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

Cost comparison between surgical treatments and endoscopic submucosal dissection in patients with early gastric cancer in Korea

BACKGROUND/AIMS

This study was conducted to evaluate whether medical costs can be reduced using endoscopic submucosal dissection (ESD) instead of conventional surger-ies in patients with early gastric cancer (EGC).

METHODS

Pa-tients who underwent open gastrectomy (OG), laparoscopy-assisted gastrectomy (LAG), and ESD for EGC were recruited from three medical institutions in 2009. For macro-costing, the medical costs for each patient were derived from the ex-penses incurred during the patient's hospital stay and 1-year follow-up. The overall costs in micro-costing were determined by multiplying the unit cost with the resources used during the patients' hospitalization.

RESULTS

A total of 194 patients were included in this study. The hospital stay for ESD was 5 to 8 days and was significantly shorter than the 12-day hospital stay for OG or the 11- to 17-day stay for LAG. Using macro-costing, the average medical costs for ESD during the hospital stay ranged from 2.1 to 3.4 million Korean Won (KRW) per patient, and the medical costs for conventional surgeries were estimated to be between 5.1 million and 8.2 million KRW. There were no significant differences in the 1-year follow-up costs between ESD and conventional surger-ies.

CONCLUSIONS

ESD patients had lower medical costs than those patients who had conventional surgeries for EGC with conservative indications. (Gut Liver, 2015;9174-180).

Gastric epithelial dysplasia: characteristics and long-term follow-up results after endoscopic resection according to morphological categorization

BACKGROUND

Gastric epithelial dysplasia (GED) can be morphologically categorized into adenomatous and foveolar types. To date, there have been few studies on the clinical characteristics of GEDs according to the morphologic types. Therefore, we here aimed to elucidate the clinicopathologic characteristics of patients with GED and the long-term follow-up results after endoscopic resection according to the morphologic characteristics of GEDs.

METHODS

A total of 357 patients who underwent endoscopic resection for GEDs at Pusan National University Hospital between January 2008 and December 2009 were included in the study. GEDs were morphologically categorized into adenomatous, foveolar, and hybrid types on histologic examination. The clinicopathologic characteristics of patients with GEDs and outcomes of endoscopic resection were analyzed.

RESULTS

Patients with GED were divided into 3 groups: adenomatous (n = 167, 46.8%), foveolar (n = 103, 28.9%), and hybrid (n = 87, 24.3%) types. Compared to the adenomatous type, foveolar type lesions were more frequently located in the antrum/pylorus, flat/depressed lesions, and normal/reddish in color; and showed more frequent high-grade dysplasia. During the follow-up period (median, 37.3 months), the overall incidence of synchronous and metachronous lesions was 20.8% and 20.1%, respectively; of these, the incidence of synchronous and metachronous gastric cancer was 8.7% and 5.4%, respectively. There were no significant differences in the incidence of synchronous and metachronous lesions according to morphologic types.

CONCLUSION

GEDs appear to have different clinicopathologic characteristics according to morphologic types. Irrespective of the morphology, synchronous and metachronous gastric cancers are commonly found after endoscopic resection of GEDs. Therefore, close follow-up surveillance after endoscopic resection of GEDs should be performed for all patients.

Optimal Interval for Repeated Gastric Cancer Screening in Normal-Risk Healthy Korean Adults: A Retrospective Cohort Study

PURPOSE

This retrospective cohort study was conducted to estimate the optimal interval for gastric cancer screening in Korean adults with initial negative screening results.

MATERIALS AND METHODS

This study consisted of voluntary Korean screenees aged 40 to 69 years who underwent subsequent screening gastroscopies after testing negative in the baseline screening performed between January 2007 and December 2011. A new case was defined as the presence of gastric cancer cells in biopsy specimens obtained upon gastroscopy. The follow-up periods were calculated during the months between the date of baseline screening gastroscopy and positive findings upon subsequent screenings, stratified by sex and age group. The mean sojourn time (MST) for determining the screening interval was estimated using the prevalence/incidence ratio.

RESULTS

Of the 293,520 voluntary screenees for the gastric cancer screening program, 91,850 (31.29%) underwent subsequent screening gastroscopies between January 2007 and December 2011. The MSTs in men and women were 21.67 months (95% confidence intervals [CI], 17.64 to 26.88 months) and 15.14 months (95% CI, 9.44 to 25.85 months), respectively.

CONCLUSION

These findings suggest that the optimal interval for subsequent gastric screening in both men and women is 24 months, supporting the 2-year interval recommended by the nationwide gastric cancer screening program.

Prevalence of Precancerous Conditions and Gastric Cancer Based upon the National Cancer Screening Program in Korea for 7 Years, Single Center Experience

Aims. Gastric cancer is the second most prevalent cancer and the third leading cause of cancer-related deaths in Korea. The National Cancer Screening Program (NCSP) has implemented esophagogastroduodenoscopy (EGD) biennially for all Koreans starting in their 40s. This study was conducted to estimate the clinical relevance of NCSP through identifying the prevalence of gastric disease, including cancer. Materials and Methods. Data from 40,821 subjects who received the screening EGD in the single center for 7 years were retrospectively investigated. Results. The overall prevalence of nonatrophic/atrophic/metaplastic gastritis, peptic ulcer, adenoma, early gastric cancer (EGC), and advanced gastric cancer (AGC) was 44.28%, 27.97%, 14.95%, 0.59%, 0.43%, 0.21%, and 0.09%, respectively. The prevalence of metaplastic gastritis, peptic ulcer, adenoma, EGC, and AGC was significantly higher in men than in women. The prevalence of preneoplastic/neoplastic disease significantly increased with age. Judged from the ratio of EGC to AGC, the proportion of EGC made up to 70% of all cancers. Conclusions. Screening endoscopy starting for people in their 40s should be strongly recommended for the elderly. Through the NCSP, the early detection of gastric cancer might contribute to the decreased mortality rate due to gastric cancer in Korea.

Endoscopic quality indicators for esophagogastroduodenoscopy in gastric cancer screening

BACKGROUND

Quality indicators of screening esophagogastroduodenoscopy are essential to improve the detection rate of gastric cancer. However, a reliable, practical indicator of the performance of endoscopists in screening esophagogastroduodenoscopy has not yet been identified.

AIMS

We aimed to identify quality indicators of esophagogastroduodenoscopy for the detection of early gastric neoplasms, including gastric dysplasia and early gastric cancer, focusing on the endoscopic findings.

METHODS

The records of 54,889 individuals who underwent esophagogastroduodenoscopy for gastric cancer screening at the Yonsei University Severance Hospital Health Promotion Center, Seoul, Korea, between February 2006 and July 2013 were analyzed. The detection rates for various gastric lesions including early gastric neoplasms were analyzed for each endoscopist.

RESULTS

Gastric dysplasia, early gastric cancer, and advanced gastric cancer were detected in 97 (0.18 %), 54 (0.10 %), and 21 (0.04 %) of 54,889 individuals, respectively. Multivariate analysis showed that the detection rates of gastric subepithelial lesions and gastric diverticuli were independent factors associated with the detection rate of early gastric neoplasms (regression coefficients of 0.096 and 0.532, respectively). A quality score formula was deduced using these regression coefficients to predict the ability of an endoscopist to detect early gastric neoplasms. A trend test confirmed that the group of endoscopists with a higher quality score showed a significantly higher rate of early gastric neoplasm detection (P < 0.001).

CONCLUSIONS

The detection rates of gastric subepithelial lesions and gastric diverticuli are well correlated with that of early gastric neoplasms. In addition, the proposed quality scoring system could be a good quality indicator for the detection of early gastric neoplasms.

In vivo molecular imaging of gastric cancer in human-murine xenograft models with confocal laser endomicroscopy using a tumor vascular homing peptide

The early detection of premalignant lesions and cancers are very important for improving the survival of patients with gastric malignancies. Confocal laser endomicroscopy (CLE) is a novel imaging tool for achieving real-time microscopy during the ongoing endoscopy at subcellular resolution. In the present study, to evaluate the feasibility of real-time molecular imaging of GEBP11 by CLE in gastric cancer, CLE was performed on two types of tumor-bearing mice models, as well as surgical specimens of patients with gastric cancer, after the application of GEBP11. A whole-body fluorescent imaging device was first used to screen for the strongest specific fluorescent signal in xenograft models. Next, the tumor sites, as well as human tissues, were scanned with CLE. After this, targeted specimens were obtained for fluorescence microscopy and histology. We confirmed that GEBP11 could specifically bind to co-HUVECs by means of CLE in cell experiments. Thereafter, a specific signal was observed in both subcutaneous and orthotopic xenograft models in vivo after the injection of FITC-GEBP11 via tail vein, whereas the group injected with FITC-URP showed no fluorescent signals. In human tissues, a specific signal of GEBP11 was observed in 26/28 neoplastic specimens and in 8/28 samples of non-neoplastic specimens from the patients (p < 0.01). The findings from ex vivo immunofluorescence microscopy of cryostat sections correlated well with that obtained by CLE. These findings indicate that the peptide, GEBP11, might be a potential candidate for the molecular imaging of gastric cancer.

Prevention strategies for gastric cancer: a global perspective

Despite the substantial burden of gastric cancer worldwide, population strategies for primary prevention have not been introduced in any country. Recognizing the causal role of Helicobacter pylori infection, there is increasing interest in population-based programs to eradicate the infection to prevent gastric cancer. Nonetheless, the paucity of available evidence on feasibility and effectiveness has prevented implementation of this approach. There are very few secondary prevention programs based on screening with endoscopy or radiography, notably in the Republic of Korea and Japan, two of the countries with the highest incidence rates of gastric cancer. In Korea, where the organized screening program is in place, survival rate of gastric cancer is as high as 67%. More research is needed to quantify the specific contribution of the screening program to observed declines in mortality rates. Gastric cancer screening is unlikely to be feasible in many Low-Middle Income Countries where the gastric cancer burden is high. Prevention strategies are still under development and the optimal approach may differ depending on local conditions and societal values. The present review gives an overview of the etiology and burden of the disease, and possible prevention strategies for countries and regions confronted with a significant burden of disease.

Risk factors of atrophic gastritis and intestinal metaplasia in first-degree relatives of gastric cancer patients compared with age-sex matched controls

Background:

To identify whether first-degree relatives (FDRs) of gastric cancer (GC) patients have increased risk for atrophic gastritis (AG) and intestinal metaplasia (IM) in relation to other risk factors of GC.

Methods:

The study cohort consisted of 224 pairs of age-sex matched controls and FDRs. AG and IM in the gastric mucosa were scored histologically using the updated Sydney classification. Risk of having AG and IM was studied by comparing FDRs to controls. Impacts of age, H. pylori infection, smoking, dietary and socioeconomic factors on the presence of AG and IM were studied.

Results:

In multivariate regression analysis, FDRs had adjusted OR of 2.69 (95% CI 1.06–6.80, P=0.037) for antral IM in male population. Adjusted OR for antral AG and IM were 9.28 (95% CI 4.73–18.18, P<0.001) and 7.81 (95% CI 3.72–16.40, P<0.001) for the H. pylori infected subjects in total population. Getting old by 5 years increased the ORs of having AG and IM by approximately 1.25 fold (P<0.001). Spicy food increased the OR of antral IM by 2.28 fold (95% CI 1.36–3.84, P=0.002).

Conclusions:

Family history of GC was an independent risk factor for antral IM in male in our study, which could be one reason for the increase of gastric cancer in the family member of gastric cancer. It could be an evidence for the necessity of frequent endoscopy in the presence of family history of GC compared to general population in male.

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.

Methodological issues for determining intervals of subsequent cancer screening

The gap between nationwide recommendations of cancer screening and the related evidences obtained from Korean adults should be filled. Estimation of the mean sojourn time (MST) in a specific cancer is important to determine the intervals of subsequent screening. This author arranged the methods for calculating MST into 5 categories based on the parameters used. Under the legal barrier for protection of individual privacy and confidentiality in a Korean academic situation, the methods involving the use of transition rates or prevalence/incidence ratio would be applicable among these methods.

Effects of screening on gastric cancer management: comparative analysis of the results in 2006 and in 2011

Purpose

This study aimed to analyze the effect of screening by using endoscopy on the diagnosis and treatment of gastric cancer.

Materials and Methods

The clinicopathologic characteristics of gastric cancer were compared in individuals who underwent an endoscopy because of symptoms (non-screening group) or for screening purposes (screening group). The distributions of gastric cancer stages and treatment modalities in 2006 and 2011 were compared.

Results

The proportion of patients in the screening group increased from 45.1% in 2006 to 65.4% in 2011 (P<0.001). The proportion of stage I cancers in the entire patient sample also increased (from 60.5% in 2006 to 70.6% in 2011; P=0.029). In 2011, the percentages of patients with cancer stages I, II, III, and IV were 79.9%, 8.2%, 10.9%, and 1.1%, respectively, in the screening group, and 47.9%, 10.8%, 29.8%, and 11.5%, respectively, in the non-screening group. The proportion of laparoscopic and robotic surgeries increased from 9.6% in 2006 to 48.3% in 2011 (P<0.001), and endoscopic submucosal dissection increased from 9.8% in 2006 to 19.1% 2011 (P<0.001).

Conclusions

The proportion of patients diagnosed with gastric cancer by using the screening program increased between 2006 and 2011. This increase was associated with a high proportion of early-stage cancer diagnoses and increased use of minimally invasive treatments.

Low prevalence of microsatellite instability in interval gastric cancers

BACKGROUND AND AIM

Esophagogastroduodenoscopy (EGD) is recommended at 2-year intervals in countries with a high prevalence of gastric cancer. The aim of this study was to determine whether interval gastric cancers that develop within 2 years of a previous complete screening are associated with microsatellite instability (MSI).

METHODS

Newly diagnosed gastric cancer patients who had undergone gastrectomy were included. Of these 459 patients, 177 were classified as interval gastric cancer since they were diagnosed within 2 years of a previous EGD. Noninterval gastric cancer patients were subclassified into 65 patients who underwent previous EGD between the past 2 and 10 years and 217 patients without EGD during the last 10 years. Analysis for MSI was conducted using two mononucleotide and three dinucleotide markers.

RESULTS

MSI was found more frequently in noninterval gastric cancers than in interval gastric cancers (p = 0.009). Interval gastric cancers were associated with a higher prevalence of early gastric cancer (p = 0.006), smaller size (p < 0.001), and lower TNM stages (p = 0.006). On logistic regression analysis, noninterval gastric cancers were related to MSI (p = 0.010) and larger size (≥4 cm) (p = 0.009). Subjects with interval gastric cancer showed better survival than those with noninterval gastric cancer (p = 0.006).

CONCLUSIONS

During a 2-year screening interval, noninterval gastric cancers tend to be larger, more advanced, and associated with MSI. Biannual EGD screening is effective for detecting small gastric cancers at an early stage, but is not useful in detecting gastric cancers with MSI.

Long-term outcomes of endoscopic submucosal dissection for early gastric cancer: a single-center experience

BACKGROUND

In Korea, endoscopic submucosal dissection (ESD) has been widely accepted for the treatment of early gastric cancers (EGCs). However, the understanding of the long-term clinical outcome of ESD for EGC remains insufficient. Therefore, the aim of the present study was to assess the long-term clinical outcome and efficacy of ESD for the treatment of EGCs, including the clinical application of the expanded criteria for ESD.

METHODS

From January 2006 to December 2010, a total of 515 patients with 522 EGCs were treated by ESD in our hospital; study enrollment was based on the expanded criteria. Comparisons of resectability (en bloc or piecemeal resection), curability (curative or non-curative), and complications (bleeding and perforation) between the standard and expanded groups were assessed. Thereafter, 336 patients with 342 EGCs were finally included in a long-term analysis of local tumor recurrence, development of synchronous and metachronous cancers, and overall and disease-specific survival rates.

RESULTS

En bloc and curative resection rates of 96.7 % and 88.3 %, respectively, were achieved. The curative resection rate was significantly lower in the expanded group than in the standard group (82.1 % vs. 91.5 %, p = 0.001). During a median follow-up of 24 months, the local tumor recurrence rate was also higher in the expanded group than in the standard group (7.0 % vs. 1.8 %, p = 0.025). Local recurrence was more frequent in lesions with non-curative resection than in those with curative resection (20.0 % vs. 1.3 %, p < 0.001). The 5-year overall and disease-specific survival rates were 88 % and 100 %, respectively; the difference between the standard and expanded groups was not significant (p = 0.834).

CONCLUSIONS

ESD appears to be a feasible and effective method for treating EGCs, based on the standard and expanded criteria. Close follow-up surveillance, after ESD, should be standard for all patients.

Current evidence of effects of Helicobacter pylori eradication on prevention of gastric cancer

Gastric cancer is the second most common cause of cancer death worldwide and is usually detected at a late stage, except in Korea and Japan where early screening is in effect. Results from animal and epidemiological studies suggest that Helicobacter pylori infection, and subsequent gastritis, promote development of gastric cancer in the infected mucosa. Relatively effective treatment regimens are available to treat H. pylori infection, and in general, mass eradication of the organism is not currently recommended as a gastric cancer prevention strategy. However, regional guidelines vary regarding the indications and recommendations for H. pylori treatment for gastric cancer prevention. In this review, we discuss the results from intervention studies, provide insight regarding current guideline recommendations, and discuss future study directions.

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.

Comparing endoscopy and upper gastrointestinal X-ray for gastric cancer screening in South Korea: a cost-utility analysis

BACKGROUND

There are limited data evaluating the cost-effectiveness of gastric cancer screening using endoscopy or upper gastrointestinal x-ray in the general population.

OBJECTIVE

To evaluate the cost- effectiveness of population-based screening for gastric cancer in South Korea by decision analysis.

METHODS

A time-dependent Markov model for gastric cancer was constructed for healthy adults 30 years of age and older, and a deterministic sensitivity analysis was performed. Cost-utility analysis with multiple strategies was conducted to compare the costs and effects of 13 different screening alternatives with respect to the following eligibility criteria: age at the beginning of screening, screening interval, and screening method. The main outcome measurement was the incremental cost-effectiveness ratio.

RESULTS

The results revealed that annual endoscopic screening from ages 50-80 was the most cost-effective for the male population. In the females, biennial endoscopy screening from ages 50-80 was calculated as the most cost-effective strategy among the 12 screening alternatives. The most cost-effective screening strategy may be adjustable according to the screening costs and the distribution of cancer stage at screening. The limitation was that effectiveness data were obtained from published sources.

CONCLUSIONS

Using the threshold of $19,162 per quality-adjusted life year on the basis of the Korean gross domestic product (2008), as suggested by the World Health Organization, endoscopic gastric cancer screening starting at the age of 50 years was highly cost-effective in the Korean population. The national recommendation for gastric cancer screening should consider the starting age of screening, the screening interval, and the screening modality.

Differential gene expression pattern in early gastric cancer by an integrative systematic approach

To elucidate the molecular basis of early gastric cancer (EGC), the genome-wide expression pattern of cancer and normal tissues from 27 patients were analyzed by a microarray-based method. Using an integrative systematic bioinformatics approach, we classified the differentially expressed genes in EGC. Interestingly, the more highly expressed genes in EGC exhibited the most significant correlation with cell migration and metastasis. This implies that, even at the early stage of gastric cancer, the molecular properties usually observed in late-stage cancer are already present. Furthermore, we have found a novel association between the expression pattern and molecular pathways of EGC and estrogen receptor α (ERα)-negative breast cancer through cross-experimental analysis. These results provide new insights into the biological properties of EGC, as well as yielding useful basic data for the study of molecular mechanisms of EGC carcinogenesis.

The clinical accuracy of endoscopic ultrasonography and white light imaging in gastric endoscopic submucosal dissection

Purpose

Gastric mucosal neoplastic lesions should have characteristic endoscopic features for successful endoscopic submucosal dissection.

Materials and Methods

Out of the 1,010 endoscopic submucosal dissection, we enrolled 62 patients that had the procedure cancelled. Retrospectively, whether the reasons for cancelling the endoscopic submucosal dissection were consistent with the indications for an endoscopic submucosal dissection were assessed by analyzing the clinical outcomes of the patients that had the surgery.

Results

The cases were divided into two groups; the under-diagnosed group (30 cases; unable to perform an endoscopic submucosal dissection) and the over-diagnosed group (32 cases; unnecessary to perform an endoscopic submucosal dissection), according to the second endoscopic findings, compared with the index conventional white light image. There were six cases in the under-diagnosed group with advanced gastric cancer on the second conventional white light image endoscopy, 17 cases with submucosal invasion on endoscopic ultrasonography findings, 5 cases with a size greater than 3 cm and ulcer, 1 case with diffuse infiltrative endoscopic features, and 1 case with lymph node involvement on computed tomography. A total of 25 patients underwent a gastrectomy to remove a gastric adenocarcinoma. The overall accuracy of the decision to cancel the endoscopic submucosal dissection was 40% (10/25) in the subgroup that had the surgery.

Conclusions

The accuracy of the decision to cancel the endoscopic submucosal dissection, after conventional white light image and endoscopic ultrasonography, was low in this study. Other diagnostic options are needed to arrive at an accurate decision on whether to perform a gastric endoscopic submucosal dissection.

Effect of endoscopic screening at 1-year intervals on the clinicopathologic characteristics and treatment of gastric cancer in South Korea

BACKGROUND AND AIM

The recommended interval of endoscopic screening for gastric cancer (GC) in a general population is 2 years in Korea. However, it has not been determined whether endoscopic screening with a shorter interval is beneficial, especially for high-risk groups.

METHODS

A total of 415 patients with GC were categorized according to whether they had (vigilant screening group) or not (non-vigilant screening group) undergone endoscopic screening within 1 year before being diagnosed with GC. Clinicopathologic GC characteristics of the two groups were compared. Next, the same analyses were conducted in subgroups of patients with high risk for GC including males, current smokers, first-degree relatives of GC; and patients with Helicobacter pylori infection, gastric atrophy, or intestinal metaplasia (IM).

RESULTS

The proportion of vigilant screening patients was 36.1%. Early gastric cancer (EGC) was more frequently observed in the vigilant screening group than the non-vigilant screening group (62.7% vs 49.4%, P = 0.009). In the high-risk factor analyses, EGC was more frequently detected among patients with severe IM in the vigilant screening group than the non-vigilant screening group (66.7% vs 35.5%, P = 0.047). In addition, more patients in the vigilant screening group had undergone endoscopic submucosal dissection (ESD; 26.7% vs 0%, P = 0.008) and had stage I (84.6% vs 41.7%, P = 0.012) than in the non-vigilant screening group.

CONCLUSIONS

Endoscopic screening for GC at 1-year intervals would be beneficial for patients with severe IM in South Korea; this method could detect EGC for which the curative modality would be ESD.

Effect of annual endoscopic screening on clinicopathologic characteristics and treatment modality of gastric cancer in a high-incidence region of Korea

We investigated risk factors for gastric cancer (GC) and effect of annual endoscopic screening on detection and treatment modality of GC. Asymptomatic adults who underwent upper endoscopy during health checkups at Seoul National University Hospital Healthcare System Gangnam Center were enrolled. We compared clinicopathologic characteristics of GC according to screening interval (repeated vs. infrequent, annual vs. biennial). After age- and sex-matching, relative risk was computed by hazard ratio (HR) using Cox proportional regression with multivariate adjustment. Of the 58,849 subjects who received screening endoscopy, 277 (0.47%) were found to have GC. Intestinal type comprised 55.4% (102/184) followed by diffuse type (n = 65, 35.3%). Age ≥ 50 years, family history and smoking independently increased the risk of GC for both types, whereas male gender [HR = 4.81, 95% confidence interval (CI): 2.72-8.03] and intestinal metaplasia (IM) (HR = 10.87, 95% CI: 3.36-22.30) were significant predictors for intestinal type only. Proportion of early gastric cancer (EGC) was 98.6% (71/72) in annual screening group and 80.7% (46/57) in biennial screening group (p < 0.01). In the former, tumor size was smaller (1.7 ± 1.3 vs. 2.3 ± 1.8 cm; p < 0.01] and proportion of intramucosal cancer was larger (75.0 vs. 56.1%; p = 0.04). Endoscopic resection was performed more frequently in annual screening group (56.9 vs. 33.3%; p = 0.02). IM along with male gender and older age was a strong risk factor for intestinal type GC. Annual screening group improved detection of early-stage and endoscopically treatable GC suggesting that intensive screening and surveillance may be useful for high-risk subpopulations with epidemiologic risk factors or premalignant lesions such as IM.

Surveillance strategy of atrophic gastritis and intestinal metaplasia in a country with a high prevalence of gastric cancer

BACKGROUND

It is not clear which screening examinations are best suited for gastric cancer prevention, especially in patients with atrophic gastritis and intestinal metaplasia. Therefore, we investigated the gastric cancer screening methods and intervals that are performed in clinical practice in an area with a high prevalence of gastric cancer.

METHODS

Eighty-seven physicians voted by keypad and discussed the consistency of endoscopic diagnosis of atrophic gastritis and intestinal metaplasia at the Annual Symposium of the Korean College of Helicobacter and Upper Gastrointestinal Research. Additionally, 100 core members of this academic society were asked via e-mail to complete the questionnaires related to screening strategies for gastric cancer.

RESULTS

The most common recommendation for the subjects with intestinal metaplasia was an annual endoscopic follow-up (95.5% vs. 80.4% in the expert and non-expert groups, respectively; P = 0.118). Annual endoscopic follow-up was also the most predominant recommendation for atrophic gastritis (95.5% vs. 76.5%; P = 0.092), regardless of the physicians' endoscopic experience, position, and degree of the hospital. However, the correct answer rate for the diagnosis of normal endoscopic findings was only 16.7 and 14.1% in the expert and non-expert groups, respectively (P = 0.883).

CONCLUSIONS

The most common practical screening strategy for patients with atrophic gastritis and intestinal metaplasia in Korea was annual endoscopic examination. However, a new program estimating individualized gastric cancer risk might be needed because of the low inter-observer agreement in the endoscopic diagnosis of atrophic gastritis and intestinal metaplasia.

Stomach cancer screening and preventive behaviors in relatives of gastric cancer patients

AIM: To investigate gastric cancer screening and preventive behaviors among the relatives of patients with gastric cancer [i.e., gastric cancer relatives (GCRs)].

METHODS: We examined the Korean National Health and Nutrition Examination Survey 2005 (KNHANES III) database and compared the gastric cancer screening and preventive behaviors of GCRs (n = 261) with those of non-GCRs (n = 454) and controls without a family history of cancer (n = 2842).

RESULTS: The GCRs were more likely to undergo gastric cancer screening compared with the control group (39.2% vs 32.3%, adjusted odds ratio: 1.43, CI: 1.05-1.95), although the absolute screening rate was low. Dietary patterns and smoking rates did not differ significantly between the groups, and a high proportion of GCRs reported inappropriate dietary habits (i.e., approximately 95% consumed excessive sodium, 30% were deficient in vitamin C, and 85% were deficient in dietary fiber).

CONCLUSION: The gastric cancer screening and preventive behaviors of GCRs have yet to be improved. To increase awareness among GCRs, systematic family education programs should be implemented.

Metachronous ovarian metastases following resection of the primary gastric cancer

PURPOSE

We performed this study to evaluate the clinical presentation as well as the proper surgical intervention for ovarian metastasis from gastric cancers and these tumors were identified during postoperative follow-up. This will help establish the optimal strategy for improving the survival of patients with this entity.

MATERIALS AND METHODS

22 patients (3.2%) with ovarian metastasis were noted when performing a retrospective chart review of (693) females patients who had undergone a resection for gastric cancer between 1981 and 2008. The covariates used for the survival analysis were the patient age at the time of ovarian relapse, the size of the tumor, the initial TNM stage of the gastric cancer, the interval to metastasis and the presence of gross residual disease after treatment for Krukenberg tumor. The cumulative survival curves for the patient groups were calculated with the Kaplan-Meier method and they were compared by means of the Log-Rank test.

RESULTS

The average age of the patients was 48.6 years (range: 24 to 78 years) and the average survival time of the 22 patients was 18.8 months (the estimated 3-year survival rate was 15.8%) with a range of 2 to 59 months after the diagnosis of Krukenberg tumor. The survival rate for patients without gross residual disease was longer than that of the patients with gross residual disease (P=0.0003). In contrast, patient age, the size of ovarian tumor, the initial stage of gastric adenocarcinoma, the interval to metastasis and adjuvant chemotherapy were not prognostic indicators for survival after the development of ovarian metastasis.

CONCLUSIONS

Early diagnosis and complete resection are the only possible hope to improve survival. As the 3-year survival rate after resection of Krukenberg tumor is 15.8%, it seems worthwhile to consider performing tumorectomy as the second cytoreduction.

Is endoscopic ultrasonography indispensable in patients with early gastric cancer prior to endoscopic resection?

BACKGROUND

Endoscopic resection as curative treatment of early gastric cancer (EGC) requires accurate staging for depth of invasion (T) before therapy. This study aimed to compare T staging of EGC using a miniprobe with that of conventional endoscopy (CE).

METHODS

A total of 388 patients with suspected of EGC by CE were prospectively enrolled in the study. After miniprobe staging by an experienced endosonographer, CE staging was performed by another endoscopist who was blinded to the miniprobe assessment. Patients underwent either endoscopic resection (n = 325) or surgery (=63) according to staging results. Results of each method were compared with the histology of the resected specimen. Clinicopathological factors affecting accuracy of each test were also evaluated.

RESULTS

Overall accuracy of miniprobe and CE staging was 78.9% (306/388) and 81.4% (316/388), respectively (p = 0.052). Sensitivity for T1m was more than 95% (miniprobe 98.7%, CE 97.7%), whereas sensitivity for T1sm was lower at 6.6% for miniprobe and 23.7% for CE (p = 0.002). Among nine lesions identically considered submucosal invasion by both methods, three were T1sm cancer. Diagnostic accuracy of the miniprobe was lower than that of CE with respect to lesions located in the lower third of the stomach, differentiated histology, or massive submucosal invasion.

CONCLUSIONS

Overall accuracy of the miniprobe and CE for T staging in EGC was approximately 80% with no significant difference. Accurate prediction of both techniques for submucosal invasion was poor, even by using a combination of the two methods. The use of the miniprobe may not increase the positive predictive value for T staging over the use of CE alone.

Role of Helicobacter pylori infection in gastric cancer pathogenesis: a chance for prevention

Gastric cancer in the absence of strategies implemented for early detection continues to have a dismal prognosis. There are limited options for a curative therapy once patients present with clinical manifestations of this malignant disease. Helicobacter pylori (H. pylori) infection plays a key role in gastric carcinogenesis, supported by epidemiological, preclinical and clinical studies. The recognition of H. pylori infection as a critical risk factor in the development of gastric cancer opens the chance for new venues in prevention strategies.

[Gastric cancer screening and diagnosis]

Gastric cancer is the most common cancer in Korea and has overall survival rate of around 50%. Gastric cancer detected in early stage can be cured by endoscopic resection or less invasive surgical treatment and the subsequent prognosis is excellent. National cancer screening program for gastric cancer has been available for several years. The evaluation for efficacy of our screening strategy is strongly needed in terms of mortality reduction and cost-effectiveness. Accurate diagnosis and staging evaluation is important for proper management and prediction of a patients prognosis. It is recommended to understand the advantages and limitations of currently available guidelines and diagnostic modalities. The 7th edition of gastric cancer staging system from AJCC may have significant effect on our knowledge and patient management.

Factors associated with use of gastric cancer screening services in Korea

AIM: To identify the factors associated with participation in gastric cancer screening programs.

METHODS: Using data from the Korea National Health and Nutrition Examination Survey 2005 (KNHANES III), a nationwide health-related survey in Korea, a cross-sectional study was performed to investigate the multiple factors associated with gastric cancer screening attendance among persons aged at least 40 years. The study population included 4593 individuals who completed a gastric cancer screening questionnaire and had no previous cancer history. Four groups of individual-level or environmental level covariates were considered as potential associated factors.

RESULTS: Using KNHANES III data, an estimated 31.71% of Korean individuals aged at least 40 years adhered to gastric cancer screening recommendations. Subjects who graduated from elementary school [adjusted odds ratio (aOR), 1.66; 95% CI: 1.21-2.26], middle/high school (aOR, 1.38; 95% CI: 1.01-1.89), and university or higher (aOR, 1.64; 95% CI: 1.13-2.37) were more likely to undergo gastric cancer screening than those who received no formal education at all. The population with the highest income tertile had more attendance at gastric screening compared to those with the lowest income tertile (aOR, 1.36; 95% CI: 1.06-1.73). Gastric screening was also negatively associated with excessive alcohol consumption (aOR, 0.71; 95% CI: 0.53-0.96). A positive attitude to preventive medical evaluation was significantly associated with better participation in gastric cancer screening programs (aOR, 5.26; 95% CI: 4.35-6.35).

CONCLUSION: Targeted interventions for vulnerable populations and public campaigns about preventive medical evaluation are needed to increase gastric cancer screening participation and reduce gastric cancer mortality.

Prognostic significance of peritoneal washing cytology in patients with potentially resectable gastric cancer

BACKGROUND/AIMS

The prognostic value of cytological examination of intraoperative washings in potentially resectable gastric cancer is controversial.

METHODOLOGY

Between February 1993 and August 2001, clinicopathological features and surgical outcome of 26 consecutive patients with gastric cancer with positive cytological findings of peritoneal washings without peritoneal dissemination were retrospectively analyzed.

RESULTS

The overall 1, 2, 3-year survival rates for 26 patients were 69%, 35%, and 0%, respectively. The median survival was 17.5 months. The median survival of patients with curative resection (n=16) and non-curative resection (n=10) was 19 months and 12.5 months, respectively. There was no significant difference in survival between curative resection and non-curative resection (p=0.10). Recurrent disease frequently occurred as peritoneal dissemination (69%). No patient survived for more than 34 months.

CONCLUSIONS

Aggressive surgical resections do not provide any survival benefit for gastric cancer with positive cytological findings of peritoneal washings even in the absence of peritoneal dissemination.

Myosin heavy chain kinase from developed Dictyostelium cells. Purification and characterization

Background:

Although gastric cancer screening is common among countries with a high prevalence of gastric cancer, there is little data to support the effectiveness of this screening. This study was designed to determine the differences in stage at diagnosis of gastric cancer according to the screening history and screening method (upper gastrointestinal series (UGIS) vs endoscopy).

Methods:

The study population was derived from the National Cancer Screening Programme (NCSP), a nationwide organised screening programme in Korea. The study cohort consisted of 19 168 gastric cancer patients who had been diagnosed in 2007 and who were invited to undergo gastric cancer screening via the NCSP between 2002 and 2007.

Results:

Compared with never-screened patients, the odds ratios for being diagnosed with localised gastric cancer in endoscopy-screened patients and UGIS-screened patients were 2.10 (95% CI=1.90–2.33) and 1.24 (95% CI=1.13–1.36), respectively.

Conclusions:

Screening by endoscopy was more strongly associated with a diagnosis of localised stage gastric cancer compared with screening by UGIS.