p27蛋白与细胞周期蛋白D1在疣状胃炎和胃癌组织中的表达及其意义

背景：疣状胃炎是一种具有特殊形态的慢性胃炎,与胃癌可能存在一定关系,但其癌变的分子机制尚不清楚。p27蛋白与细胞周期蛋白D1（cyclin D1）的异常表达参与了胃癌的发生、发展。目的：探讨p27蛋白和cyclin D1在疣状胃炎和胃癌组织中的表达及其意义。方法：收集慢性非萎缩性胃炎、未成熟型疣状胃炎、成熟型疣状胃炎、胃癌组织标本各40例,采用免疫组化法检测p27蛋白、cyclin D1表达,并分析两者与疣状胃炎患者性别、年龄、Hp感染、肠化生、异型增生的关系。结果：未成熟型疣状胃炎组p27蛋白阳性表达率显著高于胃癌组（77．5％对45．0％,P〈0．05）,与慢性非萎缩性胃炎组相比无明显差异（P〉0．05）。成熟型疣状胃炎组p27蛋白阳性表达率显著低于慢性非萎缩性胃炎组和未成熟型疣状胃炎组（52．5％对85．0％、77．5％,P〈0．05）,与胃癌组相比无明显差异（P〉0．05）。未成熟型、成熟型疣状胃炎组cyclin D1阳性表达率均显著高于慢性非萎缩性胃炎组（40．0％、42．5％对12．5％,P〈0．05）,但均显著低于胃癌组（P〈0．05）。疣状胃炎患者p27蛋白表达与肠化生、异型增生有关（P〈0．05）,cyclin D1表达与肠化生有关（P〈0．05）;p27蛋白、cyclin D1表达与性别、年龄均无关。结论ip27蛋白、cyclin D1可能参与了疣状胃炎的发生和癌变过程。     

胃癌及其癌前病变中细胞凋亡与细胞增殖间关系的研究

目的　通过观察胃癌及其癌前病变中细胞凋亡与细胞增殖间的关系,探讨细胞凋亡在胃癌发生中的作用．方法　利用脱氧核糖核酸末端转移酶介导的ｄ ＵＴＰ 缺口末端标记（ＴＵＮＥＬ） 技术及增殖细胞核抗原（ ＰＣＮＡ） 免疫组织化学染色对１０ 例正常胃粘膜、１６ 例萎缩性胃炎、３６ 例肠化生、２０ 例异型增生和５３ 例胃癌中的凋亡细胞、增殖细胞进行原位观察和比较．结果　萎缩性胃炎、肠化生、异型增生中凋亡细胞指数（１１－９ ％ ;１４－７ ％ ,８－０ ％ ） 均显著高于正常胃粘膜和 胃癌（３－５ ％ ,５－８ ％ ,ｔ ＝ ２－０５８ ～７－９０１ ,Ｐ＜ ０－０１ ～Ｐ ＜ ０－０５） ;异型增生、胃癌与肠化生相比,凋亡细胞明显减少、增殖细胞明显增多（ Ｐ＜ ０－０５） ;胃癌细胞增殖指数（４７－５ ％ ） 显著高于异型增生（３０－１ ％ ,Ｐ＜ ０－０１） ． 胃癌前病变及胃癌组织中的凋亡细胞指数与 增 殖细 胞指 数 呈显 著相 关（ ｒ ＝ ０－９６６ , － ０－８９７ ,Ｐ＜ ０－０５） ．结论　胃粘膜癌变过程中不仅存在活跃的细胞增殖,而且存在细胞凋亡异常． 高增殖能力的细胞可能通过选择而占据优势,导致胃癌的发生． 细胞凋亡与细胞增殖平衡失调在胃癌发病中可能起重要作用     

Mutant p53 expression and apoptotic activity of Helicobacter pylori positive and negative gastritis in correlation with the presence of intestinal metaplasia

BACKGROUND: Mutation of the p53 gene is detectable in most cases of gastric cancer, as it is the most common genetic alteration in human malignancies. It is also well documented that Helicobacter pylori infection plays an important role in gastric carcinogenesis. There is still no clarification, however, concerning how genetic instability influences the homeostasis of gastric epithelium. We have studied the effect of H. pylori infection on apoptosis of the antral epithelium in the presence/absence of intestinal metaplasia and the expression of the p53 oncoprotein. The relationship between these two processes is analysed. METHODS: Antral biopsies were taken from 36 patients who underwent routine upper endoscopy (17 men, 19 women, mean age 61.0 years). The biopsies were fixed in formalin and embedded in paraffin. Patients were classified into two histological groups: (1) as chronic gastritis without intestinal metaplasia (n = 19), and (2) chronic gastritis with intestinal metaplasia (n = 17). An immunohistochemical method was used to detect the expression of p53 oncoprotein, and the terminal transferase mediated dUTP nick end-labelling (TUNEL) method was used to detect apoptotic cells. RESULTS: In the absence of intestinal metaplasia, both the apoptotic index (0.0272 +/- 0.011 vs 0.0128 +/- 0.006) and expresssion of p53 (35.55 +/- 31.16 vs 18.33 +/- 19.65) were significantly higher in H. pylori positive cases compared to H. pylori negative cases. In the presence of intestinal metaplasia, p53 expression was further increased (P < 0.05), but apoptosis was similar to that observed in H. pylori negative gastritis without intestinal metaplasia. In the presence of intestinal metaplasia, H. pylori infection did not influence apoptosis (0.013 +/- 0.004 vs 0.011 +/- 0.004), or p53 ratio (70.16 +/- 22.54 vs 68.50 +/- 28.96). In the sequence of gastritis-intestinal metaplasia the two indices show a close negative correlation (P < 0.05). CONCLUSION: In the absence of intestinal metaplasia H. pylori infection increases both apoptotic activity and expression of p53 oncoprotein in the gastric mucosa. The lack of increased apoptosis with a higher p53 expression in the presence of intestinal metaplasia suggests an increased genetic instability and also may suggest that mutation of the p53 gene is an early step in the multistep process of gastric carcinogenesis.     

Atrophy-metaplasia-dysplasia-carcinoma sequence in the stomach: a reality or merely an hypothesis?

The results of recent investigations have suggested that the old hypothesis of an atrophy-metaplasia-dysplasia-carcinoma sequence in the stomach needs to be qualified. The most common cause of intestinal metaplasia is Helicobacter pylori gastritis. The consequence of this intestinal metaplasia is focal atrophy. Helicobacter pylori infection may also trigger an autoimmune gastritis of the corpus mucosa, with atrophy and intestinal metaplasia. Most intestinal metaplasias are only 'paracancerous' but not 'precancerous' lesions. Diffuse gastric carcinomas, such as the signet ring cell carcinoma, arise independently of intestinal metaplasia. Histogenetically, numerous carcinomas of the stomach are primarily of the gastric type, and may secondarily change into the intestinal type.High-grade intra-epithelial neoplasias (dysplasias) detected during the biopsy-based diagnostic work-up appear to be a marker for carcinoma and must, therefore, be removed endoscopically.The detection of intestinal metaplasia in routinely obtained biopsy material is subject to sampling error and is, therefore, not a suitable marker for an increased risk of a gastric carcinoma developing. As an alternative, the concept of gastritis of the carcinoma phenotype, which is more frequently found in early gastric carcinomas and in the relatives of gastric carcinoma patients, has been developed. In this concept, the diffuse parameters of grade and activity of the gastritis in the antrum and corpus, which are independent of sampling error, are subjected to a comparative analysis. A risk gastritis of the carcinoma phenotype is diagnosed when the grade and activity of the gastritis in the corpus are at least equally as pronounced as in the antrum. Currently, this concept is being tested in a prospective ongoing study. Future studies must show whether, and if so which, immunohistochemical or molecular-genetically detectable changes can be applied as risk markers in the diagnostic work-up. Helicobacter pylori eradication probably does not lead to complete regression of the intestinal metaplasia and ensuing focal atrophy. However, eradication of H. pylori does lead to the normalization of changes that can lead to mutations of the stem cells of the gastric mucosa (free radicals, nitric oxide, cell proliferation and vitamin C secretion).     

早期胃癌和进展期胃癌患者幽门螺杆菌感染与胃黏膜组织学特点的关系

背景幽门螺杆菌(H.pylori)感染已被确认为慢性胃炎的主要病因,由慢性非萎缩性胃炎、慢性萎缩性胃炎至肠化生,经过数十年最终可能导致胃癌发生。目的评价H.pylori感染与胃镜检查正常者、慢性胃炎、早期胃癌和进展期胃癌患者胃黏膜组织学特点的关系。方法在受检者胃窦大弯侧、胃体大弯侧和胃角处各取一块黏膜活检标本,以Giemsa染色和免疫组化染色检测H.pylori感染情况;以HE染色评价胃黏膜炎症、活动性、萎缩和肠化生情况。结果慢性胃炎、早期胃癌和进展期胃癌患者的总体H.pylori感染率均显著高于胃镜检查正常者(52.4%、52.4%和81.2%对44.9%,P<0.05),慢性胃炎与早期胃癌患者的感染率无显著差异,但均显著低于进展期胃癌患者(P<0.05)。胃镜检查正常和慢性胃炎组H.pylori感染者的胃黏膜炎症、活动性、萎缩和肠化生检出率均显著高于无感染者(P<0.05);早期胃癌和进展期胃癌组H.pylori感染者的炎症活动性检出率显著高于无感染者(P<0.05),而炎症、萎缩和肠化生检出率与无感染者无显著差异。结论由H.pylori感染引起的胃黏膜慢性炎症、萎缩和肠化生可能在胃癌的发生、发展过程中起直接或间接作用。     

The intestinal and diffuse type of the gastric carcinoma (author's transl)

According to the Laurén classification 357 carcinomas of the stomach were reclassified into intestinal and diffuse types. 58.2% were assigned to the intestinal type, 37.5% to the diffuse and 4% to a "mixed" group. There is obvious correlation between the intestinal type, the patients' advancing age and the incidence of chronic, atrophising gastritis with intestinal metaplasia. The diffuse type on the other hand occurs irrespective of gastric changes - mostly in younger persons. The intestinal type of gastric carcinoma frequently is found in risk areas where incidence is "epidemic" in nature; morphology and genetic origin seem to be gastric mucosa changes and intestinal metaplasia or dysplasia. Classifying gastric carcinoma according to Laurén (two groups) is also an appropriate method in our regions as was confirmed by the results we obtained; it is superior to the much more differentiated macro- and microscopic classifications used so far. Because of its simplicity, it is better suited for epidemiological and pathogenetic studies of the gastric carcinoma.     

Livin和CyclinD1在慢性萎缩性胃炎伴肠化黏膜中的表达及意义

目的:探讨凋亡抑制蛋白Livin和细胞周期蛋白D1(CyclinD1)在慢性萎缩性胃炎(chronicatrophicgastritis,CAG)伴肠化癌变过程中的表达及其相关性.方法:应用免疫组织化学染色S-P法检测Livin和CyclinD1在30例慢性浅表性胃炎(chronicsuperficialgastritis,CSG)、35例CAG非肠化、35例CAG伴肠化、30例胃癌组织中的表达,并同时研究二者在CAG伴肠化癌变中表达的相关性.结果:在CSG、CAG非肠化、CAG伴肠化、胃癌中Livin、CyclinD1的阳性表达率分别为:0%、10%;28.57%、14.29%;45.71%、37.14%;66.67%、53.33%,二者在CAG(非肠化)和CSG对比均有统计学意义(P<0.05);CAG(伴肠化)与CAG(非肠化)相比,CyclinD1的阳性表达率有统计学意义(P<0.05);Livin和CyclinD1在CAG伴肠化、胃癌组织中表达呈正相关.结论:Livin、CyclinD1蛋白在CAG(伴肠化)和胃癌组织中表达呈上调状态,且CAG(伴肠化)和胃癌组织间无显著差异,二者表达一致,提示CAG(伴肠化)已具有癌变的分子生物学特征.二者在胃癌的发生、发展中起协同作用,对其进行联合检测将有助于胃癌的早期诊断.     

Helicobacter pylori-associated gastritis and gastric cancer in Nigeria.

BACKGROUND: The etiology of gastric cancer has not been clearly delineated. There is some evidence of an association of gastric cancer with Helicobacter pylori-induced chronic gastritis, atrophic gastritis and intestinal metaplasia. Previous studies report a high rate of H. pylori infection and chronic gastritis among Nigerians. METHODS: We retrospectively reviewed 84 tissue specimens with gastric cancer seen in our department over an 18-year period for for the presence of H. pylori infection, chronic gastritis, atrophic gastritis, and intestinal metaplasia in the adjacent non-cancerous gastric mucosa. RESULTS: H. pylori infection was detected in 15 (17.9%) of 84 specimens. Moderate to severe gastritis was found in non-cancerous areas in 77 (91.7%) specimens, and was equally frequent in patients with 'intestinal' and 'diffuse' types of cancer. Atrophic gastritis and intestinal metaplasia were observed in 22 (26.2%) and 35 (41.7%) specimens, respectively, and were more common in 'intestinal' type of gastric cancer. CONCLUSION: Chronic gastritis was seen in the adjacent non-cancerous mucosa in most specimens with gastric cancer. However, its severity did not correlate with the histological subtype of gastric cancer.     

Different gastritis features are linked to different gastric neoplasms.

OBJECTIVES: Helicobacter pylori infection induces gastritis, which may evolve to carcinoma or lymphoma. Whether duration of infection and inflammation pattern determine the outcome of the neoplastic process is not known. The aim of this study was to investigate the features of the gastritis associated with neoplasia. METHODS: Gastritis found in association with carcinoma (100 cases) and lymphoma (45 cases) were graded using the Sydney system. RESULTS: In particular in the antrum, gastric carcinomas, in particular of the intestinal type, were associated with a chronic (94%, n = 34/36) atrophic (92%, n = 33/36) gastritis and intestinal metaplasia (81%, n = 29/36). In diffuse type carcinomas inflammation was either absent or mild. An active (64%, n = 16/25), chronic gastritis (100%, n = 25/25) with lymphoid hyperplasia (72%, n = 18/25) was found in marginal zone cell lymphoma. CONCLUSIONS: Our study shows that the (pre)atrophic phases of inflammation are associated with gastric carcinomas. In contrast the active phase of inflammation, characterized by severe activity as well as severe chronicity, is found next to marginal zone cell lymphoma.     

Helicobacter pylori infection and expression of the angiogenic factor platelet-derived endothelial cell growth factor by pre-neoplastic gastric mucosal lesions and gastric carcinoma

BACKGROUND: Expression of the angiogenic factor platelet-derived endothelial cell growth factor is induced in some gastric carcinomas. Whether angiogenesis is induced early in the development of gastric pre-neoplastic lesions and whether Helicobacter pylori infection affects platelet-derived endothelial cell growth factor expression is not known. AIM: To assess whether chronic gastritis, intestinal metaplasia, gastric dysplasia and gastric carcinomas express platelet-derived endothelial cell growth factor and whether Helicobacter pylori infection might affect the expression of platelet-derived endothelial cell growth factor in these lesions. PATIENTS AND METHODS: Patients with gastric carcinomas, atrophic gastritis with associated intestinal metaplasia, dysplasia and controls without infection or carcinoma were studied. RESULTS: Platelet-derived endothelial cell growth factor was detected by immunohistochemistry in 9 out 19 gastric carcinomas (45%). Only focal immunostaining was detected in intestinal metaplasia adjacent to dysplasia and in dysplastic cells. Of the tumours, 90% contained platelet-derived endothelial cell growth factor-positive interstitial cells. A significant correlation was found between active Helicobacter pylori infection and a larger number of platelet-derived endothelial cell growth factor-positive interstitial cells in areas of intestinal metaplasia (p<0.05). CCONCLUSION:Helicobacter pylori infection does not influence the expression of platelet-derived endothelial cell growth factor, once gastric cancer has developed. However, Helicobacter pylori infection may increase the extension of expression of platelet-derived endothelial cell growth factor by infiltrating interstitial cells in premalignant lesions, such as intestinal metaplasia, which may help create a favourable environment for tumour development. This may possibly be due to non-specific increase in recruitment of inflammatory cells caused by Helicobacter pylori infection. Further studies, with a larger number of samples, are now needed in order to confirm this finding.     

吉法酯治疗慢性萎缩性胃炎伴肠上皮化生的疗效评价

背景:慢性萎缩性胃炎伴肠上皮化生被视为胃癌前病变,探索其有效治疗药物对降低胃癌发病率和死亡率具有重要意义。目的:探讨吉法酯对慢性萎缩性胃炎伴肠化生的疗效。方法:133例慢性萎缩性胃炎伴肠化生患者随机进入吉法酯组和对照组。吉法酯组:吉法酯100 mg tid,疗程3个月;对照组:胃复春1400 mg tid,疗程3个月。治疗前和治疗结束后3个月采用AB-PAS和HID-AB染色法行肠化生分型,采用HE染色法对胃黏膜炎症程度进行分级。结果:治疗结束3个月后,吉法酯组慢性萎缩性胃炎伴肠化生转变为非萎缩性胃炎的比例(逆转率)与对照组相比显著升高(32.84%对15.15%,P=0.017),其中不完全性小肠化生的逆转率与对照组相比显著升高(48.28%对16.67%,P=0.016),完全性小肠化生的逆转率与对照组相比有所升高,但差异无统计学意义(33.33%对16.67%,P=0.375)。吉法酯组小肠型化生的逆转率显著高于结肠型化生的逆转率(44.74%对17.24%,P=0.018)。吉法酯组胃黏膜慢性炎症程度减轻较对照组显著(χ2=11.061,P=0.011)。结论:吉法酯对慢性萎缩性胃炎具有较好的疗效,且能有效逆转不完全性小肠化生。     

Helicobacter pylori and early gastric cancer.

The relation between Helicobacter pylori, intestinal metaplasia, and early gastric cancer was studied by examining gastrectomy specimens from 31 intestinal type and 22 diffuse type carcinomas. A total of 298 patients with antral gastritis were used as controls. Atrophic changes and intestinal metaplasia were significantly more common in intestinal type early gastric cancer compared with diffuse type early gastric cancer (p < 0.05 and p < 0.001, respectively). H pylori was found in 61.3% of intestinal type early gastric cancer and in 54.5% of diffuse type early gastric cancer (NS). The age adjusted prevalence of intestinal metaplasia in the patients with antral gastritis was higher in H pylori positive patients in all age groups studied. Comparing gastritis patients with patients with intestinal type early gastric cancer showed the age adjusted prevalence of intestinal metaplasia to be significantly higher in the patients with early gastric cancer in all age groups studied. In conclusion, H pylori is associated with both types of early gastric carcinoma. Intestinal metaplasia formation seems to be a multifactorial process in which H pylori may play a part. These findings suggest that gastric cancer may be included in the spectrum of H pylori associated diseases, although many questions about causality remain to be answered.     

BSG President's Report for 1994-5

p53 Protein accumulation in early gastric carcinoma was studied in relation to the histological type (Lauren classification) and the type of growth pattern, including the chronology of p53 protein accumulation during carcinogenesis. Forty five, paraffin embedded gastrectomy specimens from early carcinomas were examined for the presence of chronic atrophic gastritis, subtypes of intestinal metaplasia, and dysplasia. The Lauren type and the type of growth pattern were reassessed for all early carcinomas. p53 Protein accumulation was examined using the monoclonal antibody DO-7. Complete absence of p53 protein accumulation was observed in normal gastric mucosa, chronic atrophic gastritis, and intestinal metaplasia, irrespective of subtype. In gastric dysplasia (one mild, two moderate, and one severe), only severe dysplasia was p53 positive. Intestinal type (n = 20) and diffuse type early gastric carcinomas (n = 25) were p53 positive in 70% and 52% of cases, respectively. Both tumour types differed significantly in the percentage of p53 positive tumour cells per tumour (p < 0.01) and in staining intensity (p < 0.05). No significant difference in p53 protein accumulation was found between early carcinomas with different types of growth pattern. It is concluded that p53 protein accumulation--usually reflecting missense p53 gene mutation--seems to be a late event in gastric carcinogenesis. Moreover, it is suggested that missense p53 gene mutation occurs in a final pathway common to both intestinal and diffuse type of early gastric carcinoma. Finally, the types of growth pattern do not seem to differ in p53 protein accumulation.     

Bax and Bcl-2 protein expression in gastric precancerous lesions: immunohistochemical study

BACKGROUND AND AIMS: Bcl-2 protein prolongs cell survival in the face of classical apoptotic stimuli, and is considered to be a suppressor of apoptosis. Bax plays a key role in apoptosis by accelerating cell death after an apoptotic stimulus. The aim of our study was to determine the roles of the Bax proapoptotic gene and the Bcl-2 antiapoptotic gene in the carcinogenesis of gastric cancer. METHODS: One hundred and forty-five gastric biopsy specimens of chronic gastritis, atrophic gastritis, intestinal metaplasia and gastric dysplasia were studied. Using immunohistochemical methods, Bax and Bcl-2 protein expression was observed. RESULTS: Bax was expressed in epithelial cells in all cases of chronic gastritis. Bax was not detected in 26% of specimens of atrophic gastritis. As intestinal metaplasia develops, Bax is further suppressed. In biopsy samples with dysplasia, Bax expression was demonstrated only in 12% of biopsy samples. Although Bcl-2 protein was not detected in chronic gastritis, aberrant expression was found in gastric epithelial intestinal metaplasia and dysplasia. CONCLUSIONS: The suppression of Bax and overexpression of Bcl-2 protein is an early event in gastric tumorigenesis, before gastric dysplastic changes occur.     

Prevalence of Helicobacter pylori infection in advanced gastric carcinoma

BACKGROUND: [corrected] There is substantial evidence that infection with Helicobacter pylori plays a role in the development of gastric cancer and that it is rarely found in gastric biopsy of atrophic gastritis and gastric cancer. On advanced gastric tumors, the bacteria can be lost from the stomach. AIMS: To analyze the hypothesis that the prevalence of H.pylori in operated advanced gastric carcinomas and adjacent non-tumor tissues is high, comparing intestinal and diffuse tumors according to Lauren's classification METHODS: A prospective controlled study enrolled 56 patients from "Hospital Universitário", Federal University of Rio Grande do Norte, Natal, RN, Brazil, with advanced gastric cancer, treated from February 2000 to March 2003. Immediately after partial gastrectomy, the resected stomach was opened and several mucosal biopsy samples were taken from the gastric tumor and from the adjacent mucosa within 4 cm distance from the tumor margin. Tissue sections were stained with hematoxylin and eosin. Lauren's classification for gastric cancer was used, to analyse the prevalence of H. pylori in intestinal or diffuse carcinomas assessed by the urease rapid test, IgG by ELISA and Giemsa staining. H. pylori infected patients were treated with omeprazole, clarithromycin and amoxicillin for 7 days. Follow-up endoscopy and serology were performed 6 months after treatment to determine successful eradication of H. pylori in non-tumor tissue. Thereafter, follow-up endoscopies were scheduled annually. Chi-square and MacNemar tests with 0.05 significance were used. RESULTS: Thirty-four tumors (60.7%) were intestinal-type and 22 (39.3%) diffuse type carcinomas. In adjacent non-tumor gastric mucosa, chronic gastritis were found in 53 cases (94.6%) and atrophic mucosa in 36 patients (64.3%). All the patients with atrophic mucosa were H. pylori positive. When examined by Giemsa and urease test, H. pylori positive rate in tumor tissue of intestinal type carcinomas was higher than that in diffuse carcinomas. In tumor tissues, 34 (60.7%) H. pylori-positive in gastric carcinomas were detected by Giemsa method. H. pylori was observed in 30 of 56 cases (53.5%) in tissues 4 cm adjacent to tumors. This difference was not significant. Eradication of H. pylori in non-tumor tissue of gastric remnant led to a complete negativity on the 12th postoperative month CONCLUSIONS: The data confirmed the hypothesis of a high prevalence of H. pylori in tumor tissue of gastric advanced carcinomas and in adjacent non-tumor mucosa of operated stomachs. The presence of H. pylori was predominant in the intestinal-type carcinoma.     

Atrophy–metaplasia–dysplasia–carcinoma sequence in the stomach: a reality or merely an hypothesis?

The results of recent investigations have suggested that the old hypothesis of an atrophy–metaplasia–dysplasia–carcinoma sequence in the stomach needs to be qualified. The most common cause of intestinal metaplasia is Helicobacter pylori gastritis. The consequence of this intestinal metaplasia is focal atrophy.Helicobacter pylori infection may also trigger an autoimmune gastritis of the corpus mucosa, with atrophy and intestinal metaplasia. Most intestinal metaplasias are only ‘paracancerous’ but not ‘precancerous’ lesions. Diffuse gastric carcinomas, such as the signet ring cell carcinoma, arise independently of intestinal metaplasia. Histogenetically, numerous carcinomas of the stomach are primarily of the gastric type, and may secondarily change into the intestinal type.High-grade intra-epithelial neoplasias (dysplasias) detected during the biopsy-based diagnostic work-up appear to be a marker for carcinoma and must, therefore, be removed endoscopically.The detection of intestinal metaplasia in routinely obtained biopsy material is subject to sampling error and is, therefore, not a suitable marker for an increased risk of a gastric carcinoma developing. As an alternative, the concept of gastritis of the carcinoma phenotype, which is more frequently found in early gastric carcinomas and in the relatives of gastric carcinoma patients, has been developed. In this concept, the diffuse parameters of grade and activity of the gastritis in the antrum and corpus, which are independent of sampling error, are subjected to a comparative analysis. A risk gastritis of the carcinoma phenotype is diagnosed when the grade and activity of the gastritis in the corpus are at least equally as pronounced as in the antrum. Currently, this concept is being tested in a prospective ongoing study. Future studies must show whether, and if so which, immunohistochemical or molecular-genetically detectable changes can be applied as risk markers in the diagnostic work-up.Helicobacter pylori eradication probably does not lead to complete regression of the intestinal metaplasia and ensuing focal atrophy. However, eradication ofH. pylori does lead to the normalization of changes that can lead to mutations of the stem cells of the gastric mucosa (free radicals, nitric oxide, cell proliferation and vitamin C secretion).     

Expression of MUC2 in gastric carcinomas and background mucosae

BACKGROUND AND AIM: Gastric carcinomas contain elements of both intestinal and diffuse types. Such heterogeneous components may distort the evaluation of the role of the mucin MUC2 in gastric carcinoma. The role of MUC2 expression in background mucosa is not yet clarified. METHODS: We analyzed the expression of MUC2 in gastric mucosa and intestinal metaplasia adjacent to the tumoral area and carcinomas (n = 98) using immunohistochemistry. The immunoreactivity was quantified using an immunohistochemical scoring system. RESULTS: In the intestinal metaplasia adjacent to the tumoral area, MUC2 was detected in 76 (97.4%) of 78 intestinal metaplasia, and MUC2 expression was inversely associated with the depth of wall penetration (P = 0.026) and tumor stage (P = 0.021). Although the expression rate of MUC2 antigens was higher in intestinal-type adenocarcinoma than in diffuse-type adenocarcinoma, a significant correlation with pathologic staging of the TNM system (pTNM staging) and MUC2 expression could not be found in each subtype of gastric carcinomas. CONCLUSION: The expression of MUC2 in intestinal metaplasia was higher in tumors of earlier stages. These findings suggest that increased MUC2 expression in intestinal metaplasia in the neighborhood of the carcinomas may play an important role in gastric carcinomas. Further investigations regarding the role of MUC2 expression in gastric carcinoma and background mucosae are necessary.     

Epithelial cell turnover, p53 and bcl-2 protein expression during oncogenesis of early and advanced gastric cancer in a Western population

OBJECTIVES: To investigate epithelial cell turnover alterations, and p53, bcl-2 protein expression during development of early and advanced gastric cancer in a Western population. METHODS: We investigated cell apoptosis and proliferation rates, p53 and bcl-2 protein expression in 17 early and 34 advanced gastric carcinomas and in the adjacent non-dysplastic mucosa. Cell proliferation, p53 and bcl-2 expression were detected immunohistochemically using MIB-1, anti-p53 and anti-bcl-2 monoclonal antibodies. Apoptosis was measured by TUNEL. The rate of the positive stained cells (labelling index) was count using image analysis technique. RESULTS: No difference was observed of either apoptotic (10 vs. 11) or proliferation (35 vs. 25) index between early and advanced cancers. However, the apoptotic index was significantly higher in intestinal type advanced tumors. While both apoptotic and proliferation indices were significantly higher in tumors than in the adjacent mucosa, no difference was observed of either apoptotic (2 vs. 2) or proliferation (8 vs. 13) index between the tissues adjacent to early and advanced tumors. p53 protein expression was significantly higher in advanced cancers (7 vs. 5, p=0.001) and in the non-dysplastic tissue adjacent to advanced tumors (3.5 vs. 2, p=0.001). bcl-2 labelling index was significantly higher in the mucosa adjacent to advanced carcinomas (15 vs. 5, p=0.016) but this difference did not reach significance in the tumors (20 vs. 15, p=0.37). CONCLUSIONS: Our data indicate similar cell turnover during tumorigenesis of early and advanced cancer. p53 and bcl-2 protein accumulation is more intense in gastric mucosa adjacent to advanced tumors and p53 immunoreactivity peaks in advanced carcinomas.     

The gastric mucosa in gastric cancer patients in a low-incidence area

BACKGROUND AND AIMS: Atrophic gastritis, intestinal metaplasia, and pyloric metaplasia are frequent precursors of noncardial intestinal-type gastric adenocarcinoma in populations in which both gastric cancer and Helicobacter pylori infection are common. We hypothesized that such lesions would be less prevalent in European gastric cancer patients. METHODS: Slides from patients who underwent gastrectomy for adenocarcinoma between 1997 and 2004 were reviewed. Tumors were categorized as intestinal or diffuse; non-neoplastic mucosa was evaluated for gastritis, atrophy, intestinal metaplasia and pyloric metaplasia. RESULTS: We studied 81 patients: 48 Swiss (mean age 68.5 years); 17 Italians (mean age 67.8 years); and 16 Iberians (mean age 54.8 years; P<0.001). Twelve tumors were proximal (all intestinal type), 12 in the corpus (six intestinal-type), and 57 antral (30 intestinal type). Patients with diffuse cancers were younger than those with intestinal type (P<0.05). Nineteen patients (23.4%) had a normal stomach; 30% of T1 tumors and 90% of T4s arose in a normal stomach (P<0.02). H. pylori gastritis was found in 47 patients (58%); they did not differ in age, sex, national origin, cancer location or type from those without gastritis. Intestinal metaplasia correlated with H. pylori gastritis (P=0.002). Pyloric metaplasia was infrequent and limited to rare microfoci. CONCLUSIONS: A quarter of the patients had a normal stomach, and pyloric metaplasia was distinctly uncommon. Approaches to prevention and early detection of gastric cancer based on bioptic or serological demonstration of atrophy and metaplasia could overlook at least 25% of the people at risk in certain populations and may need to be adapted to local conditions.