Minute gastric cancers less than 5 mm in diameter

Gastric Intestinal Metaplasia: Real Culprit or Innocent Bystander as a Precancerous Condition for Gastric Cancer?

Gastric intestinal metaplasia (GIM), which denotes conversion of gastric mucosa into an intestinal phenotype, can occur in all regions of the stomach, including cardiac, fundic, and pyloric mucosa. Since the earliest description of GIM, its association with gastric cancer of the differentiated (intestinal) type has been a well-recognized concern. Many epidemiologic studies have confirmed GIM to be significantly associated with subsequent gastric cancer development. Helicobacter pylori, the principal etiologic factor for gastric cancer, plays the most important role in predisposing to GIM. Although the role of GIM in the stepwise progression model of gastric carcinogenesis (the so-called "Correa cascade") has come into question recently, we review the scientific evidence that strongly supports this long-standing model and propose a new progression model that builds on the Correa cascade. Eradication of H pylori is the most important method for preventing gastric cancer globally, but the effect of eradication on established GIM, is limited, if any. Endoscopic surveillance for GIM may, therefore, be necessary, especially when there is extensive corpus GIM. Recent advances in image-enhanced endoscopy with integrated artificial intelligence have facilitated the identification of GIM and neoplastic lesions, which will impact preventive strategies in the near future.

Small endometrial carcinoma 10 mm or less in diameter: clinicopathologic and histogenetic study of 131 cases for early detection and treatment

Natural history and clinicopathologic features of early endometrial carcinoma are not evident. Its knowledge is essential to make up strategies for prevention, early detection, and treatment of endometrial carcinoma. Especially it is important to know pathways of endometrial carcinogenesis and frequency of endometrial carcinomas arising from endometrial hyperplasia. Clinicopathologically 131 patients with endometrial carcinoma measuring ≤10 mm in diameter (“small endometrial carcinoma”) were studied to get useful information for early diagnosis, treatment, and histogenesis. The entire endometrium of surgically removed uterus was step-cut and examined. The patients were, on average, 5 years younger than the controls whose carcinomas measure >10 mm (P < 0.0001). Of the 131 patients, 20% were asymptomatic although only 5% of the controls were asymptomatic (P < 0.0001). Seventy-six percent had the carcinomas located in the upper third section of the uterine corpus. Macroscopically 44% of the tumors were flat and 56% were elevated. Incidence of nodal and ovarian metastases were <1%. Forty percent of “small endometrial carcinomas” were associated with endometrial hyperplasia and 60% were not. It is logical to believe that there are two pathways of endometrial carcinogenesis: carcinomas occurring from hyperplasia (40%) and carcinomas occurring from normal endometrium (60%). As hyperplasia-carcinoma sequence is not a main route, we cannot probably prevent carcinomas only by treatment of hyperplasia. Effort must be focused on detecting early de novo carcinomas. As most “small endometrial carcinomas” arise in the upper third of the corpus, careful endometrial sampling there is important for early detection.

Small hepatocellular carcinoma: current and future approaches

Over 3 decades have passed since the first report of small hepatocellular carcinoma (SHCC), which has been confirmed as one of the most significant prognostic factors. Obviously, it is indeed very important to know when an early SHCC will become more aggressive and lead to worse clinical outcome once it grows beyond a critical size. However, so far, no consensus has been achieved on the size criterion for SHCC among different authors or different clinical practice guidelines that have been used worldwide, although there are currently numerous cutoff values for tumor size used to define SHCC, including 5, 3 and 2 cm in diameter, etc. Herein, based on our current understanding concerning the pathobiological features of SHCC, we briefly review the history of SHCC study, analyze the advantages and limitations of the above criteria for SHCC, and discuss the pathobiological characteristics as well as the clinical significance of SHCC.

Depressed type of intramucosal differentiated-type gastric cancer has high cell proliferation and reduced apoptosis compared with the elevated type

BACKGROUND

The depressed type of early gastric cancer, in comparison to the elevated type, tends to invade the submucosal layer and metastasize to the lymph nodes. This study compared the differences in tumor cell proliferation and apoptosis between the elevated and depressed types of intramucosal differentiated gastric cancer.

METHODS

A total of 57 intramucosal differentiated gastric cancers were studied. Twenty samples were the elevated type and 37 were the depressed type. The tumor cells were analyzed by immunohistochemistry for Ki-67, Bcl-2, and Bax, and terminal deoxynucleotidyl transferase 2´-deoxyuridine, 5´-triphosphate (dUTP)-biotin nick end labeling was carried out to detect apoptotic cells.

RESULTS

(1) The Ki-67 labeling index (KI) was higher in the depressed type (median: 38.6) than in the elevated type (median: 21.2). (2) Immunopositivity for Bax and the apoptosis index (AI) were lower in the depressed type (median AI: 0.20) than the elevated type (median AI: 1.05). (3) The AI/KI was lower in the depressed type (median: 0.17) than in the elevated type (median: 5.57). (4) The AI in the tumors with a Bcl-2-negative and Bax-positive pattern (median: 2.0) was higher than that in the tumors with a Bcl-2-positive and Bax-negative pattern (median: 0.2).

CONCLUSION

These results show that, regarding cell proliferation and apoptosis, the depressed type of intramucosal differentiated-type gastric cancer has high malignant potential in comparison to the elevated type.

Defining the pathologic diagnosis of metaplasia, atrophy, dysplasia, and gastric adenocarcinoma

Epidemiologic and pathologic studies have confirmed that the development of gastric cancer spans over several decades starting with Helicobacter pylori chronic active gastritis followed, over time and only in a subset of patients, with the development of intestinal metaplasia and atrophy, dysplasia, and finally gastric adenocarcinoma. It has also been established that the pathogenesis of gastric cancer is a multifactorial process in which both environmental and host-related factors play significant role. Improvement in upper endoscopic techniques make possible the detection of not only early gastric cancers but also the mucosal alterations that predate malignant degeneration. A better understanding of the gastric carcinogenic sequence will allow us to better identify the patients at risk and to implement preventive strategies. We review the histopathologic steps that predate the development of gastric cancer and evaluate the risks of transformation that they confer.

Patterns of gastric atrophy in intestinal type gastric carcinoma

BACKGROUND

Multifocal atrophic gastritis (MAG) is currently considered a precancerous lesion leading to intestinal type gastric carcinoma. The current study aimed to describe the topography of atrophy in stomachs with early gastric carcinoma.

METHODS

Resected stomachs from patients with intestinal type gastric carcinoma were routinely processed, sectioned (an average of 108 sections/stomach), and stained with a triple stain. Sections were scored on a visual analog scale for Helicobacter pylori and intestinal metaplasia. The type of epithelium (antral, oxyntic, transitional) was recorded. Atrophy was defined as the loss of normal glandular components and included intestinal metaplasia and/or pseudo-pyloric metaplasia of the corpus. Pseudo-pyloric metaplasia was identified by the presence of pepsinogen I in mucosa that was topographically corpus but phenotypically antrum.

RESULTS

Sixteen stomachs with intestinal type gastric carcinoma were examined. In none of the specimens examined was MAG (independent foci of atrophy) identified. In the majority (88%), atrophy was present as a continuous sheet. Islands of intestinal metaplasia (multifocal intestinal metaplasia) were present within a sheet of pseudo-pyloric metaplasia. A few specimens (12%) had a non-atrophic corpus with almost total replacement of antral epithelium with intestinal metaplasia. Multifocal dysplasia distant from the original tumor was found both in areas with and without intestinal metaplasia.

CONCLUSIONS

Contrary to popular belief, atrophy in intestinal type gastric carcinoma is not present as independent foci, but rather as a continuous sheet. Previous studies failed to identify pseudo-pylori metaplasia as a marker for atrophy.

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).

Loss of E-cadherin expression in gastric intestinal metaplasia and later stage p53 altered expression in gastric carcinogenesis

Gastric cancers are commonly subdivided into intestinal and diffuse subtypes on a morphologic basis, supported by corollary evidence of differences at the pathogenetic and molecular levels. Chronic atrophic gastritis with intestinal metaplasia is a common precursor lesion for the intestinal type of carcinoma. To identify early molecular changes, in this study we have examined 13 surgical specimens both for the expression of E-cadherin, p53 and beta-catenin by immunohistochemistry and for methylation of the CDH1 promoter (E-cadherin) by bisulfite genomic sequencing of laser capture microdissected samples. Each specimen examined contained areas of normal (nonmetaplastic) gastric mucosa, as well as areas of intestinal metaplasia and/or carcinoma. Reduced or absent E-cadherin and partial to complete methylation of one to multiple CpG sites examined in the CDH1 promoter were observed in all of the metaplasia samples. Thus, the methylation status of the CDH1 promoter and expression of E-cadherin together provide strong evidence that loss of E-cadherin is an early event in intestinal type gastric carcinogenesis. In contrast, expression of p53, assumed to be mutant p53, was generally not detected (except for isolated cells) until the carcinoma stage in tissues from these patients. These results suggest that mutation of p53 is a late event in intestinal type gastric cancer. The level of beta-catenin expression did not appear to change between normal, metaplastic and carcinoma cells of intestinal type, and no nuclear staining was visible in any of the tissues. These results suggest that the Wnt signaling pathway is not upregulated in this type of cancer.

Frequent p53 mutation in brain (fetal)-type glycogen phosphorylase positive foci adjacent to human 'de novo' colorectal carcinomas

'de novo' carcinogenesis has been advocated besides 'adenoma carcinoma sequence' as another dominant pathway leading to colorectal carcinoma. Our recent study has demonstrated that the distribution of brain (fetal)-type glycogen phosphorylase (BGP) positive foci (BGP foci) has a close relationship with the location of 'de novo' carcinoma. The aims of the present study are to investigate genetic alteration in the BGP foci and to characterize them in the 'de novo' carcinogenesis. 17 colorectal carcinomas without any adenoma component expressing both immunoreactive p53 and BGP protein were selected from 96 resected specimens from our previous study. Further investigations to examine the proliferating cell nuclear antigen (PCNA)-labelling index, and the p53 and the codon 12 of K-ras mutation using the polymerase chain reaction-single strand conformation polymorphism were performed in the BGP foci, BGP negative mucosa and carcinoma. The BGP foci were observed sporadically in the transitional mucosa adjacent to the carcinoma in all cases. The PCNA labelling index in the BGP foci was significantly higher than that in the BGP negative mucosa (P< 0.001). p53 mutations were observed in 8 carcinomas, but no K-ras mutation was detected. Interestingly, although none of the overexpressions of p53 protein was detected immunohistochemically in the BGP positive foci, the p53 gene frequently (41.2% of the BGP foci tested) mutated in spite of no K-ras mutation. The present study demonstrates potentially premalignant foci in the colorectal transitional mucosa with frequent p53 gene mutation. It is suggested that BGP foci are promising candidates for the further investigation of 'de novo' colorectal carcinogenesis.

Effect of lifestyle, smoking, and diet on development of intestinal metaplasia in H. pylori-positive subjects

OBJECTIVES

This study aimed to evaluate the influence of environmental and sociodemographic factors and the effect of smoking, alcohol, and dietary habits on the risk of gastric intestinal metaplasia (IM) in Helicobacter pylori-infected subjects.

METHODS

The investigation was based on 2598 consecutive volunteer blood donors tested for the presence of antibodies against H. pylori from March 1995 to March 1997. Endoscopy with multiple biopsies was offered to all H. pylori-positive, symptomatic subjects. The presence or absence of IM was diagnosed by gastric biopsies. A serologically H. pylori-positive subject with gastric IM was defined as a case, whereas serologically H. pylori-positive subjects without IM were used as controls. All patients answered a detailed questionnaire collecting sociodemographic characteristics and smoking, alcohol drinking, and dietary habits. Odds ratios (ORs) and their 95% CIs were estimated by unconditional logistic regression, including terms for age and sex, to assess the association between the data collected and IM.

RESULTS

Three hundred forty-four subjects with serological H. pylori infection and upper-GI symptoms underwent GI endoscopy, during which biopsies were taken for histological diagnosis. Histology revealed metaplasia in 74 subjects (21.5%). Incomplete IM was found in 37.8% of these cases. No significant associations were found between IM and anthropometric or sociodemographic factors. There was a significant association between age and IM (chi2 for trend, 6.67; p value, 0.009). Current smokers of over 20 cigarettes per day had a 4-fold risk of IM (OR, 4.75, 95% CI, 1.33-16.99). A 2-fold increased risk was found for high butter consumers (OR, 2.17; 95% CI, 1.14-4.11). No significant specific associations were found between the variables studied and complete or incomplete IM.

CONCLUSIONS

This study found that smoking and high butter consumption may increase the risk of having gastric IM in H. pylori-positive subjects.

p53 mutations in the non-neoplastic mucosa of the human stomach showing intestinal metaplasia

In order to ascertain whether genetic alterations occur during the early stages of gastric carcinogenesis, abnormal accumulation of p53 protein and mutation of its gene in stomach tissue showing intestinal metaplasia were investigated using immunohistochemistry and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. Immunohistochemistry detected 19 foci showing nuclear accumulation of p53 protein in non-neoplastic gastric mucosa in a total of 756 sections (477 of which contained intestinal metaplasia) from 16 resected stomachs containing gastric adenocarcinomas. Of these 19 p53-positive foci, 17 were diagnosed histologically as incomplete-type intestinal metaplasia and 2 as pseudopyloric glands in the regenerative mucosa. Furthermore, 14 such foci were detected in 6 patients with multiple gastric cancers. No correlation between high-iron diamine (HID)-positive sulfomucin production and p53-positive glands was observed. The DNAs were extracted selectively from these p53-positive metaplastic glands and examined for p53 mutations by PCR-SSCP analysis followed by direct sequencing. In only 10 lesions could exons; 5 to 8 be investigated completely, and of these, 4 were shown to possess p53 mutations, which were on exon 5 in 3 cases and on exon 7 in 1 case. These results indicate that irreversible genetic changes had already occurred in morphologically non-neoplastic gastric mucosa with intestinal metaplasia, and are consistent with the hypothesis that intestinal metaplasia, especially the incomplete type, may contain precursor lesions of gastric cancer.

Prognostic factors for gastric cancer influencing clinical practice

Despite a slow decline in the incidence of gastric cancer over the last 90 years, we can still expect to see over 100,000 patients die of this disease each decade in England and Wales. The 5-year survival rate has not improved during this century, which is largely due to the stage at diagnosis being unchanged. There are a number of prognostic determinants in gastric cancer which have clinical relevance. Age is an important determinant; patients under 40 years commonly have more advanced diffuse lesions than older patients so that a higher index of suspicion needs to be maintained in younger patients with persistent symptoms. Conflicting reports make it unclear whether the duration of symptoms bears any relationship to tumor stage, but there is some evidence that actively shortening the symptom duration by early investigation can have a beneficial effect in the proportion of patients diagnosed with early cancers. The site of the tumor is important; unfortunately, the proportion of patients with cardia lesions is increasing and this has had the effect of reducing the overall survival. Tumor size should not play a part in the decision to resect a lesion as most studies show no clear relationship between tumor size and stage. Tumor stage is the most important prognostic determinant and efforts to increase the proportion of stage I cancers presenting for surgery can be shown to alter the natural history of the disease, by diagnosing it when it is still surgically curable.

Detection of minute intestinal metaplastic lesions by video microscopy

Using video microscopy in 225 resected stomachs we detected 32 minute solitary lesions of intestinal metaplasia histologically. The magnified features of the minute lesions showed a characteristic appearance and were classified into three types: mesh-like (type A), villoid (type B), and tubular (type C). All the lesions classified as type A exhibited the incomplete type of intestinal metaplasia according to the results of histopathological and/or histochemical examination. In contrast, most lesions classified as type B exhibited the complete type of intestinal metaplasia. We concluded that intentional detection of minute lesions in resected stomachs by video microscopy is simple and useful, especially in cases of minute lesions < 5 mm in diameter. Moreover, our findings demonstrate that the minute intestinal metaplastic lesions have morphological characteristics based on which they can be classified into three types of lesions. These morphological characteristics correlate with their histopathological findings.

Precursors of gastric carcinoma: a critical review with a brief description of early (curable) gastric cancer

Gastric adenocarcinoma is among the most common malignancies worldwide. Its etiopathogenesis is complex and, as yet, incompletely understood; however, diet, infection with Helicobacter pylori, and genetic factors are involved. It may be classified into two main types, intestinal and diffuse. The intestinal type has decreased in incidence, whereas the diffuse tumors as well as those confined to the cardia are increasing. Numerous conditions, such as gastritis, gastric atrophy, and intestinal metaplasia (IM), are associated with intestinal type gastric cancer in retrospective studies, but only epithelial dysplasia has a positive predictive value for malignancy. These precursor conditions and lesions are analyzed for their clinicopathological significance in this review, which concludes with a brief summary of curable (early) forms of gastric cancer.

Intestinal metaplasia of the stomach. A status report

Intestinal metaplasia in the stomach increases the risk of gastric cancer, and the increased risk is proportional to the extent of the metaplasia. This risk could be generated by one or more mechanisms: (1) the metaplastic tissue is an early step in a multistep induction process; (2) the metaplastic tissue is an epigenetic change that raises the pH of gastric juice by replacing oxyntic mucosa, favoring the growth of a bacteria capable of generating endogenous mutagens; and/or (3) the metaplasia is only a marker for chronic gastritis due to H. pylori infection or pernicious anemia. With the last mechanism, the inflammatory response favors intramural mutagenesis that might result in metaplasia or neoplasia as independent events. Finding gene rearrangements common to both metaplastic and neoplastic tissue may establish a direct link between them, but too few have been identified to account for the large number of stomach cancers that develop in high risk populations. Histochemical and immunochemical stains that identify enzymes or mucosubstances may suggest that metaplastic epithelial cells resemble small or large intestinal cells, but they are distinctly different from both. Moreover, these stains do not indicate whether a given cytologic change is genetic or epigenetic; therefore, they cannot be used to define the relationship between metaplasia and neoplasia. It is unnecessary for practicing physicians to await resolution of this question. It can be assumed that any person with extensive metaplasia is at high risk for gastric cancer and should be subject to periodic screening. The extent of the metaplastic process is probably more important than the metaplastic subtype.

Site-dependent development of complete and incomplete intestinal metaplasia types in the human stomach

The topographical distribution of complete and incomplete types of intestinal metaplasia in human stomach samples was investigated in order to elucidate their mutual histogenetic relationship and significance in carcinogenesis. Subgross stereomicroscopic examination of alcian blue and hematoxylin‐stained gastric mucosae allowed clear distinction of complete and incomplete intestinal metaplasia types as white (with or without purple hue) and purple foci, respectively, against the background magenta areas of non‐intestinalized mucosa. Intestinal metaplasias which developed in the fundic area were predominantly of the complete type whereas those of the antrum were a mixture of both with a distinct predilection for expression of the incomplete type. Although there was some variation among foci regarding the hue of white or purple, the color feature was principally homogeneous within each individual intestinal metaplasia focus. Thus phenotypic analysis indicated intestinal metaplasia expression to be clearly influenced by intragastric topography. The study did not provide any evidence that a shift from incomplete to complete type intestinal metaplasia may occur with time or that the incomplete type may be more intimately associated with development of well‐differentiated carcinomas.

The topographic distribution of lymphocytic gastritis in gastrectomy specimens

Forty-eight entire gastrectomy specimens received consecutively at this Department were cut into blocks for histologic examination. Focal or more extended areas of chronic gastritis (i.e. superficial or atrophic with or without intestinal metaplasia) were present in all 48 specimens. In addition, two of the 48 specimens had a large number of lymphocytes in the surface and foveolar epithelium of the mucosa. In the literature the latter is regarded as "lymphocytic gastritis". Lymphocytic gastritis was found in all 156 sections obtained from the two specimens. This lympho-epithelial phenomenon was present even in areas lacking chronic inflammation in the subjacent lamina propria mucosae. From our results it would appear that while chronic gastritis has a focal or a regional topographic distribution, lymphocytic gastritis includes the entire surface-foveolar epithelium of the gastric mucosa.

Adenocarcinoma of the stomach: a review of 35 years and 1,710 cases

The records of 1,710 patients with adenocarcinoma of the stomach treated at Charity Hospital over a 35-year period were reviewed to note any trends which might help in understanding the decreasing incidence and poor prognosis of the disease. The yearly number of gastric cancer patients has dropped from 234/100,000 in the 1950's to 195/100,000 in the 1960's to 108/100,000 patients in the last decade. The percentage of affected white males is decreasing at a rate equal to the increasing frequency of black female patients, while the ratios for black males and white females remain constant. The median age rose from 61.5 years to 66 years over the study period. The operability rate decreased from 82.4% to 72.8% and the resectability rate was 49%. Subtotal gastrectomy was the most common procedure, but radical subtotal gastrectomy gave the best 5-year survival. There are fewer lesions of the antrum today, but the highest number of 5-year survivors had antral lesions. Long-term survival of patients with lesions of the cardia improved from zero in the first 25 years to 14% in the last decade. For the last 2 decades, patients with stage III and IV lesions comprised one-half of the 5-year survivors. Our overall 5-year survival was 7.9%, but in the last decade it was 8.9%. Our 5-year survival for all patients who underwent a resection was 17.9%, but increased to 24.8% for the last decade. These improvements, in combination with a decrease in incidence, have dropped the overall mortality from gastric cancer.

Early and advanced gastric cancer during follow-up of apparently benign gastric ulcer: significance of the presence of epithelial dysplasia

One hundred and forty-four patients with apparently benign gastric ulcer were endoscopically followed up in order to evaluate the outcome of the lesion. Particular attention was given to: (a) detect possible delay in diagnosing gastric cancer; (b) ascertain the frequency of association with epithelial dysplasia; (c) establish the role of markers, such as serum pepsinogen group I (PGI), and gastric juice CEA in predicting gastric ulcer evolution. Endoscopic and bioptic check-ups were carried out during the first year at 3, 6 and 12 months after endoscopic healing of the ulcer, and then at every symptomatic recurrence. Ten patients (6.9%) were found to present histological evidence of malignancy (within 3 months in six cases, between 6 and 12 months in three cases, and after 41 months in the rest). Four cases were early gastric cancers, and six had shown dysplastic changes of the mucosa at the edge or scar of the ulcer. Serum PGI levels were not significantly different in gastric cancer patients, while gastric juice CEA levels were sharply increased compared to those of gastric ulcer patients: nine out of ten patients had values above normal range. These data suggest that: (a) there may be some delay in diagnosing gastric carcinoma, and gastric ulcer patients should be controlled routinely more than once; (b) the presence of dysplasia indicates the need for prolonged follow-up, because of the high risk of association with or evolution into gastric cancer, and because of the higher number of early gastric cancer detections that this protocol allows; (c) further support in monitoring patients "at risk" may be afforded by gastric juice CEA determination.

DNA ploidy in clinical malignant gastric lesions less than 5 mm in diameter

Nuclear DNA content was microspectrophotometrically measured in 18 patients with a mucosal carcinoma of the stomach less than 5 mm in diameter. The findings were compared with data on 56 patients with a lesion greater than 5 mm. DNA distribution patterns were grouped into low and high ploidies. A mucosal carcinoma, classed as high ploidy, was confirmed in 27.8%, 22.2%, and 28.9% of the lesions with a diameter of less than 5 mm, 5 to 20 mm, and 20 to 40 mm, respectively. In the high-ploidy group with a lesion exceeding 5 mm, there was a preponderance of an elevated lesion, well- and moderately differentiated adenocarcinomas, and location in the lower third of the stomach. Such pathologic features showed the same tendency in the high-ploidy group with a lesion less than 5 mm. An aneuploid carcinoma may be present even in a lesion confined to the mucosa, and less than 5 mm in diameter.

A variant of early gastric carcinoma. Histologic and histochemical studies of early signet ring cell carcinomas discovered beneath preserved surface epithelium

Gastric carcinomas hidden beneath flat and intact mucosal surface epithelium are rarely discovered. Such a tumor in the early stage is at best diagnosed as an incidental finding, so that the diagnosis is probably always a surprise to the clinician. Six such cases of early gastric carcinoma were presented. Four were intramucosal lesions and the remaining two were invasive with submucosal extension. All the tumors are composed purely of signet-ring cells (diffuse-type by Lauren's classification). Histologic examination of the six cases revealed that certain features, which are not characteristically observed in ordinary signet-ring cell carcinomas, were commonly recognized. These included compact nests of uniform signet-ring cells sharing a common cytoplasmic wall, lack of desmoplastic stromal response, and intracytoplasmic mucin predominantly composed of neutral mucopolysaccharide. These six tumors are considered to be an incipient stage of signet-ring cell carcinoma. The findings also suggest a close histogenetic relationship between these tumors and the mucous neck cells in the basal region of gastric glands. The grossly unremarkable mucosal surface and histologically innocuous appearance associated with this form of tumor are emphasized for diagnosis.

Multifocal early gastric cancer: morphology and histogenesis

69 foci from 27 multifocal EGC are compared morphologically with 90 solitary EGC. In the multifocal group there was a preponderance of gross types IIa and IIb, Small and Minute carcinomas, an intramucosal growth pattern and a well differentiated intestinal histotype. Although the differences in gross type and tumor size are related in some measure to the stage of neoplastic growth at the time of diagnosis, the higher frequency of well differentiated intestinal carcinomas in multifocal EGC probably reflects a different histogenesis. This hypothesis seems to be borne out by the greater extent of intestinal metaplasia and the larger number of dysplastic foci detectable in the surrounding gastric mucosa.

Development of adenocarcinomas in the stomach

To elucidate the histogenesis of gastric adenocarcinomas, the author looked for smaller carcinomas, and studied their histologic features and the histologic characteristics of the neighboring gastric mucosa. In 325 resected stomachs, 27 microcarcinomas, including initial lesions, were detected. Most of them were typical adenocarcinomas, whose histologic features were different from those of dysplasias. The gastric mucosa around the microcarcinomas was mostly intestinalized. However, the smaller the carcinomas, the less complete was the form of intestinal metaplasia, and the metaplasia was under progression in many gastric tubules. The smallest carcinomas consisted of a few, newly formed glandular complexes, confined to the neck region of the tubules, whereas the upper and the lower part of the tubules were still lined by normal gastric cells. The smallest dysplasia was an in situ lesion, also confined to the neck region of the tubules. These findings indicate that a starting point of adenocarcinomas and dysplasias is in the proliferative cell zone at the neck region. Intestinal metaplasia, dysplasia, and adenocarcinoma arise coincidentally. This implies that no precursor is present for each of them. It appears that most adenocarcinomas arise in gastric tubules when an abnormal differentiation is induced in stem cells after intestinal metaplasia. They are not a consequence of dysplasia, but share a common origin with it.

Endoscopic diagnosis of minute gastric cancer of less than 5 mm in diameter

The accuracy of diagnosis by endoscopic visual and histocytologic examination of minute gastric cancers of less than 5 mm in longest diameter was investigated. Between 1959 and 1981, 55 minute cancers were found in 54 patients at The Center for Adult Diseases, Osaka in Japan: 15 foci were solitary and 40 were associated with other larger gastric cancer. Histologic and/or cytologic confirmation of carcinoma was obtained before operation in 73.3% of cases with a solitary lesion, but in only 7.5% of cases with multiple lesions, for an overall positive result of 25.5%. The diagnostic rate was higher for elevated type and depressed type with converging folds than for flat type and depressed type without converging folds. No cancers of less than 3 mm in longest diameter were correctly diagnosed before operation. Because endoscopic visual diagnosis itself is not sufficiently reliable in determining the nature of the minute lesions, the final diagnosis should be confirmed by endoscopic direct biopsy. However, the first biopsy should be done as carefully as possible, because bleeding in the target area may prevent multiple direct biopsy specimens from being taken. Results also indicate that lesions which could not be diagnosed before operation could not be endoscopically inspected. Therefore, endoscopic detection and subsequent accurate biopsy of suspicious lesions is very important for diagnosis of minute gastric cancer.

Early gastric cancer. Clinico-pathological analysis of 125 cases of early gastric cancer (EGC)

The frequency and the pathological findings of 125 early gastric cancers (ECGs), and particularly of small and minute lesions, were evaluated in a retrospective study of 839 surgical specimens of gastric carcinoma. Sixty two ECGs were believed to have risen from gastric epithelium, 27 from areas of intestinal metaplasia, and 3 from cardio-pyloric mucosa. The remaining lesions showed mixed histological patterns. The most frequent macroscopic type was IIc (24.8%) followed by IIb (16.8%), I (16.8%), and III (14.4%). In 63 cases (50.4%) the cancer was limited to the mucosa. In all specimens, and particularly in small and minute lesions, the surrounding mucosa was accurately analyzed to detect any lesions, from which the cancer could have developed. Intestinal ECGs, especially if protruded, seem to arise from areas of intestinal metaplasia or of chronic atrophic gastritis. Rarely ECGs seem to stem from polypoid lesions both hyperplastic and adenomatous. On the contrary, most important seems to be the role of ulcerative lesions, since in 14 cases of our series, carcinomatous foci were observed within the regenerative epithelium covering the crater. No correlation was found between histologic type, size, staging, and frequency of node metastasis; this suggests the existence of ECGs with different biologic behaviour.

Clinical diagnosis of minute gastric cancer less than 5 mm in diameter

When 58 minute gastric cancers less than 5 mm in diameter from 55 patients were classified into 22 of the single group (minute gastric cancer alone) and 36 of the multiple group (associated with other large gastric cancers), the preoperative correct diagnostic rate by x-ray was 22.7% and 11.1% in the single group and in the multiple group, respectively, with a total rate of 15.5%. The diagnostic rate by endoscopy, aided by endoscopic biopsy, was 95.5%, 13.9%, and 44.8%, respectively. Therefore, it appears that endoscopy and endoscopic biopsy are most efficient diagnostic tools for the detection of such minute gastric cancers. Since the detection of the depressed type (IIc) of minute gastric cancers is considered most significant because of their frequent submucosal invasion, their characteristic endoscopic findings are emphasized: (1) irregular and polygonal shape, (2) distinct depression, (3) clear demarcation, (4) nodular margins, and (5) moth-eaten appearance and abrupt thinning of the mucosal folds.

Intestinal metaplasia of the regenerative epithelia in 549 gastric ulcers

Histopathologic changes in the regenerative epithelia of 549 foci of gastric ulcer were studied. About 70 per cent of the regenerative epithelia revealed intestinal metaplasia of the so-called complete or incomplete type. Parietal cells and chief cells were occasionally observed in the regenerative epithelia of ulcers located in fundic gland areas or at fundopyloric gland borders. It is possible that the regenerative epithelium frequently reverts to intestinal epithelium during the regenerative process, later redifferentiating into normal gastric mucosa or remaining as intestinal metaplasia and that, thus, only a few foci of intestinal metaplasia are precancerous lesions.

Simple alkaline treatment induces intestinal metaplasia in the stomach of rats

By infusing caustic soda (NaOH) into the stomach of rats, the gastric mucosa fell off and regeneration could be induced. In 18 of 26 rats, intestinal metaplasia associated with goblet cells was observed in the regenerative epithelium. Recently, induction of intestinal metaplasia by weak carcinogenic agents are reported with some emphasis on its precancerous meaning. However, our results suggest that, as intestinal metaplasia can be induced by a benign process of regeneration, it is not directly related with carcinogenesis.