Abstract A01: Gastric cancer pre-screener project: Development of a comprehensive gastric cancer risk questionnaire
Authors: In Haejin , Langdon-Embry Marisa , Wylie-Rosett Judith , Rapkin Bruce 
Published: May 2019

Background: Gastric adenocarcinoma is the fifth most common cancer and third leading cause of cancer mortality in the world. In the US, outcomes for gastric cancer are dismal with only 28% surviving to 5 years. Upper gastrointestinal endoscopy is the gold standard for early detection of gastric tumors and used in countries with high prevalence for mass screening. However, due to the low prevalence of gastric cancer in the general U.S. population, a national screening program is not cost effective. Tools to identify patients at higher risk of gastric cancer may help identify subpopulations that should be referred for opportunistic screening.

Purpose: To characterize the questionnaire development of a comprehensive gastric cancer risk assessment survey instrument that will be used to collect primary data in a large-scale case-control study. This primary data will be used to create a predictive model and determine items that best discriminate between gastric cases and controls, to ultimately create a simple pre-screening instrument that can be used in pre-diagnostic settings to identify at-risk patients who should be referred for upper GI endoscopy.

Procedures: Phase 1) comprehensive literature review to identify established risk factors for gastric cancer. Survey instruments that established individual risks for gastric cancer were brought together to create the initial questionnaire. Phase 2) questionnaire refinement through focus groups and cognitive interviews. Focus groups were used to examine the measure for wording, layout, clarity and relevance. The item pool was then translated into Mandarin Chinese, Spanish and Korean, and cognitive interviews were conducted to ensure the questionnaire carried semantic equivalence across languages. Interview notes were aggregated on a question-by-question basis to produce a cognitive interviewing outcome report to guide questionnaire revisions.

Results: A 300-item questionnaire was adapted from 16 survey instruments previously validated for gastric cancer. Identified risk factors for gastric cancer included dietary habits, demographics, racial disparities, Helicobacter pylori exposure, smoking and alcohol habits, socioeconomic status and pre-existing conditions. Only risk factors that were not hereditary and could be determined in questionnaire format were included.

29 English-speaking participants with and without gastric completed survey questions and provided feedback in focus group discussions. Participants noted items that needed clarification or simplification, or were redundant or irrelevant. Special attention was given to complex measures such as dietary history and acculturation to ensure that questions about details of ethnicity and timing of immigration were sensitive, appropriate and non-threatening.

60 gastric cancer cases and controls participated in cognitive interviews to ensure the questionnaire carried semantic equivalence across languages. Participants included 40 first-generation immigrants from Asia, Central/South America, Europe and Africa (approximately 10 in each group) and 20 US-born English speakers. Revisions included language/ethnic-specific wording to increase semantic equivalence across translations, examples to improve comprehension, and changes to instructions to improve consistent use of response options. The questionnaire underwent a total of 24 iterations during the focus group and cognitive interview processes and resulted in a 227-item questionnaire.

Conclusion: A valid, comprehensible, relevant and ethnically appropriate survey instrument that comprehensively assesses all validated risk factors for gastric cancer has been developed, and will be used for primary data collection in a future case-control study aimed at ultimately creating a simple pre-screening instrument that can be used for the opportunistic screening for gastric cancer.

Citation Format: Haejin In, Marisa Langdon-Embry, Judith Wylie-Rosett, Bruce Rapkin. Gastric cancer pre-screener project: Development of a comprehensive gastric cancer risk questionnaire. [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(5 Suppl):Abstract nr A01.