Helicobacter pylori serology in a birth cohort of New Zealanders from age 11 to 26

Performing the ABC Method Twice for Gastric Cancer Risk Stratification: A Retrospective Study Based on Data from a Large-Scale Screening Facility

The ABC method is a classification method used for stratifying the risk of gastric cancer. However, whether the ABC method should be performed only once or multiple times throughout an individual’s lifetime remains unclear. Therefore, this study aimed to analyze whether performing ABC screening twice in a lifetime is useful. We retrospectively analyzed the data of individuals who participated in health checkups in 2010 and 2015. We collected data on patient characteristics, pepsinogen levels, anti-Helicobacter pylori antibody titers, and the presence of gastric cancer. Overall, 7129 participants without a history of H. pylori eradication were included in this study. The participants’ average age in 2010 was 48.4 ± 8.3 years, and 58.1% were male. In addition, 11 and 20 cases of new H. pylori infection (0.15%) and spontaneous eradication (0.28%), respectively, were recorded. No significant difference was found in the incidence of gastric cancer between participants who underwent the ABC method once and those who underwent it twice (Group A: 0.16% vs. 0.16%; Group B: 0.47% vs. 0.39%; and Group C + D: 1.97% vs. 1.82%). Therefore, performing the ABC method twice, 5 years apart, does not significantly improve gastric cancer risk stratification.

Previous Helicobacter pylori infection-induced atrophic gastritis: A distinct disease entity in an understudied population without a history of eradication

Individuals with chronic atrophic gastritis who are negative for active H. pylori infection with no history of eradication therapy have been identified in clinical practice. By excluding false-negative and autoimmune gastritis cases, it can be surmised that most of these patients have experienced unintentional eradication of H. pylori after antibiotic treatment for other infectious disease, unreported successful eradication, or H. pylori that spontaneously disappeared. These patients are considered to have previous H. pylori infection-induced atrophic gastritis. In this work, we define these cases based on the following criteria: absence of previous H. pylori eradication; atrophic changes on endoscopy or histologic confirmation of glandular atrophy; negative for a current H. pylori infection diagnosed in the absence of proton-pump inhibitors or antibiotics; and absence of localized corpus atrophy, positivity for autoantibodies, or characteristic histologic findings suggestive of autoimmune gastritis. The risk of developing gastric cancer depends on the atrophic grade. The reported rate of developing gastric cancer is 0.31%-0.62% per year for successfully eradicated severely atrophic cases (pathophysiologically equal to unintentionally eradicated cases and unreported eradicated cases), and 0.53%-0.87% per year for spontaneously resolved cases due to severe atrophy. Therefore, for previous H. pylori infection-induced atrophic gastritis cases, we recommend endoscopic surveillance every 3 years for high-risk patients, including those with endoscopically severe atrophy or intestinal metaplasia. Because of the difficulty involved in the endoscopic diagnosis of gastric cancer in cases of previous infection, appropriate monitoring of the high-risk subgroup of this understudied population is especially important.

Trends in Helicobacter pylori infection among Māori, Pacific, and European Birth cohorts in New Zealand

BACKGROUND

The aim of this paper is to estimate the seroprevalence of Helicobacter pylori infection in the New Zealand population by ethnicity and year of birth.

METHODS

A systematic search identified seven studies in New Zealand that reported prevalence of H. pylori infection among 4463 participants. Prevalence data were pooled to estimate the Māori, Pacific, and European seroprevalence of H. pylori in four birth cohorts (1926-40, 1941-55, 1956-70, and 1971-85), by assuming that infection is acquired in childhood and seroprevalence is stable with aging. The best estimates of national seroprevalence were obtained by geographic regional weighting and corrections for selection and measurement bias.

RESULTS

Infection rates among all ethnic groups declined in more recent birth cohorts. Prevalence was highest among Pacific peoples (ranging from 39-83%) followed by Māori (18-57%) and then European (7-35%). The absolute ethnic differences in seroprevalence decreased in subsequent cohorts, but the relative ethnic differences increased.

CONCLUSIONS

There is scope to much further reduce Māori and especially Pacific people's risk of H. pylori infection. Solutions to reduce H. pylori prevalence and its sequelae should focus on people at greatest risk of the infection. Further evaluation of strategies to address H. pylori infection is warranted. Interventions to be evaluated could include household crowding reduction and eradication therapy for asymptomatic infected persons to reduce their risk of noncardia stomach cancer.

Sex hormones, hormonal interventions, and gastric cancer risk: a meta-analysis

Estrogens may influence gastric cancer risk, but published studies are inconclusive. We therefore carried out a meta-analysis addressing the associations of gastric cancer in women with menstrual and reproductive factors and with use of estrogen- and antiestrogen-related therapies. Searches of PubMed up to June, 2011 and review of citations yielded a total of 28 independent studies, including at least one exposure of interest. Random effects pooled estimates of relative risk (RR) and corresponding 95% CIs were calculated for eight exposures reported in at least five studies, including: age at menarche, age at menopause, years of fertility, parity, age at first birth, oral contraceptive use, hormone replacement therapy (HRT), and tamoxifen treatment. Longer years of fertility (RR = 0.74, 95% CI: 0.63-0.86) and HRT (RR = 0.77; 95% CI: 0.64-0.92) were each associated with decreased gastric cancer risk. Conversely, tamoxifen treatment was associated with increased risk (RR = 1.82; 95% CI: 1.39-2.38). The other five exposures were not significantly associated. Our analysis supports the hypothesis that longer exposure to estrogen effects of either ovarian or exogenous origin may decrease risk of gastric cancer. Additional studies are warranted to extend this finding and to identify the underlying mechanisms.

Apparent incidence of Helicobacter pylori in adulthood: to what extent do new infections reflect misclassification?

BACKGROUND

Helicobacter pylori infection is a key risk factor for a variety of gastrointestinal diseases. About half of the world population is infected. Most infections are acquired early in childhood, but the occurrence of new infections among adults has also been suggested.

METHODS

We review epidemiological studies providing estimates of incidence of H. pylori infection among adults and evaluate to what extent incidence estimates might have been affected by measurement error of infection status.

RESULTS

Thirty-two studies could be included in the review. Annual incidence was lower than 1.0 % in 17 studies; no correlation between length of follow-up and cumulative incidence was observed. Apparent cumulative incidences of the magnitudes observed in most studies would be expected, because of less than perfect sensitivity and specificity of the diagnostic tests, even in the absence of any true new infections. CONCLUSION/IMPACT: Apparent incidence rates of H. pylori infection among adults in Western populations should be interpreted with utmost caution.

Epidemiology of Helicobacter pylori infection

Differences may occur in the mode of transmission of Helicobacter pylori between developed and developing countries: direct human-to-human contacts have been suggested as the primary route in the former while the fecal-oral route, also, through contaminated water, in the latter. Data on intrafamilial transmission of H. pylori among children continue to be produced. The importance of low socioeconomic conditions on the acquisition of H. pylori infection has been confirmed in a number of population-based studies. Due to the improvement of living standards, the prevalence of the infection has fallen dramatically in many countries. It varies from 8.9 to 72.8% among children from developed and developing countries, respectively, the re-infection rate being also significantly higher in the latter. Conflicting data have been reported on the effect of breastfeeding against H. pylori colonization in infancy as well as on the occupational risk for acquiring H. pylori. This review summarizes recent results from the literature on these topics.

HELICOBACTER PYLORI INFECTION AND TREATMENT OUTCOME IN AN URBAN AUSTRALIAN POPULATION

BACKGROUND

To examine the rate of Helicobacter pylori infection in a group of symptomatic patients using rapid urease test and antral histology and report on their treatment outcomes.

METHODS

From a single-surgeon series in a tertiary teaching hospital, 200 consecutive symptomatic patients undergoing their first diagnostic upper gastrointestinal endoscopy during 2003-2004 were included in this retrospective audit. Campylobacter-like organism (CLO) test results were compared with the results of conventional histological examination plus Giemsa staining. Eradication rates and demographic data were collected.

RESULTS

One hundred and seventy-nine of 200 (89.5%) patients had antral biopsies for histology and for CLOtest. The CLOtest was positive in 31% (56/179) of patients. Thirty-two of 56 (57%) patients had an early-positive CLOtest (<24 h). The remaining 43% (24/56) of patients had a late-positive CLOtest (>24 h). Histological examination of the antral biopsy showed evidence of H. pylori in 28/56 (50%) patients with a positive CLOtest. H. pylori eradication therapy was prescribed in 51/56 (91%) patients with a positive CLOtest. Forty-five of 51 (88%) of these patients had a subsequent urea breath test. Urea breath test was positive in 17/45 (29%) patients after H. pylori eradication therapy was prescribed.

CONCLUSION

Rate of H. pylori in this series of symptomatic patients was 31%. As nearly half of the CLOtests became positive after 24 h, we suggest that the CLOtest should be re-examined 24 h after gastroscopy. Standard antral histology and CLOtest were in agreement in only 50% of cases, suggesting that the CLOtest is a more sensitive test. The failure rate of 29% for initial H. pylori eradication therapy reinforces the need for follow up after treatment.