RESUMO
Helicobacter pylori (H. pylori) infection is considered a cause of gastric cancer (GC), though evidence for this association is scarce in high-risk areas. Possible case control and/or ethnic differences were investigated as to the presence of H. pylori and its immunogloblin G antibody titer in the multi-ethnic city of São Paulo, where the incidence of GC is relatively high. We performed a cross-sectional comparison of antibody titers to H. pylori in Japanese Brazilian, and non-Japanese Brazilian GC patients and their controls. Japanese Brazilian patients were matched by age, sex and ethnicity with two controls, while non-Japanese Brazilian patients were matched as above with one control. Among Japanese Brazilians, 59 of 93 (63.4%) patients with GC and 127 of 186 (68.3%) controls were positive for H. pylori-specific antibody (odds ratio (OR) = 0.80, 95% confidence interval (CI) = 0.47 - 1.36), while among non-Japanese Brazilians, 171 of 228 patients with GC (75.7%) and 178 of 226 controls (78.8%) were positive (OR = 0.84, 95% CI = 0.54 - 1.30). The median serum antibody titer was lower in cases than in controls in both ethnic groups. A high titer (H. pylori titer > or = 50) was associated with less likelihood of GC for both ethnic groups (for Japanese Brazilians, OR = 0.39, 95% CI = 0.16 - 0.92; for non-Japanese Brazilians, OR = 0.56, 95% CI = 0.31 - 1.02). The high titer can be regarded as a sign of the necessity of eradication, and low titer is regarded as a sign of the necessity of close screening for GC in both ethnic groups, because extended atrophy may cause spontaneous disappearance of H. pylori from the stomach.
Assuntos
Adenocarcinoma/etnologia , Anticorpos Antibacterianos/análise , Infecções por Helicobacter/etnologia , Helicobacter pylori/imunologia , Imunoglobulina G/sangue , Neoplasias Gástricas/etnologia , Adenocarcinoma/etiologia , Adenocarcinoma/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Estudos de Casos e Controles , Intervalos de Confiança , Feminino , Infecções por Helicobacter/complicações , Infecções por Helicobacter/imunologia , Humanos , Japão/etnologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , Estudos Soroepidemiológicos , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/imunologiaRESUMO
A low level of serum pepsinogen I (Pg I) is a risk factor for gastric cancer (GC); low levels of Pg I and the pepsinogen ratio (Pg I:Pg II) are correlated with chronic atrophic gastritis. We report serum Pg levels and compare the degree of association with GC among Japanese and non-Japanese Brazilians. Sera were cross-sectionally ascertained from 93 Japanese Brazilian patients category matched by age and sex with 110 controls, and 228 non-Japanese Brazilian patients individually matched by age and sex with one control. Among non-Japanese Brazilians, GC was associated with a Pg I level <30 ng/ml (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.7-3.8) and a Pg I:Pg II ratio < 3.0 (OR, 3.4; 95% CI, 2.2-5.3). However, among Japanese Brazilians, the association was present with a level of Pg I < 30 ng/ml (OR, 3.5; 95% CI, 1.9-6.3), and was weak with a Pg I:Pg II ratio < 3.0 (OR, 1.3; 95% CI, 0.73-2.4). Serum Pg I may be preferred to the Pg I:Pg II ratio to study the association between Pg and GC among Japanese Brazilians.
Assuntos
Povo Asiático/genética , Biomarcadores Tumorais/sangue , Etnicidade/genética , Proteínas de Neoplasias/sangue , Pepsinogênio A/sangue , Pepsinogênio C/sangue , Neoplasias Gástricas/enzimologia , Adulto , África/etnologia , Idoso , Idoso de 80 Anos ou mais , População Negra/genética , Brasil/epidemiologia , Europa (Continente)/etnologia , Feminino , Gastrite Atrófica/enzimologia , Humanos , Indígenas Sul-Americanos/genética , Japão/etnologia , Masculino , Pessoa de Meia-Idade , Lesões Pré-Cancerosas/enzimologia , Fatores de Risco , Neoplasias Gástricas/etnologia , População Branca/genéticaRESUMO
BACKGROUND: Helicobacter pylori infection and atrophic gastritis (AG) are markedly more prevalent in Japan than in other industrialized countries, however, the reasons for such a high prevalence are not fully understood. To add to information on H. pylori infection and its association with AG, the authors studied Japanese living in less developed countries. METHODS: Cross-sectional surveys were conducted of randomly selected Japanese residents aged 40-59 years in São Paulo, Brazil and Lima, Peru. Serum IgG antibody to H. pylori and pepsinogen I (PGI) and II (PGII) were measured as markers of AG. RESULTS: The prevalence of H. pylori infection was similar in both populations, 77% (95% CI: 70-83) in São Paulo and 75% (95% CI: 65-82) in Lima, and was within the range of five populations in Japan from our previous study. However, the prevalence of AG, defined by PGI < 70 ng/ml and PGI/PGII < 3.0 was more prevalent among Japanese in São Paulo (39% [95% CI: 32-47]), than Japanese in Lima (18% [95% CI: 12-27]). This difference was not explained by sex, age, generation or H. pylori infection. CONCLUSIONS: Helicobacter pylori infection among Japanese in less developed countries was similar to Japanese in Japan, although prevalence of AG varied. Factors other than H. pylori infection are important in the development of AG among Japanese.