Surveillance of Esophageal Cancer in the Republic of Uzbekistan from 2000 to 2018.

BACKGROUND: Differences in the geographical distributions of esophageal cancer (EC) are associated with environmental influences and genetic risk factors. The inhabitants of the Republic of Uzbekistan are at high-risk for EC; however, detailed epidemiological data regarding the dynamics of EC are not available. METHODS: To address this gap in our knowledge, here we reviewed trends in the incidence of EC in Uzbekistan from 2000 through 2018. We acquired the epidemiological data for 17,144 patients with EC from the national epidemiological data base of Uzbekistan. RESULTS: The mean incidence (per 100,000 persons) during the study period was 2.8, which peaked at 3.9 in 2007 and decreased below 2.5 in 2014 and thereafter. The incidence was highest for patients aged 61 years to 70 years (37.5%). Among patients with EC, 13,331 (80.0%) and 3,333 (20.0%) were diagnosed with squamous cell carcinoma or adenocarcinoma, respectively. The incidences of patients with EC with adenocarcinoma were 0.6 from 2010-2018 and 0.4 from 2000 to 2009. The majority of patients were diagnosed with stage III EC, which was associated with a 5-year survival rate that increased from approximately 15% (2000-2009) and plateaued at approximately 25% (2012-2018). CONCLUSIONS: We conclude that preventing the progression of EC to stage III is required to improve the prognosis of patients with EC who reside in Uzbekistan.

Association of rs2294008 and rs9297976 Polymorphisms in PSCA Gene with Gastric Cancer Susceptibility in Uzbekistan.

INTRODUCTION: Genetic factors play an important role in the development of gastric cancer (GC), a prevalent malignancy in Central Asia. Recent studies have shown that single-nucleotide polymorphisms (SNPs) in several genes are associated with increased GC risk, indicating that genetic variation contributes to gastric carcinogenesis. Located on chromosome 8q24.2, the prostate stem cell antigen (PSCA) gene encodes a 123-amino acid glycoprotein related to the cell-proliferation inhibition and cell-death induction activity. SNPs in PSCA gene have been found to be associated with gastric cancer risk in a genome-wide association study, but results were not conclusive. This study aimed to investigate the association between two polymorphic variants of PSCA gene (rs2294008 and rs9297976) and the susceptibility to gastric cancer in Uzbekistan. METHODS: Two hundred sixty eight patients with gastric cancer and a control group of 248 healthy individuals were included in this study. DNA samples isolated from these groups were genotyped using PCR-RFLP method. Comparative analysis of resulting genotypes showed a statistically significant association between CT genotype and gastric cancer (p=0.03, additive model of inheritance, Cochran-Armitage trend test). RESULTS: Comparative analysis of the distribution of genotypes of rs2976392 polymorphism did not show a statistically significant difference; however, analysis of the distribution of the rs2976392 genotypes in a subgroup of young women revealed a statistically significant (p = 0.04, additive model of inheritance, Cochran-Armitage trend test) increase in the incidence of AA (38%) and AG (56%) genotypes in patients with GC, compared to the controls (20% and 40%). CONCLUSION: Our findings support that PSCA rs2294008 and rs9297976 polymorphism may contribute to the susceptibility to gastric cancer. Genotyping of these polymorphisms can potentially be recommended as one of the criteria for identification of high risk groups for gastric cancer development in Uzbekistan.