Olga Sjomina

Dr. Olga Sjomina


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 July 2022 in Diagnostics
Verified
Journal Article
Open access
PDF file
CRClaudia Robles
Claudia Robles
DRDace Rudzite
Dace Rudzite
IPInese Polaka
Inese Polaka
OSOlga Sjomina
Olga Sjomina
LTLivian Tzivian
Livian Tzivian
Marcis LejaMarcis Leja
Marcis Leja
Introduction––Serum pepsinogen tests for gastric cancer screening have been debated for decades. We assessed the performance of two pepsinogen assays with or without gastrin-17 for the detection of different precancerous lesions alone or as a composite endpoint in a Latvian cohort. Methods––Within the intervention arm of the GISTAR population-based study, participants with abnormal pepsinogen values by ELISA or latex-agglutination tests, or abnormal gastrin-17 by ELISA and a subset of subjects with all normal biomarker values were referred for upper endoscopy with biopsies. Performance of biomarkers, corrected by verification bias, to detect five composite outcomes based on atrophy, intestinal metaplasia, dysplasia or cancer was explored. Results––Data from 1045 subjects were analysed, of those 273 with normal biomarker results. Both pepsinogen assays showed high specificity (>93%) but poor sensitivity (range: 18.4–31.1%) that slightly improved when lesions were restricted to corpus location (40.5%) but decreased when dysplasia and prevalent cancer cases were included (23.8%). Adding gastrin-17 detection, sensitivity reached 33–45% while specificity decreased (range: 61.1–62%) and referral rate for upper endoscopy increased to 38.6%. Conclusions––Low sensitivity of pepsinogen assays is a limiting factor for their use in population-based primary gastric cancer screening, however their high specificity could be useful for triage.

6 June 2023 in Gut
Verified
Journal Article
Closed access
PDF file
OSOlga Sjomina
Olga Sjomina
RVReinis Vangravs
Reinis Vangravs
EĻElīna Ļeonova
Elīna Ļeonova
IPInese Poļaka
Inese Poļaka
DPDārta Pūpola
Dārta Pūpola
Marcis LejaMarcis Leja
Marcis Leja

31 March 2018 in Journal of Gastrointestinal and Liver Diseases
Verified
Journal Article
Closed access
OSOlga Sjomina
Olga Sjomina
JPJelizaveta Pavlova
Jelizaveta Pavlova
IDIlva Daugule
Ilva Daugule
PJPavel Janovic
Pavel Janovic
IKIlze Kikuste
Ilze Kikuste
MLMarcis Leja
Marcis Leja
Aims: The aim of the study was to evaluate the rationale of blood pepsinogen (PG) testing in population based screening settings.Methods: Participants from a cross-sectional population-based study of cardiovascular risk factors in Latvia were invited to participate in the current study. Pepsinogen I and II were measured in blood samples taken during the initial study and at follow-up; upper gastrointestinal endoscopy was performed. There were three groups of patients: with moderately decreased (PG I< 70 ng/ml and PG I/PG II ratio < 3), with strongly decreased (PG I< 30 ng/ml and PG I/PG II ratio < 2), and with normal PG level. Biopsy with H. pylori detection was performed (updated Sydney system).Results: Results from 259 patients were analyzed. Pepsinogens were decreased in 133 (51.4%), H. pylori was positive in 177 (66.0%) cases. Mean age was significantly lower in patients with normal compared to strongly decreased PG level group (52.8 vs. 64.1 years, p<0.001). Prevalence of severe corpus atrophy was higher in the strongly decreased compared to the normal PG test group: 7.0% vs. 0%; the same tendency was noted in the distribution of OLGA stages III-IV – 10.5% and 0.0%, OLGIM stages III-IV – 3.5% and 0%, and low-grade dysplasia – 15.8% and 2.4% (p<0.05). Two cases of gastric cancer were found; both presented decreased PG levels. A strong association between H. pylori eradication and PG ratio dynamics was found (p<0.05).Conclusions: All high-risk lesions were found in the decreased PG test groups; two cancer cases were revealed.However, PG demonstrated low specificity and low value of repeated testing. The value of PG as a sole test for gastric cancer risk is limited.