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: Globally, gastric cancer accounts for 1,089,000 new cases and 769,000 deaths annually, ranking fifth in overall cancer incidence and third in cancer-related mortality. The aim to determine HER2 expression in patients with gastric cancer and to evaluate its correlation with clinical and immunological biomarkers, as well as the need for further laboratory diagnostics. Aim: To determine HER2 expression in patients with gastric cancer and to evaluate its association with clinical and immunological biomarkers, as well as the potential need for further laboratory diagnostics. Materials and Methods: A retrospective study was conducted using archived materials from patients with gastric cancer at the Clinical Pathology, Molecular Genetics, and Pathology Laboratories of the National Cancer Center of Mongolia, covering the period from 2019 to June 2025. HER2 protein expression in tumor tissue was assessed using immunohistochemistry (IHC), and chromogenic in situ hybridization (CISH-HER2) was employed to confirm gene amplification. Statistical analysis was performed using the Prisma-10 software. Results: In our study, among 210 cases of gastric cancer evaluated by IHC for HER2, 46 (21.9%) were HER2-positive and 164 (78.1%) were HER2-negative. When comparing patients with gastric cancer stratified into HER2 1+ (negative) and HER2 3+ (positive) groups, no statistically significant differences (p < 0.05) were observed in age, sex, tumor location (surgically resected tissue), morphology, or disease stage. However, a higher proportion of males was noted in the HER2 3+ group (80.9%), though this did not reach statistical significance (p = 0.0879). Significant associations were found with tumor markers. Elevated serum CA-72-4 (>5 ng/mL) was more frequent in the HER2 3+ group (58.8%; p = 0.0069). In contrast, elevated CA-19-9 (>35 U/mL) was more common in the HER2 1+ group (93.5%; p = 0.0117), and elevated CEA (>6.9 U/mL) was also predominant in the HER2 1+ group (90.6%; p = 0.002). These findings suggest that HER2 3+ status predominates in cases with elevated CA-72-4, which may influence diagnostic strategies and HER2-targeted therapies (e.g., trastuzumab). Conversely, elevated CA-19-9 and CEA were more associated with HER2 1+ status, indicating a need for further detailed investigation of these markers in relation to HER2 expression. In patients evaluated by CISH for HER2 expression, stratification into HER2-positive and HER2-negative groups revealed no statistically significant differences (p < 0.05) in age, sex, tumor location, morphology, stage, or serum tumor markers (CA-72-4, CA-19-9, CEA). This suggests that HER2 status (positive/negative) may be independent of these variables. Although HER2 positivity was higher in poorly differentiated tumors (48% vs. 30.6% negative; p=0.1414) and in stage IV disease (50% vs. 39.3% negative; p=0.2607), these differences were not statistically significant. Elevated serum markers (CA-72-4, CA-19-9, CEA) were observed but showed no significant correlation with HER2 status. Conclusion Determining the molecular profile of gastric cancer patients can significantly contribute to refining clinical diagnosis, developing treatment strategies, enhancing therapeutic outcomes, and improving patients’ quality of life.

Background: Infectious keratitis is a disease caused by inflammation, infection, and other ocular damage to the outer and other deep layers of corneal epithelium. It is a major cause of monocular blindness and visual disability worldwide regardless of age and gender. Therefore, we aimed to determine the clinical features and risk factors of infectious keratitis among Mongolians and to identify the causative microorganism and compared them with the treatment results. Methods: We collected the data of 149 patients who diagnosed as infectious keratitis at the Ophthalmology Department of the First State Central Hospital in 2017-2020 and using a case series model of descriptive study. Statistical analysis was calculated using Stata14 software. Results: The majority of patients in our study were male, with a male-to-female ratio is 2.1:1. The cause of infectious keratitis were categorized and eye injury-induced keratitis accounted for the highest percentage of 38.3% (n=57), with the majority being men 73.7% (n=42) (p=0.028). As for the type of treatment, antibacterial drugs 103 (69.1%) and evisceration 27(45%) predominate. Conclusion Our study shows that the majority of infectious keratitis in Mongolia is due to trauma in male patients. Forty-five percent of all surgeries involve evisceration surgery, which reduces the client's quality of life.

Introduction: An international study coordinated by the International Agency for Research on Cancer (IARC) and published today in The Lancet Oncology shows that in 2001–2010, childhood cancer was 13% more common than in the 1980s, reaching an annual incidence rate of 140 per million children aged 0–14 years worldwide. Cancer incidence and mortality statistics reported by International Cancer Research Center (2016), over 300,000 children develop cancer worldwide each year, 215000 children aged 0-14 years and 85000 children aged 15-19 years. Internationally comparable data on childhood cancer incidence in the past two decades are scarce. Based on the need for comparison of childhood cancer incidence in Mongolia to the global level, the study aimed to categorize cancer among children aged 0-19 years. Goal: To study the insidence rates and trend from childhood cancer last 10 year in Mongolia Materials and Methods: The study was conducted in 786 new cases childhood who were cancer diagnosed, between 2008 and 2017 year. Age-standardized incidence rates were calculated by the direct method using age-specific incidence rates and weights based on the age distribution of the standard world population Results: Over the past 10 years, childhood cancer accounted for 1.5% of total cancer in Mongolia. By WHO and IARC data, worldwide childhood cancer age standardized rate (ASR) is 106.0, in Mongolia childhood cancer ASR (101.6) is lower than world average. The most common childhood cancers worldwide are: 1st leukemia, 2nd lymphoma, 3rd central nervous system cancer, 4th retinoblastoma, 5th soft tissue cancer. Over the past 10 years the most common childhood cancers in Mongolia are: 1st leukemia, 2nd central nervous system cancer, 3rd joint bone cancer, 4th lymphoma, 5th soft tissue cancer. Our country’s childhood cancer ASR is below compared to other countries, but expected growth rate is gradually increasing (3.0 per year). Conclusions
1. Leukemia is the most common childhood cancer in worldwide and also in Mongolia.
2. By sex, childhood cancer incidence is higher in boys than girls.
3. By age group, childhood cancer incidence is the highest in 0-4 age group.
4. By region, childhood cancer incidence is the highest in central region.
5. The overall incidence of childhood cancer (1 million children) in Mongolia is expected to increase by 3.0 over the next 5 years.

BACKGROUND: There are two general types of age-related macular degeneration: dry and wet. During wet or neovascular age-related macular degeneration new abnormal vessels grow and leak in the macula. As anti-vascular endothelial growth factor (anti-VEGF) was invented, it revolutionized the treatment of nAMD by inhibiting the progress of this disease. The incidence of AMD increases as life expectancy grows and there is a growing need to study this disease. We aimed to evaluate the outcome of anti-VEGF therapy for the treatment of nAMD and the incidence of ocular serious adverse events (SAE) after injections.. METHODS: In our retrospective, single-center study, medical records of patients receiving a single dose of anti-VEGF treatment (Bevacizumab) for nAMD between 17th of April, 2016 and October, 2017 were evaluated. Outcome measures were the change in the baseline visual acuity (VA) score at post-injective month one, incidence of ocular SAE and patients’ baseline characteristics affecting VA. Patients, whose treatment were started before April 2016 and had anti-VEGF treatment for the diseases other than nAMD, were excluded.. RESULTS: 15 eyes in 15 patients between 52 and 85 years of age received single dose of anti-VEGF (Bevacizumab/Avastin) injection. The mean baseline VA improved from pre-injective average of 0.21 to post-injective 1-month average of 0.37 by Snellen. Furthermore, there was no vision loss or other severe adverse effects, such as endophthalmitis, vitreous hemorrhage, retinal detachment, traumatic cataract after 4 weeks. CONCLUSION: Anti-vascular endothelial growth factor therapy has promising short-term outcomes on treating neovascular age-related macular degeneration.

BACKGROUND: Loss of skin elasticity due to redundancy of the upper eyelid (dermatochalasis) and falling of the upper eyelid border to a lower position (blepharoptosis) are often the earliest signs of facial aging. Upper eyelid blepharoplasty is an effective procedure to establish a good eyelid position, and is the most common facial cosmetic procedure [1]. When performing upper eyelid blepharoplasty, eyelid symmetry is essential for a satisfactory surgical outcome. Even if not possible, every surgeon tries to achieve complete symmetry when performing aesthetic eyelid surgery [2]. Several previous studies by surgeons with > 10 years of experience reported how preoperative incision markings should be made to achieve satisfactory surgical outcomes and excellent surgical results for upper eyelid blepharoplasty [3-7]. However, none of these studies investigated naturally occurring asymmetry when applying a preoperative design for upper blepharoplasty incision markings. During the preoperative design step, we noticed certain asymmetric tendencies. We therefore characterised these differences to ensure a more effective preoperative design for upper blepharoplasty incision markings for both eyelids. METHODS: This retrospective study examined 22 patients who underwent bilateral upper blepharoplasty surgery resulting from senile dermatochalasis and/or blepharoptosis. The initial preoperative incision design markings were drawn with the patient sitting upright. Then, with the patient in a supine position, preoperative design photographs were taken. We measured medial canthal excision angle (MCA), maximal lid excision height (MLH), maximal lid excision width (MLW), peak point angle, and peak point distance and compared measurements between both upper eyelids designs using Image J software. RESULTS: The mean MCA for the right side (30.68 ± 10.16°) was significantly different to that for the left side (35.39 ± 13.82°; p < 0.001). The mean MLH for the right side (1.17 ± 0.24 cm) was significantly different to that for the left side (1.24 ± 0.25 cm; p = 0.002). The mean MLW for the right side (0.72 ± 0.19 cm) was significantly different to that for the left side (0.77 ± 0.21 cm; p = 0.011). The mean peak point angle for the right side (15.67 ± 5.09°) was significantly different to that for the left side (18.11 ± 5.49°; p = 0.001). The mean peak point distance for the right side (2.41 ± 0.31°) was significantly different to that for the left side (2.22 ± 0.28 cm; p = 0.001). CONCLUSION: In upper blepharoplasty, the preoperative incision marking design measurements of the left side were significantly greater than those of the right side. The symmetry can therefore be maximised by including the asymmetries in the preoperative design.

BACKGROUND: Pterygium is a fibrovascular wing shaped encroachment of conjunctiva onto the cornea. Although the pathogenesis remains obscure, the ultraviolet radiations (UVR), especially UVR-A and UVR-B (290-400 nm), are considered the most dangerous in developing pterygium among other environmental factors (hot, dry, windy, dusty and smoky environments and hereditary factors. The main histopathological change in primary pterygium is elastotic degeneration of conjunctival collagen. Patient complaints include foreign body feeling and visual loss due to corneal astigmatism or growth over the pupil and cosmetic problems. Anti-inflammatory drugs and lubricants have an important role minimizing the patient’s discomfort, but they do not cure the disease. After surgical removal there are still many recurrences regardless of the method used. Autologous conjunctival grafting seems to be the best method, given both the low recurrence rate and high safety. As described first by Kenyon et al. in 1985, a conjunctival autograft reported a recurrence rate of 5.3% with infrequent and relatively minor complications. The primary disadvantage of this technique is the prolonged operative time required when compared to the bare sclera technique. These disadvantages are outweighed by the lack of sight-threatening complications and the relatively low recurrence rate, which made this procedure gain popularity in many centers. The application of intraoperative 0.02% mitomycin C for the 5 minutes is efficient in reducing the recurrence rate to a minimum. METHODS: This retrospective case series, single center study was conducted on 239 patients, who underwent pterygium excision from Jan 2017 to Dec 2017 at the Department of Ophthalmology of the First Central Hospital. All patients had a detailed ophthalmic examination before the surgical intervention. Data were collected through a prepared questionnaire. Postoperative follow-up examination sheets were evaluated. Data for recurrence rate of pterygium excision were collected and analyzed by using SPSS version 17.. RESULTS: Among the 239 patients, who underwent an operation, 37.2% (n=89) were male and 62.8% (n=150) were female. Participants’ age ranged from 29 -70 years with mean age of 49.5 years old. There is no statistical significance between the stages of the disease and its post-operative outcome in the patients, who underwent pterygium excision surgery in 2017. Postoperative pterygium recurrence was in 9 patients (3.8%); 5 (55.5%) out of all 9 patients with recurred pterygium had underwent pterygium excision without conjunctival autograft. MMC was not used intraoperatively for all 9 (3.8%) patients with recurrence post pterygium excision. CONCLUSION: The relationship between pterygium stage and its post-operative recurrence was not statistically significant (P=0.683). The recurrence rate after pterygium excision with conjunctival autograft was low (P≤0.001) which showed significant statistically. There was no recurrence after pterygium excision with MMC (P≤0.001). The results of studies from Canada, Hong-Kong, India, Philippines and Iran were similar to our outcome.

Introduction: Base excision repair (BER) is mainly responsible for the correction of small base changes of DNA damage. BER pathway involved many enzymes including OGG1 and XRCC1. The defective DNA repair is associated with an increased risk of various cancers including hematologic malignancies-leukemia and myelodysplastic syndrome (MDS). However, it is deniably these polymorphisms alter the susceptibility and clinical outcome of MDS patients. The aim: This study was to evaluate the impact of polymorphisms in gene encoding one protein of BER system: XRCC1 Arg399Gln in MDS and healthy population. Methods: In this study, we recruited 60 health control group [median 47.9 years, 9 MDS subjects [median 56.6 years] were included in this study. Genotyping was carried out by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Allele and genotype frequencies were calculated by direct counting. Result: The frequencies of genotypes of XRCC1 Arg399Gln were as follows: Arg /Arg 1 (11%), Arg/Gln 6 (66%), Gln/Gln 2 (22%) in MDS and Arg /Arg 18.4%, Arg/Gln40%, Gln/Gln41.6% in health control for XRCC1 Arg399Gln. The result revealed that genotypes Arg399Gln increased the risk of MDS In conclusion this study is the first to analyze XRCC1 SNPs and their associated risk of MDS in Mongolian samples. To fully understand the role of DNA damage and DNA repair in the MDS, prospective studies are needed and other genes (OGG1 Ser326Cys, MUTYH Gln324His, APE Asp148Glu) of base excision repair pathway should be analyzed.

GoalTo evaluate the quality, results, and processing of cytology analyses of early detection program ofuterine cervical cancer implemented in Mongolia, which based on Pap test, at Ulaanbaatar city level.Materials and MethodsInformation was collected from the databases of the recalling system of screening program of theCancer registration and information unit of the NCC of Mongolia and districts pathology laboratoreis.Statistical significant level of 1.96 (95% CI) andthe margins of error 0.05 were considered andsample size was calculated by using the information that 10% of unsatisfied results appear onquality assurance of international level. Thus calculations were madefortotal of 1723 (585 positiveand negative 1138) samples, by collecting 287smears from each district.At the district level all the selected slides were reviewed blindly and compared to the previouscytological conclusion. Diagnostic validity was defined by calculating parameters such as specificityand sensitivity, positive and negative predicted values. The Kappa index criteriais used for statisticalcalculation of the cytological diagnosis conclusion matches.ResultsThe target group women coverage of cervical cancer screening program is 40.8%. Out of all positiveresults of early screening cytology, 77% were at an early stage and 23% were at an advanced stage.Thus positive signs were showed with increased detection results in early stage of uterine cervicalcancer (P = 0.05). Positive results of Pap test were follows; ASCUS (53.2%), ASC-H (10.0%), LSIL(19.2%), HSIL (13.4%), CIS (3.4%), and SCC (0, 8%). Out of total slides, 86.7% were as satisfactory.The test results conducted at the district level were90.1% of sensitivity, 88.8% of specificity and9.9% of false negative response. The discrepancy of results of cytology test in districts and repeatedseen is 31.4% (K = 0.749; p = 0.001).ConclusionThe coverage of cervical cancer screening program that has been implementing in our country isnot enough. There are problems at the district level including severe damages of uterine cervix andincomplete diagnosis. The quality of the cytology test is relatively unsatisfied.

National cancer center of Mongolia has responsibility to produce National cancer registry annual reportwhich is collected cancer reports from primary, secondary and tertiary level of government hospitals andprivate hospitals, laboratories. MCR and indicators of incidence and mortality are important for planningand evaluation of all levels for cancer control, primary prevention, diagnosis, treatment, rehabilitation.ObjectiveThe aim of this study was to determine ASR and ASMRs of cancer incidence and deaths in Mongoliafrom 2008 to 2012 for comparing the results of data.Material and MethodsData on new cancer cases diagnosed in 2008-2012 in permanent residents of Mongolia, collected bycancer registry of the National Cancer Center, were used for the analysis. Incidence and mortality rateswere calculated as mean annual numbers per 100,000 residents. ASRs (Age-standardized incidencerate) and ASMRs (Age-standardized mortality rates) were calculated by the direct method from agespecificincidence and mortality rates, weighted to the World Population standard.ResultsFirst five most frequent cancers (liver, stomach, lung, esophagus, cervix uteri) comprise 76% of all newcancer cases.In males, the most frequent cancer site was liver, followed by stomach, lung, esophageal, colon andrectal cancer. In females, liver is in the first place, followed by stomach, cervical, lung, esophagealcancer.Mean annual crude incidence rate of all cancer sites was 155 per 100 000 population,in males 165, infamale 165 in 2008-2012 years.During this period, mean annual age-standardized incidence rate of all cancer sites was 218,3 per 100000 population, for male 258.9 in female 188.1with higher percentage of men.As we age, morbidity of the cancer increases approximately 2 fold in both sexes and also study revealsmen has more tendency to have cancer than women