胃癌及癌前病变胃粘膜的粘液组织化学研究

本文应用粘液组织化学方法对168例肠化生、96例异型增生和89例胃癌胃粘膜活检标本进行观察,发现87.6％的胃癌和40.6％的异型增生组织有异常粘液分泌;不全结肠型肠化生和硫酸粘液阳性肠化生在癌旁和异型增生的检出率显著地高于萎缩性胃炎组(P<0.05);伴不全结肠型肠化生和伴其它型肠化生的胃癌患者平均年龄分别为59.5岁和54.4岁、男女比为6∶1和2.25∶1.结果提示有异常粘液分泌的异型增生、伴不全结肠型化生的异型增生、不全结肠型化生的高龄男性、伴不全结肠型化生的胃良性疾病和硫酸粘液阳性肠化生宜被看作是胃癌的癌前病变,其中前三组的癌变趋向性更大.     

胃粘膜癌前病变P21和P53蛋白的表达

目的检测胃粘膜肠化生和异型增生病变部位Ｐ２１和Ｐ５３蛋白表达与胃癌发生的关系．方法内窥镜及病理学证实为胃粘膜肠化生者４４例，男２６例，女１８例，平均年龄４７５岁．异型增生者１４例，男９例，女５例，平均年龄６４５岁．粘液组化将肠化生分型，免疫组化测定Ｐ２１及Ｐ５３蛋白表达．结果Ⅱｂ型肠化生Ｐ２１及Ｐ５３蛋白阳性率分别为７００％和３００％，均显著高于Ⅰｂ型肠化生（２５８％和６４％，Ｐ＜００１）．异型增生Ｐ２１及Ｐ５３阳性率为４２８％和２８５％，高于肠化组３４％和１１８％．Ⅱｂ型肠化异型增生Ｐ２１和Ｐ５３阳性率为６２５％和３７５％，也高于Ⅰｂ型肠化异型增生组１６６％和１６６％．结论分泌非中性粘液的Ⅱｂ型肠化异型增生带有更多与胃癌相同的生物学性状，可能与胃癌的发生关系密切．     

胃癌组织中hTERT基因表达及意义

目的探讨hTERT基因在胃癌发生、发展中的作用及机制。方法采用免疫组化SP法及核酸原位杂交法检测胃黏膜肠化生、异型增生及胃癌组织中hTERT蛋白及hTERT mRNA表达情况。结果胃黏膜肠化生、异型增生及胃癌组织中hTERT蛋白及hTERTmRNA阳性表达率均显著高于正常胃黏膜（P〈0.05）。hTERT蛋白表达阳性者hTERTmRNA表达阳性率显著高于hTERT蛋白表达阴性者（P〈0.01）。结论 hTERT基因与癌前病变及胃癌的发生有关,可能是胃癌的生物学标志之一。     

胃癌组织中Bcl-2、Bax的表达及其与细胞凋亡的关系

目的观察Bcl-2及Bax在胃癌组织中的表达变化及其与细胞凋亡的关系。方法选择70例慢性胃炎、49例肠上皮化生、64例异型增生及81例胃癌手术切除标本，用免疫组化法检测其Bcl-2和Bax蛋白，用TUNEL技术检测凋亡细胞。结果Bcl-2、Bax在重度异型增生中阳性表达率最高，在肠化生与异型增生中的阳性表达率较慢性胃炎和胃癌高。从慢性胃炎到肠化生，再到异型增生的演变过程中，细胞凋亡指数逐渐增高，至中度异型增生时达最高峰，随后开始下降，至胃癌时最低。Bcl-2、Bax蛋白表达与胃癌细胞凋亡指数呈负相关（r分别为-0．760、-0.844，P均〈0．01）。结论Bal-2的表达可能是胃癌发生过程中的早期行为。Bax对Bcl-2的抑凋亡功能有对抗作用。     

大肠型肠化生伴发胃癌危险性大

据健康报　（记者傅冬红）对我国胃癌高发区山东临朐县３０００多人的一项调查表明，大肠型肠化生是小肠型肠化生进一步发展的结果，大肠型肠化生与异型增生的关系与胃癌的伴发率较小肠型肠化生更为密切，在内镜病理活检及胃癌预防工作中应引起重视．胃癌的发病率和死亡率居我国恶性肿瘤的首位，肠上皮化生被认为是肠型胃癌发生过程中的一个重要环节．肠上皮化生是胃粘膜的一种较常见的病变，在高龄人群中发生很普遍，但是并非所有的肠化生都被视为癌前病变．北医大临床肿瘤学院病理科、流行病学研究室、消化内科等研究人员对临朐县３５岁～…     

胃黏膜肠上皮化生、胃上皮内瘤变与胃癌的组织发生

胃癌是严重危害人民健康的疾病之一,其发病机制尚不明确.胃癌的发生常在癌变之前经历相当漫长的演变过程,即由正常胃黏膜转变成胃癌前病变,部分再发展成胃癌.目前公认,胃黏膜异型增生和肠上皮化生是胃癌前病变.鉴于胃癌的高度恶性,且其病因发病机制尚未完全阐明,实施针对病因的一级预防比较困难.本文就胃上皮内瘤变、异型增生和肠化生的定义和分类,幽门螺杆菌感染、萎缩性胃炎、肠化生与胃癌发生的相关性等问题进行综述,旨在提高对胃癌前病变的认识水平,以便于临床医师对胃癌前病变、特别是萎缩性胃炎进行密切的监测及予以及时有效的干预.     

慢性萎缩性胃炎伴异型增生的治疗进展

慢性萎缩性胃炎伴胃黏膜异型增生属于癌前病变。目前国内外学者一致认同肠型胃癌发生的Correa模式[1]即＂正常胃黏膜—慢性浅表性胃炎—慢性萎缩性胃炎—肠上皮化生—异型增生—胃癌＂的发展模式。如能对胃黏膜异型增生进行积极的随访监测,并加以有效干预,从而阻断其向胃癌发展,那将显著降低胃癌的发生率和病死率。     

慢性萎缩性胃炎与胃癌

萎缩性胃炎是指胃的固有腺体数目减少甚至消失,常伴有广泛的肠上皮化生和异型增生,肠上皮化生及异型增生为胃癌的癌前病变。正常胃黏膜．浅表性胃炎一萎缩性胃炎一肠上皮化生一异型增生一胃癌是Correa提出的慢性胃炎向胃癌演变的规律模式,已得到相关学者的广泛认同。越来越多证据表明,慢性萎缩性胃炎作为一种癌前疾病与胃癌的发生及发展密切相关。     

中医药治疗胃癌前期病变的现状与展望

胃癌死亡率居于我国恶性肿瘤之首，有效地防治胃癌前期病变，阻断其向癌发展，是预防胃癌、减少其发病率的根本措施和手段，因此胃癌前期病变已成为学术界研究的重点。国外有文献报道‘”，浅表性胃炎中胃癌的危险性增加虽低于萎缩性胃炎，但显著高于正常胃粘膜，而且肠型和弥漫型胃癌的危险性均增高。比较而言，中、重度萎缩性胃炎肠型胃癌的危险性显著增高。萎缩性胃炎伴不完全型肠化生和（或）中、重度异型增生为真正的癌前病变已成为公认，胃粘膜发生癌变有一个演变过程即慢性胃炎～胃粘膜萎缩一肠化一异型增生一胃癌”’。目前西医对本…     

袁红霞教授运用经方治疗慢性萎缩性胃炎并癌前病变临证举隅

正慢性萎缩性胃炎(chronic atrophic gastritis,CAG)是消化系统常见的疾病,表现为胃黏膜上皮及腺体萎缩、黏膜变薄、黏膜肌层增厚,常伴有肠化生及异型增生,而"慢性胃炎→胃黏膜萎缩→肠化生→异型增生→胃癌"这一模式[1]已被广泛接受,2010年《WHO消化系统肿瘤病理学和遗传学》第4版[2]新分类中,将肠化生和异性增生视为胃癌的癌前病变(precancerous lesion of gastric cancer,PLGC)。     

Microsatellite instability in gastric cancer and pre-cancerous lesions

AIM: To investigate the microsatellite instability (MSI) in cancer and pre-cancerous lesions of the stomach and its mechanisms underlying the development of gastric cancer. METHODS: Thirty-six gastric cancer samples were obtained from patients undergoing surgery. Forty-one gastric mucosa samples with dysplasia and 51 with intestinal metaplasia (IM) were obtained from patients with chronic gastritis undergoing gastro-endoscopy. Genomic DNA was extracted from the samples. Silver staining single strand conformation polymorphis-polymerize chain reaction (SSCP-PCR) was used to screen MSI markers at 5 loci (Bat-25, Bat-26, D5S346, D17S250, and D2S123) in fresh tissues and formalin-fixed, paraffin-embedded samples and their corresponding normal gastric mucosa. RESULTS: The abnormal shifting of the single-strand DNA (MSI) was identified in 21 out of 36 (58.3%) gastric cancers. Seven cases showed high-level MSI (two or more loci altered) and 14 showed low-level MSI (one locus altered). Gastric cancer with MSI had a tendency to be located in the distal stomach. MSI was also detected in 11 out of 41 (26.8%) dysplasia samples and in 9 of 51 (17.6%) IM samples respectively. Three cases of dysplasia and one case of IM showed high-level MSI. Eight cases of dysplasia and 8 cases of IM displayed low-level MSI. MIS in IM was found only in moderate or severe-grade IM. No association was detected between MSI and dysplasia grade. CONCLUSION: Accumulation of MSI in dysplasia and intestinal metaplasia of gastric mucosa may be an early molecular event during gastric carcinogenesis and may contribute to the acquisition of transformed cell phenotype and the development of gastric cancer.     

幽门螺杆菌感染和端粒酶活性以及c-myc、p16基因的表达在胃黏膜癌变中的相关性研究

幽门螺杆菌(H.pylori)是胃癌的主要致病因子,H.pylori、端粒酶和肿瘤相关基因的关系在胃黏膜癌变发生过程中研究很少。目的:观察H.pylori感染和端粒酶活性以及c-myc、p16基因在胃癌中的关系。方法:通过胃镜活检和外科手术获取171例胃组织标本,快速尿素酶试验和H.pylori培养确定有无H.pylori感染;酶联免疫法检测H.pylori感染患者的血清CagA-IgG水平;聚合酶链反应.酶联免疫吸附测定(PCR-ELISA)法检测端粒酶活性;免疫组化法检测c-myc、p16基因的表达。结果:胃癌(GC)组端粒酶表达率显著高于其他各组(P<0.01);慢性萎缩性胃炎(CAG)伴中、重度肠化(IM)组端粒酶和c-myc表达率显著高于CAG伴轻度IM组(P<0.05);而慢性浅表性胃炎(CSG)和CAG伴轻度IM组p16表达率显著高于CAG伴中、重度IM、异型增生(Dys)和GC组(P<0.05)。在CAG伴轻、中、重度IM组中,H.pylori阳性组端粒酶活性比阴性组高:无论有无H.pylori感染,胃癌组端粒酶活性都非常高。在CAG伴中、重度IM、Dys和GC组中,H.pylori阳性亚组c-myc表达显著高于阴性亚组(P<0.01),而在ECAG伴中、重度IM和Dys组中,H.pylori阳性亚组p16基因表达显著低于阴性亚组(P<0.01)。结论:H pylori感染很可能主要通过c-myc基因的激活和p16基因的失活以及其他基因的变化来诱导CAG伴中、重度     

Immunohistochemical expression of cell-cycle proteins in gastric precancerous lesions

Background: The early indicator for the subject predisposed to gastric cancer is abnormal proliferation of gastric epithelial cells, such as atrophic gastritis (AG), intestinal metaplasia (IM), and dysplasia, which have been considered as precancerous lesions of gastric cancer. To determine whether p53 protein, cyclins D1, and D3, and p27^kip1 play a role in the carcinogenesis pathway of gastric cancer, we performed an immunohistochemical study of their expression in gastric precancerous lesions. Methods: A total of 1 45 endoscopic gastric biopsy specimens of AG, IM, and gastric dysplasia were studied. These molecular markers were localized by immunohistochemistry. Results: P53 was expressed in 15% of cases with gastric dysplasia and not in the pre‐dysplastic stages of the gastric mucosa. All cases were concerning high‐grade dysplasia. Cyclin D1 protein was almost undetectable in the precancerous lesions of gastric cancer. Cyclin D3 protein overexpression was seen in 10% of biopsies with IM, and 50% of biopsies with gastric dysplasia. High expression of p27^kip1 protein was demonstrated in all cases of chronic gastritis. As atrophy, IM, and dysplasia develop, expression of p27^kip1 protein is suppressed. In total, 15% of dysplastic cases showed no expression of p27^kip1 protein. Conclusions: (i) P53 mutation must be a late event during the development of gastric cancer. (ii) Cyclin D1 protein overexpression may not play a role in the progression from normal to neoplastic gastric mucosa, while overexpression of cyclin D3 is an earlier event during gastric carcinogenesis, and its role must be further evaluated. (iii) Reduced expression of p27^kip1 is a rather early event in gastric tumorigenesis, before dysplastic changes occur.     

胃癌雌孕激素受体表达与幽门螺杆菌感染的关系

目的 探讨胃癌雌激素受体(ER)和孕激素受体(PgR)与幽门螺杆菌(HP)感染的关系.方法:采用S-P免疫组化染色法检测64例胃癌活检组织中ER和PgR.结果:胃癌ER和PgR的阳性表达明显高于肠化生、异型增生和慢性浅表性胃炎(P<0.01);HP阳性胃癌中ER和PgR明显高于HP阴性组(P<0.01);肠化生、异型增生ER和PgR在HP阳性和HP阴性组间均无显著性差异(P>0.05).结论:胃癌中ER和PgR表达与HP感染有相关性.     

Roles of Helicobacter pylori infection and cyclooxygenase-2 expression in gastric carcinogenesis

AIM: Cyclooxygenase (COX)-2 is over expressed in gastrointestinal neoplasm. Helicobacter pylori (H pylori) infection is causally linked to gastric cancer. However, the expression of COX-2 in various stages of H pylori-associated gastric carcinogenesis pathway has not been elucidated. Therefore, the aim of this study was to clarify the role of H pylori induced COX-2 expression during carcinogenesis in the stomach. METHODS: Gastric biopsies from 138 subjects (30 cases of chronic superficial gastritis (CSG), 28 cases of gastric glandular atrophy (GA), 45 cases of gastric mucosal intestinal metaplasia (IM), 12 cases of moderate gastric epithelial dysplasia and 23 cases of gastric cancer) were enrolled. H pylori infection was assessed by a rapid urease test and histological examination (modified Giemsa staining). The expression of COX-1 and COX-2 in human gastric mucosa was detected by immunohistochemical staining. RESULTS: H pylori infection rate was 64.3% in GA and 69.5% in gastric cancer, which was significantly higher than that (36.7%) in CSG (P<0.05). The positive expression rates of COX-2 were 10.0%, 35.7%, 37.8%, 41.7% and 69.5% in CSG, GA, IM, dysplasia and gastric cancer, respectively. From CSG to GA, IM, dysplasia and finally to gastric cancer, expression of COX-2 showed an ascending tendency, whereas COX-1 expression did not change significantly in the gastric mucosa. The level of COX-2 expression in IM and dysplasia was significantly higher in H pylori-positive than in H pylori-negative subjects (P<0.01). CONCLUSION: COX-2 expression induced by H pylori infection is a relatively early event during carcinogenesis in the stomach.     

PTEN encoding product： a marker for tumorigenesis and progression of gastric carcinoma

AIM: To detect the expression of PTEN encoding productin normal mucosa, intestinal metaplasia (IM), dysplasia andcarcinoma of the stomach, and to investigate its clinicalimplication in tumorigenesis and progression of gastriccarcinoma.METHODS: Formalin-fixed paraffin embedded specimens from184 cases of gastric carcinoma, their adjacent normal mucosa,IM and dysplasia were evaluated for PTEN protein expressionby SABC immunohistochemistry. PTEN expression wascompared with tumor stage, lymph node metastasis, Lauren'sand WHO's histological classification of gastric carcinoma.Expression of VEGF was also detected in 60 cases of gastriccarcinoma and its correlation with PTEN was concerned.RESULTS: The positive rates of PTEN protein were 100 %(102/102), 98.5 %(65/66), 66.7 % (4/6) and 47.8 %(88/184)in normal mucosa, IM, dysplasia and carcinoma of the stomach,respectively. The positive rates in dysplasia and carcinomawere lower than in normal mucosa and IM (P＜0.01).Advanced gastric cancers expressed less frequent PTEN thanearly gastric cancer (42.9 % v567.6 %, P＜0.01). The positiverate of PTEN protein was lower in gastric cancer with thanwithout lymph node metastasis (40.3 % v563.3 %, P＜0.01).PTEN was less expressed in diffuse-type than in intestinal-type gastric cancer (41.5 % v557.8 %,P＜0.05). Signet ringcell carcinoma showed the expression of PTEN at the lowestlevel (25.0 %, 7/28); less than well and moderatelydifferentiated ones (P＜0.01). Expression of PTEN was notcorrelated with expression of VEGF (P＞0.05).CONCLUSION: Loss or reduced expression of PTEN proteinoccures commonly in tumorigenesis and progression of gastriccarcinoma. It is suggested that PTEN can be an objective markerfor pathologically biological behaviors of gastric carcinoma.     

Intracellular and interstitial expression of Helicobacter pylori virulence genes in gastric precancerous intestinal metaplasia and adenocarcinoma

Gastric intestinal metaplasia (IM) and gastric cancer are associated with Helicobacter pylori, but the bacterium often is undetectable in these lesions. To unravel this apparent paradox, IM, H. pylori presence, and the expression of H. pylori virulence genes were quantified concurrently using histologic testing, in situ hybridization, and immunohistochemistry. H. pylori was detected inside metaplastic, dysplastic, and neoplastic epithelial cells, and cagA and babA2 expression was colocalized. Importantly, expression of cagA was significantly higher in patients with IM and adenocarcinoma than in control subjects. The preneoplastic "acidic" MUC2 mucin was detected only in the presence of H. pylori, and MUC2 expression was higher in patients with IM, dysplasia, and cancer. These novel findings are compatible with the hypothesis that all stages of gastric carcinogenesis are fostered by persistent intracellular expression of H. pylori virulence genes, especially cagA inside MUC2-producing precancerous gastric cells and pleomorphic cancer cells.     

Role of intestinal metaplasia subtyping in the risk of gastric cancer in Korea

Background and Aim:  Gastric cancer is believed to develop by a multistage process. Intestinal metaplasia (IM) is regarded as a premalignant condition; it is classified into subtypes I, II and III. The aim of this study was to evaluate whether the subtypes of IM were associated with progression to gastric cancer.
Methods:  The study cohort consisted of 861 subjects, categorized as controls, gastric ulcers, dysplasia and cancer. The IM was scored histologically using the Sydney classification for the antrum and the body of the stomach. The biopsies were stained with high iron diamine and alcian blue (pH 2.5) (HID-AB2.5), and the IM was subtyped as I, II or III.
Results:  The proportion of IM subtypes I, II and III were 14.5%, 47.2% and 38.3% in the antrum, and 28.1%, 57.8% and 14.1% in the body of the stomach, respectively. These distributions did not show significant differences depending on disease or Helicobacter pylori positivity. In cases that were H. pylori -positive, the prevalence of IM subtype II in the cancer and dysplasia groups was higher than in the control group in the body of the stomach ( P  < 0.05). The proportion of IM subtype III in the antrum increased in proportion with age ( P  = 0.036).
Conclusions:  IM subtyping was not found to play a major role in the prediction of gastric cancer development in Korea. IM subtype III was associated with aging, and IM subtype II appeared to be related to gastric carcinogenesis in the presence of H. pylori infection.     

Helicobacter pylori associated gastric intestinal metaplasia: Treatment and surveillance

Gastric cancer(GC) is one of the leading causes of cancer related death in the world, particularly in East Asia. According to the Correa's cancer cascade, noncardia GC is usually developed through a series of mucosal changes from non-atrophic gastritis to atrophic gastritis(AG), intestinal metaplasia(IM), dysplasia and adenocarcinoma. Atrophic gastritis and IM are therefore generally considered to be pre-neoplastic gastric lesions. Helicobacter pylori(H. pylori) infection is an important initiating and promoting step of this gastric carcinogenesis cascade. Emerging long-term data showed that eradication of H. pylori reduced the risk of subsequent cancer development. It however remains confusing whether eradication of the bacterium in individuals with pre-neoplastic gastric lesions could regress these changes as well as in preventing cancer. Whilst H. pylori eradication could likely regress AG, the presence of IM may be a point of no return in this cascade. Hence, surveillance by endoscopy may be indicated in those with extensive IM or those with incomplete IM, particularly in populations with high GC risk. The optimal interval and the best tool of surveillance endoscopy remains to be determined in future studies.