RESUMEN
BACKGROUND: Mongolia has the highest mortality rate of gastric cancer. The early detection of cancer and down-staging screening for high risk patients are essential. Therefore, we aimed to validate serum markers for stratifying patients for further management. METHODS: Endoscopy and histological examination were performed to determine high risk and gastric cancer patients. Rapid urease test, culture and histological tests were performed to diagnose Helicobacter pylori infection. Serum pepsinogen (PG) I and II and anti-H. pylori IgG were measured by ELISA. Receiver Operating Characteristic analysis was used to extract the best cut-off point. RESULTS: Totally 752 non-cancer and 50 consecutive gastric cancer patients were involved. The corpus chronic gastritis (72%: 36/50 vs. 56.4%: 427/752), corpus atrophy (42.0%: 21/50 vs. 18.2%: 137/752) and intestinal metaplasia (IM) (64.0%: 32/50 vs. 21.5%: 162/752) were significantly higher in gastric cancer than non-cancer patients, respectively. Therefore, corpus chronic gastritis, corpus atrophy and IM were considered as high risk disease. The best serum marker to predict the high risk status was PGI/II < 3.1 (sensitivity 67.2%, specificity 61%) and PGI/II further reduced to < 2.2 (sensitivity 66%, specificity 65.1%) together with PGI < 28 ng/mL (sensitivity 70%, specificity 70%) were the best prediction for gastric cancer. The best cut-off point to diagnose H. pylori infection was anti-H. pylori IgG > 8 U/mL. Multivariate analysis showed that anti-H. pylori IgG > 8 U/mL and PGI/II < 3.1 increased risk for high risk status and PGI/II < 3.1 remained to increase risk for gastric cancer. CONCLUSION: The serum diagnosis using PGI/II < 3.1 cut-off value is valuable marker to predict high risk patients for population based massive screening.
Asunto(s)
Biomarcadores de Tumor/sangre , Pepsinógenos/sangre , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antibacterianos/sangre , Femenino , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/epidemiología , Helicobacter pylori/aislamiento & purificación , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Mongolia/epidemiología , Neoplasias Gástricas/sangre , Neoplasias Gástricas/microbiologíaRESUMEN
BACKGROUND: The incidence and mortality of gastric cancer in Mongolia is among the highest in the world. METHODS: This was a case-control study in which upper gastrointestinal endoscopy, gastric histology, Helicobacter pylori testing, and risk factor questionnaires were obtained. Histologic subtypes were determined by Lauren's classification. RESULTS: We enrolled 45 gastric cancer and 108 non-gastric cancer patients. Gastric cancers were located in upper part of stomach in 53.3%, main gastric body in 37.8%, and lower part of stomach in 8.9%. The majority (60%) were diffuse type, followed by intestinal type (36.7%) and indeterminate type (3.3%). H. pylori infections were CagA positive in 100% with cancer vs 81% without cancer (P = .02). The majority of CagA was non-East Asian type (95% with cancer and 94.1% without cancer). Cancer patients had typically related with excessive use of salt, hot beverages, tobacco smoking, and low ingestion of fruits. CONCLUSION: The characteristic topography of gastric cancer in Mongolia being in the gastric corpus differed from East Asian countries and was more similar to western countries. The risk factors for gastric cancer in Mongolia were similar to other high-risk areas (ie, H. pylori infection, excessive use of salt, tobacco smoking, and low ingestion of fruits).
Asunto(s)
Infecciones por Helicobacter/diagnóstico , Neoplasias Gástricas/diagnóstico , Adulto , Anciano , Estudios de Casos y Controles , Endoscopía Gastrointestinal , Femenino , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/patología , Helicobacter pylori/genética , Helicobacter pylori/aislamiento & purificación , Helicobacter pylori/fisiología , Humanos , Masculino , Persona de Mediana Edad , Mongolia/epidemiología , Neoplasias Gástricas/epidemiología , Neoplasias Gástricas/microbiología , Neoplasias Gástricas/patologíaRESUMEN
Helicobacter pylori infection possessing East-Asian-type CagA is associated with carcinogenesis. Mongolia has the highest mortality rate from gastric cancer. Therefore, we evaluated the CagA status in the Mongolian population. High risk and gastric cancer patients were determined using endoscopy and histological examination. H. pylori strains were isolated from different locations in Mongolia. The CagA subtypes (East-Asian-type or Western-type, based on sequencing of Glu-Pro-Ile-Tyr-Ala (EPIYA) segments) and vacA genotypes (s and m regions) were determined using PCR-based sequencing and PCR, respectively. In total, 368 patients were examined (341 gastritis, 10 peptic ulcer, and 17 gastric cancer). Sixty-two (16.8%) strains were cagA-negative and 306 (83.1%) were cagA-positive (293 Western-type, 12 East-Asian-type, and one hybrid type). All cagA-negative strains were isolated from gastritis patients. In the gastritis group, 78.6% (268/341) had Western-type CagA, 2.9% (10/341) had East-Asian-type, and 18.2% (61/341) were cagA-negative. However, all H. pylori from gastric cancer patients possessed Western-type CagA. Histological analyses showed that East-Asian-type CagA was the most virulent strains, followed by Western-type and cagA-negative strains. This finding agreed with the current consensus. CagA-positive strains were the most virulent type. However, the fact that different CagA types can explain the high incidence of gastric cancer might be inapplicable in Mongolia.