星 DNA多态性的检测出现了许多方法。由于检测 MSI可以反映肿瘤分子水平的变化 ,加之 PCR技术的优势 ,因此 MSI检测可成为预测肿瘤发生及早期诊断肿瘤的有效手段。1　微卫星不稳定性的常用检测方法微卫星多态性是微卫星 DNA不稳定性的表现 ,微卫星多态性…     

MSI、PD-L1在NSCLC患者中的表达及其与预后的相关性

目的探讨微卫星不稳定性(MSI)、程序性死亡配体-1(PD-L1)在非小细胞肺癌(NSCLC)患者中的表达水平及其预后相关性。方法收集2010年6月至2014年12月在本院收集的86例NSCLC患者手术切除癌组织及对应距病灶5 cm以上癌旁正常组织。利用PCR技术检测172例样品中BAT-25、BAT-26、D2S123、D5S346、D17S250五个位点的MSI,判断MSI表达情况。采用免疫组化法检测PD-L1的水平。对MSI、PD-L1与临床病理因素的关系进行分析,所有患者根据病情给予手术切除联合抗PD-L1等相应治疗,对影响NSCLC患者5年生存率的独立因素进行分析,观察MSI、PD-L1表达对患者5年生存率的影响。结果非小细胞癌组织中MSI表达率为63.95%,明显高于癌旁组织,差异有统计学意义(P<0.05)。PD-L1表达率明显高于癌旁正常组织,差异有统计学意义(P<0.05)。PD-L1表达与肿瘤分化程度、淋巴是否转移、TNM分期有关(P<0.05);MSI状态与肿瘤分化程度、淋巴结转移情况、TNM分期有关(P<0.05)。MSS及MSI-L患者术后生存时间明显低于MSI-H患者,差异有统计学意义(P<0.05)。PD-L1阳性患者术后生存时间明显低于阴性组,差异有统计学意义(P<0.05)。Logistic回归分析显示PD-L1阳性(OR=3.888)、淋巴结转移(OR=3.823)、TNM分期Ⅲ~Ⅳ期(OR=3.380)为影响患者5年生存率独立危险因素,MSI-H阳性为NSCLC患者5年生存率的保护因素(OR=0.289)(P<0.05)。结论 MSI和PD-L1的表达与NSCLC临床病理特征及预后密切相关,可作为NSCLC预后预测的重要指标。     

微卫星不稳定性与胃癌预后的研究

目的探讨微卫星不稳定性(MSI)与胃癌预后的关系.方法采用聚合酶链-简单序列长度多态性(PCR-SSCP)的方法对胃癌MSI进行检测,明确MSI与临床病理参数(肿瘤大小、部位、分化、Lauren′s分型、分期)之间的关系.其次,应用图像细胞仪(ICM)对胃癌组织进行细胞核DNA含量测定,比较MSI阳性组与MSI阴性组之间DNA含量的差异.平均DNA含量及细胞增殖指数作为观察指标.结果51例胃癌MSI总阳性率为43.1%(22/51).中-高分化腺癌MSI检出率(65.2%)显著高于低分化腺癌(25.0%)(P＜0.01);肠型胃癌MSI阳性率(57.7%)高于弥漫型胃癌(25.0%)(P＜0.05).MSI阳性组平均DNA含量、细胞增殖指数均显著低于MSI阴性组(10.01616±0.96677 VS 16.33144±2.97253 & 0.39066±0.08901VS 0.73955±0.10433,P＜0.01).结论MSI阳性胃癌预后可能相对较好.     

胃癌术后卡培他滨和奥沙利铂方案辅助化疗的毒副反应护理

胃癌是最常见的恶性肿瘤之一,围手术期综合治疗被认为是进一步改善胃癌预后的关键。临床试验表明,术后进行辅助化疗能明显提高胃癌术后患者的生存率[1,2]。氟尿嘧啶类联合铂类为基础的化疗方案已作为胃癌围手术期化疗的推荐     

多排螺旋CT增强扫描预测dMMR/MSI胃癌的初步研究

目的：应用多排螺旋CT(MSCT)增强检查对术前DNA错配修复缺陷/微卫星不稳定性（dMMR/MSI）胃癌的影像特征进行分析，寻找诊断dMMR/MSI胃癌的独立预测因素。资料与方法：回顾性分析我院经病理证实的dMMR/MSI胃癌（44例）及错配修复（完整型）/微卫星稳定（pMMR/MSS）胃癌（70例），所有患者术前均接受MSCT增强检查。收集记录每位患者肿瘤影像学信息（包括肿瘤位置、最大厚度、最大径线、平扫及各增强时相CT平均值、有无溃疡和坏死、有无浆膜侵犯和淋巴结转移等）。采用单因素分析和多因素Logistic回归方程，对两组数据进行统计分析。结果：在多因素Logistic回归分析中，4个CT特征是dMMR/MSI胃癌诊断的独立预测因素，包括瘤灶低动脉期增强斜率（OR:0.010;95%CI:0.002～0.066;P<0.001）、小瘤灶最大厚度（OR:0.111;95%CI:0.021～0.584;P=0.009）、无浆膜侵犯（OR:0.080;95%CI:0.015～0.431;P=0.003）、无瘤灶溃疡（OR:0.098;95%CI:0.016～0.597;P=0....     

转化生长因子β的表达及微卫星不稳定性在膀胱癌诊疗中的研究进展

转化生长因子β(TGFβ)是显著的负性生长因子，微卫星不稳定性(microsatellite instability，MSI)指肿瘤组织中DNA重复单位的增加或缺失。在许多肿瘤中存在TGFβ的表达异常和MSI。本文就二者在膀胱癌诊疗中的意义作一综述。     

Microsatellite instability and DNA mismatch repair deficiency testing in hereditary and sporadic gastrointestinal cancers

The reference cancers associated with DNA mismatch repair (MMR)deficiency are the adenocarcinomas of patients with hereditary nonpolyposis colorectal cancer, also known as Lynch syndrome.Sporadic gastrointestinal (GI) carcinomas, most commonly colorectal and gastric carcinomas, may also be associated with deficiencies of DNA mismatch repair. Deficiency in cellular MMR leads to wide-spread mutagenesis and neoplastic development and progression.An important diagnostic feature of MMR-deficient tumors is the high rate of mutations that accumulate in repetitive nucleotide regions, and these mutations are known as microsatellite instability(MSI). A standard panel of markers to test for MSI in tumors has been recommended and efficiently separates tumors into those with high, low, or no microsatellite instability (MSI-H, MSI-L, or MSS).Tumors characterized by MSI-H characteristically show loss of one of the main DNA MMR proteins, mLH1 or MSH2, and rarely MSH6 and PMS2, detected by immunohistochemistry (IHC). The combination of MSI testing and IHC for MMR proteins in tumors tissues is used to identify underlying DNA MMR deficiency andis clinically relevant screen patients who might have hereditary non-polyposis colorectal cancer for DNA repair gene germline testing.Increasing evidence demonstrates that tumors with a positive MSI status have lower lymph node metastases burden, and these patients have an overall improved survival, suggesting that the MSI and MMR status may contribute to decision making regarding treatment approaches. Updated guidelines for MSI and IHC for DNAMMR testing, and the biological and potential clinical implications of MMR deficiency and microsatellite instability in GI polyps and cancers are reviewed.     

微卫星不稳定性在胃癌组织中的表达

目的 研究微卫星在胃癌发生中的作用及其与胃癌临床病理特征之间的关系。方法 采用PCR、PCR-变性聚丙烯酰凝胶及银染法检测38例胃癌及相应的22例癌旁肠化生组织的MSI。结果 胃癌MSI阳性率为39．5％（15／38），DIS 123和BAT 26的MSI阳性率略高于其它位点，癌旁肠化生组织MSI阳性率为27．3％（6／22），6例MSI阳性肠化生标本对应的胃癌组织均为MSI—H，MSI与胃癌的分化程度和发生部位有关。结论 肠化生组织中MSI的进行积累可能在一部分胃癌的发生中起作用，NSI可能是胃癌的早期发展过程。     

Microsatellite analysis of hereditary nonpolyposis colorectal cancer-associated colorectal adenomas by laser-assisted microdissection: correlation with mismatch repair protein expression provides new insights in early steps of tumorigenesis

Although microsatellite instability (MSI) testing is a useful tool for molecular screening of hereditary nonpolyposis colorectal cancer (HNPCC) carcinomas, conflicting results have been obtained in colorectal adenomas. This might result from different techniques of tissue sampling and MSI analysis. Alternatively, some HNPCC-associated adenomas may follow a molecular route that differs from the MSI pathway. In the present study we examined the MSI status of 18 adenomas from 17 HNPCC patients by comparing manual adenoma dissection under gross visual control with laser microdissection of single adenoma crypts. After manual gross dissection, 50% (9 of 18) and 11.1% (2 of 18) of the adenomas displayed high-level (MSI-H) and low-level (MSI-L) MSI, respectively. The same set of adenomas split into 83.3% (15 of 18) MSI-H and 5.6% (1 of 18) MSI-L after laser microdissection. The expression pattern of mismatch repair (MMR) proteins showed a higher concordance rate with the MSI status in laser-dissected (94%) than gross-dissected (47%) adenomas. Whereas two adenomas remained microsatellite stable (MSS) and MMR proficient even after laser-assisted dissection, two MSI-H cases showed either rare instabilities at coding microsatellites or intratumoral heterogeneity of MSI with and without MSH2 expression. This suggests that in some adenomas development of MMR dysfunction occurs stepwise with MSI, arising before complete loss of MMR gene expression, whereas other HNPCC-associated adenomas might develop independently of MMR deficiency.     

Molecular screening of potential HNPCC patients using a multiplex microsatellite PCR system

Microsatellite instability (MSI) is a molecular hallmark of the H ereditary N on- P olyposis C olorectal C ancer (HNPCC) syndrome occurring in about 80-90% of the tumours and also in sporadic tumours of different organs, albeit at lower frequency. Highly unstable colorectal tumours (MSI-H) have different histopathological features and tend to have a better prognosis compared to neoplasms without (MSS) or with low levels of microsatellite instability (MSI-L). Since MSI classification allows the identification of potential HNPCC patients and might represent a valuable diagnostic parameter an increasing demand for high-throughput microsatellite analysis will arise. Therefore, we have adapted five diagnostic microsatellites, m(odified) ACTC, mBAT26, mD5S107, mD5S406 and mD13S153, to allow coamplification. Using this multiplex polymerase chain reaction (PCR) system 29 colorectal tumour tissues with known MSI status could be unambiguously identified as MSI-H (13 cases) or MSI-L/MSS (16 cases). Highly unstable colorectal tumour detection frequency of individual markers reached 77% (mD5S406), 85% (mACTC), 85% (mD5S107), 92% (D13S153) and 100% (mBAT26) showing similar sensitivity but improved specificity as compared with a microsatellite reference panel. In a prospective analysis of 31 colorectal tumours, the multiplex PCR system identified five MSI-H cases. Multiplex MSI PCR is a time saving and cost-effective method not restricted to specific technical equipment and applicable to a variety of microsatellite-based genotyping approaches.     

老年胃癌根治术120例预后因素分析

[目的]探讨老年(≥65岁)胃癌根治术预后影响因素.[方法]对本院2002 ～2010年住院的120例行胃癌根治术的有完整随访资料老年胃癌患者进行回顾性分析,探讨影响老年胃癌根治术预后的相关因素.[结果]全组1年、3年和5年生存率分别为66.7%、51.7%、43.3%.单因素分析结果显示:肿瘤大小、TNM分期、Bor...     

Automated and simultaneous identification of microsatellite instability by fluorescence-based polymerase chain reaction (PCR) in four loci

Genomic instability is sometimes due to impairment of DNA repair systems, which results in a change in the number of microsatellite repeats in tumor cells, produced by slippage during DNA replication. Such abnormal repeats are manifested as microsatellite instability (MSI). We have devised a simple assay using four-color fluorescence for the detection of MSI by an automatic sequencer. Using this method, MSI and loss of heterozygosity (LOH) at four microsatellite loci can be identified simultaneously. We have also developed an algorithm and software for automated analysis of MSI and LOH with this method. Using our method for the detection of MSI in four microsatellite loci and the algorithm and software that we developed, 18 (94.7%) of 19 patients with hereditary nonpolyposis colorectal cancer (HNPCC), meeting the Amsterdam Minimum Criteria, were found to exhibit MSI.     

Quality assessment and correlation of microsatellite instability and immunohistochemical markers among population- and clinic-based colorectal tumors results from the Colon Cancer Family Registry

The detection of defective mismatch repair (MMR), as assessed by the presence of tumor microsatellite instability (MSI) and/or loss of MMR protein expression by IHC, has been useful for risk assessment, prognosis, and prediction of treatment in patients with colorectal cancer. We analyzed tumors for the presence of defective MMR from 5927 Colorectal Cancer Family Registry patients recruited at six international consortium sites. We evaluated the appropriate percentage instability cutoff used to distinguish the three MSI phenotypes [ie, stable (MSS), low instability (MSI-L), and high instability (MSI-H)]; the sensitivity, specificity, and performance characteristics of individual markers; and the concordance between MSI and IHC phenotypes. Guided by the results of the IHC testing, our findings indicate that the distinction between an MSI-H phenotype from a low-instability or MSS phenotype can best be accomplished by using a cutoff of 30% or greater of the markers showing instability. The sensitivity and specificity of the mononucleotide markers were higher than those of the dinucleotide markers. Specifically, BAT26 and BAT25 had the highest sensitivity (94%) and specificity (98%), and the use of mononucleotide markers alone identified 97% of the MSI-H cases correctly. As expected, the presence of MSI-H correlated with an older age of diagnosis, the presence of tumor in the proximal colon, and female sex.