Chronological changes of characteristics of early gastric cancer and therapy: experience in the Cancer Institute Hospital of Tokyo, 1950-1994

Relationship Between Appendectomy Incidence and Computed Tomography Scans Based on Korean Nationwide Data, 2003-2017

BACKGROUND

Advances in medicine and changes in the medical environment can affect the diagnosis and treatment of diseases. The main purpose of the present study was to investigate whether the difference in accessibility to diagnosis and treatment facilities influenced the occurrence of appendectomy in Korea.

METHODS

We collected data on 183,531 appendectomy patients between 2003 and 2017 using the National Health Insurance Services claims. Retrospective analysis of relationship between the age-standardized rate (ASR) of appendectomy and clinical variables affecting medical accessibility was performed. Pearson's correlation analyses were used.

RESULTS

The incidence of appendectomy decreased from 30,164 cases in 2003 to 7,355 cases in 2017. The rate of computerized tomography (CT) scans for diagnosis of appendicitis increased from 4.73% in 2003 to 86.96% in 2017. The ASR of appendectomy in uncomplicated and complicated appendicitis decreased from 48.71 in 2005 to 13.40 in 2010 and 8.37 in 2005 to 2.96 in 2009, respectively. The ASR of appendectomy was higher in the high-income group. The proportion and ASR of appendectomy in older age group increased steadily with years. The total admission days continued to decrease from 6.02 days in 2003 to 4.96 days in 2017.

CONCLUSION

The incidence of appendectomy was seemingly associated with the rate of CT scan. In particular, the incidence of appendectomy in uncomplicated appendicitis was markedly reduced. Through enhanced accessibility to CT scans, accurate diagnosis and treatment of appendicitis can be facilitated.

Gastric Cancer in Young Adults: A Different Clinical Entity from Carcinogenesis to Prognosis

Approximately 5.0% of gastric cancer (GC) patients are diagnosed before the age of 40 and are not candidates for screening programs in most countries and regions. The incidence of gastric cancer in young adults (GCYA) has declined over time in most countries except in the United States. Genetic alterations, environmental factors, and lifestyle may predispose some young adults to GC. According to molecular classifications, the cancer of most GCYA patients belongs to the genomically stable or microsatellite stable/epithelial-mesenchymal transition subtype, with the common genetic aberrations being mutations in CDH1. What characterizes GCYA are a higher prevalence in females, more aggressive tumor behaviors, diagnosis at advanced stages, fewer comorbidities and being better treatment candidates, and a similar or better survival outcome when compared with older patients. Considering the greater loss of life-years in younger patients, lowering the incidence of GC and diagnosing at a relatively early stage are the two most effective ways to decrease GC mortality. To achieve these goals, the low awareness of GCYA among general people, policy-makers, clinicians, and researchers should be changed.

CHARACTERIZATION OF THE MUCIN PHENOTYPE CAN PREDICT GASTRIC CANCER RECURRENCE AFTER ENDOSCOPIC MUCOSAL RESECTION

BACKGROUND

Endoscopic mucosal resection is still considered an accepted treatment for early gastric cancer for selected cases. Histopathologic criteria for curative endoscopic resection are intramucosal well-differentiated adenocarcinoma, lateral and deep margins free of tumor, no histological ulceration, and no venous or lymphatic embolism. A 5% local recurrence rate has been described even when all the above-mentioned criteria are met. On the other hand, antigen expression by tumoral cells has been related to the biological behavior of several tumors.

OBJECTIVE

To evaluate whether early gastric cancer mucin immunoexpression, p53 and Ki-67, can predict recurrence after endoscopic mucosal resection, even when standard histopathologic criteria for curative measures have been attempted.

METHODS

Twenty-two patients with early gastric cancer were considered to have been completely resected by endoscopic mucosal resection. Local recurrence occurred in 5/22 (22.7%). Immunohistochemical study was possible in 18 (81.8%) resected specimens. Patients were divided in two groups: those with and those without local recurrence. They were compared across demographic, endoscopic, histologic data, and immunohistochemical factors for MUC2, MUC5a, CD10, p53, and Ki-67.

RESULTS

Mucin immunoexpression allowed a reclassification of gastric adenocarcinoma in intestinal (10), gastric (2), mixed (4), and null phenotypes (2). Mixed phenotype (positive for both MUC2 and MUC5a) was found in 80% of cases in the local recurrence group, while the intestinal type (positive MUC2 and negative MUC5a) was found in 76.9% of cases without local recurrence (P=0.004). Other observed features did not correlate with neoplastic recurrence.

CONCLUSION

The mixed phenotype of early gastric adenocarcinoma is associated with a higher probability of local recurrence after endoscopic mucosal resection.

Periodic Endoscopies Might Not Increase the Detection of Early Gastric Cancer in a Young Population

Background

Screening endoscopies in individuals 40 years or older in regions where gastric cancer is prevalent increase the diagnosis of gastric cancer at an early stage. However, the benefits of screening endoscopies in a young population (<40 years) have not been evaluated.

Methods

We reviewed data from patients less than 40 years old who underwent endoscopic submucosal dissection or surgery for initial-onset gastric cancer. We also administered a questionnaire to gather information concerning periodic endoscopic inspections and the period from the penultimate endoscopy to diagnosis.

Results

Of the 564 patients in this study, 101 (17.9%) patients underwent screening endoscopy within 24 months of their gastric cancer diagnosis. Lesion size was significantly smaller in the ≤24 months group than in the >24 month group (23.8 mm [standard deviation, 22.2 mm] vs. 30.5 mm [standard deviation, 23.1 mm], P = 0.008). However, the proportion of patients with early gastric cancer did not differ between the two groups (≤24 months vs. >24 months group; 67.6% vs. 65.7%, P = 0.712). On multivariable analysis, periodic endoscopies did not influence the early diagnosis of gastric cancer (with >24 months as the reference group: ≤24 months, odds ratio = 0.939, 95% confidence interval = 0.583–1.513).

Conclusion

Although periodic endoscopies aided in the detection of gastric cancer when lesions were smaller in size, they seemed not to increase the proportion of patients with early gastric cancer in young patients diagnosed with resectable gastric cancer.

The Japanese Viewpoint on the Histopathology of Early Gastric Cancer

Japanese histopathologists have traditionally had greater opportunity to study the histology and clinical course of early gastric cancer because of technological developments including double contrast radiography and endoscopy systems, combined with the higher incidence of gastric cancer in the general population in Japan. Endoscopic resection is now considered best practice for treatment of early gastric cancers with a negligible risk of lymph node metastasis. Histopathologic evaluation plays a critical role in assessing the likelihood of lymph node metastasis on endoscopically resected specimens. There remains disparity between Western and Japanese histopathologists in the conceptual approach to the histopathologic evaluation of neoplastic lesions in the upper gastrointestinal tract, in particular regarding lesions straddling the borderline between noninvasive and invasive disease. Although in routine practice, the clinical impact of these conceptual differences is small, this disparity does complicate international exchange of datasets and the development of globally applicable formal definitions. Here we review the current practice in histological diagnosis of early gastric cancer in Japan and discuss some of the conceptual differences between Japanese and Western histopathological assessment of lesions in the neoplastic stomach.

The new modified ABCD method for gastric neoplasm screening

BACKGROUND

The ABCD screening method was developed for risk stratification of gastric cancer. It is unclear whether the ABCD method can predict the risk of gastric neoplasms, including gastric adenomas, as observed for gastric cancer. We aimed to devise a modified ABCD method for predicting gastric neoplasms.

METHODS

We reviewed 562 patients who had undergone upper gastrointestinal tract endoscopy and whose serum IgG anti-Helicobacter pylori antibody, gastrin, and pepsinogen (PG) I and PG II data were available. Patients were classified into the following four groups: H. pylori antibody negative and normal PG level (group A), H. pylori antibody positive and normal PG level (group B), H. pylori antibody positive and low PG level (group C), and H. pylori antibody negative and low PG level (group D).

RESULTS

The PG I/PG II ratio was lower in patients with gastric neoplasms than in patients without these lesions (gastric adenoma vs gastric cancer vs no neoplasm, 3.7 ± 2.0 vs 3.8 ± 1.8 vs 4.9 ± 2.1, P < 0.001). The optimal cutoff values of the PG I/PG II ratio for predicting gastric neoplasms were 3.1 for H. pylori antibody negative patients and 4.1 for H. pylori antibody positive patients. A higher group grade was associated with a significantly higher proportion of gastric neoplasms [odds ratio (95 % confidence interval), group A, reference; group B, 1.783 (1.007-3.156); group C, 3.807 (2.382-6.085); and group D, 5.862 (2.427-14.155)].

CONCLUSIONS

The modified ABCD method using two different cutoff values according to the H. pylori antibody status was useful for predicting the presence of gastric neoplasms. This method might be a supplementary screening tool for both gastric adenoma and gastric cancer. However, further studies will be required to provide a definitive conclusion.

Dysplasia in Gastric Mucosa and its Reporting Problems

BACKGROUND

The recognition, terminology used and histopathologic evaluation of two essential elements in gastric carcinogenesis, atrophy and dysplasia, are characterized by controversy.

MATERIALS AND METHODS

One hundred fifteen cases, with slides and their histopathologic reports from the archive of the Laboratory of Pathology were studied for the diagnostic value, reporting of dysplasia, interobserver variability, the relation of dysplastic lesions with inflammation, atrophy and metaplasia. After retrospectively studying the histopathologic reports from the archive we distributed the cases according to endoscopic and histopathologic diagnosis, together with the reexamination of the slides. The comparison of the median values of the numeric variables was made with the Mann-Whitney test (non-parametric equivalent of the Student's "t" test).

RESULTS

The endoscopic clinical diagnosis were: malignancy/suspicious for malignancy 88 cases (76%) and non-neoplastic diagnosis (like ulcer or gastritis) 27 cases (24%). From the reexamination of the cases it resulted that there is no difference in reporting the malignancy, but there is a difference in the cases reported as dysplasia (p = 0.001) and negative for neoplasia (p = 0.063, borderline).

CONCLUSION

Clinicians and pathologists can feel directly the discrepancy called "interobserver variability" and should be assured that the use of guidelines will cause a lowering of this variability.

The role of hepatectomy in the management of metastatic gastric adenocarcinoma: a systematic review

BACKGROUND

Gastric cancer has a high mortality, with many patients presenting with advanced disease. Many patients who undergo curative gastrectomy will subsequently develop metastatic disease. Hepatectomy has an established place in treating metastases from a variety of cancers but its role in gastric cancer is not clear. This review sought to systematically appraise the literature to establish the role of hepatectomy in treating gastric cancer metastases.

METHOD

Medline and EMBASE were searched for all papers publishing data on survival of patients with metastatic gastric adenocarcinoma who underwent hepatectomy.

RESULTS

Seventeen studies with 438 patients were included. There were no randomised controlled trials. Perioperative mortality was 2%, with morbidity between 17 and 60%. Patients with solitary metastases appeared to have better survival. Other favourable survival characteristics included unilobar disease, and metachronous presentation. No advantage was demonstrated with either adjuvant or neoadjuvant chemotherapy.

DISCUSSION

Few patients with hepatic metastases from gastric cancer are suitable for hepatectomy, but for those suitable there appears to be survival benefit. Patients with synchronous, multiple or bilobar metastases have worse survival.

CONCLUSION

The evidence supporting the role of hepatectomy in the treatment of hepatic metastases from gastric cancer is weak. However in a selected group there appears to be a survival advantage; patients with solitary metastases had better survival outcomes than those with multiple metastases and metachronous presentation was associated with a better prognosis than synchronous presentation. Hepatectomy should be considered in these patients in the setting of a randomised trial.

The optimal endoscopic screening interval for detecting early gastric neoplasms

BACKGROUND

The optimal interval between endoscopic examinations for detecting early gastric neoplasms, including gastric adenomas, has not previously been studied.

OBJECTIVE

To clarify the optimal interval between endoscopic examinations for the early diagnosis of both gastric cancers and adenomas.

DESIGN

Retrospective study.

SETTING

University-affiliated tertiary-care hospital, Seoul, Korea.

PATIENTS

Patients who were treated for gastric neoplasms between January 2008 and August 2013.

INTERVENTIONS

Questionnaire survey for interval between the penultimate endoscopy and diagnosis of a gastric neoplasm. A total of 846 patients were divided into 5 groups according to the interval between endoscopic examinations.

MAIN OUTCOME MEASUREMENTS

The proportion of gastric neoplasms treated with endoscopic submucosal dissection and the proportion of advanced gastric cancers according to the interval between endoscopic examinations.

RESULTS

In total, 197, 430, and 219 patients were diagnosed with gastric adenoma, early gastric cancer, and advanced gastric cancer, respectively. In multivariate analysis, the proportion of gastric neoplasms treated with endoscopic submucosal dissection was significantly higher in the ≤12 months, 12 to 24 months, and 24 to 36 months endoscopy interval groups than in the no endoscopy within 5 years group (all P < .001). In addition, the proportion of advanced gastric cancers was significantly lower in the ≤12 months and 12 to 24 months endoscopy interval groups than in the no endoscopy within 5 years group (all P < .001).

LIMITATIONS

Retrospective study and recall bias.

CONCLUSION

Annual endoscopy cannot facilitate the detection of endoscopically treatable gastric neoplasms compared with biennial or triennial endoscopy. We recommend biennial endoscopic screening for gastric neoplasms in order to increase the proportion of lesions discovered while they are still endoscopically treatable and to reduce the number of lesions that progress to advanced gastric cancer.

Very well-differentiated gastric carcinoma of intestinal type: analysis of diagnostic criteria

Very well-differentiated gastric adenocarcinoma of intestinal type is a rare variant of gastric cancer characterized by low-grade nuclear atypia, and for which the diagnostic criteria and clinical behavior are not fully established. This study presents a detailed histologic, immunohistochemical, and clinical analysis of 21 cases. Nuclear atypia was mild in all cases. Characteristic architectural features of this gastric adenocarcinoma variant were pit and glandular anastomosis, spiky glands, distended glands, discohesive cells, abortive glands, and glandular outgrowth. At least three of these features were present in all the cases. Retrospective review of preoperative biopsies in 18 patients revealed that half of the biopsies were originally reported as negative or indeterminate for malignancy. On the basis of immunohistochemical stains for intestinal (MUC2, CD10, and CDX-2) and gastric (MUC5AC and MUC6) markers, 11 (52%) cases had an intestinal immunophenotype and 10 (48%) cases had a mixed immunophenotype. Foci of discohesive neoplastic cells, indicating dedifferentiation toward a poorly cohesive carcinoma, were observed exclusively in neoplasms of mixed immunophenotype (n=5). All patients with follow-up but one were alive without disease at a mean of 19 months (range 1-60 months). One individual with a pT4 tumor with associated poorly cohesive carcinoma died of disease. In summary, very well-differentiated gastric adenocarcinomas are diagnostically challenging. Architectural features are critical to making the diagnosis. Cases with pure intestinal immunophenotype have not been associated with transformation into poorly cohesive carcinoma, and appear to behave as biologically low grade. Those with mixed immunophenotype appear more likely to dedifferentiate and behave more aggressively.

Cost-effectiveness outcomes of the national gastric cancer screening program in South Korea

BACKGROUND

Although screening is necessary where gastric cancer is particularly common in Asia, the performance outcomes of mass screening programs have remained unclear. This study was conducted to evaluate cost-effectiveness outcomes of the national cancer screening program (NCSP) for gastric cancer in South Korea.

MATERIALS AND METHODS

People aged 40 years or over during 2002-2003 (baseline) were the target population. Screening recipients and patients diagnosed with gastric cancers were identified using the NCSP and Korea Central Cancer Registry databases. Clinical outcomes were measured in terms of mortality and life-years saved (LYS) of gastric cancer patients during 7 years based on merged data from the Korean National Health Insurance Corporation and National Statistical Office. We considered direct, indirect, and productivity-loss costs associated with screening attendance. Incremental cost-effectiveness ratio (ICER) estimates were produced according to screening method, sex, and age group compared to non-screening.

RESULTS

The age-adjusted ICER for survival was 260,201,000-371,011,000 Korean Won (KW; 1USD=1,088 KW) for the upper-gastrointestinal (UGI) tract over non-screening. Endoscopy ICERs were lower (119,099,000-178,700,000 KW/survival) than UGI. To increase 1 life-year, additional costs of approximately 14,466,000-15,014,000 KW and 8,817,000-9,755,000 KW were required for UGI and endoscopy, respectively. Endoscopy was the most cost-effective strategy for males and females. With regard to sensitivity analyses varying based on the upper age limit, endoscopy NCSP was dominant for both males and females. For males, an upper limit of age 75 or 80 years could be considered. ICER estimates for LYS indicate that the gastric cancer screening program in Korea is cost-effective.

CONCLUSION

Endoscopy should be recommended as a first-line method in Korea because it is beneficial among the Korean population.

Endoscopy and role of endoscopic resection in gastric cancer

Patient selection for endoscopic resection is based on meticulous endoscopic examination and histological assessment so as to avoid performing this procedure on patients with a high risk of lymph node involvement or metastatic disease. Currently, endoscopic mucosal resection (EMR) is used for tumors <2 cm, and endoscopic submucosal dissection (ESD) should be considered for tumors >2 cm. The advantage of ESD is that it achieves en-bloc resection of larger tumors, potentially reducing the risk of disease recurrence.

Metachronous liver metastasis from early gastric cancer

INTRODUCTION

Early gastric cancer (EGC) has an excellent prognosis, but tumors recur in some patients even after apparently successful treatment. Among recurrent sites, the liver is one of the most common. In this study, we investigated clinicopathological features and factors predicting the development of liver metastasis from EGC.

PATIENTS AND METHODS

We examined the medical records of 2,707 consecutive patients who underwent open gastrectomy for EGC (pT1; m, sm) between 1991 and 2005. We assessed clinicopathological features and predictive factors for EGC metastasis in the liver.

RESULTS

Fifteen (0.6%) of the 2,707 patients developed liver metastasis. All primary gastric tumors of patients with liver recurrence demonstrated invasion to the submucosal layer. Macroscopically, nine patients had elevated-type and six depressed-type. Nodal metastasis was documented in seven patients (47%). Lymphatic and vascular involvements were seen in 11 (73%) and 7 (47%) patients, respectively. Multivariate analysis of patients with submucosal invasion revealed macroscopic elevated type and vascular involvement to be independent risk factors for liver metastasis.

CONCLUSIONS

With submucosal cancer, the macroscopic elevated type and vascular involvement are significant predictive factors for EGC recurrence in the liver.

Long-term survival results and prognostic factors of early gastric cancer

In spite of the favorable prognosis of early gastric cancer (EGC), recurrence or second primary cancers present in certain patients after curative surgery. It is crucial to identify who are at high risk and when. In the present study, 323 patients with EGC who underwent curative surgery were studied. A total of 22 patients (6.8%) died of recurrence, 9 patients (2.8%) died of a second primary cancer and 65 patients (20.1%) died of comorbid diseases during the 0.3-33 years of follow-up. Among the 22 patients with recurrence, hematogenous metastases were noted in over half of the cases (77.3%, 17/22); of these cases 15 patients had a recurrence within the first decade after surgery. Histological differentiation and nodal status were correlated with recurrence. Among the second primary cancers, remnant gastric, liver, lung and colon were the most common sites, and the second primary cancers primarily occurred in the second decade after surgery (6/9). Multivariate analysis identified nodal status (HR=4.20), vessel involvement (HR=3.40) and histological differentiation (HR=3.52) as independent prognostic factors for disease-free survival. However, gender, age and differentiation were independent influencing factors for overall survival. Comorbid diseases, recurrence and second primary cancers are the main cause of death in EGC patients after curative resection. Thus, treatment of comorbid diseases and a periodic follow-up schedule may contribute to improved prognosis.

Risk for local recurrence of early gastric cancer treated with piecemeal endoscopic mucosal resection during a 10-year follow-up period

BACKGROUND

Endoscopic mucosal resection (EMR) is a therapy for early gastric cancer (EGC) that can be provided relatively easily and safely in any institution. Identification of the resection margin is a problem in EMR, especially in cases of piecemeal EMR. Despite the long-standing widespread use of piecemeal EMR for EGC, its limitation and long-term outcomes in clinical practice have not been fully evaluated. This study aimed to determine the risk factors of piecemeal EMR, the local recurrence rates, and the mortality rate.

METHODS

A cross-sectional, retrospective cohort study was performed to investigate the risks of piecemeal EMR for patients with the diagnosis of differentiated adenocarcinoma localized to the mucosa. Local recurrence of EGC was investigated by annual follow-up esophagogastroduodenoscopy (EGD) for 10 years. EMR was performed with snare electrocautery using a two-channel scope. When a resection margin was clearly positive for cancer, additional surgery was performed soon after the initial EMR.

RESULTS

For the 149 EGC patients (mean age, 68.8 ± 9.8; male, 77%) who underwent EMR between 1995 and 2001, EMR was performed en bloc in 66 cases and piecemeal in 83 cases. The comorbid conditions existing in 34 of the 149 patients included other malignancies (n = 12), heart failure (n = 5), pulmonary disease (n = 7), liver cirrhosis (n = 4), and other illness (n = 6). However, EMR was completed without complication. The mean area (length × width) of the lesions was 404 ± 289 mm(2) in the piecemeal group and 250 ± 138 mm(2) in the en bloc groups. The en bloc and piecemeal EMR groups differed significantly in terms of unclear horizontal margins but not in terms of unclear vertical margins. Multiple logistic regression suggested that the adjusted odds ratio for maximum diameters exceeding 20 mm for piecemeal EMR was 2.71 (95% confidence interval [CI], 1.30-5.64). According to Kaplan-Meier estimates, the local recurrence rate was 30% (95% CI, 20-40%) at both 5 and 10 years. No recurrence was observed in the en bloc group. The adjusted hazard ratio of unclear horizontal margins for local recurrence was 1.63 (95% CI, 1.12-2.36). A total of 24 patients died after EMR because of comorbid conditions, including other malignancies (n = 11), cardiovascular disease (n = 6), pulmonary disease (n = 4), liver cirrhosis (n = 2), and traffic accident (n = 1). However, no patient died of gastric cancer during the 10-year follow-up period.

CONCLUSIONS

An evaluation of horizontal margins in terms of local recurrence after piecemeal EMR is important, and en bloc resection is recommended. Close follow-up assessment is warranted, especially within 5 years in cases of unclear margin resection after piecemeal EMR. The use of EMR is safe even for patients with severe comorbid conditions.

Effect of repeated endoscopic screening on the incidence and treatment of gastric cancer in health screenees

OBJECTIVES

Early gastric cancer (EGC) can be treated by minimally invasive endoscopic resection and has an excellent prognosis. The aim of this study was to investigate whether repeated esophagogastroduodenoscopy (EGD) screening is an effective method for detecting EGC that can be treated by endoscopic resection.

METHODS

For patients diagnosed with gastric cancer in the Korean National Cancer Center screening program, we analyzed the incidence of gastric cancer, clinicopathological characteristics, and treatment modality according to whether they had (repeated screening group) or not (infrequent screening group) undergone EGD screening within 2 years before diagnosis.

RESULTS

Of the 18,414 patients who underwent EGD, 81 (0.44%) were found to have gastric cancer. Incidence of gastric cancer in repeated screening group was lower than that of infrequent screening group (multiple adjusted odds ratio=0.45, 95% confidence interval: 0.26-0.77, P=0.004). The proportion of EGCs was 96% (25 of 26) n the repeated screening group and 71% (34 of 48) in the infrequent screening group (P=0.01). Mean (SD) tumor size was smaller [1.9 (1.2) vs. 3.0 (1.6) cm, P=0.01] and the proportion of intramucosal cancer was higher [81% (21 of 26) vs. 50% (24 of 48), P=0.02] in the former than in the latter. Endoscopic resection was performed more frequently in the repeated screening group [54% (14 of 26) vs. 23% (11 of 48), P=0.007].

CONCLUSION

Repeated endoscopic screening within 2 years decreased the incidence of gastric cancer and endoscopic resection could be applied to more patients who underwent EGD screening within 2 years.

Predictive factors for local recurrence and incomplete resection of early gastric cancer treated by endoscopic resection: a Western experience

BACKGROUND

Early gastric cancer (EGC) is defined as adenocarcinoma limited to the mucosa or submucosa regardless of lymph node involvement. Local EGC recurrence rates have been described in up to 6% of cases.

OBJECTIVES

To evaluate predictive factors for incomplete resection and local recurrence of EGC treated by endoscopic mucosal resection (EMR) that was followed up for at least one year.

METHODS

From June 1994 to December 2005, 46 patients with EGC underwent EMR. Possible predictive factors for incomplete endoscopic resection and local recurrence were identified by medical chart analysis. Demographic, endoscopic and histopathological data were retrospectively evaluated. EMR was considered complete or incomplete. Patients from the complete resection group were divided into subgroups (with and without local EGC recurrence).

RESULTS

Complete resection was possible in 36 cases (76.6%). Predictive factors for incomplete resection were tumour location (P=0.035), histological type (P=0.021), lesion size (P=0.022) and number of resected fragments (P=0.013). On multivariate analysis, undifferentiated histological type (OR 0.8; 95% CI 0.036 to 0.897) and number of resected fragments (OR 7.34; 95% CI 1.266 to 42.629) were independent predictive factors for incomplete resection. In the complete resection group, a larger lesion size was associated with a higher the number of resected fragments (P=0.018). Local recurrence occurred in nine cases (25%). Use of the cap technique was the only predictive factor for local recurrence in five of seven cases (71.4%) (P=0.006).

CONCLUSIONS

A larger lesion size was associated with a higher number of resected fragments. Undifferentiated adenocarcinoma and piecemeal resection were predictive factors for incomplete resection. Technique type was a predictive factor for local EGC recurrence.

Is diagnostic and therapeutic endoscopy currently appropriate?: suggestions for improvement

Endoscopy is the driving force in gastroenterology today, and recent exciting advances in technology have extended its frontiers at an unprecedented rate. We have a wider range of diagnostic and therapeutic possibilities at our disposal with more detailed methods available to analyse what we see on our video screens. We can access the small bowel lumen with consistency and intra-abdominal operations have been performed through the mouth and anus so where are the current limitations of the procedure? In spite of these remarkable advances many challenges remain for both the endoscopist and for industry, they are mainly ones associated with human weakness. Endoscopy is an art, performed by individuals who require training and continued education and it is done to patients who are vulnerable, afraid and often seriously unwell. It is human aspects of endoscopy that require improvement. This chapter addresses the areas where endoscopy is falling short and suggests what can be done to improve practice. Changes are needed in management, information technology, education, team working, quality, patient comfort and safety. There also remain a number of areas where improved technology may be able to reduce human error.

Detection of early gastric cancer: misunderstanding the role of mass screening

BACKGROUND

The proportion of early gastric cancer (EGC) increased from 15% during the 1960s to 50% recently, leading to a remarkable improvement of the 5-year survival rate of gastric cancer patients from 40% to 70%. This has been attributed to mass screening together with extended lymphadenectomy. However, more and more patients with EGC are diagnosed outside of mass screening. The aim of this study was to determine whether patients are symptomatic at the time of early detection and the method of tumor detection.

METHODS

From 2001 to 2003, a total of 1226 patients (male/female 2.2 : 1.0, age 26-95 years) with EGC were treated at the National Cancer Center Hospital, Tokyo. We reviewed their medical records.

RESULTS

Of these 1226 patients, 512 (41.8%) were symptomatic, and 714 (58.2%) reported no symptoms. Among the symptomatic patients, 468 (91.4%) were examined at outpatient clinics, 39 (7.6%) by private health assessment clinics, and 5 (1.0%) by mass screening. In total, 91.6% of the symptomatic patients directly underwent esophagogastro-duodenoscopy (EGD). Of the asymptomatic patients, 320 (44.8%) were examined at outpatient clinics, 306 (42.9%) by private health assessment clinics, and 88 (12.3%) by mass screening. EGD was the initial assessment in 67.8% and radiography in 32.2% of asymptomatic patients.

CONCLUSION

Most patients with EGC were detected outside of mass screening. This suggests that the Japanese public and physicians are well aware of the risk of gastric cancer and the importance of early detection. The effect of mass screening is misunderstood.

Serum pepsinogen and gastric cancer screening

Since the 1990's, the test for serum pepsinogen as a marker for chronic atrophic gastritis has been incorporated into gastric cancer screening programs, on a trial basis, to identify people at high risk for gastric cancer. The addition of the serum test to the cancer screening program has been shown to improve the detection rate of cancer and pepsinogen testing is useful in detecting early-stage gastric cancers arising from atrophic gastric mucosa, which macroscopically tend to be elevated and histologically differentiated. Furthermore, the cost for the detection of a single cancer case is much less than that for conventional screening. Thus, with the introduction of pepsinogen testing, complimenting barium X-ray, a more efficient screening system is available.

Longterm outcomes after endoscopic mucosal resection for early gastric cancer

BACKGROUND

Despite the widespread use of endoscopic mucosal resection (EMR) in patients with early gastric cancer (EGC), its longterm outcomes have not been fully evaluated. Our aim was to evaluate longterm survival after complete EMR for EGC.

METHODS

From patients who underwent EMR between 1978 and 1996 at our center, we enrolled 131 patients with differentiated mucosal EGCs less than 2 cm (without ulcerative change) that had been completely removed by EMR. The vital status of the patients at the end of December 1998 was confirmed by the hospital cancer registry, which is linked to the Osaka Cancer Registry.

RESULTS

A total of 124 patients (95%) were completely followed-up. Two patients (1.5%) died of gastric cancer and 26 died of other causes during the mean observation period of 58 months. The overall 5- and 10-year survival rates were 84% and 64%, respectively. The disease-specific 5- and 10-year survival rates were 99% and 99%.

CONCLUSION

En bloc EMR ensured an excellent prognosis, and should be the first choice of treatment in patients with small differentiated mucosal EGC. Careful histological examination and longterm endoscopic surveillance are important.

Clinical outcome of high segmental gastrectomy for early gastric cancer in the upper third of the stomach

BACKGROUND

Reflux oesophagitis is commonly encountered in the surgical treatment of cancer of the upper third of the stomach. The aim of this study was to describe a novel surgical technique and evaluate the clinical outcome of high segmental gastrectomy for early-stage proximal gastric cancer.

METHODS

Thirty consecutive patients with early gastric cancer located in the upper third of the stomach were included, of whom 12 underwent high segmental gastrectomy and 18 underwent proximal gastrectomy with jejunal interposition. The incidence of reflux oesophagitis and nutritional parameters were compared between the two groups at 1 year after operation.

RESULTS

One patient had mild reflux symptoms and two had endoscopic evidence of oesophagitis 1 year after high segmental gastrectomy. Half of the patients who had proximal gastrectomy had reflux symptoms of varying severity and 14 had endoscopic evidence of oesophageal changes at 1 year after surgery. There were significant differences between groups in the incidence of reflux symptoms (P = 0.016) and endoscopically detected gastro-oesophagitis (P < 0.001). There were no adverse events in either group, and the survival rate after high segmental gastrectomy appeared favourable.

CONCLUSION

Selected patients with early-stage proximal gastric cancer benefit from high segmental gastrectomy in terms of reduced reflex oesophagitis, without jeopardizing curability.

Gastric cancer screening of a high-risk population in Japan using serum pepsinogen and barium digital radiography

With the aim of developing more efficient gastric cancer screening programs for use in Japan, we studied a new screening program that combines serum pepsinogen (PG) testing and barium digital radiography (DR). A total of 17 647 middle-aged male subjects underwent workplace screening over a 7-year period using a combination of PG testing and DR. This program's effectiveness, as well as other characteristics of the program, was analyzed. Forty-nine cases of gastric cancer were detected (comprising 88% early cancer cases). The detection rate was 0.28%, and the positive predictive value was 0.85%. The PG test detected 63.3% of cases, DR detected 69.4% of cases, and both tests were positive in 32.7% of cancer cases. The two methods were almost equally effective, and were considerably more effective than conventional screening using photofluorography. Each screening method detected a distinct gastric cancer subgroup; the PG test efficiently detected asymptomatic small early cancer with intestinal type histology, while DR was efficient at detecting cancers with depressed or ulcerated morphology and diffuse type histology. The cost for the detection of a single cancer was much less than that for conventional screening. In fact, it is possible to further reduce the cost of detecting a single cancer to a cost comparable to that of surgically resecting a single gastric cancer. Thus, it is probable that a highly efficient gastric cancer screening system can be implemented by combining the two screening methods. Such a screening program would be beneficial in a population at high risk for gastric cancer.

Survival after surgical treatment of early gastric cancer, surgical techniques, and long-term survival

Early gastric cancer (EGC) is well accepted as having a favorable prognosis after surgical treatment. Difference in treatment strategies for EGC between Japan and western countries indicates a need for current information to be evaluated with regard to long-term survival rates of EGC patients throughout the world. To analyze survival rates and recurrence after resection of EGC, we investigated 51 reports in English that each included more than 50 cases of EGC treated by gastrectomy and had been published during the past 12 years (1992-2003). Prevalence of EGC among all gastric cancers was 45%-51% in Japan, but only 7%-28% in western countries. Mean age at diagnosis was less than 60 years in Japan and Korea, but was more than 60 in most of the Western countries. Actuarial and disease-specific 5-year survival rates for EGC were 72%-95.8% and 88%-98.3%, respectively. Those for EGC that were invading the submucosal layer were 71.6%-94.1% and 82%-96.6%, respectively. Those for EGC with lymph node metastasis were 57%-89.1% and 72%-93.5%, respectively. Prevalence of recurrence ranged from 1.0% to 13.8%. Larger clinical series with more EGC cases showed a lower prevalence of recurrence (P=0.531, P=0.0026). Liver and blood-borne distant metastasis represented the predominant pattern of relapse, accounting for over half (54%). Local recurrence and peritoneal dissemination represented 20% and 18% of all recurrences, respectively. Clinicopathological studies have shown lymph node metastasis to be closely related to depth of invasion, size of lesion, histological type, presence of ulcer or ulcer scar, and vessel involvement. Information on these factors is the key to successful treatment of EGC. When sufficient information has been assessed preoperatively, surgeons can select patients for whom less-invasive surgery should not increase the risk of recurrence.

Percutaneous traction-assisted EMR by using an insulation-tipped electrosurgical knife for early stage gastric cancer

BACKGROUND

EMR now is accepted as a minimally invasive treatment for early stage gastric cancer. However, the endoscopic approach sometimes is limited by the size and location of the tumor. The technique and early results of percutaneous, traction-assisted EMR for resection of larger early stage gastric cancers is described.

METHODS

EMR, by using an insulation-tipped electrosurgical knife, was performed with the simultaneous assistance of laparoscopy devices. A small snare was introduced into the gastric lumen through a gastric port (2-mm diameter) to grasp and pull the EGC away from the muscularis propria to facilitate resection.

RESULTS

The technique was performed successfully in our endoscopic suite in the first patient under general anesthesia and the remaining seven under conscious sedation. Tumors situated in any part of the stomach could be reached with percutaneous assistance, and this facilitated en bloc resection of large specimens (mean size 50 mm). The procedure was performed in about 60 minutes. Seven patients (88%) resumed eating 1 or 2 days after surgery. All patients were discharged after 1 week without complication.

CONCLUSIONS

Percutaneous, traction-assisted EMR is useful for resection of large lesions en bloc and can be performed easily and safely under direct vision.

Local endoscopic therapy for intraepithelial high-grade neoplasia and early adenocarcinoma in Barrett's oesophagus: acute-phase and intermediate results of a new treatment approach

BACKGROUND

Radical oesophageal resection has until now been regarded as the gold standard for treatment in intraepithelial high-grade neoplasia or early adenocarcinoma of the oesophagus. However, the mortality and morbidity rates are substantial.

DESIGN

A new therapeutic approach involving low-risk endoscopic therapy modalities was examined in the framework of a prospective study.

PATIENTS

A total of 115 patients with intraepithelial high-grade neoplasia (19) and early adenocarcinoma (96) in Barrett's oesophagus.

METHODS

Endoscopic mucosal resection (EMR) was used in 70 patients, and photodynamic therapy (PDT) was used in 32 patients. The two procedures were combined in ten patients. Three patients underwent primary treatment with argon plasma coagulation (APC). The average follow-up was 34 +/- 10 months (range 24-60 months).

RESULTS

Complete local remission was achieved in 98%. The overall complication rate was 9.5%. Major complications, such as perforation and severe bleeding, did not occur. Minor complications included not haemoglobin relevant bleeding (drop of haemoglobin less than 2 g/dl) (5) and stenosis (3) after EMR, and long-lasting odynophagia (1) and sunburn (2) after PDT. In all, 13 patients have died so far, but in only one case due to the underlying disease. The calculated overall 3-year survival rate is 88%. During the follow-up period, a 30% rate of metachronous lesions was observed; endoscopic therapy was performed successfully in all but one of these patients.

CONCLUSIONS

These good acute-phase and intermediate results, along with low morbidity rates and no mortality, suggest that the organ-preserving local endoscopic procedure including EMR and PDT is an attractive alternative to oesophageal resection. Therefore, endoscopic therapy might replace radical oesophageal resection in future in cases of intraepithelial high-grade neoplasia and early mucosal adenocarcinoma in Barrett's oesophagus.

The recognition and endoscopic treatment of early gastric and colonic cancer

As the prognosis of both gastric and colonic cancer remains poor, the challenge is to detect lesions at an early and treatable stage. The benefit of early detection is not only improved survival, but also that patients may be treated with endoscopic mucosal resection, a low-cost, low-morbidity and low-mortality alternative to surgery. In spite of the increasing use of endoscopy in the West, we are not detecting as many early cancers as in Japan. This chapter will discuss the possible reasons for this discrepancy and give a practical guide to 'Japanese endoscopy techniques'. Finally, we have compiled a comprehensive review of the indications, techniques and complications of endoscopic mucosal resection. Throughout the chapter, controversies have been highlighted to give an insight into the limits of our knowledge and stimulate future research.

Gastric dysplasia: the Padova international classification

A worldwide-accepted histologic, classification of the gastric carcinomatous and precancerous lesions is a prerequisite for a consistent recording of epidemiologic data and for both developing and evaluating primary and secondary preventive efforts. Different nomenclatures have been proposed for gastric precancerous lesions in eastern countries and in Japan. This article presents a classification of gastric precancerous lesions resulting from an international consensus conference involving pathologists of different countries. Five main diagnostic categories are identified. To allow comparisons with the nomenclature proposed by the Japanese Research Society for Gastric Cancer, each category was also assigned a numeric identification: 1 = normal, 2 = indefinite for dysplasia, 3 = noninvasive neoplasia, 4 = suspicious for invasive cancer, and 5 = cancer. The interobserver reproducibility of the histologic classification was tested in a series of 46 cases. By collapsing benign alterations (categories 1+2) versus noninvasive neoplasia (category 3) versus suspicious for invasive cancer and fully appearing carcinomatous lesions (categories 4+5), the general agreement value was 77.7%, whereas kappa coefficient was 0.63. By examining gastric precancerous lesions from diverse populations, the authors agreed that the gastric precancerous process is universal and the differences in nomenclatures are merely semantics. The international Padova classification of the gastric precancerous lesions is submitted to the attention of the international scientific community, which is invited to test and to improve on it.

Is lymphadenectomy necessary for early gastric cancer?

BACKGROUND

Although early gastric cancer (T1, NX) in Japan has been reported to have an excellent prognosis, the experience with this cancer in the United States is limited. The treatment of these tumors in Japan is becoming less aggressive as "good prognostic factors" are increasingly recognized. Our objective was to identify predictors of nodal disease and survival in a large cohort of Western patients with T1 tumors.

METHODS

A retrospective review of our prospective data base from July 1985 to March 1998 revealed 165 patients undergoing surgical resection for T1 gastric tumors. Clinicopathological factors analyzed and compared included presence of positive nodes, tumor size (> or =4.5 vs. <4.5 cm), depth (mucosal vs. submucosal), grade (poor vs. moderate and well), and tumor site (proximal vs. distal), presence of venous or perineural invasion, and Lauren's classification. Factors predicting lymph node involvement and disease-specific survival were evaluated by univariate and multivariate analysis.

RESULTS

Median follow-up time was 36 months. The actuarial 5-year survival was 88%. Thirteen patients (8%) died of disease. Lymph node involvement was present in 31 tumors (19%), with a 5-year survival of 91% with negative nodes vs. 78% with positive nodes. On univariate and multivariate analysis, the presence of tumor submucosal invasion (P<.05), venous invasion (P = .02), and size of 4.5 cm and larger (P = .02) was significantly associated with an increased risk for nodal positivity. On univariate analysis of survival, node-positive tumors (P = .02) and tumors 4.5 cm and larger (P = .008) were significantly associated with decreased survival. On multivariate analysis, only node-positive tumors were significantly (P = .01) associated with decreased survival. Those tumors that were limited to the mucosa and less than 4.5 cm in size (n = 47) had a 4% rate of positive nodes. In contrast, those tumors that were 4.5 cm and larger and had penetrated into the submucosa (n = 16) had a 56% chance of positive nodes.

CONCLUSIONS

Early gastric carcinoma in North America has an excellent prognosis, similar to that in Japan. Tumors that are limited to the mucosa and smaller than 4.5 cm could be considered for limited resection without lymphadenectomy.

Treatment of gastric tumors by endoscopic mucosal resection with a ligating device

BACKGROUND

This study attempted to determine the indication for endoscopic mucosal resection with a ligating device (EMRL) and to assess the efficacy of radical (complete) resection of early gastric carcinoma and adenoma.

METHODS

Sixteen patients with early gastric carcinoma (17 lesions) and 21 patients with gastric adenoma (23 lesions) underwent EMRL with an endoscope with a ligating device. After epinephrine solution was injected into the submucosa, the lesions were aspirated, ligated, and resected.

RESULTS

Twelve of 17 early carcinomas (70.6%) and 18 of 23 adenomas (78.3%) were radically resected by EMRL. The average size of the resected specimens was 12.8 x 11.0 mm. The rate of successful radical resection by EMRL, including piecemeal resection, was 100% (15/15) for lesions located in the antrum, 80% (4/5) in the angle, 61.1% (11/18) in the body, and 0% (0/2) for lesions at the cardia. Repeat EMRL was performed successfully in cases of partial resection (n = 3). No serious complication was encountered. No recurrence of the tumors was identified in cases of radical resection during a median follow-up period of 22.8 months.

CONCLUSION

EMRL is suitable for the treatment of gastric tumorous lesions. For the treatment of early carcinoma, well-differentiated mucosal carcinomas smaller than 10 mm located in the distal stomach represent the best indication for EMRL.

Angiogenesis as an unfavorable factor related to lymph node metastasis in early gastric cancer

BACKGROUND

Recent studies suggest that angiogenesis enhances tumor growth and metastasis. Lymph node metastasis influences the prognosis and selection of treatment modalities in cancers. In this study, the authors investigated the correlation between angiogenesis and clinicopathologic features to determine whether angiogenesis correlated with lymph node metastasis in early-stage gastric cancer.

METHODS

A total of 97 specimens from patients with early gastric cancer were studied by immunohistochemical methods using anti-Factor VIII-related antigen antibody.

RESULTS

Tumor size was significantly correlated with microvessel count, which increased as tumor size increased. Microvessel counts from tumors with lymphatic vessel invasion, lymph node metastasis, and submucosal invasion were significantly higher than those without. Furthermore, microvessel count was an independent factor that influenced lymph node metastasis (P = .0016) by multivariate logistic regression analysis.

CONCLUSION

In the early stage of gastric carcinoma, angiogenesis is an independent factor that impacts on lymph node metastasis.