Background: Lung cancer remains the leading cause of cancer-related mortality worldwide, accounting for approximately 1.8 million deaths annually and representing 18% of all cancer deaths¹. According to the GLOBOCAN 2024 report, 2.4 million new cases were registered globally, ranking second after breast cancer². Non-small cell lung cancer (NSCLC) constitutes 85% of lung cancer cases, with adenocarcinoma being the most common subtype³. The objective of this study is to map the prevalence of HER2 activation and mutations in EGFR, EML4-ALK, ROS1, BRAF, and KRAS genes among lung cancer patients in Mongolia, and to evaluate their correlations with clinical and morphological parameters (age, sex, smoking status, stage, and morphology). Aim: To determine the distribution pattern of HER2 activation and EGFR, EML-ALK, ROS1, BRAF, KRAS gene mutations among patients with lung cancer in Mongolia, and to evaluate their associations with clinical and morphological characteristics. Materials and Methods: A retrospective study was conducted using archived materials from lung cancer patients at the Clinical Pathology, Molecular Genetics, and Pathology Laboratories of the National Cancer Center of Mongolia, covering the period from 2019 to June 2025. DNA Extraction from Tumor Tissue: Formalin-fixed paraffin-embedded (FFPE) tissue blocks from patients diagnosed with lung cancer, stored in the pathology department archives, were selected for the study. Sections of 5–10 μm thickness were cut, mounted on glass slides, stained with hematoxylin and eosin (H&E), and reviewed by a pathologist. Areas containing ≥20–30% tumor cells were identified and macro-dissected for analysis. Real-Time PCR Assay for Detection of EGFR/BRAF/KRAS/EML4-ALK/ROS1 Mutations: EGFR mutation detection was performed using the PANAMutyper™ EGFR Mutation Detection Kit (Panagene, Daejeon, South Korea) according to the manufacturer’s instructions. PCR reactions were carried out on a compatible instrument (Roche LightCycler 480, Germany) as recommended by the manufacturer. Statistical analysis was performed using Prisma-10 software. Results: A total of 282 lung cancer cases were included in the study. EGFR mutations were detected in 44% of cases and were absent in 56%. No significant age-related differences were observed (p=0.2636); however, EGFR mutations were significantly more frequent in females (36.6% vs. 19.6%, p=0.0019). No statistically significant differences were found across disease stage, T, N, or M classifications (p>0.05). No association was identified between smoking status and EGFR mutations (p=0.4178). Morphologically, EGFR mutations were significantly more prevalent in adenocarcinoma (54.83%) compared to squamous cell carcinoma (SCC) (31.8%; p=0.002). Of the 282 cases, adenocarcinoma accounted for 155 (54.9%) and SCC for 116 (41.1%). Overall, EGFR mutations were positive in 43.97% of cases, with a higher prevalence in adenocarcinoma (24.82%) than in SCC (13.1%). By exon: - Exon 18 mutations were detected in 6% of cases, predominantly in adenocarcinoma (6%, 4.25%). - Exon 19 mutations occurred in 8.15% and are associated with sensitivity to targeted therapy. - Exon 20 mutations were found in 3.19%, with the T790M resistance variant in 1.77%. - Exon 21 mutations were observed in 9.57%, more common in adenocarcinoma (9.57%) than in SCC (3.19%). Survival analysis stratified by stage at diagnosis showed significantly longer median survival in early-stage patients (18.6 months). Kaplan-Meier curve comparison, log-rank test, and hazard ratio calculations confirmed statistically significant differences (p < 0.05), indicating that disease stage is a key prognostic factor. Conclusion The study findings reveal a high prevalence of EGFR mutations among Mongolian patients with lung adenocarcinoma, underscoring the need for widespread implementation of targeted therapy (EGFR-TKIs). In contrast, mutation rates were lower in SCC and other morphological subtypes, highlighting the importance of investigating alternative molecular markers in these subgroups.

Background: Tick-borne encephalitis is human viral infection involving the nervous system and transmitted by the bite of infected tick. The TBE Virus is distributed in different geographical areas by three widespread subtypes of the virus: The Far East, Europe, and Siberia. The Far East type has a mortality rate was 30-35%, the European type has a mortality rate of 2.2%, and the Siberian type has a mortality rate of 6-8% (A.G. Pletnev, 1998) [2].
In recent years, human cases of tick-borne infections have been reported in 19 European countries and four Asian countries (Mongolia, China, Japan, and South Korea) [3].
Human cases of tick-borne encephalitis, tick-borne rickettsiosis, and tick-borne borreliosis have been registered in Mongolia since 2005. Deaths have been reported year by year [5].
During 2005 to 2021, tick-borne rickettsiosis (71.6%), tick-borne encephalitis (17.3%) and tick-borne borreliosis (52.9%) were confirmed by epidemiological, clinical and laboratory tests at the NCZD.
Tick-borne encephalitis was registered in 63 soums of 15 provinces and 9 districts of the capital city, of which 90% were infected with tick bites in Selenge and Bulgan provinces. The average mortality rate is 4.9% (14), of which 28.6% in Bulgan province and 2.7% in Selenge province.
Tick-borne encephalitis is the leading cause of death in Bugat soum of Bulgan province and more infected men about 40 years of age [7]. Purpose : Collect ticks from selected soums of the provinces, identify tick species, species composition, distribution, tick densities, pathogens of tick-borne diseases, conduct population surveys to assess the risk of tick-borne infections, and identify tick-borne infections. Material and Method: Ticks were collected by flag from birch trees in birch forests and meadows with biotope and overgrown berries, determined morphological analyze and molecular biological investigation for detecting tickborne pathogens.
Questionnaires were collected from selected soum residents according to a specially designed randomized epidemiological and clinical survey card, collected information and forms were submitted to soum hospitals with a history of tick bites (according to clinical criteria). Serological tests were performed to detect IgG-specific antibodies to the collected serum mites. Result and conclusion Collected 121 ticks (120 I. persulcatus and 1 D. nuttalli) and not wound egg, larvae, nymphs. By molecular biological investigation detected 3.5% of I.persulcatus from Khutag-Undur soum of Bulgan province, 3.5% of anaplasmosis, and 14.1% of I.persulcatus mites from Bugat soum. 1.5% borreliosis, 3.1% anaplasmosis.
Detected DNA of 100% tick-borne rickettsiosis from D.nutalli ticks and determined circulation of infection among tick in Bugat and Khutag-Undur soums of Bulgan province.
247 people were surveyed, 56 blood serum from cases. Detected Q fever, erysipelas, and anaplasmosis, tick-borne borreliosis 3 (5.4%), tick-borne rickettsiosis 26 (46.4%), Japanese encephalitis 3 (5.4%), tick-borne encephalitis tick-borne rickettsiosis 6 (13.0%), tick-borne rickettsiosis tick-borne borreliosis 1 (1.8%), tick’s rickettsiosis Japanese encephalitis 1 (1.8%), tick-borne encephalitis tick-borne borreliosis 1 (1.8%).
By investigation, vaccination (88%) and wearing long-sleeved shirts and pants (81%) were the most effective ways to prevent tick bites (81%) [15]. According to our research, the percent of population knowledge in Bulgan province was insufficient (40.9%) which there is a lack of information, training and advertisement among the population in the province.

Introduction: The introduction of minimally invasive surgery has revolutionized multiple disciplines of surgical practice. Objectives: This meta-analysis of matched case control studies aimed to compare the perioperative outcomes of video-assisted thoracic surgery (VATS) with open thoracotomy for patients with early-stage non-small cell lung cancer (NSCLC). Methods: We searched from PubMed and Embase electronic database and revealed seven relevant studies. Endpoints included perioperative mortality and morbidity, postoperative complications and duration of hospitalization. Two investigators (L.S and D.N) independently reviewed each retrieved article. The values of RR and 95% CI were estimated. We used the fixed and random-effects models to estimate the size of the treatment benefit. Results: Results indicate that perioperative mortality was similar between VATS and open thoracotomy (RR-0.62(95%CI 0.39-0.98). However, patients who underwent VATS were found to have fewer overall complications (RR-0.68(95%CI 0.59-0.78), and patients who underwent VATS had a significantly shorter length of hospitalization compared with those who underwent open thoracotomy (MD= -2.98(95%CI-4.09:-1.87)). Conclusions The present meta-analysis demonstrated superior perioperative outcomes for patients who underwent VATS, including overall complication rates and duration of hospitalization. Therefore, our study suggests that VATS should be performed widely to treat patients with lung cancer in the future.

Introduction: Biliary Atresia is a fibroobliterativedisorder of the intra andextrahepatic bile ducts in infancy, which isgoing progressively cholestatic liver disease.The failed Kasaiportoenterostomy requiresliver transplantation. The goal of this studyis to show the outcome of Kasai operation,recent improvement and correlation the datato overseas.Methods and Materials: This study wasconducted in the department of generalsurgery of National Center for Maternal andChild Health of Mongolia between 2010 and2016 on a total of 66 infancies with biliaryatresia.Results: Patient diagnosed with biliaryatresia, which performed Kasai operationwithin first 2 months the outcome is verygood early and late post-operation period.There were 3 patients with 10 year survival, 4patients with 5-10 year and 28 patients with5 year survival after Kasai operation. The mostcomport age for liver transplantation is 1 yearlater after Kasai operation in Mongolia. Livertransplantation programme is necessary forMongolian pediatric surgery, and we thoughtour team was assembled.Conclusion: The children with biliary atresiaperform the Kasai operation within 2 monthsthe outcome is very good. Children with biliaryatresia often experience long wait times fortransplant unless exception points are grantedto reflect severity of disease.In Mongolia livertransplantation done in 2 child.

Afl atoxins are a type of mycotoxin produced by Aspergillus species of fungi, such as A. fl avus andA.parasiticus. Afl atoxins are the most potent hepatocarcinogen and mutagen among mycotoxins.Afl atoxins can effects a wide range of commodities, including crops, cereals, peanuts, maize, beans,and milk and fruits. Thus, we carried out a monitoring surveillance survey on the afl atoxins level in somefood commodities. In early stage of this survey we tested a total of 112 samples of foods including fl our,rice, peanuts, maize, dried fruits, milk, and cereals. According to the preliminary results of this survey,59 (52.7%) samples of foods including fl our, rice, peanuts, maize, dried fruits, milk, and cereals’ sampleswere positive for a total afl atoxins (AFB1+AFB2+AFG1+AFG2). Although levels of total afl atoxins in allsamples were at permissible limits by the commission regulation of EU, the strategies for the preventionand control of mycotoxin are required in Public health system and Agricultural organization in Mongolia.Since afl atoxins is the most well-known mycotoxin ever thoroughly studied and its prevention and controlhas been most successfully practiced in various countries, therefore, this paper will focus on the strategyfor the prevention and control of afl atoxins’s mycotoxin contamination food in Mongolia.

This cross-sectional survey was conducted in seven district of the capital city Ulaanbaatar ofMongolia, and border post in Zamiin-Uud, and Altanbulag province from March to December 2015.A total of 380 samples including 70 flours, 114 rice’, 41 various peanuts, 15 maize and maizeproducts, 24 milks, 6 yoghurts, 39 beers, 27 dried fruits and 44 herbal teas were randomly collectedfrom supermarkets, hypermarkets, department stores, factories, and bazaars in Ulaanbaatar city,and Zamiin-Uud, and Altanbulag province.HPLC (High performance liquid chromatography), and enzyme-linked immunosorbent assay (ELISA)were used for the total aflatoxins (B1+B2) and aflatoxin M1 detection.The survey found that (148) 38.9% of all analysed food samples were contained aflatoxins (B1+B2),and aflatoxin M1 were ranging from 0.0094 μg kg-1to 2.4μg kg-1. The levels of aflatoxins (B1+B2)were below the maximum tolerance limit in EU and worldwide regulations. Mean concentrationlevel of aflatoxins (B1+B2) was 0.17 μg kg-1 in all positive samples. Mean daily low and high foodintake were respectively, 63 g and 245 g. Based on the daily food consumption data, estimatedexposure dose of aflatoxins (B1+B2) was 0.16734 mg kg-1bw day-1 in individuals with a daily low foodintake, and 0.65078 mg kg-1bw day-1 in individuals with a daily high food intake (95th percentile). Theexposure dose of aflatoxins from daily high food intake exceeds the estimated provisional maximumtolerable daily intakes, 0.4 μg kg-1 body weight day-1 for adults with hepatitis B (Kuiper-Goodman,1998). Furthermore, estimated excess cancer risk values to liver cancer incidence by ingestion ofthese foods for aflatoxins (B1+B2) and aflatoxin M1were calculated to be 0.0448 mg kg-1bw day-1forindividuals negative for hepatitis Band 1.344 mg kg-1bw day-1 for individuals positive for hepatitis B.Thus, the findings of our survey showed that the potential hazard associated with aflatoxin in foodin Mongolia has not been serious. However, most researchers suggested that no level of aflatoxinexposure is considered safe.Conclusion: Currently, the levels of the total aflatoxins and aflatoxin M1 were lower than the maximumpermissible levels in UE and the USFDA, and worldwide regulations. Currently, estimated exposuredose of the total aflatoxins and M1aflatoxin through daily high food intake was risked in populationwith hepatitis B virus. However, in Mongolian population has not been excess liver cancer risk.

ObjectiveThis study aimed to assess the prevalence of the total aflatoxin in peanuts, and their concentration level.Material and MethodThis cross-sectional survey was conducted in seven district of Ulaanbaatar, the capital city of Mongolia,from March to December 2015.A total of 41 samples of peanuts were randomly collected from the survey area, from March to December2015. An ELISA test was used for detection the total aflatoxins(B1+B2). The relative humidity andtemperatures of the storage areas were measured at the time of sampling the peanut.ResultsThe Frequency statistics analysis showed that 61% of all analyzed peanut samples had detectablelevels of the total aflatoxinat 0.05 μg kg-1. The prevalence of samples contaminated with the totalaflatoxins(B1+B2) were higher among analysed samples of the tree nuts, peanuts imported from China,and canned nuts (P<=0.01). Levels of the total aflatoxins were less than the maximum permissible limitsof 15 μg kg by the regulation of European Union and worldwide. The mean values of the storage relativehumidityat the time of sampling peanuts were higher than the recommended storage relative humidity incorn cereals (<13%). Furthermore, the mean values of the storage temperatures at the time of samplingpeanuts were higher in groundnut peanuts, cedar’s nut and peanuts imported from China than therecommended level of the storage temperature in corn cereals (10°C-21°C).Conclusion:The prevalence of the total aflatoxin in peanuts was higher. The level of the total aflatoxins were less thanthe maximum permissible limits of 15 μg kg-1 by the regulation of European Union and worldwide. Thestorage relative humidity and temperatures of peanuts may encourage the growth of fungi-producingaflatoxins. Thus, a national strategy for the elimination of aflatoxin in foods is needed in Mongolia.

Aflatoxins are the secondary metabolites of the fungi namely, Aspergillus flavus and A. parasiticus. They can colonize and contaminate grain before harvest or during storage. There are about twenty related secondary forms of aflatoxins, and subtypes B₁, B₂, G₁, G₂. These aflatoxins frequently contaminate the foods and feeds (Yu J et al, 2000, Imanaka BT et al, 2007). Aflatoxin B1, the most toxic, is a potent hepatocarcinogenic and genotoxigenic metabolites that have been classified as group I carcinogens by International Agency of Research on Cancer (International Agency for Research on cancer, 1993). Aflatoxin M1 is found in milk of lactating cows that have consumed feeds contaminated with aflatoxin B₁. Aflatoxin M₁ was originally classified as a Group 2B human carcinogen in 1993, but subsequent evidences of its cytotoxic, genotoxic and carcinogenic effects led to a new categorization of aflaoxin M1 as Group I (International Agency for Research on cancer, 2002). Aflatoxins can affect a wide range of commodities, including crops, cereals, oilseeds, spices, tree nuts, milk, meat, and dried fruit (Wilson DM et al, 1994, Bao L et al, 2010). Mongolia has been imported foods about 60 percent of food demands including wheat, flour, rice, milk, dairy products, peanuts and maize. This situation is required to study aflatoxin contamination in food in Mongolia. Epidemiological studies have found that dietary exposure to aflatoxin and chronic infection with hepatitis B, C virus are three major risk factors for HCC (Viviani et al. 1997; Hall et al. 2003). HCC as a result of chronic aflatoxin exposure has been well documented, presenting most often in persons with chronic hepatitis B virus (HBV) infection (Wild and Gong, 2010). The risk of liver cancer in individuals exposed to chronic HBV infection and aflatoxin is up to 30 times greater than the risk in individuals exposed to aflatoxin (Groopman et al., 2008). According to the WHO, the national liver cancer incidence rates was 54.1 per 100.000 population, the prevalence of HBV and HCV infection in 11.8%, 15.6% were respectively (J.Abarsanaa, 2012). This situation is a serous public health problem in Mongolia. Thus, we aimed to carry out the monitoring surveillance survey on the aflatoxin contamination level in some food.