Seroprevalence of Helicobacter pylori Infection in a National Cohort of Veterans With Noncardia Gastric Adenocarcinoma

Inverse Association Between Gluteofemoral Obesity and Risk of Non-Cardia Gastric Intestinal Metaplasia

BACKGROUND & AIMS

It is unclear whether obesity confers increased risk of non-cardia gastric adenocarcinoma and its precursor, gastric intestinal metaplasia. Here, we examined whether various dimensions of adiposity independently predispose to the development of non-cardia gastric intestinal metaplasia.

METHODS

We compared data from 409 non-cardia gastric intestinal metaplasia cases and 1748 controls without any gastric intestinal metaplasia from a cross-sectional study at the VA Medical Center in Houston, Texas. Participants completed standardized questionnaires, underwent anthropometric measurements, and underwent a study endoscopy with gastric mapping biopsies. Non-cardia gastric intestinal metaplasia cases included participants with intestinal metaplasia on any non-cardia gastric biopsy. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) using logistic regression models.

RESULTS

Increasing body mass index (BMI) was not associated with risk of non-cardia gastric intestinal metaplasia (per unit BMI adjusted OR, 0.98; 95% CI, 0.96-1.00). Similarly, we found no associations with increase in waist circumference (per 10-cm increase adjusted OR, 0.94; 95% CI, 0.87-1.03) and waist-to-hip ratio (WHR) (per unit WHR adjusted OR, 2.34; 95% CI, 0.37-14.7). However, there was a significant inverse association with gastric intestinal metaplasia and increasing hip circumference, reflecting gluteofemoral obesity (per 10-cm increase adjusted OR, 0.89; 95% CI, 0.80-0.98). The inverse association was observed for both extensive and focal gastric intestinal metaplasia.

CONCLUSIONS

The independent dimensions of adiposity (BMI, waist circumference) are not associated with increased risk of non-cardia gastric intestinal metaplasia. The inverse association between gluteofemoral obesity and risk of gastric intestinal metaplasia warrants additional study.

Associations of Duration, Intensity, and Quantity of Smoking With Risk of Gastric Intestinal Metaplasia

GOAL

Determine whether various dimensions of smoking increase risk for gastric intestinal metaplasia.

BACKGROUND

Cigarette smoking has been implicated in the etiology of gastric cancer, but it is not clear if smoking is a risk factor for gastric intestinal metaplasia, a precursor lesion of gastric cancer.

MATERIALS AND METHODS

We compared data from 385 gastric intestinal metaplasia cases and 1577 controls without gastric intestinal metaplasia recruited into a cross-sectional study at the Michael E. DeBakey VA Medical Center in Houston, Texas. All participants completed standardized questionnaires and underwent a study endoscopy with gastric mapping biopsies. Gastric intestinal metaplasia cases included participants with intestinal metaplasia on any noncardia gastric biopsy. We calculated odds ratios and associated 95% confidence intervals using multivariable logistic regression models.

RESULTS

Compared with never smokers, current smokers had 2-fold increased risk for gastric intestinal metaplasia (odds ratio, 2.05; 95% confidence interval, 1.47-2.85). Among ever smokers, increasing duration and total dose were significantly associated with increased risk for gastric intestinal metaplasia (P-trend, 0.004 and 0.01, respectively). Among former smokers, risk for gastric intestinal metaplasia decreased over time and was no different to never smokers after 15 years smoking cessation. Cases with gastric intestinal metaplasia were more likely than controls to have Helicobacter pylori infection (53.2% vs. 21.7%); however, smoking effect on gastric intestinal metaplasia was not different by H. pylori infection status.

CONCLUSIONS

Cigarette smoking is a risk factor for gastric intestinal metaplasia. Risk of gastric intestinal metaplasia among former smokers remained significantly elevated until 15 years postcessation.

Follow-up analysis and histopathological study of gastric mucosa in patients with Helicobacter pylori infection

Objective

To investigate the histomorphological characteristics of the gastric mucosa and the prognosis in patients with Helicobacter pylori infection.

Methods

Progressive damage to the gastric mucosa was examined by immunohistochemistry in 2294 patients with H. pylori infection and follow-up information was analyzed.

Results

H. pylori initially colonized the mucus layer covered by the gastric mucosa epithelium, then selectively adhered to and destroyed the surface mucus cells causing intra-gastric and extra-gastric lesions. Gastric mucosal damage induced by H. pylori was divided into five stages according to the depth of H. pylori invasion and degree of lesion deterioration: mucilaginous, surface mucocellular, lamina propria lesion, mucosal atrophy, and intraepithelial neoplasia stages. Morphological follow-up analysis revealed no significant difference in 6-month curative effects between stage I and stage II, but significant differences were found between stages II and III, stages III and IV, and between stages IV and stage V, respectively.

Conclusions

This novel staging strategy may be a valuable tool for diagnosing and predicting the results of gastric mucosal damage induced by H. pylori infection.

Low Rates of Retesting for Eradication of Helicobacter pylori Infection After Treatment in the Veterans Health Administration

BACKGROUND & AIMS

Expert consensus mandates retesting for eradication of Helicobacter pylori infection after treatment, but it is not clear how many patients are actually retested. We evaluated factors associated with retesting for H pylori in a large, nationwide cohort.

METHODS

We performed a retrospective cohort study of patients with H pylori infection (detected by urea breath test, stool antigen, or pathology) who were prescribed an eradication regimen from January 1, 1994 through December 31, 2018 within the Veterans Health Administration (VHA). We collected data on demographic features, smoking history, socioeconomic status, facility poverty level and academic status, and provider specialties and professions. The primary outcome was retesting for eradication. Statistical analyses included mixed-effects logistic regression.

RESULTS

Of 27,185 patients prescribed an H pylori eradication regimen, 6486 patients (23.9%) were retested. Among 7623 patients for whom we could identify the provider who ordered the test, 2663 patients (34.9%) received the order from a gastroenterological provider. Female sex (odds ratio, 1.22; 95% CI, 1.08-1.38; P = .002) and history of smoking (odds ratio, 1.24; 95% CI, 1.15-1.33; P < .001) were patient factors associated with retesting. There was an interaction between method of initial diagnosis of H pylori infection and provider who ordered the initial test (P < .001). There was significant variation in rates of retesting among VHA facilities (P < .001).

CONCLUSIONS

In an analysis of data from a VHA cohort of patients with H pylori infection, we found low rates of retesting after eradication treatment. There is significant variation in rates of retesting among VHA facilities. H pylori testing is ordered by nongastroenterology specialists two-thirds of the time. Confirming eradication of H pylori is mandatory and widespread quality assurance protocols are needed.

The association of Helicobacter pylori with pancreatic cancer

Background & Aims

Infection with Helicobacter pylori (HP) affects 50% of the world. Previous studies have suggested an association between HP and pancreatic adenocarcinoma (PC). These association studies have been limited in their ability to identify the incidence and risk factors of PC among HP infected individuals and the impact of HP eradication on PC.

Methods

Retrospective cohort study within the Veterans Administration of 103,595 patients (median age 62.3; 92.0% male) with HP diagnosis based on pathology, stool antigen, urea breath test, or serum antibody between 1/1/1994-12/31/2018. Primary outcome was future PC diagnosis. A time to event with competing risk analysis was performed, evaluating patient demographics and history, method of HP diagnosis, and whether the patient received HP treatment. Secondary analysis of those treated evaluated whether confirmed eradication was associated with PC.

Results

The cumulative incidence of PC at 5 and 10 years was 0.37% and 0.54%, respectively. Patients who developed PC were older, male, reside in areas with higher poverty. Preceding diabetes and chronic pancreatitis were strongly associated with PC. Factors not associated with PC included receiving an eradication regimen, diagnosis of an active infection (versus prior exposure alone), and eradication of HP.

Conclusions

PC after HP is rare. Chronic pancreatitis is the main risk factor for PC. Active HP infection, treatment of HP infection, or eradication of HP are not associated with future PC. This study calls into question the association between PC and HP.

Risk Factors and Incidence of Gastric Cancer After Detection of Helicobacter pylori Infection: A Large Cohort Study

BACKGROUND & AIMS

Nearly all studies of gastric adenocarcinoma in the United States have relied on national cancer databases, which do not include data on Helicobacter pylori infection, the most well-known risk factor for gastric cancer. We collected data from a large cohort of patients in the United States to calculate the incidence of and risk factors for nonproximal gastric adenocarcinomas after detection of H pylori. Secondary aims included identifying how treatment and eradication affect cancer risk.

METHODS

We performed a retrospective cohort study, collecting data from the Veterans Health Administration on 371,813 patients (median age 62 years; 92.3% male) who received a diagnosis of H pylori infection from January 1, 1994, through December 31, 2018. The primary outcome was a diagnosis of distal gastric adenocarcinoma 30 days or more after detection of H pylori infection. We performed a time to event with competing risk analysis (with death before cancer as a competing risk).

RESULTS

The cumulative incidence of cancer at 5, 10, and 20 years after detection of H pylori infection was 0.37%, 0.5%, and 0.65%, respectively. Factors associated with cancer included older age at time of detection of H pylori infection (subhazard ratio [SHR], 1.13; 95% confidence interval [CI], 1.11-1.15; P < .001), black/African American race (SHR, 2.00; 95% CI, 1.80-2.22), Asian race (SHR, 2.52; 95% CI, 1.64-3.89) (P < .001 for race), Hispanic or Latino ethnicity (SHR, 1.59; 95% CI, 1.34-1.87; P < .001), and history of smoking (SHR, 1.38; 95% CI, 1.25-1.52; P < .001). Women had decreased risk of gastric adenocarcinoma compared with men (SHR, 0.52; 95% CI, 0.40-0.68; P < .001); patients whose H pylori infection was detected based on serum antibody positivity also had a reduced risk of cancer (SHR 0.74; 95% CI, 0.54-1.04; P = .04). Patients who received treatment for their H pylori infection still had an increased risk of gastric cancer (SHR, 1.16; 95% CI, 0.74-1.83; P = .51) but confirmed H pylori eradication after treatment reduced risk of gastric cancer (SHR, 0.24; 95% CI, 0.15-0.41; P < .001).

CONCLUSIONS

In a study of 371,813 veterans with a diagnosis of H pylori infection, we found significantly higher risks of gastric cancer in racial and ethnic minorities and smokers. Treatment of H pylori infection decreased risk only if eradication was successful. Studies are needed on the effects of screening high-risk persons and to identify quality measures for diagnosis, resistance patterns, and treatment efficacy.