Gastric cancer is associated with high morbidity and mortality worldwide. To reduce the socioeconomic burden related to gastric cancer, it is very important to identify and manage high risk group for gastric cancer. In this review, we describe the general risk factors for gastric cancer and define high risk group for gastric cancer. We discuss strategies for the effective management of patients for the prevention and early detection of gastric cancer. Atrophic gastritis (AG) and intestinal metaplasia (IM) are the most significant risk factors for gastric cancer. Therefore, the accurate selection of individuals with AG and IM may be a key strategy for the prevention and/or early detection of gastric cancer. Although endoscopic evaluation using enhanced technologies such as narrow band imaging-magnification, the serum pepsinogen test, Helicobacter pylori serology, and trefoil factor 3 have been evaluated, a gold standard method to accurately select individuals with AG and IM has not emerged. In terms of managing patients at high risk of gastric cancer, it remains uncertain whether H. pylori eradication reverses and/or prevents the progression of AG and IM. Although endoscopic surveillance in high risk patients is expected to be beneficial, further prospective studies in large populations are needed to determine the optimal surveillance interval.
Gastroscopy ; Helicobacter Infections/complications/diagnosis ; Humans ; Risk Factors ; Socioeconomic Factors ; Stomach Neoplasms/*diagnosis/etiology/prevention & control/therapy

Proton pump inhibitor (PPI) is a prodrug which is activated by acid. Activated PPI binds covalently to the gastric H+, K+-ATPase via disulfide bond. Cys813 is the primary site responsible for the inhibition of acid pump enzyme, where PPIs bind. Omeprazole was the first PPI introduced in market, followed by pantoprazole, lansoprazole and rabeprazole. Though these PPIs share the core structures benzimidazole and pyridine, their pharmacokinetics and pharmacodynamics are a little different. Several factors must be considered in understanding the pharmacodynamics of PPIs, including: accumulation of PPI in the parietal cell, the proportion of the pump enzyme located at the canaliculus, de novo synthesis of new pump enzyme, metabolism of PPI, amounts of covalent binding of PPI in the parietal cell, and the stability of PPI binding. PPIs have about 1hour of elimination half-life. Area under the plasmic concentration curve and the intragastric pH profile are very good indicators for evaluating PPI efficacy. Though CYP2C19 and CYP3A4 polymorphism are major components of PPI metabolism, the pharmacokinetics and pharmacodynamics of racemic mixture of PPIs depend on the CYP2C19 genotype status. S-omeprazole is relatively insensitive to CYP2C19, so better control of the intragastric pH is achieved. Similarly, R-lansoprazole was developed in order to increase the drug activity. Delayed-release formulation resulted in a longer duration of effective concentration of R-lansoprazole in blood, in addition to metabolic advantage. Thus, dexlansoprazole showed best control of the intragastric pH among the present PPIs. Overall, PPIs made significant progress in the management of acid-related diseases and improved health-related quality of life.
2-Pyridinylmethylsulfinylbenzimidazoles ; Benzimidazoles ; Gastric Acid ; Genotype ; Half-Life ; Hydrogen-Ion Concentration ; Imidazoles ; Nitro Compounds ; Omeprazole ; Proton Pump Inhibitors ; Proton Pumps ; Protons ; Pyridines ; Quality of Life

Serum pepsinogen (sPG) is a marker of gastric mucosal atrophy, a condition that has been associated with an increased risk of gastric neoplasia. A low sPGI level and a low PG I/II ratio have been associated with severe gastric atrophy, and are frequently found in gastric cancer. Because the prevalence of gastric cancer is high in Korea, it would be convenient if a good biomarker for gastric cancer were developed. Two studies recently investigated the efficacy of sPG along with Helicobacter pylori (H. pylori) as a screening tool for gastric cancer. In these studies, sPG was measured using a Latex enhanced Turbidimetric Immunoassay. We found that H. pylori IgG status, age and gender were associated with serum pepsinogen levels. Thus, to increase the ability of the PG I/II ratio to detect atrophic gastritis, the cutoff value for the PG I/II ratio should be stratified according to the H. pylori IgG status. In addition, a PG I/II ratio (< or =3.0), which has been widely used as an international standard for gastric cancer, was found to be a reliable marker for the detection of gastric dysplasia or gastric cancer, especially of the intestinal type. The efficacy of the test in Korea was lower than the efficacy in Japan. However, the detecting power of a PG I/II ratio (< or =3.0) was significantly increased in the presence of H. pylori. The ratio together with H. pylori psotivitiy could provide a means of identifying persons at high risk of developing gastric cancer in Korea.
Atrophy ; Gastrins ; Gastritis, Atrophic ; Helicobacter pylori ; Humans ; Immunoassay ; Immunoglobulin G ; Japan ; Korea ; Latex ; Mass Screening ; Pepsinogen A ; Prevalence ; Stomach Neoplasms

Gastric cancer, the most common cancer in Korea, has come to be more frequently detected in the early stage thanks to regular endoscopy regardless of gastrointestinal symptoms. Early gastric cancer can be treated by endoscopic submucosal dissection or laparoscopic surgery, and its prognosis is very excellent. Thus, it is of an utmost importance to develop efficient screening method and set appropriate interval for the accurate diagnosis of early gastric cancer. Endoscopic screening for every two year is recommended, but the interval could be shortened in case of precancerous condition such as atrophic gastritis and intestinal metaplasia or subjects in a family with a history of gastric cancer. During the investigation, the benefit of using serology of H. pylori infection and serum pepsinogen I/II ratio of less than or equal to 3, instead of direct endoscopy, should also be considered for the selection of a high risk group of gastric cancer in Korea. Recently, appropriate screening and accurate diagnosis of early gastric cancer has become one of the most important issues.
Endoscopy ; Gastritis, Atrophic ; Humans ; Korea ; Laparoscopy ; Mass Screening ; Metaplasia ; Pepsinogen A ; Precancerous Conditions ; Prognosis ; Stomach Neoplasms

Helicobacter pylori (H. pylori) infection is a common bacterial infection for humans. Current knowledge implies that acquisition of H. pylori seems to occur predominantly in childhood and that a major role of intrafamilial spread is not controversial. However, the major route of transmission remains poorly understood. According to the nation-wide seroprevalence study for 5,732 asymptomatic Korean population in 1998, the seroprevalence of H. pylori infection was 46.6%, showing the transition from a developing country to a developed country. The seroprevalence in children (neonate-15 yr) and adult (16-79 yrs) were 17.2% and 66.9%, respectively. According to multivariate analysis, variables such as sex, age, geographic area, crowding (number of person per room) in childhood, economic status in childhood, and types of housing in childhood were significantly and independently associated with H. pylori seroprevalence of adults. In children, age, geographic area, household income, mother's education, and drinking water source were significant factors of H. pylori infection. The seroprevalence survey in 2005 showed that it decreased to 59.6% from 66.9% in the adult (16-79 yrs) over the period of 7 years, especially, in young subjects less than 50 years, Seoul and Gyeonggi suggesting that this decrease may be due to the improvement of socioeconomic status and hygiene.
Adult ; Bacterial Infections ; Child ; Crowding ; Developed Countries ; Developing Countries ; Drinking Water ; Education ; Family Characteristics ; Gyeonggi-do ; Helicobacter pylori ; Housing ; Humans ; Hygiene ; Multivariate Analysis ; Prevalence* ; Seoul ; Seroepidemiologic Studies ; Social Class

There has been an accumulation of data regarding the chemopreventive effects of Helicobacter pylori (H. pylori) eradication. However, it remains unclear how H. pylori infection causes gastric cancer (GC) and how H. pylori eradication can prevent GC. Atrophic gastritis (AG) and intestinal metaplasia (IM) are known as precancerous lesions which mainly lead to intestinal-type GC but to some extent, can also lead to diffuse-type GC. The most important mechanism of AG/IM is H. pylori-induced chronic gastritis. Thus, the reversibility of AG and IM by H. pylori eradication therapy is very important in the prevention of GC. There have been many studies providing data supporting the improvement of AG by the eradication of H. pylori to some extent. In contrast, IM has been regarded as “the point of no return.” However, more recent studies have implied the improvement of IM after eradication, suggesting the importance of early eradication therapy in reversible histological status. In this review, we focused on the reversibility of AG and IM by H. pylori eradication and tried to investigate the predicting factors for the improvement of AG and IM including age, sex, smoking, and diet, as well as H. pylori infection.

BACKGROUND/AIMS: The Helicobacter pylori (H. pylori) eradication rate of standard triple therapy is unsatisfactory in Korea, and sequential therapy (SQT) has been suggested to be a practical first-line alternative regimen. The aim of this prospective study was to document changes in annual eradication rates of SQT. METHODS: A total of 983 H. pylori-positive subjects were enrolled from 2010 to 2018 and their data were subjected to intention-to-treat (ITT) and per-protocol (PP) analysis. All subjects received 10-day sequential therapy consisting of 40 mg esomeprazole and 1 g amoxicillin b.i.d for 5 days followed by 40 mg esomeprazole b.i.d, 500 mg clarithromycin b.i.d and 500 mg metronidazole t.i.d for 5 days. The 13C-urea breath test, rapid urease test (CLO test®), and histology were used to confirm eradication. Compliance and side effects were also investigated. RESULTS: ITT and PP eradication rates of SQT were 69.9% (687 of 983) and 87.1% (657 of 754), respectively. The annual eradication rate of ITT remained consistent over the 8-year study period (p for trend=0.167), whereas PP analysis showed the eradication rate increased (p for trend=0.042). The overall adverse event rate for SQT was 41.7% (410 subjects). CONCLUSIONS: Despite high antibiotic resistance rates in Korea, the eradication rate of SQT did not decrease over the 8-year study period.
Amoxicillin ; Breath Tests ; Clarithromycin ; Compliance ; Drug Resistance, Microbial ; Esomeprazole ; Helicobacter pylori ; Helicobacter ; Intention to Treat Analysis ; Korea ; Metronidazole ; Prospective Studies ; Urease

Although there are many guidelines recommending Helicobacter pylori (H. pylori) eradication therapy for atrophic gastritis (AG) and intestinal metaplasia (IM), there have been contradictory reports regarding the reversibility of precancerous lesions such as AG and IM after eradication of H. pylori. There have been many reports that have shown AG seems to improve upon eradication of H. pylori to some extent. In contrast, IM has been regarded as ‘the point of no return’ according to previous reports. However, as recent studies have suggested the improvement of intestinal metaplasia as well, early eradication therapy for reversible histological status is important and necessary for the prevention of gastric cancer. In this review, we focused on the progress of gastritis resulting in AG and IM mainly by H. pylori, the relationship of AG and IM with gastric cancer, the subtype of IM, and the reversibility of AG and IM by eradication of H. pylori. Finally, we introduced the recent extension of indications for H. pylori eradication with coverage by medical insurance, which was published by the Korean Ministry of Health and Welfare in January 2018.
Gastritis ; Gastritis, Atrophic* ; Helicobacter pylori* ; Helicobacter* ; Insurance ; Metaplasia* ; Stomach Neoplasms

Although genetic background is known to contribute to colon carcinogenesis, the exact etiology of the disease remains elusive. The organ’s extensive interaction with microbes necessitated research on the role of microbiota on development of colon cancer. In this review, we summarized the defense mechanism of colon from foreign organism, and germ-free animal models that have been employed to elucidate microbial effect. We also comprehensively discussed the metabolic property of microbiota such as butyrate production, facilitation of heme toxicity, bile acid transformation, and nitrate reduction that has been shown to contribute to the development of the tumor. Finally, up-to-date subjects such as the effect of age and gender on microbiota are briefly discussed.
Bile ; Bile Acids and Salts ; Butyrates ; Butyric Acid ; Carcinogenesis ; Colon ; Colonic Neoplasms ; Genetic Background ; Heme ; Microbiota ; Models, Animal

The distribution of gut microbiota varies according to age and sex. Gut microbiota are known to contribute to gastrointestinal (GI) diseases such as irritable bowel syndrome, inflammatory bowel disease, and colon cancer; however, the exact etiology remains elusive.Sex hormone such as estrogen and testosterone control the microbiota mainly due to different effect on the immunity. In addition, the diet depending on gender also affect the gut microbiota. Furthermore, the metabolism of estrogen and androgen was reported to be related to the gut microbiome. However, there have been few comprehensive review articles regarding the effect of microbiota on GI diseases. In this review, the factors which affect the gut microbiota and the interplay of microbiota and GI diseases in terms of sex- and gender differences were briefly summarized.