Abstract PR15: Projecting individualized absolute risk of developing gastric cancer in Koreans

Background: Despite the rapid decline of the incidence and mortality over the past few decades, gastric cancer still remains to be the third leading cause of cancer death and the fifth most common cancer worldwide. Furthermore, the absolute number of gastric cancer cases is increasing globally due to the aging of the world population. With available methods to detect and treat precancerous and early stage lesions, development of a prediction model to estimate the probability of developing gastric cancer for various age intervals and risk profiles have important public health implications. Methods: Candidate predictors were selected combining expert opinion and literature search. Using a case-control study with 4,603 Korean subjects, a logistic regression model was used for estimating relative risks, separately for men and women. The discriminatory ability of the models was assessed by receiver operator characteristic area under the curve (AUC). Absolute risk parameters were then calculated combined with the relative risk estimates with baseline age-specific cancer hazard rates from Korean Cancer Registry data. The developed models were validated using an independent prospective cohort data, a Japanese population-based cohort study, which includes 40,173 subjects, by calculating the ratio of expected number (E) over observed number (O) and 95% confidence interval (CI). Results: The models for both men and women included low education, past medical history of diabetes mellitus, no regular use of nonsteroidal inflammatory drugs intake, smoking, no regular exercising, and consumption of high salted food, less fruit, less nonstarchy vegetables, and less nonfermented soy food. The AUC for the relative risk model was 0.73 (95% CI 0.71-0.75) for men and 0.76 (95% CI 0.74-0.79) for women. The overall E/O ratio was 1.05 (95% CI 0.98-1.12) in men, and 0.93 (95% CI 0.83-1.04) in women in the external validation population. Conclusions: To our knowledge this is the first study to estimate the absolute risk of gastric cancer in Korean population. The mathematical models developed in the present study will help predict the occurrence of gastric cancer for an individual considering combined risk factors which will help at a personalized level by enabling early detection and preventive efforts. A further development of a model incorporating biomarkers can provide strategies to select individuals at high risk, for screening for gastric cancer. This abstract is also being presented as PosterB11. Citation Format: Minkyo Song, Jae Jeong Yang, Hyuna Sung, Seong-Ho Kong, Hyuk-Joon Lee, Hyung-Ho Kim, Sang Gyun Kim, Han-Kwang Yang, Norie Sawada, Shoichiro Tsugane, Manami Inoue, Daehee Kang. Projecting individualized absolute risk of developing gastric cancer in Koreans. [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 PR15.