小肠的恶性胃肠道间质瘤伴淋巴结转移病理分析

目的 探讨伴淋巴结转移的小肠恶性胃肠道间质瘤的临床病理特征、c-kit基因突变情况,以及对甲磺酸伊马替尼(imatinib mesylate,Glivec)的治疗反应.方法 对2例发生在小肠伴发淋巴结转移的胃肠道间质瘤进行光镜观察、免疫组织化学标志及基因突变分析并随访甲磺酸伊马替尼的治疗效果.结果 2例均为小肠浆膜面肿块,镜下观察肿瘤均以梭形细胞为主,伴有少量上皮样细胞,呈多结节状,并出现大片凝固性坏死;免疫组织化学标志肿瘤细胞CD117阳性,基因突变检测发现均存在c-kit基因第11号外显子的突变.例1显示第11号外显子559～569位点杂合性缺失,伴570、571位点TACATA杂合性突变为GACAGA;例2显示第11号外显子559～565杂合性缺失.结论 小肠胃肠道间质瘤伴淋巴结转移是一种少见病变,需要同发生在此处的其他恶性软组织肿瘤鉴别;该肿瘤对甲磺酸伊马替尼的治疗效果取决于c-kit基因的具体突变类型.     

小肠的恶性胃肠道间质瘤伴淋巴结转移病理分析

目的 探讨伴淋巴结转移的小肠恶性胃肠道间质瘤的临床病理特征、c-kit基因突变情况,以及对甲磺酸伊马替尼(imatinib mesylate,Glivec)的治疗反应.方法 对2例发生在小肠伴发淋巴结转移的胃肠道间质瘤进行光镜观察、免疫组织化学标志及基因突变分析并随访甲磺酸伊马替尼的治疗效果.结果 2例均为小肠浆膜面肿块,镜下观察肿瘤均以梭形细胞为主,伴有少量上皮样细胞,呈多结节状,并出现大片凝固性坏死;免疫组织化学标志肿瘤细胞CD117阳性,基因突变检测发现均存在c-kit基因第11号外显子的突变.例1显示第11号外显子559～569位点杂合性缺失,伴570、571位点TACATA杂合性突变为GACAGA;例2显示第11号外显子559～565杂合性缺失.结论 小肠胃肠道间质瘤伴淋巴结转移是一种少见病变,需要同发生在此处的其他恶性软组织肿瘤鉴别;该肿瘤对甲磺酸伊马替尼的治疗效果取决于c-kit基因的具体突变类型.     

胃肠道间质瘤患者伊马替尼血药浓度的监测及意义

胃肠间质瘤（GIST）是消化道常见的间叶源性肿瘤,多发生于胃部,其免疫组化CD117及DOG-1常表达阳性,介导Kit基因突变是导致该病的主要机制。伊马替尼是一种酪氨酸酶抑制剂,可以很好的抑制c-Kit的活性,作为复发、不可切除或者晚期的GIGT患者一线用药甲磺酸伊马替尼,它已被证实是治疗中晚期GIST患者最有效的药物,可以显著改善预后。在常规的治疗过程中,伊马替尼的血药浓度在不同的GIST患者中存在很大差异,既有血药浓度不足导致疗效较差,也有血药浓度过高导致不良反应太大,血药浓度的监测对于提高患者的依从性及预后具有重要的意义。同时我们也可以通过马替尼血药浓度的检测去探究疾病的原因,然而对于甲磺酸伊马替尼血药浓度的监测主要集中在国外,国内相关研究甚少。本文从伊马替尼的药代动力学、伊马替尼血药浓度的现状及问题、监测的意义等方面进行综述,探讨伊马替尼血药浓度的监测对GIST患者的意义。     

15例原发性胃肠外来源胃肠间质瘤的临床病理特征及预后分析并文献复习

目的　探讨原发性胃肠外来源胃肠间质瘤（extragastrointestinal stromal tumors,EGISTs）的临床病理特征及预后影响因素,并复习相关文献。 方法　回顾性收集2006年1月~2017年8月广东省人民医院收治的原发性EGISTs临床资料,并进行描述性分析。 结果　共收集到15例原发性EGISTs,所有病例经病理确诊。其中男性11例,女性4例;中位发病年龄为45岁（33~70岁）。首发症状多为腹盆腔包块或腹痛。原发部位中,有4例位于腹膜后,4例位于结肠系膜,3例位于小肠系膜,1例位于盆腔,1例位于左侧胸膜腔,1例位于胰腺被膜,1例位于小网膜囊。中位随访时间为53个月（1~102个月）。免疫组化显示,14例CD117表达阳性（14/15）,10例CD34表达阳性（10/15）,6例患者DOG-1表达阳性（6/8）。有7例患者接受基因检测,2例c-KIT基因外显子9突变,2例c-KIT基因外显子11突变,1例PDGFRa基因外显子12同义突变,2例未检测到c-KIT基因及PDGFRa基因突变。依据改良NIH（National Institutes of Health）标准进行危险度分级,5例高危病例行R0术后接受伊马替尼靶向治疗,平均生存期为67个月;高危患者中8例未行辅助靶向治疗,平均生存期为36.58个月。有8例在随访过程中出现复发转移,8例出现肿瘤相关性死亡。 结论　EGISTs发病率低,症状多为腹盆腔包块,预后差;其病理特征与常见的胃肠来源的GISTs相仿。R0手术切除是治疗首选,伊马替尼辅助治疗有利于改善预后并预防复发转移。     

胃肠道间质瘤中PDGFR-α突变亚型的生物学及临床特点

要］ 大多数胃肠道间质瘤（GISTs）都存在编码Ⅲ型酪氨酸激酶受体的KIT基因的功能获得性突变,但仍有部分GIST中未检测出KIT的激活突变,其中血小板源性生长因子受体α（PDGFR-α）基因突变的发现代表了GIST中具有独特的遗传学、生物学和表型特征的一类亚型。PDGFR-α基因突变是导致GIST发生发展的关键机制之一,突变类型多样,与GIST患者的临床病理表现及预后密切相关。应用伊马替尼对包含该突变体的肿瘤进行分子靶向治疗,多数患者表现为药物抵抗。     

KIT阴性的胃肠道间质肿瘤

胃肠道间质肿瘤 (gastrointestinalstromaltumor,GIST)是消化道最常见的间叶源性肿瘤 ,显示出类似Cajal间质细胞的形态学特点和免疫表型 ,特征性表达KIT蛋白(CD117)。多数GIST具有KIT癌基因突变 ,从而导致细胞增殖。KIT抑制剂伊马替尼 (商品名格列卫 )治疗GIST显效证实了KIT在GIST发病机制中的重要作用。然而 ,某些肿瘤具有GIST的临床病理特征 ,但KIT阴性。这类肿瘤是否真是GIST以及伊马替尼治疗是否有效尚存争议。作者研究了 2 5例具有GIST临床病理特征但KIT免疫组化阴性的肿瘤。此组患者发病年龄 (2 9～ 79岁 )和肿瘤…     

与神经纤维瘤病Ⅰ型伴发的胃肠道间质瘤临床病理学和分子遗传学研究进展

大多数散发性胃肠道间质瘤(gastrointestinal stromaltumors,GIST)具有c-kit基因或血小板衍生的生长因子受体A(PDGFRA)的突变,最常发生于胃,其次是小肠、肛门直肠等。通常单发,偶见多发。部分多发性GIST与Ⅰ型神经纤维瘤病(NF1)有关。NF1可伴发多种病变,GIST被认为是最常见的与NF1相关的胃肠道肿瘤,NF1患者发生GIST的危险性明显提高,多项研究证实:NF1伴发的GIST与散发性GIST在临床病理、c-kit和PDGFRA基因突变状态等方面均有不同,是一种独特的肿瘤,表现为多中心发生、好发于小肠,瘤细胞呈梭形,缺乏KIT及PDGFRA突变,不对甲磺酸伊马替尼的治疗产生应答,大多数临床经过良好。     

胃肠道间质瘤c-Kit及PDGFRA基因突变与临床病理特征、免疫表型及预后的关系

目的探讨胃肠道间质瘤(gastrointestinal stromal tumors,GIST)中c-Kit/PDGFRA基因突变与临床病理特征、免疫表型及预后的关系。方法采用直接测序法检测185例GIST标本中c-Kit和PDGFRA基因突变类型。结果 c-Kit基因突变中,外显子11突变最常见,以缺失突变、点突变及混合突变为主,并见3例双外显子突变。外显子9在小肠GIST中的突变率显著高于胃GIST,且均为A502-Y503串联重复突变,提示小肠GIST有独特的基因型。PDGFRA在上皮样细胞型和混合细胞型GIST中的突变率显著高于梭形细胞型GIST。c-Kit基因外显子11缺失突变的中高危GIST易出现术后复发转移,且复发转移患者中发生二次突变率较高,表现为c-Kit基因外显子13、14、17或18点突变,以13号外显子V654A最为常见。CD117和DOG1的表达与基因突变之间无相关性,不能作为预测疾病基因突变的指标。单因素分析结果显示,肿瘤直径、核分裂象、Ki-67增殖指数、危险程度分级、术后复发和转移是影响GIST预后的重要因素,术后靶向药物治疗可一定程度改善预后。c-Kit基因外显子11缺失突变和外显子9突变的GIST患者预后较差。结论 c-Kit基因9号外显子在小肠GIST中突变率较高,PDGFRA基因在上皮样细胞型和混合细胞型GIST中突变率较高。c-Kit基因外显子11缺失突变的中高危GIST易发生二次突变导致术后复发转移,外显子11缺失突变可作为GIST预后不良的独立影响因素之一。     

胃肠道间质瘤中PDGFRα基因突变的检测

目的检测胃肠道间质瘤（gastrointestinal stromal tumors,GIST）中PDGFRa基因的突变位点及类型,探讨其在GIST发病机制中的作用。方法运用PCR—SSCP法和DNA测序检测22例GIST标本中PDGFRaexon12和exon18的基因突变,并以3例平滑肌瘤、1例神经鞘瘤、20例正常胃肠道组织作为对照。结果22例GIST中共有5例发生了PDGFRα突变（22．7％）,平滑肌瘤、神经鞘瘤和正常胃肠道组织中未检测出PDGFRα的突变。PDGFRa的突变在良恶性、性别、年龄、肿瘤部位、大小及组织学分型之间的差异均无显著性。结论PDGFRα基因突变可能参与了GIST的发生发展,但突变是否有助于判断肿瘤的良恶性和提示预后,仍需更多的研究和观察。     

中国胃肠道间质瘤诊断治疗共识

胃肠道间质瘤(gastrointestinal stromal tumors,GIST)是胃肠道最常见的间叶源性肿瘤,免疫组织化学染色大多数呈CD117阳性.传统放疗和化疗对GIST几乎无效.酪氨酸激酶抑制剂甲磺酸伊马替尼的临床应用使GIST的治疗发生了重大的改变,为部分晚期GIST患者带来了延长生存期的疗效.同时由于对GIST基因突变认识的进一步提高,使GIST的诊断率显著提高.     

Pathology of gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors in the gastrointestinal tract. It was found that most GIST expressed KIT, a receptor tyrosine kinase encoded by protooncogene c-kit. In normal gastrointestinal wall, KIT is expressed by interstitial cells of Cajal (ICC), which are a pacemaker for autonomous gastrointestinal movement. Because both GIST and ICC are double-positive for KIT and CD34, and because familial and multiple GIST appear to develop from diffuse hyperplasia of ICC, GIST are considered to originate from ICC or their precursor cells. It was also found that approximately 90% of the sporadic GIST have somatic gain-of-function mutations of the c-kit gene, and that the patients with familial and multiple GIST have germline gain-of-function mutations of the c-kit gene. These facts strongly suggest that the c-kit gene mutations are a cause of GIST. Approximately half of the sporadic GIST without c-kit gene mutations were demonstrated to have gain-of-function mutations in platelet-derived growth factor receptor-alpha (PDGFRA) gene that encodes another receptor tyrosine kinase. Because KIT is immunohistochemically negative in a minority of GIST, especially in PDGFRA gene mutation-harboring GIST, mutational analyses of c-kit and PDGFRA genes may be required to diagnose such GIST definitely. Imatinib mesylate was developed as a selective tyrosine kinase inhibitor. It inhibits constitutive activation of mutated KIT and PDGFRA, and is now being used for KIT-positive metastatic or unresectable GIST as a molecular target drug. Confirmation of KIT expression by immunohistochemistry is necessary for application of the drug. The effect of imatinib mesylate is different in various types of c-kit and PDGFRA gene mutations, and the secondary resistance against imatinib mesylate is often acquired by the second mutation of the identical genes. Mutational analyses of c-kit and PDGFRA genes are also significant for prediction of effectiveness of drugs including newly developed agents.     

Novel V600E BRAF mutations in imatinib-naive and imatinib-resistant gastrointestinal stromal tumors

BRAF and NRAS are commonly mutated in cancer and represent the most frequent genetic events in malignant melanoma. More recently, a subset of melanomas was shown to overexpress KIT and harbor KIT mutations. Although most gastrointestinal stromal tumors (GISTs) exhibit activating mutations in either KIT or PDGFRA, about 10% of the cases lack mutations in these genes. It is our hypothesis following the melanoma model that mutations in BRAF or NRAS may play a role in wild-type GIST pathogenesis. Alterations in RAS/MEK/ERK pathway may also be involved in development of imatinib resistance in GIST, particularly in tumors lacking secondary KIT or PDGFRA mutations. Imatinib-naive wild-type GISTs from 61 patients, including 15 children and 28 imatinib-resistant tumors without secondary KIT mutations were analyzed. Screening for hot spots mutations in BRAF (exons 11 and 15) and NRAS (exons 2 and 3) was performed. A BRAF exon 15 V600E was identified in 3 of 61 GIST patients, who shared similar clinical features, being 49- to 55-years-old females and having their tumors located in the small bowel. The tumors were strongly KIT immunoreactive and had a high risk of malignancy. An identical V600E BRAF mutation was also identified in one of 28 imatinib resistant GIST lacking a defined mechanism of drug resistance. In conclusion, we identified a primary BRAF V600E mutations in 7% of adult GIST patients, lacking KIT/PDGFRA mutations. The BRAF-mutated GISTs show predilection for small bowel location and high risk of malignancy. A secondary V600E BRAF mutation could represent an alternative mechanism of imatinib resistance. Kinase inhibitors targeting BRAF may be effective therapeutic options in this molecular GIST subset.     

KIT and PDGFRA mutations in gastrointestinal stromal tumors (GISTs)

Mutually exclusive KIT and PDGFRA mutations are central events in GIST pathogenesis, and their understanding is becoming increasingly important, because specific treatment targeting oncogenic KIT and PDGFRA activation (especially imatinib mesylate) has become available. KIT mutations in GIST are clustered in four exons. Most common are exon 11 (juxtamembrane domain) mutations that include deletions, point mutations (affecting a few codons), and duplications (mostly in the 3' region). The latter mutations most often occur in gastric GISTs. Among gastric GISTs, tumors with deletions are more aggressive than those with point mutations; this does not seem to hold true in small intestinal GISTs. Exon 9 mutations (5-10%) usually are 2-codon 502-503 duplications, and these occur predominantly in intestinal versus gastric GISTs. Lesser imatinib sensitivity of these tumors has been noted. Kinase domain mutations are very rare; GISTs with such mutations are variably sensitive to imatinib. PDGFRA mutations usually occur in gastric GISTs, especially in the epithelioid variants; their overall frequency is approximately 30% to 40% of KIT mutation negative GISTs. Most common is exon 18 mutation leading Asp842Val at the protein level. This mutation causes imatinib resistance. Exon 12 and 14 mutations are rare. Most mutations are somatic (in tumor tissue only), but patients with familial GIST syndrome have consitutitonal KIT/PDGFRA mutations; >10 families have been reported worldwide with mutations generally similar to those in sporadic GISTs. GISTs in neurofibromatosis 1 patients, children, and Carney triad seem to lack GIST-specific KIT and PDGFRA mutations and may have a different disease mechanism. Secondary mutations usually occur in KIT kinase domains in patients after imatinib treatment resulting in resistance to this drug. Mutation genotyping is a tool in GIST diagnosis and in assessment of sensitivity to kinase inhibitors. This is a US government work. There are no restrictions on its use.     

The role of KIT in the management of patients with gastrointestinal stromal tumors

In recent years, immunohistochemical staining for KIT (CD117) has become integral to the diagnosis of gastrointestinal stromal tumors (GISTs), nearly 90% of which harbor activating mutations in the KIT receptor tyrosine kinase gene. Approximately 80% of patients with metastatic GIST show at least some clinical response to the targeted small molecule KIT inhibitor imatinib. The response to imatinib is closely correlated with the presence and type of KIT mutation. GISTs with the most common KIT exon 11 mutations have the highest response rate by far, whereas GISTs lacking mutations in KIT or the alternative receptor tyrosine kinase PDGFRA show much lower rates of response to imatinib. Less than 5% of GISTs are KIT-immunonegative; and many of these tumors have activating mutations of PDGFRA, some of which are also inhibited by imatinib. Most patients who initially respond to imatinib become resistant and eventually progress, which coincides with the selection of imatinib-resistant secondary KIT mutations in the kinase domain. Sunitinib has recently been approved for patients with GIST, principally those who fail imatinib therapy; and additional small molecule inhibitors are in the pipeline. It is becoming evident that alternative approaches to direct KIT inhibition will be required for long-term survival of patients with advanced GISTs. This review examines the role of KIT in the diagnosis and management of patients with GIST.     

GIST under imatinib therapy

The prognosis of patients with a GIST improved significantly since the introduction of imatinib mesylate treatment, leading to disease control in 70% to 85% of patients. The response depends on the presence/ absence and type of mutations in the KIT or Platelet derived growth factor receptor. Unfortunately, we are increasingly faced with the problem of resistance to imatinib treatment, mainly secondary resistance, which by definition occurs after at least 6 months of initial response to the drug. The effects of imatinib on a GIST are still in full exploration and this review focuses upon the available data on the phenotype and genotype of a GIST treated with imatinib. Two settings are elaborated separately, a responding/stable GIST, and a resistant GIST. In addition, the attention will be drawn to remarkable (immuno)phenotypic changes that can occur in a GIST under imatinib treatment.     

Clinical significance of oncogenic KIT and PDGFRA mutations in gastrointestinal stromal tumours

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Despite clinicopathological differences, GISTs share oncogenic KIT or platelet-derived growth factor-alpha ( PDGFRA ) mutations. Imatinib, KIT and PDGFRA inhibitor, has been successfully used in the treatment of metastatic GISTs. There are primary KIT or PDGFRA mutations diagnosed before imatinib treatment, linked to GIST pathogenesis, and secondary mutations detected during treatment, causing drug resistance. KIT exon 11 mutations are the most common. Gastric GISTs with exon 11 deletions are more aggressive than those with substitutions. KIT exon 11 mutants respond well to imatinib. Less common KIT exon 9 Ala502_Tyr503dup mutants occur predominantly in intestinal GISTs and are less sensitive to imatinib. An Asp842Val substitution in exon 18 is the most common PDGFRA mutation. GISTs with such mutation are resistant to imatinib. PDGFRA mutations are associated with gastric GISTs, epithelioid morphology and a less malignant course of disease. GISTs in neurofibromatosis 1, Carney triad and paediatric tumours generally lack KIT and PDGFRA mutations. Secondary KIT mutations affect exons 13–17. GISTs with secondary mutations in exon 13 and 14 are sensitive to sunitinib, another tyrosine kinase inhibitor. KIT and PDGFRA genotyping is important for GIST diagnosis and assessment of sensitivity to tyrosine kinase inhibitors.     

Mutation analysis of gastrointestinal stromal tumors: increasing significance for risk assessment and effective targeted therapy

Molecular characterization of gastrointestinal stromal tumors (GISTs) plays an increasing role not only for the patient's prognosis but also for treatment options and in the context of resistance to therapy. Several mutational subtypes in KIT or platelet-derived growth factor receptor-alpha (PDGFRalpha) have been identified to be correlated with a different clinical behavior of GISTs. In KIT exon 11, deletions in the proximal part are associated with a high metastatic risk, whereas duplications in the distal part lead to a less aggressive phenotype. GISTs of the small bowel with a duplication in KIT exon 9 are often high risk tumors. In contrast, PDGFRalpha exon 18 mutated GISTs tend to have a low malignant potential. The authors suggest to include these molecular data together with classical parameters such as mitotic count and tumor size into the risk assessment of GISTs. The first choice for treatment of GISTs is still the surgical resection. In advanced tumors, which cannot be R0 resected, the neoadjuvant treatment with the tyrosine kinase inhibitor imatinib is now well established. Furthermore, an adjuvant treatment of locally R0-resected intermediate and high risk tumors is evaluated in several international clinical trials. For metastatic disease, treatment with imatinib is still the first option, but with new upcoming substances, the molecular characterization of GISTs may become mandatory. Very recently, it has been shown that sunitinib may be especially effective in GISTs with KIT exon 9 mutation, whereas these tumors show only an intermediate response to imatinib. A European Organisation for Research and Treatment of Cancer clinical trial randomizing patients according to their mutational status is under preparation. Secondary resistance to imatinib treatment is increasing, at least partly due to secondary mutations in the tyrosine kinase domain of the KIT receptor. Once a lesion has been shown to carry such a mutation, the local excision may be useful, mean while still responding metastases are further controlled by continuing imatinib. Taken together, the molecular characterization of GISTs turns out to play a central role before and during the treatment with tyrosine kinase inhibitors, which have improved the treatment of GIST patients dramatically.     

Prognostic significance of angiogenesis in gastrointestinal stromal tumor.

Angiogenesis is important in the growth and metastasis of various kinds of solid tumors. To investigate the potential role of angiogenesis in gastrointestinal stromal tumor (GIST), an immunohistochemical analysis was performed in 95 cases of GISTs for microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression. MVD was evaluated with immunohistochemical staining for CD31. A high level of MVD was significantly correlated with overexpression of VEGF, tumor location (intestine>stomach), tumor size (> or =5 cm), tumor grade (high>intermediate>low grade) (P=<0.0001, 0.0422, 0.0006, 0.0359, respectively). Of the 70 GISTs analyzed, KIT exon 11 mutations were detected in 45 cases (64.3%) and KIT exon 9 mutations in two cases (2.9%). No mutations were found in KIT exons 13 and 17, and platelet-derived growth factor receptor-alpha exons 12 and 18. Interestingly, VEGF expression level was significantly higher in the non-KIT exon 11 mutant group than in the KIT exon 11 mutant group (P=0.0266). In univariate analysis, tumor grade (high grade), tumor size (> or =5 cm), mitotic count (> or =5/50 high-power fields), Ki-67 labeling index (> or =4.6%), MVD (> or =7.0/0.95 mm(2)) and VEGF expression (high) were significantly associated with a shorter period of disease-free survival (P=<0.0001, 0.0199, 0.0055 0.0027, 0.0028 and 0.0302, respectively). In multivariate analysis, tumor grade and MVD were identified as independent worse prognostic factors (P=0.0007, 0.0152, respectively). In conclusion, our results suggest that the evaluation of MVD and VEGF expression is useful for predicting the aggressive biologic behavior of GIST, and that angiogenesis associated with VEGF may play an important role, at least in part, in the progression of GIST.     

Clinical and prognostic significances of nuclear and cytoplasmic KIT expressions in extrahepatic bile duct carcinomas.

After receiving FDA approval as a therapeutic regimen in gastrointestinal stromal tumors, the tyrosine kinase inhibitor imatinib mesylate has been applied to the treatment of other solid malignant neoplasms. To evaluate the usefulness of imatinib mesylate as a possible therapeutic regimen in extrahepatic bile duct carcinomas, an immunohistochemical study for KIT was performed in 289 cases of extrahepatic bile duct carcinomas, and mutational analysis of exon 11 of the c-kit gene was performed in 20 cases that were arbitrarily retrieved from the cases with KIT expression. Cytoplasmic KIT expression was observed in 54 cases (19%) and nuclear KIT in 58 cases (20%) of extrahepatic bile duct carcinoma. Nuclear KIT expression was more frequent in cases with vascular invasion (P<0.001), whereas cytoplasmic KIT expression was more common in tumors of T1-T3 than in those of T4 (P=0.04), and was more frequently observed in cases with a papillary growth pattern (P=0.03). Patients with cytoplasmic KIT-positive tumors had significantly better survival both by univariate (P=0.01) and multivariate analyses (P=0.04). Infrequent cytoplasmic KIT expression without mutation of exon 11 suggests that imatinib mesylate may not be effective for the treatment of extrahepatic bile duct carcinoma. However, immunohistochemical study for KIT may be helpful in routine pathologic examinations for evaluating better prognosis for patients with extrahepatic bile duct carcinoma. In addition, more frequent nuclear expression of KIT in cases with vascular invasion suggests that nuclear KIT expression may contribute to the progression of extrahepatic bile duct carcinoma.     

胃肠道间质瘤156例临床病理学特征与预后的分析

目的探讨胃肠道问质瘤（GIST）的生物学行为,分析临床病理特征对于GIST患者生存率的影响,同时检测c—kit基因11号外显子的突变,试图发现对GIST预后判断有意义的指标。方法收集解放军总医院病理科156例发生于胃与小肠的GIST,总结临床病理特征包括年龄、临床分期、肿瘤直径、核分裂象计数、坏死、风险分级等,并进行统计学分析。套式PCR扩增c—kit基因11号外显子,变性高效液相色谱法筛查,并进行DNA直接测序检测突变。结果胃GIST83例,平均年龄55．4岁,62例获得随访,17例复发或转移,5年生存率为66．5％±17．1％。小肠GIST73例,平均年龄50．6岁,43例获得随访,22例发生复发或转移,5年生存率为61．8％4-18．3％。对于胃GIST患者,年龄小于50岁（P=0．046）,临床分期晚（P=0．0001）,肿瘤直径大（P=0．0001）,核分裂象计数多（P=0．0001）,肿瘤组织出现坏死（P=0．0001）和风险分级高（P=0．004）提示生存率低。COX风险比例模型发现临床分期晚（P=0．001）、肿瘤直径大（P=0．001）、核分裂象计数多（P=0．002）、风险分级高（P=0．018）与患者预后差相关。在小肠GIST中,肿瘤组织坏死（P=0．036）、临床分期晚（P=0．010）与患者生存率低相关,其中临床分期为独立的预后提示因子。c—kit基因11号外显子突变检测发现共25例患者存在突变,胃GIST的突变率为32．0％,主要发生于50岁以上患者,小肠GIST的突变率为22．5％,主要发生于40～49岁患者。结论根据临床病理特征可以对GIST患者的预后进行判断,其中胃GIST患者可以根据临床分期、肿瘤直径、核分裂象计数、风险分级来判断预后,小肠GIST患者可依据临床分期及肿瘤组织坏死来判断预后。小肠GIST比胃GIST更易复发或转移。胃与小肠GIST基因的突变可能与患者的年龄相关。