This protocol is a single-institution feasibility study to identify the molecular and epidemiological risk factors in the development of gastric cancer in high-risk predominantly Hispanic South Texas population. The study is broken down into two main parts: 1) To identify molecular differences in gastric adenocarcinoma (GAC) between Non-Hispanics and Hispanics, stratified by age, and in benign, pre-malignant, and malignant gastric lesions; and 2) To identify environmental and clinicopathological factors in Hispanics associated with specific molecular changes linked to the development of GAC.
The first part of the study will be accomplished by performing molecular testing on formalin-fixed paraffin-embedded (FFPE) tissues on retrospectively identified patients with GAC. Germline testing will be done on both retrospectively and prospectively identified cohort of patients with diagnosis of GAC. The second part of the study will be accomplished via survey administration on retrospectively and prospectively identified patients with diagnosis of GAC and to test Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV) infection status, which are known risk factors for the development of GAC, on their FFPE gastric specimen. The data from part 1 and part 2 will be analyzed and correlated. The overall goal of the study is to identify molecular markers and environmental risk factors in GAC unique to Hispanics relative to Non-Hispanics in South Texas, and to define molecular alterations in pre-malignant gastric lesions associated with the development of GAC. The long-term goal is to improve racial disparities by defining prognostic and therapeutic molecular markers and environmental risk factors in Hispanics and ultimately for all patients with GAC. Identification of high-risk molecular markers and environmental factors in the development of GAC will help future deployment of improved prevention and surveillance modalities.
Study Type
OBSERVATIONAL
Enrollment
150
Molecular testing on formalin fixed paraffin-embedded (FFPE) tissues on retrospectively identified patients with gastric adenocarcinoma.
Germline testing will be done on prospectively identified patients and in retrospectively identified patients who are still alive.
Survey will be administered on prospectively identified patients and in retrospectively identified patients who are still alive. Survey will be administered in person or via telephone. The survey in the language of the participants choice (English or Spanish) on sociodemographic information, current and/or prior PPI (proton pump inhibitor), H2 blocker, antibiotic, tobacco, alcohol, and recreational drug use. Questionnaire will include other risk factors for gastric adenocarcinoma such as certain dietary constituents (high salt diet, high consumption of processed meat, etc.) and occupational exposures.
Mays Cancer Center, UT Health San Antonio
San Antonio, Texas, United States
RECRUITINGTo identify molecular differences in GAC between Non-Hispanics and Hispanics
DNA from archived FFPE gastric cancer tissue from patients with diagnosis of GAC will be analyzed for the top 25 mutated genes identified in The Cancer Genome Atlas. The results will be compared and analyzed between Hispanics and non-Hispanics. In addition, germline testing using a 156 gene panel using saliva will be performs on patients with GAC and compared between Hispanics and non-Hispanics. Difference in somatic and germline mutations will be analyzed in patients with GAC between Hispanics and non-Hispanics.
Time frame: 5 years
To identify molecular differences in GAC between benign, pre-malignant, and malignant gastric lesions
Archived FFPE slides will be separated into malignant, normal, and pre-malignant sections after histopathology review. These include normal or pre-malignant adjacent tissue from GAC specimen or from prior gastric biopsy specimen. FFPE samples will be stratified into 4 main groups: 1) normal/superficial gastritis (SG); 2) atrophic gastritis (AG)/intestinal metaplasia (IM); 3) dysplasia; and 4) gastric adenocarcinoma (GCA). Top genes among the 25 analyzed in Outcome 1 will be studied on 50 benign and 100 pre-malignant samples and compared to the results from GAC samples from Outcome 1.
Time frame: 5 years
To identify environmental and clinicopathological factors in Hispanics associated with specific molecular changes
A comprehensive survey will be administered to patients with diagnosis of GAC retrospectively (to those who are still alive) and prospectively to query their anthropomorphic data, medical co-morbidities, sociodemographic information, dietary constituents, and exposures to known risk factors in the development of GAC. FFPE with gastric cancer tissue will be tested for EBV and H. pylori retrospectively and prospectively to test for prior exposure to these infections that are known risk factors for GAC.
Time frame: 5 years
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