Natural history of "early" gastric cancer: results of a 10-year regional survey

Gastric cancer-associated microRNA expression signatures: integrated bioinformatics analysis, validation, and clinical significance

Background

Gastric cancer (GC) is one of the common gastrointestinal malignancy worldwide and exhibits a poor prognosis. Increasing studies have indicated that microRNAs play critical roles in the cancer progression and have shown great potential as useful biomarkers. The search for potential diagnostic and prognostic biomarkers of gastric cancer (GC) with integrated bioinformatics analyses has been undertaken in previous studies.

Methods

In this study, the robust rank aggregation (RRA) method was used to perform an integrated analysis of differentially expressed miRNAs (DEMs) from five microarray datasets in the Gene Expression Omnibus (GEO) database to find robust biomarkers for GC. Ultimately, seven miRNAs were filtered from fourteen primary miRNAs using the validation set of The Cancer Genome Atlas (TCGA) database. Based on these results, diagnostic and survival analyses were performed, and logistic regression and Cox regression were used to determine the clinicopathological characteristics of the DEM expression and overall survival.

Results

Nine eligible miRNA datasets related to GC were selected from the GEO database for integrated analysis in this study. Diagnostic analysis implied that these miRNAs could be regarded as promising candidate diagnostic biomarkers in GC tissues, but whether the results of the tissue analysis are consistent with those of peripheral blood analysis requires further validation. The logistic regression indicated that the ectopic expression of these DEMs was relevant to the histological type, anatomical region, and pathological grade of GC. However, the survival and Cox regression analyses suggested that the poor prognosis of GC patients was not strongly dependent on the ectopic expression of the seven miRNAs, but rather, a poor prognosis was associated with age, metastasis, and histological grade.

Conclusions

Based on the results presented in this study it can be concluded that these miRNAs (miR-455-3p, miR-135b-5p, let-7a-3p, miR-195-5p, miR-204-5p, miR-149-5p, and miR-143-3p) might be potential biomarkers for the early diagnosis of GC patients, but this finding should be regarded with caution. A large-scale, prospective, and multicenter cohort study should be performed.

Dysregulation of NCAPG, KNL1, miR-148a-3p, miR-193b-3p, and miR-1179 may contribute to the progression of gastric cancer

BACKGROUND

Emerging evidence indicate that miRNAs play an important role on gastric cancer (GC) progression via regulating several downstream targets, but it is still partially uncovered. This study aimed to explore the molecular mechanisms of GC by comprehensive analysis of mRNAs and miRNA expression profiles.

METHODS

The mRNA and miRNA expression profiles of GSE79973 and GSE67354 downloaded from Gene Expression Omnibus were used to analyze the differentially expressed genes (DEGs) and DE-miRNAs among GC tissues and normal tissues. Then, targets genes of DE-miRNAs were predicted and the DE-miRNA-DEG regulatory network was constructed. Next, function enrichment analysis of the overlapped genes between the predicted DE-miRNAs targets and DEGs was performed and a protein-protein interactions network of overlapped genes was constructed. Finally, RT-PCR analysis was performed to detect the expression levels of several key DEGs and DE-miRNAs.

RESULTS

A set of 703 upregulated and 600 downregulated DEGs, as well as 8 upregulated DE-miRNAs and 27 downregulated DE-miRNAs were identified in GC tissue. hsa-miR-193b-3p and hsa-miR-148a-3p, which targeted most DEGs, were highlighted in the DE-miRNA-DEG regulatory network, as well as hsa-miR-1179, which targeted KNL1, was newly predicted to be associated with GC. In addition, NCAPG, which is targeted by miR-193b-3p, and KNL1, which is targeted by hsa-miR-1179, had higher degrees in the PPI network. RT-qPCR results showed that hsa-miR-148a-3p, hsa-miR-193b-3p, and hsa-miR-1179 were downregulated, and NCAPG and KNL1 were upregulated in GC tissues; this is consistent with our bioinformatics-predicted results.

CONCLUSIONS

The downregulation of miR-193b-3p might contribute to GC cell proliferation by mediating the upregulation of NCAPG; as additionally, the downregulation of miR-193b-3p might contribute to the mitotic nuclear division of GC cells by mediating the upregulation of KNL1.

Neoangiogenesis of gastric submucosa-invasive adenocarcinoma

Early gastric cancer may be defined as mucosal or submucosal invasive carcinoma, and exhibits a good prognosis: 90% of patients survive >10 years. Early gastric cancer infrequently exhibits lymph node metastasis, although submucosal invasion, the presence of vascular invasion and/or lymphatic permeation are independent risk factors for lymph node metastasis in early gastric cancer. The analysis of tumor lymphangiogenesis and angiogenesis are important to determine the extent of invasive progression and metastasis in patients. Previously, the presence of vessels expressing the D2-40 antibody and the factor-VIII protein has been identified immunohistochemically. The vessels that are immunoreactive for D2-40 and factor-VIII are morphologically similar to lymphatic vessels or small-size veins, also termed venules. In the present study, the association between tumor invasion and neoangiogenesis in early gastric cancer was examined. The D2-40/factor-VIII double-stained vessel (DSV) density was analyzed, in addition to lymphatic and blood vessel (vein and artery) density, using 46 submucosa-invasive and 50 mucosal carcinomas, and 20 non-neoplastic gastric tissues. The lymphatic density and DSV density of submucosa beneath the carcinoma and submucosa of the surrounding region in submucosa-invasive carcinoma were significantly increased (P<0.001) in comparison with those in mucosal carcinoma or non-neoplastic gastric tissue. No significant difference was observed in blood vessel density between non-neoplastic gastric, mucosal carcinoma and submucosa-invasive carcinoma tissues other than that of mucosa. The present study suggests the potential for the presence of D2-40/factor-VIII DSV and the importance of this vessel for neoangiogenesis in early gastric cancer.

Can we resect EGC with Signet ring cells in Europe?

PURPOSE

The proposed guideline for performing endoscopic resection of early gastric carcinoma (EGC) in Paris classification is a well-differentiated carcinoma with maximum involvement Sm1. Signet ring cell carcinomas (SRC) are excluded from this recommendation. Authors from Eastern countries have proposed extending this resection to include selected undifferentiated EGC. Via an analysis of a series of cases of signet ring carcinoma, we will discuss whether it is possible to resect EGC with signet ring cells in Europe.

METHODS

We retrospectively included patients with histological classification pT1 of EGC showing SRC. Data was extracted from the hospital gastrectomy register. Lymphadenomectomy D1.5 was performed on all patients. Histology results were retrospectively obtained from the electronic patient file.

RESULTS

Twelve patients (mean age = 55.4, four women, eight men) underwent surgery, without previous chemotherapy, between 2000 and 2012, for EGC with SRC. Mean size of the lesions was 20.2 mm (5-35 mm). Seven lesions were located in the antrum, five in the fundus. In the case of nine patients, histology showed no lymphovascular involvement. None of these nine patients presented lymph node metastases (LNM). Five patients had intramucosal carcinoma, four were classified as Sm1, one patient was Sm2, and one patient was Sm3. On surgery, the three patients with lymphovascular invasion showed LNM.

CONCLUSION

Endoscopic resection of EGC with SRC does not systematically imply complementary treatment by surgery, although criteria for endoscopic resection are difficult to determine because of the lack of data in Europe.

Preinvasive neoplasia in the stomach: diagnosis and treatment

This article discusses the proper handling of biopsy samples from mucosal lesions taken from the stomach when there is a suspicion of a malignant process. In addition, the use of endoscopic mucosal resection for therapy and staging of gastric neoplasia is discussed.

Early diagnosis of early gastric cancer

The prognosis of gastric cancer is closely related to the stage of disease at diagnosis. Early gastric cancer, whereby disease is limited to mucosa and submucosa, confers a survival rate of greater than 90% in 5 years in many centres. Gastric cancer is still a major cause of cancer mortality worldwide. In high incidence areas such as Japan, screening of asymptomatic population has been advocated. However, in Western countries, mass screening is not cost-effective. Hence, strategy has been directed to screen symptomatic individuals who are at higher risk of gastric cancer. Most patients with early gastric cancer present with symptoms indistinguishable from benign peptic ulcer disease. Screening for this group of patients improves detection rate of early gastric cancer and therefore its prognosis. Endoscopy for surveillance of premalignant lesions has been explored with this objective in mind. Serology testing for biomarkers such as pepsinogen, anti-Helicobacter pylori antibody and gastrin has been studied as an alternative to endoscopy. There is compelling evidence for the role of H. pylori in the initiation of Correa's cascade (stepwise progression from chronic active gastritis, atrophic gastritis, intestinal metaplasia, dysplasia and finally adenocarcinoma). Regression of premalignant lesions has been demonstrated with H. pylori eradication. However, it is not known whether this might effectively prevent gastric cancer in either low or high-risk population.

Original communications recurrence in early gastric cancer

In a retrospective study of 503 cases of early gastric cancer, 17 of the patients had died of a recurrence of the gastric cancer and 72 had died of unrelated causes. The cumulative recurrence mortality rates were 2.2% at 9 years for mucosal cancer and 8.4% at 8 years for submucosal cancer. The recurrence patterns of early gastric cancer were hematogenic metastasis to the liver, lung, or bone (nine cases), recurrence from lymph nodes (three cases), and recurrence in the residual stomach (five cases). Submucosal cancers with a macroscopically elevated appearance, lymph node metastasis, and evidence of vessel invasion were the high-risk cancers for hematogenic recurrence, and adjuvant chemotherapy should be prescribed. Two cases of lymph node recurrence were attributed to inadequacy of lymph node dissection. Because metastasis to the group 2 lymph nodes was noted in 1.5% of cases of early gastric cancer and a macroscopic diagnosis of nodal status was inaccurate, complete dissection should be performed regardless of identification of metastasis. Five cases of recurrence in the residual stomach were attributed to overlooked lesions of multiple carcinoma and were detected at an advanced stage. Careful and regular postoperative follow-up is required to detect these recurrences at an early stage. (SURGERY 1990;107:489–95).

Câncer gástrico precoce: contribuição ao diagnóstico e resultado do tratamento cirúrgico

OBJETIVOS: Analisar o diagnóstico e tratamento de pacientes portadores de câncer gástrico precoce. MÉTODO: Foram estudados 34 pacientes portadores de neoplasia gástrica precoce (CGP) tratados no Serviço de Cirurgia do Aparelho Digestivo Alto da Faculdade de Ciências Médicas da PUC- Campinas durante o período de janeiro de 1978 a dezembro de 1998. RESULTADOS: O diagnóstico foi feito através da endoscopia digestiva alta e biópsia, sendo que em dois deles (5,9%) a biópsia revelou apenas atipias em lesão ulcerada gástrica. O estudo histopatológico das peças cirúrgicas confirmou a existência de adenocarcinoma em todos os pacientes. A localização mais freqüente da neoplasia foi o antro gástrico e os tipos macroscópicos mais encontrados foram IIc e IIc + III. Quanto à profundidade na parede do estômago, verificou-se a prevalência da localização na mucosa. Em nenhum dos casos constatou-se invasão linfonodal. Todos os doentes foram submetidos à gastrectomia subtotal com linfadenectomia D2 e a reconstrução mais freqüente foi a gastro-jejunostomia em Y de Roux (67,6%). O seguimento pós-operatório dos pacientes variou de 17 dias a 21 anos e meio, o qual mostrou complicações em três deles (8,8%). Apenas dois óbitos ocorreram (5,8%), um por complicações pós-operatórias e outro, tardiamente, por recidiva da doença. CONCLUSÕES: A incidência de câncer gástrico precoce (CGP) encontrada no presente estudo (8,7%), mostrou-se semelhante àquela referida pela literatura dos países ocidentais, sendo, entretanto, pobre em relação à incidência referida nas séries japonesas. Este fato valoriza a necessidade da realização de exames endoscópicos periódicos nos pacientes que compõem o chamado grupo de risco para a doença neoplásica do estômago. Finalmente, entendeu-se que quando o CGP está localizado na mucosa e não apresenta invasão de linfonodos e nem metástases à distância, a sobrevida é muito boa.

Results of local resection with regional lymphadenectomy for early gastric cancer

BACKGROUND

In 1999, the authors reported preliminary results of local resection with regional lymphadenectomy(LR) for early gastric cancer.

METHODS

Twenty-four patients underwent LR until May 2000. Laparoscopic techniques were recently applied. The dissected area for lymphadenectomy depended on the lymphatic flow from the tumor. Local gastric resection was performed with a 2 cm cancer-free margin. Among the 24 patients, 14 who had been followed up for more than 1 year were eligible for the nutritional study, and the nutritional parameters were compared with those for patients undergoing pylorus-preserving gastrectomy (PPG).

RESULTS

Twenty-two patients not receiving additional gastrectomy needed no restriction of food intake and had neither postgastrectomy symptoms nor recurrence. All nutritional parameters remained stable between the preoperative and the subsequent period. Nutritional superiority of LR over PPG was observed.

CONCLUSIONS

For selected patients with early gastric cancer, LR can be a treatment of choice to provide a good quality of life.

Preliminary report on local resection with lymphadenectomy for early gastric cancer

BACKGROUND

The frequency of lymph node metastasis in mucosal gastric cancers 2-4 cm in diameter was low (three (1.3 per cent) of 234) in patients treated in this unit between 1966 and 1995. This study was a prospective report on local resection with lymphadenectomy for early gastric cancer.

METHODS

Eight patients with a single early gastric cancer underwent local resection with lymphadenectomy. The tumour was excised with a non-cancerous rim of approximately 2 cm. The extent of lymphadenectomy depended on tumour location. Intraoperative endoscopic examination and frozen-section analysis of the dissected nodes were used to determine the resection line and evaluate nodal status.

RESULTS

Mean operating time, blood loss and number of dissected nodes were 171 min, 87 ml and 8 respectively. There were no operative complications. Cancer invasion was confined to the mucosa in six tumours but two patients had minute submucosal invasion. The maximum diameter of the resected specimens was 10 cm and no nodal involvement was detected. No patient developed postgastrectomy syndrome.

CONCLUSION

For selected patients with early gastric cancer, local resection with lymphadenectomy can provide a good quality of life without compromising cure rate.

Phase II study of limited surgery for early gastric cancer: segmental gastric resection

BACKGROUND

Endoscopic resection for treatment of early gastric cancer (EGC) is widely performed. Recently, however, surgeons began performing a limited operation for EGC when endoscopic resection was not indicated. This report discusses the surgical technique and the results of the limited operation, which is generally referred to as "segmental resection" (SR).

METHODS

Since 1990, a total of 50 patients with intramucosal invasive EGC of the middle stomach underwent SR. The procedure included a limited gastrectomy, limited lymph node dissection, and preservation of the vagal nerve. We examined the surgical risk, postoperative complications, and patient survival rates and compared the results for the SR-treated patients (group A) with results for patients with EGC who underwent subtotal gastrectomy and systemic lymph node dissection (group B).

RESULTS

Blood loss was less in group A (239 +/- 180 ml) than in group B (342 +/- 176 ml) (P < .05). The incidence of postoperative complications was also lower in group A (2.0%) than in group B (14.0%) (P < .05). The incidence of postoperative cholelithiasis was lower in group A (4.0%) than in group B (18.0%) (P < .05). All patients in both groups are alive without recurrence.

CONCLUSIONS

Compared with distal gastrectomy, SR for EGC of the middle stomach decreased the surgical risk and postoperative complications without increasing the recurrence rate.

The value of screening for psychiatric disorders prior to upper endoscopy

Gastrointestinal (GI) complaints are among the most common symptoms in primary care yet are frequently unexplained and often lead to costly diagnostic testing. We sought to determine the prevalence of psychiatric disorders in patients with unexplained GI complaints undergoing upper endoscopy, and the likelihood of endoscopic abnormalities in patients with and without psychiatric diagnoses. We prospectively evaluated 116 adult patients who were undergoing upper endoscopy to evaluate GI complaints. All subjects received a structured psychiatric interview prior to endoscopy using PRIME-MD, and endoscopists were blinded to the PRIME-MD results. Psychiatric disorders were detected in 70 (60%) patients. Overall, there were 113 diagnoses (some patients had multiple disorders) with the most common being somatoform (44%), depressive (29%), and anxiety (19%) disorders. Only 29 patients had major endoscopic abnormalities, including esophageal disease (14), peptic ulcer (9), severe gastritis (4), gastric cancer (1), and esophageal cancer (1). There was a much higher prevalence of psychiatric disorders in patients without major endoscopic abnormalities (74% vs. 21%, p < 0.0001). Psychiatric disease was strongly predictive of endoscopic findings (OR for major abnormality = 0.11 in women, and 0.40 in men), especially if somatoform disorder was present (OR = 0.15). We conclude that, with a simple questionnaire, psychiatric disorders can be diagnosed in a large proportion of patients with unexplained GI complaints who are referred for upper endoscopy. The presence of a psychiatric disorder, particularly if somatoform, makes it unlikely that endoscopy will reveal significant GI disease.

Improving the detection rate of early gastric cancer requires more than open access gastroscopy: a five year study

BACKGROUND/AIMS

To explore the reasons why patients with gastric cancer continue to present with advanced disease despite open access gastroscopy.

PATIENTS

All patients diagnosed with gastric cancer between 1 August 1989 and 31 July 1994.

METHODS

A retrospective study of the presentation of gastric cancer in South Tees; patients were diagnosed at open access gastroscopy or referred through conventional channels. Primary care records of 81 patients dying between 1991 and 1995 were analysed for previous symptoms, investigations, and antisecretory drug therapy. Findings were compared with 200 age and sex matched controls.

RESULTS

The overall incidence of earlier stage gastric cancer remains low at 13%. Diagnostic delay occurs in both primary and secondary care due to a high incidence of previous dyspepsia and investigation. One in six patients had been previously investigated in the three years prior to diagnosis, the majority of whom were on antisecretory drugs.

CONCLUSIONS

Early gastric cancer remains rare in South Tees health district. Advantages of open access gastroscopy appear to be compromised by delayed referral to hospital and failure of endoscopists to recognise the early disease; either they are unaware of its appearance or prior treatment with an H2 receptor antagonist masks the disease by allowing mucosal healing.

Early gastric cancer in Europe

Despite mass population screening and an incidence of EGC in Japan that is at least double that of the West, there seem to be no genuine differences in the clinicopathological features of the disease between the two regions. The macroscopic appearance, size, depth of invasion, frequency of lymph node invasion, and histology of EGC are all remarkably similar in Japan, Europe and America, as are sex and age distributions. Patients with EGC are a number of years younger than those with advanced cancer. This is not surprising: Tsukuma et al followed 56 cases of EGC that were not surgically treated and estimated that the median "duration of EGC" before becoming advanced was 37 months. This suggests that EGC undergoes a period of slow growth before becoming advanced. Further differences between early and advanced cancers include a higher frequency of synchronous cancers and a longer symptom duration in EGC. Unfavourable prognostic factors in EGC include lymph node invasion, and invasion through the muscularis mucosae, though it is not clear whether these are independent. Repeated attempts have been made to identify other prognostic factors, but no clear pattern has emerged, with the possible exceptions of patient age, tumour size, and the presence of ulceration. The postsurgical outcome of EGC in the West is marginally less favourable than in Japan. In view of the similar clinical and pathological features in the two regions it seems likely, therefore, that this is because of the more aggressive surgical techniques traditionally used in Japan. Conversely, however, EMR has recently emerged as an important technique in Japan. Despite the advantages of low operative mortality and normal function of the postoperative stomach, there are also a number of potential disadvantages. It would seem sensible, therefore, to await the results of long term follow up studies before widespread adoption of EMR in Europe. Nevertheless, this technique should be considered for frail patients unfit for more radical surgery.

Early gastric cancer: prognostic factors in 223 patients

A retrospective study of 223 patients treated for early gastric cancer (EGC) is reported, representing 21.2 per cent of the 1051 patients with gastric cancer treated over the same period. Two main types of surgical procedure were used: subtotal resection of the stomach for EGC of the two lower thirds and total gastrectomy for lesions of the upper third. A lymphadenectomy of groups 1 and 2, according to the procedure of the Japanese Research Society for Gastric Cancer (R2 resection), was performed in all patients. The mean duration of follow-up was 7.5 years. Univariate analysis showed a significant difference in survival rates only between patients with and without involved nodes (log rank = 6.05, P = 0.0139). Other prognostic factors were not identified. A bivariate analysis was performed to evaluate the joint effect of node status and the Kodama classification: survival rates for patients with EGC of the penetrating (Pen) A type and node positive falls to around 57 per cent within 6 years. This group of patients has a tumour that should probably be considered as a 'non-early' lesion. To improve the survival of patients with a Pen A, node positive lesion, adjuvant chemotherapy may be appropriate.

Minute and small early gastric cancers in a Western population: a clinicopathologic study

Early endoscopic diagnosis improves the prognosis of patients with gastric cancer, as shown by the finding that 5-year survival rates exceeding 90% are observed in Japanese patients with early gastric cancer. It has been hypothesized that tumor size may have prognostic significance; therefore, a distinction between minute, small, and large early gastric cancers has been proposed. The aim of this study was to determine the prevalence of minute and small early gastric cancers in Western countries and to compare their clinicopathologic features with those of large early gastric cancers. Of 465 Italian patients with gastric cancer who were studied, 20.5% had an early gastric cancer, and 34.7% of these were minute or small. Tumor size is correlated with intramural spreading and metastasis to perigastric lymph nodes. Nodal involvement occurs more frequently in the diffuse than in the intestinal type of early gastric cancer. Long-term survival rate is not correlated with tumor size, intramural spreading, or nodal metastasis. The minute and small early gastric cancers of Italian patients are indistinguishable from those occurring in Japanese patients. These lesions are more common than previously thought and should be carefully searched for by endoscopists. The correlation of tumor size with intramural invasion and perigastric lymph node metastasis suggests that minute and small early gastric cancers are precursors of large early gastric cancers. Although the distinction between minute, small, and large early gastric cancers is of low prognostic value, the distinction might be useful for selecting different therapeutic approaches.

Clinicopathologic study of 208 patients with early gastric cancer in Taiwan: a comparison between Eastern and Western countries

To investigate whether there are any differences between the clinicopathologic characteristics of early gastric cancer (EGC) patients in Eastern and Western countries, 208 Taiwanese patients with EGC were reviewed between 1964 and 1992. The incidence of cancer has increased slightly over the 29-year period. Men were diagnosed with EGC frequently than women, and their mean age was 56 years. Epigastralgia (58.2%) was the most common symptom, whereas 5.8% of cancers were incidentally detected by endoscopy. Physical signs and laboratory tests were of limited value in making the diagnosis. Endoscopy was a better diagnostic aid than radiology. Tumours were frequently located in the lower third (53.2%) and middle third (43.3%) of the stomach. Cancers of the elevated type (17.8%) were less frequent than the depressed type (82.2%). Type IIc (31.2%) was the most common macroscopic type. The frequency of mucosal carcinoma (51.0%) was similar to submucosal carcinoma (49.0%). Mucosal carcinoma had less lymph node metastases (3.1%) than submucosal carcinoma (12.2%; P < 0.05), with an overall frequency of metastases of 7.5% (14/186). The 5-year survival rate was 90.8%. The clinicopathologic characteristics of EGC in Taiwan were similar to those of Western countries and other Eastern countries. Improvement of diagnostic examinations and endoscopic surveillance of asymptomatic subjects may lead to early diagnosis and thus ensure a more favourable outcome.

A comparison of the logistic regression and the Cox proportional hazard models in retrospective studies on the prognosis of patients with gastric cancer

To define the independent prognostic factors reducing survival time for gastric cancer, we compared the logistic regression and the Cox proportional hazard models applied to patients who underwent curative gastrectomy. All patients were evaluated after being followed for long fixed periods. Of 1,019, 269 (26.4%) died of tumor recurrence within a 5-year period and 36 (3.5%) died over 5 years after the original surgery. With regard to survival time, multivariate analyses using the Cox proportional hazard model in a stepwise manner adjusted for the sex, age, and 10 other factors, suggested that size of tumor (P < 0.01, relative risk [rr] = 1.0962), degree of gastric wall invasion (P < 0.01, rr < 1.3520), and status of lymph node metastasis (P < 0.01, rr = 1.6572) were the most independent prognostic factors. As well as, using the stepwise logistic regression model, size of tumor, (P < 0.01, odds ratio [or] = 1.115), degree of gastric wall invasion (P < 0.01, or = 1.428), and status of lymph node metastasis (P < 0.01, or = 2.182) were also the most independent risk factors for recurrence within 5 years after surgery. Although regression coefficients are not all the same, these three factors proved significant in both multivariate analyses. This equation for risk factors for prognosis is approached when searching for an appropriate method of retrospective studies using multivariate analyses.

The spread of upper gastrointestinal endoscopy in Japan and the United States. An international comparative analysis of technology diffusion

The use of upper gastrointestinal (GI) fiberoptic endoscopy has spread at different times and rates in Japan than in the United States. Factors that explain this disparity and its effects on patient outcomes are reported. This essay outlines Japanese data in gastroenterology, giving an account of the resources and time that were spent on the development of upper GI endoscopy in Japan. It also draws implications for the assessment of endoscopy for populations at high risk for gastric cancer.

Early gastric cancer: an analysis of 44 cases with emphasis on the prognostic significance of the macroscopic and microscopic growth patterns

Forty-four consecutive cases of "early gastric cancer" were studied according to the macroscopic classification proposed by the Japanese Gastroenterological and Endoscopy Society and further analyzed in terms of growth patterns. The tumours were then classified into the small mucosal type, the superficially spreading (Super) type and the penetrating growth (Pen) type. The Lauren type (intestinal vs. diffuse), presence of lymphatic and venous invasion, and lymph node metastasis were also assessed. Most elevated tumours showed a superficial growth pattern and were classified as Lauren's intestinal type, whereas depressed lesions were associated with submucosal invasion and were classified as diffuse. Microscopic patterns did not show any correlation with Lauren's classification. Mean duration of follow-up was 67.8 months and the overall actuarial survival was 93%, 80%, and 72%, at 2, 5, and 10 years, respectively. Aside from venous invasion no correlation was found between survival and any of the morphological parameters analysed.

Pathology and prognosis of gastric carcinoma. Findings in 10,000 patients who underwent primary gastrectomy

BACKGROUND

Despite recent advances in diagnosis and treatment, gastric carcinoma remains a major cause of death in the world.

METHODS

The clinicopathologic profile of 10,000 consecutive patients who underwent primary gastrectomy during 1962-1989 were reviewed and prognostic factors influencing survival in those with gastric carcinoma were analyzed in 7031 patients.

RESULTS

Incidence of gastrectomy for carcinoma has increased steadily and the rate of early carcinoma exceeded that of advanced carcinoma in the recent period of 1985-1989. Five-year and 10-year survival rates were 46.1% and 35.2% in 3868 patients with advanced carcinoma, and 88.8% and 77.3% in 3163 patients with early carcinoma, respectively. In patients with advanced carcinoma, significantly poorer survival rates were noticed for patients older than 70 years of age, those who underwent total gastrectomy, tumors involving the entire stomach or greater than 10 cm in diameter, a macroscopic diffusely infiltrative pattern, adenosquamous histologic type, positive surgical resection margins, or lymph node metastasis. None of the above poor prognostic features were identified in patients with early gastric carcinoma group except for those older than 70 years of age. Although lymph node metastases were present in 10% of early gastric carcinomas, this feature did not impart a poor prognosis. Patients with advanced carcinoma grossly resembling an early carcinoma had an intermediate prognosis, suggesting the existence of a developmentally midstage lesion between early and advanced carcinoma.

CONCLUSIONS

The study illustrates that the most important role for clinicians treating with gastric carcinoma should be early detection and aggressive surgery for resectable tumors, followed by detailed pathologic examination.

Early gastric cancer

Early gastric cancer comprises more than 30 per cent of gastric carcinomas treated in Japan but remains an uncommon entity in the western hemisphere. A retrospective review of 48 patients with early gastric cancer undergoing operative treatment between 1965 and 1984 was carried out. The mean patient age was 70 years, in 31 men and 17 women. Preoperative diagnosis was made in 88 per cent of patients undergoing oesophagogastroduodenoscopy with biopsy but upper gastrointestinal radiography was diagnostic in only 20 per cent. Surgical management consisted of subtotal gastrectomy (86 per cent), total gastrectomy (10 per cent) and wide local excision (4 per cent). The operative mortality and morbidity rates were 0 and 38 per cent, respectively. Mean follow-up was 7.7 years, with 44 per cent of patients still alive. Multivariate analysis disclosed only a healthy Eastern Cooperative Oncology Group score (P = 0.002) and a diploid DNA tumour pattern (P = 0.05) as significant prognostic variables of survival. The overall survival rate of patients with early gastric cancer (70 per cent at 5 years) was equivalent to that of an age- and sex-matched control population.

Improving survival in gastric cancer: review of 5-year survival rates in English language publications from 1970

In this review of English language publications from 1970, 5-year survival rates after surgery for gastric cancer have been analysed. While the proportion of patients coming to operation has fallen from 92 per cent before 1970 to 71 per cent by 1990, the proportion of operated patients undergoing resection has increased from 37 per cent before 1970 to 48 per cent before 1990. This change suggests improved preoperative staging leading to better patient selection for operation. The 5-year survival rate following all resections has increased significantly from 20.7 per cent before 1970 to 28.4 per cent before 1990, an increase of 7.7 per cent (95 per cent confidence interval 7.1-8.3 per cent). The 5-year survival rate following curative or radical resection has risen from 37.6 to 55.4 per cent over the same period, an increase of 17.8 per cent (95 per cent confidence interval 17.1-18.5 per cent). It is likely that this improvement has contributed to the decrease in the mortality rate from gastric cancer. Comparison of Japanese series with others suggests that diagnosis and treatment of the disease at an earlier stage will result in an even greater increase in 5-year survival rates outside Japan. Of the papers studied, 56 per cent were excluded from analysis, the majority because the data provided about 5-year survival rates were insufficient or the survival calculations inappropriate. Results of survival after operations for gastric cancer should be calculated and presented in a standardized manner.

Early gastric cancer

Early gastric cancer is a unique form of gastric carcinoma with an excellent prognosis. Now recognized worldwide, this tumor is most commonly diagnosed in Japan secondary to aggressive screening practices. Early detection is dependent on a low threshold for esophagogastroduodenoscopy with biopsies, because specific symptoms and physical findings or diagnostic laboratory tests are rarely present with early gastric cancer. Once the disease is diagnosed, subtotal gastrectomy achieves survival rates equivalent to those of age-matched controls. Consideration of total gastrectomy is warranted with proximal tumor location or multicentric carcinoma. Radical lymphadenectomy should be undertaken in patients with regional nodal metastasis. After operative resection, patient outcome is usually excellent. Large submucosal tumors with an aneuploid DNA pattern and nodal involvement denote a more ominous outlook. Close patient follow-up is necessary to detect both the uncommon recurrence and the more common nongastric malignancy.

Death due to recurrence following curative resection of early gastric cancer depends on age of the patient

This study was done to define the relationship between age at the time of surgery and the prognosis after curative resection for patients with an early gastric cancer. Three hundred and eighty-two patients were identified and 25 patients died of tumour recurrence. Overall, the cumulative survival rate was 94.9% at 5 years and 92.4% at 10 years. Patients with a recurrence of the gastric cancer tended to be older, were more likely to have large differentiated type of tumour and lymph node metastases were often present. Stratified into age-classified groups, the survival rate decreased with increase of age (for patients under age 34 years, 35 to 44, 45 to 54, 55 to 64, 65 to 74, over age 75 years, the 5-year survival rates were 100.0, 97.7, 97.6, 94.2, 94.1 and 84.4 (%]. Of the 25 patients with a tumour recurrence and who died, the survival time of 18 patients over age 55 years was significantly shorter than that of seven patients under age 54 years (median, 1.7 vs 5.6 years, P less than 0.05). The multivariate analysis showed that, over and above the differentiated type of tumour (P less than 0.01) and the presence of lymph node metastases (P less than 0.01), age was one of the prognostic factors (P less than 0.05). We conclude that age at the time of primary surgery is a significant factor in patients with an early gastric cancer.

Early gastric cancer. Twenty-eight-year experience

A retrospective study of early gastric cancer (60 patients) was performed to evaluate its diagnosis and treatment. Ninety-five per cent of patients presented with nonspecific gastrointestinal symptoms and 53.3% had been treated for presumed benign disease for up to 48 months before diagnosis. Fiberoptic endoscopy detected these lesions more accurately than radiologic examination. The disease-free 5-year survival rate after resection was 76.4%. Survival showed no significant correlation with sex, tumor site, macroscopic appearance, extent of gastric resection, or histopathologic type. Tumors larger than 1.5 cm in diameter, invasion of submucosa, or lymph node metastasis resulted in significantly lower survival rates. Three of eight patients with nodal metastasis survived 5 or more years, including one who had second-echelon deposits. A high index of suspicion may permit more frequent detection. Extended lymphadenectomy (R2) is recommended to achieve the highest possible cure rate.

Adenocarcinoma of the stomach with invasion limited to the muscularis propria

Adenocarcinoma of the stomach having invasion limited to the muscularis propria with or without lymph node metastasis, termed PM (proper muscle) gastric cancer by Japanese investigators, has a prognosis superior to that of carcinoma extending to the serosa and approaching that of early gastric cancer in Japan. To evaluate the occurrence and significance of PM gastric cancer in the United States, we analyzed 272 gastric carcinomas resected at our institution between 1964 and 1983. Forty-two PM cancers (15%) were identified. Improved 5-year survival rate was noted for PM cancer when compared with survival rate for 215 neoplasms exhibiting serosal invasion (29% versus 7%, P less than 0.001). In univariate analysis, a survival advantage was also associated with absence of lymph node metastasis, intestinal-type histopathology of the Lauren classification, the expanding pattern of the Ming classification, and polypoid or fungating gross configuration of tumor. In multivariate analysis, depth of tumor invasion remained significantly associated with improved 5-year survival rate independently of other variables, including lymph node metastasis. Using continuous survival curves, the prognostic significance of PM cancer prevailed throughout the 5-year postgastrectomy interval. Our data indicate that PM gastric cancer occurs in the United States and need not be considered "advanced" gastric carcinoma; depth of tumor invasion should be recognized as a nodal metastasis-independent prognosticator of gastric cancer survival.

Early gastric cancer

Eighteen cases of 'early gastric cancer' have been managed over a 14-year period. This represents only 3.5% of all patients diagnosed as having adenocarcinoma of the stomach. The symptoms of early gastric cancer are similar to those of benign peptic ulcer disease and differ from those of invasive disease. The pathology of the lesions is described and the morphology shown to be similar to that seen in Japan. The overall 5-year survival rate is 82% but no patient has developed recurrence within 5 years of surgery, confirming the biological behaviour of the lesion to be identical to that noted by Japanese researchers.

The British Society of Gastroenterology early gastric cancer/dysplasia survey: an interim report

This presentation describes interim findings in a series of 319 patients referred from 41 hospitals on the basis of histopathological findings of 'early gastric cancer', 'dysplasia', or 'worrying mucosal appearances'. Data were recorded using a predefined proforma, and histopathological material circulated amongst a 'panel' of three further pathologists. After this process, 132 patients were classified as having early gastric cancer and 63 as dysplasia. There was good agreement between pathologists as to whether the cases had cancer or dysplasia - but 39 cases said by referring pathologists to have early gastric cancer were classified by the panel as having more extensive disease. Most early gastric cancer cases were diagnosed only after histopathological examination. Cancer or 'possible cancer' was only mentioned after 36% of the radiological investigations and 40.5% of the endoscopies. Computer aided analysis of the patients' symptoms placed 91.3% of the early gastric cancer cases into a 'high risk' group - but was unable to distinguish between early gastric cancer and dysplasia. The five year survival rate of the cases agreed to be early gastric cancer by the panel was well over 90%, but the four year survival rate of cases registered as 'early gastric cancer' but said by the panel to have more advanced disease was under 75%. These findings may account for some of the differences between series, and emphasise the need for precise, widely agreed criteria for the diagnosis of early gastric cancer and gastric dysplasia.

Complete ten-year postgastrectomy follow-up of early gastric cancer

The postoperative courses of 109 patients with early gastric carcinoma treated from 1970 through 1976 were followed for 10 years. The cumulative 5-year survival rate was 96 percent and the 10-year survival rate was 92 percent. In this series, there was no significant difference in the survival rates between the mucosal cancer and submucosal invasion groups or between patients with and without lymph node metastasis. Five patients died from the recurrent cancer. The other causes of death were metachronous primary cancer in eight patients, synchronous primary cancer of sigmoid colon or rectum in two, cerebrovascular accident in six, heart disease in six, other causes in four, and unknown causes in four. Although the prognosis of early gastric cancer is remarkably good, patients should be carefully followed over a long period for late recurrence of the primary cancer and possible metachronous cancer of the other organs.

[Surgical treatment of early stomach cancer]

At the department of surgery at the university hospital in Cologne 94 patients suffering from early gastric cancer of the stomach were operated in the years between 1968 and 1983. From 1972 till 1987 the department of surgery at the university hospital Mainz has had 74 patients. Survival rates and times without recurrence were calculated dependent on the surgical treatment carried out. In both collectives the prognosis for the patients with mucosal carcinoma was good no matter which operation was carried out. In the case of submucosal infiltration the frequency of recurrence was smaller and the survival rates significantly higher in those patients who subjected to a cancer operation than in those on whom only a resection of two third of the stomach was performed. The results indicate a radical approach in the treatment of early gastric cancer. At least in the case of submucosal carcinoma a dissection of the N2 lymph nodes is advisable.

Early gastric cancer

Thirty-six patients with early gastric cancer were studied. In 15 patients, malignancy was restricted to the mucosa; in 21 patients, submucosal invasion was noted. Lymph node involvement was found in four patients. Kaplan-Meier estimates for 5-year survival were 92 percent for mucosal lesions and 65 percent for submucosal lesions (overall 5-year survival rate 73 percent). Mucosal lesions were significantly larger than were submucosal lesions (3.7 +/- 0.6 cm versus 2.5 +/- 0.4 cm, mean +/- SE; p less than 0.005). Associated malignancy was recorded in 13 of 36 patients. When compared with data from a large Japanese study, early gastric cancer in the United States tends to develop more distally in the stomach and in patients approximately one decade older. Survival was not as favorable as in Japan. This may be related to patient age and the high incidence of associated nongastric malignancy.

Gastric cancer in primary care: how hard should you look?

This article addresses the question of how vigorously a physician should search for gastric cancer among dyspeptic patients. To address this subject, two major questions are posed: Which patients presenting with dyspepsia are at highest risk of having gastric cancer? Does early diagnosis of symptomatic gastric cancer affect outcome? Although early detection of gastric cancer has been increasingly reported since the advent of fiberoptic endoscopy, factors such as lead time bias and an unchanged case-fatality rate preclude a definitive conclusion of improved treatment outcomes resulting from early detection. At present, a policy of routine immediate investigation of dyspeptic patients has not been shown to reduce gastric cancer mortality.

Early gastric cancer in Korea

We reviewed the 639 cases of early gastric cancer from nation-wide 16 medical centers. The proportion of early gastric cancer among surgically resected gastric carcinoma comprised 6 to 12 percent. Male to female ratio was 1.7 to 1 with male preponderance. Mean ages of the early gastric cancer was 49.0 years and most prevalent ages was 5th decade. Macroscopically type IIc was most prevalent, reaching 59.9 percent. Depressed type lesions was more frequent than elevated type lesions by four folds. The size of lesions less than 4 cm accounted for more than 80 percent. Most frequent site of lesions were lower third by the CMA classification and lesser curvature transectionally. Lymph node metastasis was observed in 10.9 percent of all cases and it was more frequent in large tumor size more than 4 cm, elevated type, and undifferentiated carcinoma. 5-year survival rate was 91.6 percent. Gastrofiberscopic examination was superior to that of radiological examination in the diagnosis of early gastric cancer.

Early gastric cancer: 52 cases of combined experience of two south Australian teaching hospitals

Fifty-two patients with early gastric cancer are described. At presentation, the average age was 60 years and the male:female ratio was 3:2. The patients had presenting symptoms indistinguishable from those due to benign peptic ulcer disease. Endoscopic examination with multiple biopsies was the most accurate means of diagnosis, with an overall 93% detection rate. The tumours were located predominantly along the lesser curve (75%) and in the antrum (64%), with ulcerated or depressed lesions most common and flat lesions least common. Approximately 58% of lesions were of intestinal type, submucosal invasion was seen in 45% and lymph node metastases had occurred in 7% of cases. Lesser curve and antral lesions were more likely to be ulcerated. Ulcerated lesions were on average, the same size as non-ulcerated lesions. Body lesions were larger than antral lesions and lesions which had spread to the submucosa were larger than mucosal lesions. Diffuse-type lesions were more likely to be ulcerated than intestinal-type lesions and dysplasia was more commonly associated with intestinal-type lesions than with diffuse or mixed-type lesions. The crude 5-year survival rate was 80%, but only one death was associated with a recurrence of gastric cancer.

Early gastric cancer in clinical practice

A description of four patients with early gastric cancer diagnosed by endoscopy is reported. All patients presented with type III (excavated or ulcerative) early gastric cancer. Early gastric cancer appeared to be slow growing in three patients, and was difficult to diagnose in two cases, especially when associated with large gastric ulcers. Endoscopic biopsy of nonhealing or recurrent gastric ulcers and endoscopic follow-up to complete ulcer healing are recommended.