Gastric cancer has been and still considered one of the most common causes of cancer-related mortality and it continues to be a major public health issue. The incidence and mortality of gastric cancer in Mongolia is the highest in the world. For this reason, this paper provides the information about current status of gastric cancer in Mongolia in the first section. Morbidity and mortality of gastric cancer increased steadily during the last decade. In the second section we overview the most important factors that can accelerate the risk of gastric cancer. Evidence from case-control, cohort studies and meta-analysis have suggested that the risk of gastric cancer is related to several factors including genetics, Helicobacter pylori, other factors related to the environment and lifestyle. Risk factors could have different effects on the onset and the evolution of gastric cancer.

Gastric cancer is the second leading cause of death worldwide. About half of the incidence of stomach cancer has been reported in East Asian countries. In Mongolia, gastric cancer is the second most common cancer in males and the third most common in females. The age-standardized mortality rate for gastric cancer was 29.3 per 100,000 in 2016, ranking second after liver cancer. Pepsinogen (PG) is a proenzyme of pepsin, by chief and mucous neck cells in the gastric mucosa. On the basis of the source of secretion, PGs are subdivided into 2 types: PG I and II. PG I is only secreted from the fundic glands in the corpus of the stomach, whereas PG II is secreted from the corpus, as well as the pyloric glands in the antrum and proximal duodenum. PG is excreted mainly into the stomach lumen, but approximately 1% diffuses into the blood stream. Atrophic gastritis and intestinal metaplasia are well-known risk factors for gastric neoplasms including dysplasia. To identify these premalignant gastric conditions, histological biopsy or image-enhanced endoscopy is performed. Gastric cancer is usually preceded by a decades-long precancerous process driven by Helicobacter pylori infection and environmental conditions with well-defined successive lesions. In the advanced stages, they are characterized by glandular atrophy and intestinal metaplasia. These changes involve loss of the original glands and result in decrease of the mass of chief cells of the gastric corpus, where PGI is produced. Loss of chief cells leads to lower PGI levels and PGI/PGII ratio in the peripheral blood. Serum PG levels are therefore a key tool to be used in screening programs. Serum PG measurements could provide a simple and noninvasive method for screening gastric neoplasms.

Gastric and esophageal cancer is a significant global health issue. The epidemiology of these tumors has significantly increased over the past several years especially in developing and developed countries. Many dietary exposures have been proposed to protect against or increase risk for esophageal and gastrointestinal (GI) cancers, including poor diets, foods, individual nutrients, methods of food preparation, and habits of consumption. Overweight/obese status is associated with an increased risk for many cancer types such as esophageal, gallbladder, kidney, pancreatic and gastric cancer. The association between obesity and cancer is strong. Nowadays there is a recognized decrease in incidence and mortality of distal gastric cancer and an increase in incidence and mortality of proximal esophageal cancer. In Mongolia, gastric cancer is the second most common cancer in males and the third most common in females. It is very important to understand how diet and nutrition affect to gastric and esophageal cancers. In this review we will discuss the effect of diet in locally advanced gastro-esophageal cancer. Although we tried to conclude all published articles about gastric and esophageal cancers in Mongolia.
In this survey, is considered dietary risks into 5 groups as following;
• Insufficient nutrition education(don’t know food and nutrients significance and food hygiene, don’t know right consumption of food)
• Bad habits (hot tea and meals, salty tea and food, low consumption of fruits and vegetables, sometimes eating breakfast, most of daily energy of food in the night, high amount of sugar, a drink of caffeine, overweight and etc.)
• Food processing technology (such as overcooking, pickling, preserving, frying, excessive salt in tea fried and etc).
• Chemical contaminants in food products (various inorganic fertilizers, heavy metals and etc.)
• Household economic capacity is influencing
Diet can be used as a tool to evoke the positive/desirable biological responses of an organism aiming to maximize health and protection against diseases (chronic/non-communicable diseasesparticularly cancer) by mostly means of prevention.

Introduction: Gastric cancer is still one of the most leading causes of mortality in the world. The highest mortality rate of gastric cancer is estimated in Mongolia. South Korea and Japan, where leading the incidence of gastric cancer, mortality rates are observed in 51th and 31nd rank respectively. In Mongolia, gastric cancer is the second leading site, after liver cancer. Goal: We aimed to determine the cause of late diagnosis of gastric cancer and to evaluate supply of upper endoscopy devices and human resource for gastric cancer in the general hospital of provinces and districts. Materials and Methods: In this study, 84 patients suffering from gastric cancer (42 patients in III, IV TNM stage; 42 patients in I, II TNM stage)were investigated in National Cancer Center, Mongolia. A survey questionnaire which included age, gender, education, income, risk factors and clinical questions was detected from all patients. And we conducted study of supply of upper endoscopy devices and human resource for gastric cancer in general hospitals of from 21 provinces and general hospitals of 6 districts by questionnaire. Results: Seventy three(86.9%) patients were over 50 years old and the highest rates of gastric cancer were in group of 61-70 years (40.5%). From the results, the reason to visiting hospital was significantly different between two groups. 55.1% of patients suffering from early-stage gastric cancer were voluntarily diagnosed by upper endoscopy. In contrary, 55.8% of patients suffering from late-stage gastric cancer have visited the hospital due to worsening symptoms or dysphagia and vomiting. Factors such as age, gender, education, employment status and income had no significant effect on late diagnosis of gastric cancer. In totally 24(89%)general hospitals out of 27 had upper endoscopy devices and 22 (81.5%) hospitals had endoscopist. Although 75% of total general hospitals conduct annual cancer screening, 64% of them do not perform the endoscopy in annual screening. Conclusion In our country, late diagnosis of gastric cancer is related to the attitudes of patients for preventing and screening disease. Therefore, it is important to improve the health education of the population and to develop healthy, right attitudes and practices. And the study revealed that general hospitals have insufficient for upper endoscopy devices and human resource.

Introduction: In 2018, a total of 901 new cases of gastric cancer were recorded, of which 64.8% in males and 34.2% in females. The incidence rate of gastric cancer was 28.5 per 100 000 population, which 38.2 for males and 19.2 for females. Goal: We aimed to investigate the associations between some risk factors and gastric cancer among the Mongolian population. Materials and Methods: A case-control study was conducted between November 2017 and September 2019. We selected 120 cases from National cancer center of Mongolia who newly diagnosed gastric cancer. And 120 controls were selected by matching by sex, age and the place of residence. Informed consents were obtained from all subjects. All subjects were personally interviewed with researchers used by a structured questionnaire consisting of 86 questions. The SPSS 21 (version 16.0, SPSS Inc., Chicago, IL, USA) software was used for all analyses. Results: The mean age was 59.2±11.4 (26-85) years. Habits of having dinner after 6.00 pm (OR 1.42, 95%CI 1.11-1.83, p=0.008), having leftover meals (OR 2.22, 95%CI 1.27-3.86, p=0.008), daily consumption of tea with salt (OR 1.97, 95%CI 1.18-3.30, p=0.01), smoking on an empty stomach (OR 2.44, 95%CI 1.11-5.37, p=0.033), weekly consumption of ham and smoked meat (OR 1.5, 95%CI 1.17- 2.13, p=0.02), and consumption of fat grease (OR 2.09, 95%CI .03-4.24, p=0.038) were significantly increased gastric cancer risk. In contrast, habit of eating at regular times (OR 0.43, 95%CI 0.25-0.73, p=0.002), chewing thoroughly (OR 0.39, 95%CI 0.23-0.67, p=0.001), cooking meat thoroughly until it’s tender (OR 0.48, 95%CI 0.25-0.97, p=0.047), daily consumption of vegetables (OR 0.45, 95%CI 0.27-0.76, p=0.003), and daily consumption of fruit juice (OR 0.36, 95%CI 0.15-0.85, p=0.026) were significantly reduced gastric cancer risk. Furthermore, having first-degree relatives diagnosed with gastric cancer had 2-3 fold higher increased risk of gastric cancer (parents OR 2.88, 95%CI 1.07- 7.78, p=0.038, sibling (OR 3.09, 95%CI 1.09-8.81, p=0.036). Also, previous records of the digestive disease increased risk of gastric cancer (OR 3.65, 95%CI 2.10-6.35, p<0.0001). Conclusion Dietary habits, family history of gastric cancer and previous records of digestive disease were associated with risk of gastric cancer. Thus, prevention effort could be focused on the population with a family history of gastric cancer, changing bad dietary habit and screening precancerous disease of gastric cancer.

Background: The incidence of gastric cancer has been declining worldwide in recent years; on the contrary, it has increased in the last decade in Mongolia. In Mongolia, over 80% of gastric cancer cases are diagnosed in the late stage. We performed a gastroduodenoscopy for screening and histological evaluation to diagnose gastric cancer. These methods are an effective diagnostic modality for gastric diseases; however, invasive and cause discomfort, making it an undesirable procedure for patients. Aims: To determine serum PGs and H.pylori IgG in atrophic gastritis and gastric cancer patients and evaluate the risk by ABC(D) classification. Materials and Methods: We selected 40 atrophic gastritis and 36 newly diagnosed gastric cancer patients from National Cancer Center of Mongolia, before surgery and other therapies. Besides, we enrolled population-based 38 healthy controls. Subjects of three groups were matched by age (±1) and sex. Written informed consents were obtained from all subjects. The fasting blood samples were collected and tested PGI, PGII, and H.Pylori IgG levels by enzyme-linked immunosorbent assay. Also, PGI to PGII ratio (PGI/II ratio) was calculated. We classified subjects into four groups based on ABC(D) classification. All statistical analyses were performed by SPSS (version 26.0, Chicago, IL, USA) software. Results: Median age of the subjects was 62, 52.6% (n=60) were male. Proportions of family history of gastric cancer and previous history of gastric disease were significantly higher in the gastric cancer group compared with atrophic gastritis and healthy control groups (p<0.05, p<0.05). H.pylori was positive in 67 (58.8%) subjects according to H.pylori IgG assay and there was no difference between study groups. The serum PGI level and was significantly decreased in gastric cancer and atrophic gastritis groups as compared to the healthy control (p<0.05, p<0.05). The PGI/II ratio was significantly lower in the gastric cancer group compared with the healthy control (p<0.01). The optimal cut off value of PGI was ≤35.25 ng/ml (AUC 64.3, 95% CI 51.3-77.2, p<0.05) for gastric cancer and PGI was ≤75.07 ng/ml (AUC 65.2, 95% CI 53.0-77.3, p<0.05) for atrophic gastritis. Also, the optimal cut off value of PGI/II ratio was ≤5.27 (AUC 71.6, 95% CI 69.6-82.8, p<0.01) for gastric cancer and PGI/II ratio was ≤6.25 (AUC 62.7, 95% CI 50.1-75.3, p<0.05) for atrophic gastritis. According to classification of atrophic gastritis patients and healthy control, group D had higher proportion of atrophic gastritis cases than group A, B and C (OR 5.04, 95% CI 1.13-22.50, p<0.05). According to classification of gastric cancer patients and healthy control, groups C had higher proportion of gastric cancer cases than group A, B and D (OR 6.19, 95% CI 1.04-36.78, p<0.05). Conclusion Our findings suggest that PGs level and H.pylori IgG may predict development of gastric cancer and could identifying individuals at high risk of gastric cancer and precancerous lesions who may need endoscopy.

Introduction: Cancer is a major public health issue both in Asia and in Mongolia. The most prevalent cancer related deaths in Mongolia are registered for the stomach, esophagus and liver. Purpose: We aimed to investigate the incidence of stomach and esophageal cancer in Mongolian population. Materials and Methods: Epidemiologic data were collected from 2009 to 2018 through the oncology cabinet of all hospitals and medical centers from all provinces, soums (the smallest unit of provinces) and major districts of the capital city. The incidence of stomach and esophageal cancer was calculated by appropriate methods and it was presented by ArcGIS Pro 9.2 software. A P-value of less than 0.05 was considered to be statistically significant and based on two side hypotheses. All calculations were performed in the IBM SPSS Statistics software. The study design in concordance with ethical guidelines was approved by the Ethics Committee of Ministry of Health Mongolia. All clinical investigations were conducted according to the principles laid down in the Declaration of Helsinki. Results: The incidence of esophageal cancer in last ten years (2009-2018) was 10.09 in 100000 populations and the highest incidence were registered in Uvs (38.13), Bayan-Ulgii (24.15) and Zavkhan (18.18) provinces, respectively. The incidence of stomach cancer was 20.33 in 100000 populations and the highest incidences were registered in Uvs (53.01), Khovd (46.02) and Darkhan-Uul (40.50) provinces, respectively. Conclusion
1. Incidence rates for esophageal and stomach cancer are high among the Mongolian population. In the last decade, the incidence of esophageal cancer had not decreased significantly, but it’s constant.
In our study, the esophageal cancer incidence was 10.09 per 100’000 people, which includes one of the high incidence rate countries according to the WHO classification. More than 10 aimags incidence rate of esophageal cancer was higher than the National average. Most of them have occurred in the western region of the country. Most of the Western, some of Khangai and Eastern soums have had the highest incidence of esophageal cancer what we have shown on the mapping.
2. The incidence rates of stomach cancer were registered as 20.33 per 100’000 people in the last 10 years at the national level. It has shown that according to the WHO classification, our country is also one of the countries with the highest incidence of stomach cancer. The stomach cancer incidence trend was increased in the last 10 decades. Therefore, some of aimag’s soums has included the highest rate classification. In addition, some soums in the Western, Khangai, and Eastern aimags had have a very high incidence of stomach cancer.
According to results in the above, the nationwide targeted prevention program is needed especially where the highest incidence rates. Also there is a lack of cooperation between national organizations to accurate registration of gastrointestinal cancer and to fight against these harmful cancers.