Gastric cancer with special references to WHO and Laurén's classifications: glycogen and triacylglycerol concentrations in the tumor

In eighty patients with histologically verified gastric carcinoma the concentrations of glycogen and triacylglycerols were evaluated in specimens taken endoscopically from the tumor and the surrounding unchanged gastric mucosa. The results were analyzed in relation to the histological type of carcinoma according to WHO's and Laurén's classifications. The control group consisted of sixteen patients with superficial chronic gastritis. An elevated glycogen concentration was found in tumors of all types of gastric carcinoma; its level in the neoplasm was significantly higher also in relation to unchanged gastric mucosa surrounding the tumor. A particularly high glycogen level was present in the slow growing well-differentiated cancers, e.g. papillary and tubular adenocarcinomas or intestinal-type carcinoma. Reversely, in the fast growing and poorly differentiated cancers, e.g. undifferentiated or diffuse-type carcinoma, the glycogen contents were lower. Also triacylglycerol concentrations in the tumors as well as in the surrounding unchanged gastric mucosa were significantly higher than those in the control gastric mucosa specimens; no significant difference in triacylglycerol concentrations was observed between groups of patients with various types of carcinoma. It was concluded that (1) glycogen concentrations in the neoplastic tissue are cancer-growth related and characteristic for each kind of carcinoma, (2) an elevated triacylglycerol content in the tumor is probably a result of general lipid changes in the host.     

STUDY OF THE TUMOR VESSELS IN DEPRESSED‐TYPE EARLY GASTRIC CANCERS USING NARROW BAND IMAGING MAGNIFYING ENDOSCOPY AND CDNA ARRAY ANALYSIS

Background: Since endoscopic mucosal resection has been applied to differentiated gastric cancers with invasion limited to the mucosal layer, the diagnosis of their differentiation is important. The degree of differentiation varies depending on the size and location of the tumors. Correct diagnosis by biopsy can be difficult because depressed‐type early gastric cancers sometimes contain mixed histology. Methods: Fifteen patients with depressed‐type early gastric cancers were observed by magnifying endoscopy with a narrow band lighting system. The fine mucosal vascular pattern was recorded and compared with the histological differentiation and features of vessels by staining with CD34. In some patients, cDNA array analysis was performed to determine differences among histological types. Results: Tumor vascular patterns were classified into two categories. Grid‐like network patterns not only characterized differentiated type but were also associated with high microvascular density. Short twig‐like patterns typified the undifferentiated type and a low vascular density. Differentiated types highly expressed some angiogenic factors, such as VEGFc and Flt‐4. Conclusions: Tumor vessel pattern of depressed‐type early gastric cancer obtained by narrow band imaging magnifying endoscopy reflects both the histological features and the degree of expression of angiogenic factors.     

MAGNIFYING ENDOSCOPIC FINDINGS OF THE SURFACE STRUCTURE OF NON‐CANCEROUS MUCOSA SURROUNDING DIFFERENTIATED AND UNDIFFERENTIATED GASTRIC CARCINOMA

Background: Several reports have described the usefulness of magnifying endoscopy in observing the surface structure in gastric neoplasia. The aim of the present study was to evaluate the characteristics of the surface structure of non‐cancerous mucosa surrounding gastric cancer. Methods: Sixty Japanese patients with early gastric cancer were enrolled in this study. We observed the non‐cancerous gastric mucosa surrounding gastric carcinoma by magnifying endoscopy and classified the magnified view into four patterns: (A) dotted; (B) short‐linear; (C) striped; and (D) granular, according to Sakaki's classification. Results: All patients were diagnosed as having Helicobacter pylori infection, and histological evaluation revealed 46 types of differentiated and 14 types of undifferentiated‐type gastric carcinomas. There were significant differences in the gender, age and endoscopic‐atrophic‐border scale between patients with these two types. In all, the surface structure at 240 points (4 points each in 60 patients) of non‐cancerous mucosa was observed by magnifying endoscopy. The prevalences of the surface patterns of the mucosa surrounding differentiated carcinoma were: A, 1.1%; B, 8.1%; C, 28.3%; D, 62.5%, and those of the mucosa surrounding undifferentiated carcinoma were: A, 8.9%; B, 73.2%; C, 14.3%; D, 3.6%. There were significant differences in the surface structure of the non‐cancerous mucosa surrounding differentiated and undifferentiated gastric carcinoma. Conclusion: The microsurface structure of the gastric mucosa surrounding gastric cancer lesions differed between patients with differentiated and undifferentiated gastric cancer. These findings are expected to be useful for the early detection of gastric carcinoma lesions or for the determination of extensions of carcinoma lesions.     

Study on minute surface structures of the depressed‐type early gastric cancer with magnifying endoscopy

Background: Gastric surface patterns and morphology of minute surface vessels in depressed lesions were analyzed using a magnifying endoscope with high resolving power to contribute to qualitative diagnosis of gastric cancer. Methods: Subjects were diagnosed with depressed‐type early gastric cancer (pT1), there were 63 lesions, 38 differentiated‐type lesions, and 25 undifferentiated‐type lesions. There were also 40 benign depressed lesions found. After routine observations with an endoscope, amplifying observations of lesions were made by EG‐410CR (Fuji Photo Optical; Saitama, Japan) (CR). The images were compared with macroscopic patterns and histopathological patterns of the surgical specimens and endoscopic mucosal resection specimens. Results: Surface patterns of gastric depressed lesions were classified as irregular protrusion, normal papilla, pseudopapilla and amorphia. Irregular protrusion was found only in cancerous lesions. Characteristic minute vessels were observed in amorphia. Their patterns were classified into the following six types: sand, fence, round net, flat net, branch and coil. Irregular protrusion and minute vessels in amorphia (round net, flat net, branch and coil) were specific to cancers. There was a tendency for round net and flat net patterns to be found often in differentiated cancers and for branch and coil patterns to be found often in undifferentiated cancers. Conclusion: This magnifying endoscopic classification is considered useful for the qualitative diagnosis of depressed‐type early gastric cancer.     

Alterations of tumor suppressor and tumor-related genes in the development and progression of gastric cancer

The development and progression of gastric cancer involves a number of genetic and epigenetic alterations of tumor suppressor and tumor-related genes. The majority of differentiated carcinomas arise from intestinal metaplastic mucosa and exhibit structurally altered tumor suppressor genes, typified by p53, which is inactivated via the classic two-hit mechanism, i.e. loss of heterozygosity (LOH) and mutation of the remaining allele. LOH at certain chromosomal loci accumulates during tumor progression. Approximately 20% of differentiated carcinomas show evidence of mutator pathway tumorigenesis due to hMLH1 inactivation via hypermethylation of promoter CpG islands, and exhibit high-frequency microsatellite instability. In contrast, undifferentiated carcinomas rarely exhibit structurally altered tumor suppressor genes. For instance, while methylation of E-cadherin is often observed in undifferentiated carcinomas, mutation of this gene is generally associated with the progression from differentiated to undifferentiated carcinomas. Hypermethylation of tumor suppressor and tumor-related genes, including APC, CHFR, DAP-kinase, DCC, E-cadherin, GSTP1, hMLH1, p16, PTEN, RASSF1A, RUNX3, and TSLC1, can be detected in both differentiated and undifferentiated carcinomas at varying frequencies. However, the significance of the hypermethylation varies according to the analyzed genomic region, and hypermethylation of these genes can also be present in non-neoplastic gastric epithelia. Promoter demethylation of specific genes, such as MAGE and synuclein y, can occur during the progressive stages of both histological types, and is associated with patient prognosis. Thus, while the molecular pathways of gastric carcinogenesis are dependent on histological background, specific genetic alterations can still be used for risk assessment, diagnosis, and prognosis.     

EARLY GASTRIC CANCER: PROPOSAL FOR A NEW DIAGNOSTIC SYSTEM BASED ON MICROVASCULAR ARCHITECTURE AS VISUALIZED BY MAGNIFIED ENDOSCOPY

We have developed a magnified endoscopic technique for observing the microvascular architecture within the gastric mucosa in units as small as capillary and we have reported the characteristic findings of the microvascular architecture in both normal gastric mucosa and early gastric cancer. The findings in the normal stomach were different depending on the section of the stomach. The body mucosa demonatrated a regular honeycomb‐like subepithelial capillary network pattern with a collecting venule, while the antral mucosa demonstrated a regular coil‐shaped subepithelial capillary network pattern. The magnified endoscopic findings of early gastric carcinoma were different depending on the types of histological differentiation. The characteristic findings of differentiated carcinoma were (1) the presence of a demarcation line; (2) the disappearance of the regular subepithelial capillary network pattern; and (3) the presence of an irregular microvascular pattern. The findings of undifferentiated carcinoma showed only a reduction in or else the complete disappearance of the regular subepithelial capillary network pattern. In clinical practice, the magnified endoscopic findings of differentiated carcinoma are useful both for determining the margin of early gastric cancer and for making a differential diagnosis between gastritis and gastric cancer in the case of flat reddened lesions. The microvascular architecture as visualized by magnified endoscopy could be a new diagnostic system for the endoscopic diagnosis of early gastric cancer.     

Tumorigenicity,invasion, and metastasis of human gastric cancer in nude mice

Summary Tumors derived from 105 patients with gastric cancer were subcutaneously heterotransplanted into nude mice in order to study their tumorigenicity and malignant behavior. Of the 105 gastric cancers, 45 were successfully transplanted (a 42.9% tumorigenesis rate). The tumorigenesis rate of Borrmann type 1 and 2 cancers (77.8%) was significantly higher than that of type 3 and 4 cancers (34.6%). Also, the tumorigenesis rate of differentiated carcinoma (57.1 %) was significantly higher than that of undifferentiated carcinoma (30.9%). Spontaneous metastases from the subcutaneous tumors were observed in 5 of the 37 established tumor lines (13.5%), and macroscopic pulmonary metastases were common with one tumor line (SCK-29). Although most of the subcutaneous gastric cancers showed local expansion without distant metastasis, the same tumor cells implanted into the peritoneal cavity exhibited invasive growth and/or metastasis. Thus, the expression of a metastatic pheno-type by human gastric cancer was influenced by the host microenvironment. The SCK-29 tumor line with its high metastatic potential may be useful for studies on the mechanism of blood-borne metastasis.Abbreviations pap papillary adenocarcinoma - tub₁ well-differentiated adenocarcinoma - tub₂ moderately differentiated adenocarcinoma - por poorly differentiated adenocarcinoma - sig signet-ring cell adenocarcinoma - muc mucinus adenocarcinoma - giant giant cell adenocarcinoma - ud undifferentiated adenocarcinoma - ade ascitic adenocarcinoma This study was supported in part by a grant-in aid for cancer research (B.no. 63480309) from the Ministry of Education, Science and Culture, Japan     

Differences in Dihydropyrimidine Dehydrogenase Activities Between Gastric and Colorectal Cancer

We studied the relation between clinicopathological factors and dihydropyrimidine dehydrogenase (DPD) activity in gastric and colorectal carcinomas. Specimens obtained by surgery from 27 gastric and 17 colorectal carcinomas and their normal mucosa were examined. The levels of DPD activity in the gastric carcinomas and their normal mucosa were significantly higher than those in colorectal carcinomas and their normal counterparts, respectively (both P's < 0.0001). The gastric carcinomas had significantly higher DPD activities than their normal mucosa (P = 0.028), but the colorectal carcinomas did not. Among the clinicopathological factors, which included invasion/metastatic status and staging, the only effect was that of the histological differences of gastric cancer on DPD activity. That is, the level of DPD activity of the histologically undifferentiated gastric carcinoma was significantly higher than that of the differentiated type. No prognostic predictive values of DPD were recognized in either gastric and colorectal cancer. In conclusion, the higher DPD activity in gastric cancer than colorectal cancer may be due to the higher DPD activity in the background mucosa of origin, and the higher population of undifferentiated type of histological classification, compared to the colorectal counterparts.     

Immunohistochemical study of carbohydrate antigen expression in gastric carcinoma

The expression of carbohydrate antigens in malignant and non-malignant gastric mucosa was studied immunohistochemically using the monoclonal antibody AH6 directed to Ley antigen, FH2 directed to Lex antigen, and FH6 directed to sialyl-Lex antigen. Formalin-fixed gastric tissue resected from 54 patients with gastric cancer and 20 patients with gastric ulcer were tested. The incidence of positive cases in gastric cancer patients with each antibody was as follows: AH6;85%, FH2;74%, FH6;74%. The Lex antigen was expressed in 81.5% of cases histologically classified as undifferentiated type, and 66.7% of cases classified as differentiated type. It was expressed in a higher incidence in early stage cancer (93.3%) than in advanced stage cancer (66.7%). Sialyl-Lex antigen was detected in more cases of differentiated type (88.9%) than in those of undifferentiated type (59.3%), whereas none of 8 early cancers of undifferentiated type expressed the antigen. The incidence of the expression of Ley antigen did not differ in relation to histological type or invasiveness. Lex and Ley antigens were detected in noncancerous gastric epithelium. Sialyl-Lex antigen was not detected in the normal fundic gland region. These results demonstrate that Lex antigen may be a differentiation-associated antigen, and sialyl-Lex antigen might be useful as a marker of differentiated cancer and an indication for invasion of undifferentiated cancer.     

利用组织芯片技术研究PTEN和VEGF在胃癌中的表达及意义

目的研究PTEN和血管内皮生长因子（vascular endothelial growth factor，VEGF）在胃癌中的表达及临床意义。方法应用组织微阵列仪制作97孔胃癌组织芯片（tissue microarray）。用免疫组织化学S—P法检测PTEN、VEGF在72例胃癌和25例正常胃黏膜中的表达。结果胃癌组织中PTEN蛋白阳性表达率显著低于正常胃黏膜（45．8％ VS 100％，P〈0．01）；VEGF的阳性表达率显著高于正常胃黏膜（75％VSl2％，P〈0．01），PTEN在胃癌中的表达与VEGF呈负相关（P〈0．01）。PTEN、VEGF的表达在中高分化腺癌分别为68．8％、62．5％（P〉0．05），在低分化及未分化腺癌分别为27．5％、85．0％（P〈0．05）；伴淋巴结转移者分别为31．6％、86．9％（P〈0．05），无淋巴结转移者分别为61．8％、61。8％（P〉0．05）；临床病理分期Ⅰ＋Ⅱ期分别为57．1％、61．9％（P〉0．05），Ⅲ＋Ⅳ期分别为30．0％、93．3％（P〈0．05）；与性别、年龄、肿瘤大小和组织分型无显著差异（P〉0．05）。结论PTEN失活或蛋白表达降低、VEGF的高表达与胃癌临床病理特征和生物学行为有密切关系。PTEN在低分化或未分化以及伴淋巴结转移和临床Ⅲ＋Ⅳ期胃癌中的表达与VEGF呈负相关。联合检测PTEN、VEGF对胃癌的恶性程度及预后判断具有一定的临床参考意义。应用组织芯片大规模高效检测临床组织样本是可行的，具有快速、准确、方便经济的特点。     

Features of early gastric cancer and gastric adenoma by enhanced-magnification endoscopy

Background Changes to the mucosal surface of early gastric carcinomas and gastric adenomas as viewed by enhanced-magnification endoscopy with acetic acid have not been investigated thoroughly. Using this technology, we investigated the appearance of the gastric surface patterns of neoplastic and surrounding nonneoplastic mucosa. Methods Forty-seven consecutive patients with early gastric carcinomas or gastric adenomas underwent enhanced-magnification endoscopy following 1.5% acetic acid instillation. All biopsy specimens were taken from the area at which the enhanced-magnified endoscopic image was obtained. Results Surface patterns of gastric tumors and the surrounding mucosa were classified into five types: type I, small round pits of uniform size and shape; type II, slit-like pits; type III, gyrus and villous patterns; type IV, irregular arrangements and sizes of pattern types I, II and III; type V, destructive patterns of types I, II and III. The predominant pattern of the surrounding mucosa was type III, and most type III mucosa had characteristics of intestinal metaplasia. Although all elevated adenomas showed type II or type III surface patterns, both depressed adenomas showed type IV. Elevated carcinomas showed type III (42.9%) or type IV (57.1%) surface patterns, while depressed carcinomas showed type IV (70%) or type V (30%). Although differentiated tubular adenocarcinomas showed type III (10.3%), type IV (86.2%), or type V (3.5%) surface patterns, all of the signet-ring cell carcinomas and poorly differentiated tubular adenocarcinomas showed type V. Conclusions Enhanced-magnification endoscopy may be useful for identifying gastric tumors and determining the extent of horizontal spread, especially in tumors of the depressed type.     

Hemoglobin content in intramucosal gastric carcinoma as a marker of histologic differentiation: a clinical application of quantitative electronic endoscopy

BACKGROUND: It has been suggested that the endoscopic color of intramucosal gastric carcinoma is correlated with mucosal vascularity within the carcinomatous tissue. The development of electronic endoscopy has made it possible to quantitatively measure the mucosal hemoglobin volume, using a hemoglobin index. The aims of the present study were to investigate whether this hemoglobin index is useful for evaluating the change in color of early gastric carcinoma and to verify the diagnostic value of this index for distinguishing between histologic degrees of differentiation. METHODS: The ratios of the hemoglobin index of cancerous and non-cancerous mucosa for 26 differentiated and 18 undifferentiated intramucosal gastric carcinomas were determined from electronic endoscopic imaging data. RESULTS: The mean ratio of the hemoglobin index of cancerous and non-cancerous mucosa in the differentiated gastric carcinomas was higher than it was in the undifferentiated carcinomas (1.23: 95% CI [1.15, 1.31] versus 0.84: 95% CI [0.81, 0. 88]). The sensitivity and specificity for discriminating undifferentiated from differentiated carcinoma were 100% and 85%, respectively. CONCLUSION: Measurement of mucosal hemoglobin volume (hemoglobin index) is useful for evaluating the endoscopic color of early gastric carcinoma quantitatively and may be helpful in distinguishing differentiated from undifferentiated carcinoma.     

Mucosal Spreading Depressed Type Colorectal Tumors: A Report of Two Cases

Abstract: Superficial depressed type colorectal carcinomas usually show invasion into the submucosa while the tumor is small, measuring less than 10 mm in diameter. We experienced two rare cases of superficial depressed type colorectal tumors of more than 15 mm in diameter which only displayed intramucosal spread. These two lesions showed a clearly depressed appearance on colonoscopy and in the resected specimens, which were different from creeping tumors. One of the lesions was histologically diagnosed as being well differentiated adenocarcinoma without submucosal invasion, and the other was an adenoma with severe atypia. Both lesions had no Ki-ras point mutation and this result was consistent with recent genetic studies on depressed type colorectal tumor. Based on these colonoscopic findings, a simple change in the quantity of air inside the lumen may effectively distinguish a depressed type tumor larger than 15 mm, which is limited to the mucosa, from one with submucosal invasion. Thus bowel resection can be avoided in such cases.     

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.     

Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer

BACKGROUND: The color change observed endoscopically in early gastric cancer is thought to correlate with vascular density and architecture. This study investigated the endoscopic microvascular architecture in intramucosal gastric carcinoma in vivo. METHODS: Intramucosal gastric carcinomas without ulceration in 27 patients were studied by using a new magnifying upper endoscope with attention to microvascular findings. The carcinomas were divided into two major types histologically: differentiated (18) and undifferentiated (9). RESULTS: A regular subepithelial capillary network was demonstrated in noncancerous mucosa. The appearance of the carcinomas differed depending on histologic differentiation. With all of the differentiated carcinomas, there was a well-demarcated area where the regular capillary pattern of noncancerous mucosa had disappeared and irregular microvessels were proliferating. In contrast, with undifferentiated carcinomas there was only an ill-defined area with disappearance or a reduction in the density of capillaries in the noncancerous mucosa. CONCLUSIONS: Magnified endoscopic observation of microvessels may be of assistance in the identification of intramucosal gastric carcinomas that exhibit only subtle changes in color and shape at standard endoscopy.     

CEA-producing mucin-negative gastric signet-ring cell carcinoma with neuroendocrine markers: a case report.

Biopsy and autopsy materials excised from a 69-year-old woman were investigated. Serum carcinoembryonic antigen (CEA) showed a high value of 955 ng/mL. A plateaulike tumor was located in the gastric cardia and fundus to the entire gastric body. It showed severe proliferation and infiltration from the mucosa to the serosa. The tumor was comprised of signet-ring cells and poorly differentiated adenocarcinoma cells, which spread into the submucosa of the pylorus, duodenum, and jejunum. Signet-ring cells had a large, eccentric vesicular nucleus and a pale cytoplasmic inclusion. Poorly differentiated adenocarcinoma cells had a pleomorphic nucleus, small eosinophilic nucleolus, and abundant eosinophilic cytoplasm. Both neoplastic cells were positive for CEA, epithelial membrane antigen, Leu-7 (CD57), and neuron-specific enolase, and were negative for cytokeratin, vimentin, and periodic acid-Schiff, Alcian blue, and mucicarmine stains. Electron microscopy showed endocrine granules with a limiting membrane measuring approximately 238 nm in diameter in the cytoplasm. The authors diagnosed this patient as having mucin-negative gastric signet-ring cell carcinoma with neuroendocrine markers, which is suggested to exist among poorly differentiated adenocarcinoma, undifferentiated carcinoma, and signet-ring cell carcinoma.     

Immunohistochemical study of carbohydrate antigen expression in gastric carcinoma

The expression of carbohydrate antigens in malignant and non-malignant gastric mucosa was studied immunohistochemically using the monoclonal antibody AH6 directed to Le^y antigen, FH2 directed to Le^x antigen, and FH6 directed to sialyl-Le^x antigen. Formalin-fixed gastric tissue resected from 54 patients with gastric cancer and 20 patients with gastric ulcer were tested. The incidence of positive cases in gastric cancer patients with each antibody was as follows: AH6;85%, FH2;74%, FH6;74%. The Le^x antigen was expressed in 81.5% of cases histologically classified as undifferentiated type, and 66.7% of cases classified as differentiated type. It was expressed in a higher incidence in early stage cancer (93.3%) than in advanced stage cancer (66.7%). Sialyl-Le^x antigen was detected in more cases of differentiated type (88.9%) than in those of undifferentiated type (59.3%), whereas none of 8 early cancers of undifferentiated type expressed the antigen. The incidence of the expression of Le^y antigen did not differ in relation to histological type or invasiveness. Le^x and Le^y antigens were detected in noncancerous gastric epithelium. Sialy-Le^x antigen was not detected in the normal fundic gland region. These results demonstrate that Le^x antigen may be a differentiation-associated antigen, and sialyl-Le^x antigen might be useful as a marker of differentiated cancer and an indication for invasion of undifferentiated cancer.     

Clinical interpretation of the histological typing of gastric cancer using endoscopic forceps biopsy

BACKGROUND/AIMS: Histological typing of gastric cancer is important for determining the treatment strategy and predicting the prognosis. We compared the histological types obtained by endoscopic forceps biopsy with the finally determined histological types of surgically resected specimens to investigate the reliability of histologically typing gastric cancer by biopsy. METHODOLOGY: Agreement between the biopsy typing and the final histological typing based on the predominant histology of the resected tumor was studied in 115 consecutive gastric cancers. RESULTS: The overall agreement rate of histological typing of gastric cancer was 75.7%. In patients with early gastric cancer, the agreement rate was a high 82.5% and the final histological type was usually predicted. In patients with advanced gastric cancer, the agreement rate was 72.0%, which was significantly lower than for early gastric cancer (p<0.05). The agreement rate for advanced differentiated cancer was also significantly lower than that for early cancer (63.6% vs. 90.0%) (p<0.05). CONCLUSIONS: The reliability of using histological typing by biopsy to set the indications for endoscopic treatment and for preoperative prediction of the prognosis is expected to be good for differentiated early gastric cancer, but it might not be adequate for advanced cancer or undifferentiated cancer.     

Early carcinoma of the stomach after gastric surgery: comparison with early carcinoma in the non-operated stomach

The relationships between the gross and histological types of early gastric carcinoma and non tumorous gastric mucosa were investigated in 12 cases of carcinoma of the stomach after operation and 46 cases of cardiac carcinoma within 5 cm of the squamocolumnar junction. Histological studies were made by examining specimens obtained by gastrectomy. Grossly elevated and histologically differentiated carcinomas were statistically more frequent after gastric surgery, than before. Comparison between cases of elevated and differentiated adenocarcinoma that had undergone gastric surgery with those that had not showed that atrophic gastritis and intestinal metaplasia in the surrounding mucosa of the tumor were significantly slighter after gastric operation than in unoperated cases. Results suggested that early carcinomas developing after gastric surgery are different from those in the upper portion of the unoperated stomach.     

Diagnosis of early gastric cancer measuring 1 cm or less

Rates of detection roentgenological and endoscopic examinations were investigated in 87 patients with 93 lesions of early gastric cancer measuring 1 cm or less. In the depressed type, the minimum size for detection was 5 mm roentgenologically and 3 mm endoscopically. Depressed lesions with ulcer scars could be detected roentgenologically, but depressed lesions without ulcer scars could not be detected, unless the depressions were more than 0.5 mm and were accompanied by mucosal elevations surrounding the lesions. The detection of undifferentiated cancer without ulcer scars was poor, because mucosal elevations surrounding the lesions were rare in such histological types. In the elevated type, the minimum size detectable roentgenologically was 7 mm in width, 0.9 mm in height, compared to 4 mm in width, 0.3 mm in height endoscopically. On diagnosis of the depth of invasion, the depressed type of cancers without ulcer scars and with granular depressions were mostly limited to the mucosa, on the other hand, clear depression and plateau like elevation were highly indicative of submucosal invasion. In cases of elevated cancers, a central depression was highly indicative of submucosal invasion.