Risk factors associated with Barrett’s epithelial dysplasia

Helicobacter pylori infection in Xinjiang Uyghur Autonomous Region: Prevalence and analysis of related factors

BACKGROUND

14C urea breath test (14C UBT) and immunohistochemical staining (IHC) are widely used for detection Helicobacter pylori (H. pylori) infection with different sensitivity, and there is a difference in H. pylori infection rate in Uyghur and Han ethnic groups. Both need large cohort studies to evaluate the differences more accurately.

AIM

To analyze the difference between 14C UBT and IHC for H. pylori detection in Xinjiang Uyghur Autonomous Region and the difference between Uyghur and Han populations.

METHODS

There were 3944 cases of H. pylori infection detected by both IHC and 14C UBT at the same time (interval < 1 wk, with sampling site including gastric antrum, selected from 5747 patients). We compared the sensitivity of 14C UBT and IHC. We also compared 555 pairs of Han/Uyghur cases (completely matched for gender and age) for their H. pylori infection rates. The overall H. pylori infection rate of all 5747 cases and the correlation with other clinicopathological data were also further analyzed. SPSS V23.0 software was used for statistical analysis.

RESULTS

The sensitivity was 94.9% for 14C UBT and 65.1% for IHC, which was a significant difference (n = 3944, P < 0.001). However, among those cases negative for H. pylori by 14C UBT (detection value ≤ 100), 4.8% were positive by IHC. Combining both methods, the overall H. pylori infection rate was 48.6% (n = 5747), and differences in gender, age group, ethnicity and region of residence significantly affected the H. pylori positive rates. According to age group (Han/Uyghur), the positive rates were ≤ 30 years (62.2%/100.0%), 31-40 years (45.2%/85.7%), 41-50 years (47.2%/79.2%), 51-60 years (44.6%/76.1%), 61-70 years (40.9%/68.2%), 71-80 years (41.7%/54.1%) and ≥ 81 years (42.9%/NA). The H. pylori infection rates of Han/Uyghur paired cases were 41.4% and 73.3%, which was a significant difference (P < 0.001) (555 pairs). H. pylori positivity was significantly related to moderate-severe grade 2-3 chronic/active gastritis and intestinal metaplasia (all P < 0.05).

CONCLUSION

The sensitivity of 14C UBT was significantly higher, but combined application can still increase the accuracy. The prevention H. pylori should be emphasized for Uygur and young people.

Metabolic syndrome is associated with increased risk of Barrett esophagus: A meta-analysis

BACKGROUND

Barrett esophagus (BE) is considered precursor condition of esophageal adenocarcinoma. Its incidence and prevalence are increasing in general population. Studies reported that metabolic syndrome (MS) or diabetes mellitus (DM) is related to increased risk of BE. Current study was to assess and better understand the relationship between MS /DM and BE.

METHODS

Electronic search was conducted in the database Pubmed/Medline (-December, 2015), Embase (-December, 2015), Cochrane Library (-December, 2015), and Web of Knowledge (-December, 2015). Studies included were assessed with summary odds ratios (ORs) with 95% confidence intervals (CIs) and compared exposure group with control group. The heterogeneity was examined by the funnel plot and the Egger's test. Subgroup analyses and sensitive analyses were performed for the detection of possible heterogeneity and impact on stability of analysis results.

RESULTS

Twelve publications met the criteria and included 355,311 subjects were analyzed. The pooled results showed MS was closely associated with increased risk of BE (OR = 1.23; 95%CI 1.03-1.47; P = 0.024), and yet DM did not significantly increase the risk of BE (OR = 1.07; 95%CI 0.82-1.38; P = 0.627). Substantial heterogeneities were detected. No significant publication bias was detected by Egger's test (P = 0.23).

CONCLUSIONS

Based on the results of current meta-analysis, MS is associated with increased risk of BE. Further long-term follow-up prospective study needs to verify the current results, and definite pathophysiological mechanism needs to be further investigated and clearly elucidated.

Helicobacter pylori and Gastric Cancer: Timing and Impact of Preventive Measures

Helicobacter pylori (H. pylori) is a Gram negative spiraliform bacterium that is commonly found in the stomach. H. pylori infection is still one of the world's most frequent infections, present in the stomachs of approximately one-half of the world's people. H. pylori infection is etiologically linked to histologic chronic active gastritis, peptic ulcer disease, and primary B-cell gastric lymphoma (gastric MALT lymphoma) and represents the major risk factor for the development of sporadic non-cardia gastric cancer (GC) of both intestinal and diffuse type. Studies that have examined the impact of GC prevention through H. pylori eradication have shown mixed results, but recent data suggest that prevention is only efficacious in patients without intestinal metaplasia or dysplasia. This indicates that, like in Barrett's esophagus, we need better clinical risk markers to indicate which patients are at greatest risk of developing cancer to guide clinical strategies. Furthermore, recent epidemiological data have suggested a possible contribution of H. pylori in modifying the risk of developing other gastrointestinal malignancies (including esophageal, pancreatic, hepatocellular, and colorectal cancer), although mechanistically these associations remain unexplained. We review clinically relevant aspects of H. pylori infection in the context of GC development as well as studies that have examined the impact of eradication on GC development and, lastly, discuss these recent epidemiological studies connecting H. pylori infection to extragastric gastrointestinal malignancies.

Helicobacter pylori and Gastrointestinal Malignancies

Helicobacter pylori infection is the principal trigger of gastric carcinogenesis and gastric cancer (GC) and remains the third leading cause of cancer-related death in both sexes worldwide. In a big Japanese study, the risk of developing GC in patients with peptic ulcer disease who received H. pylori eradication therapy and annual endoscopic surveillance for a mean of 9.9 years was significantly lower after successful eradication therapy compared to the group with persistent infection (0.21%/year and 0.45%/year, respectively, p = .049). According to a recent meta-analysis, H. pylori eradication is insufficient in GC risk reduction in subjects with advanced precancerous conditions (i.e., intestinal metaplasia and dysplasia). A microsimulation model suggested screening smokers over the age of 50 in the U.S. for serum pepsinogens. This would allow to detect advanced gastric atrophy with endoscopic follow-up of subjects testing positive as a cost-effective strategy to reduce GC mortality. In a Taiwanese study, the anti-H. pylori IgG-based test-and-treat program had lower incremental cost-effectiveness ratios than that with (13)C-urea breath test in both sexes to prevent GC whereas expected years of life lost for GC were higher and the incremental cost-effectiveness ratios of test-and-treat programs were more cost-effective in young adults (30-69 years old) than in elders (>70 years old). With respect to gastrointestinal malignancies other than GC, a meta-analysis confirmed the inverse association between H. pylori infection and esophageal adenocarcinoma. In a Finnish study, H. pylori seropositivity was associated with an increased risk of biliary tract cancers (multivariate adjusted OR 2.63; 95% CI: 1.08-6.37), another meta-analysis showed a slightly increased rate of pancreatic cancer in patients with CagA-negative strains (OR: 1.30; 95% CI: 1.02-1.65), whereas current data suggest that the association between H. pylori and colorectal neoplasms may be population dependent.