# Project 3: Helicobacter pylori and Stomach Cancer Among Native American Populations

> **NIH NIH U54** · UNIVERSITY OF ARIZONA · 2020 · $169,868

## Abstract

PROJECT SUMMARY/ABSTRACT: PROJECT 3
HELICOBACTER PYLORI AND STOMACH CANCER AMONG NATIVE AMERICAN POPULATIONS
Helicobacter pylori (Hp) is a common gastric pathogen that is associated with the development of duodenal or
stomach ulcers, stomach cancer, and mucosa associated lymphoid-tissue (MALT) lymphomas. While the overall
incidence of gastric cancer has declined over time in the United States (US), there are clear racial and
socioeconomic health disparities in gastric cancer rates and associated outcomes. This translational, multi-
method project seeks to better understand the role of Hp infection in the development of stomach cancer
among Native Americans (NA) of Northern Arizona where stomach cancer incidence rates are approximately
three times as high compared to the general Arizona population and it is the leading cause of cancer-related
mortality. Despite this high burden, social, environmental, and pathogen-associated risk factors remain unknown
for this underserved population. While prevalence varies within populations, Hp prevalence within Navajo Nation
is likely high. Our pilot study of 72 households found 59% of 108 participants were Hp positive by urea breath
test (UBT) and 74% of households had at least one person positive. Furthermore, prior knowledge of Hp and its
link to stomach cancer is low in these communities. However, 53% of Hp+ cases did seek care at the local urban
Indian Health Service facility, indicating concern. Risk factors for Hp infection in this distinct population are
not clearly defined nor are barriers to receiving diagnosis and treatment, precluding appropriate primary
and secondary prevention strategies. Thus Aim 1 is a community-based study to identify factors associated
with infection and barriers to self-referral to clinic. Since Hp subtypes may contribute to progression from infection
to cancer and the prevalence of specific genotypes are unknown in this population, Aim 2 will focus on the
distribution of Hp subtypes in the Navajo community members referred to clinic for endoscopy. The relationship
between Hp infection and subsequent stomach cancer is related also to host immune response. Intestinal
metaplasia and Spasmolytic Polypeptide-expressing metaplasia (SPEM) are histologic changes that presage
gastric cancer development. SPEM is more intensively studied in mice than humans because it can be induced
experimentally after introducing Helicobacter. Epithelial expression of the sonic hedgehog (Shh) ligand and
mesenchymal activation of canonical Hedgehog signaling play essential roles in gastric homeostasis and
recruitment of inflammatory cells. Our earlier studies found a subset of immune cells recruited to the gastric
epithelium during infection become myeloid-derived suppressor cells (MDSCs), and this coincides with parietal
cell atrophy and SPEM. Schlafens (SLFN) are a family of molecules strongly induced by type 1 interferons that
correlate with immune cell quiescence. Using whole genome analysis of m...

## Key facts

- **NIH application ID:** 10021593
- **Project number:** 5U54CA143924-12
- **Recipient organization:** UNIVERSITY OF ARIZONA
- **Principal Investigator:** ROBIN B HARRIS
- **Activity code:** U54 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $169,868
- **Award type:** 5
- **Project period:** 2009-09-01 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10021593

## Citation

> US National Institutes of Health, RePORTER application 10021593, Project 3: Helicobacter pylori and Stomach Cancer Among Native American Populations (5U54CA143924-12). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10021593. Licensed CC0.

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