High Proportion Of Diffuse Type Gastric Cancer In Young Female Population In Over 16 Years In A Tertiary Institution Of South Korea

Background/Aims The incidence of gastric cancer (GC) of Korea is very high in the world.However, the seroprevalence of Helicobacter pylori (HP) is decreasing up to 43.9% and the eradication rate of HP is increasing to 23.5% in 2016_2017.Thus there could be some difference of gastric cancer in terms of sex, age, HP and tissue type of GC.The aim of this study is to investigate trends of GC patients depending on tissue type over 16 years.Methods: 1227 patients with GC were prospectively enrolled at Seoul National University Bundang Hospital during 2003 to 2018.Age, sex, histologic type (Lauren classification), and Helicobacter pylori (HP) were compared among three periods (2003-2007, 2008-2012, and 2013-2018).HP infection status was evaluated by histology, CLOtest, culture, serology, and history of HP eradication.Patients with severe atrophy or intestinal metaplasia by histology or pepsinogen I/II ratio ≤ 2.0 were assumed to have previous HP infection.Results: Most of GC patients underwent endoscopic submucosa dissection (ESD) or surgery.Early gastric cancer (EGC) and advanced gastric cancer (AGC) were 769 (62.7%) and 458 (37.3%), respectively and intestinal and diffuse type were 714 (58.2%) and 485 (39.5%), respectively.The proportion of EGC increased from 54.0% (252/467), 63.5% (359/565) to 81.0% (158/ 195) in 2003-2007, 2008-2012, and 2013-2018, respectively, (p<0.001).HP-positive decreased from 93.4% (436/467), 88.5% (500/565) to 82.1% (160/195), respectively during these three periods (p<0.001).The decrease of HP infection was different depending on tissue type.That is, in the intestinal type it decreased from 93.9%, 88.6% to 81.0% in 2003-2007, 2008-2012, and 2013-2018, respectively (p<0.001).However, in case of diffuse type there was marginal difference; from 92.3%, 89.6% to 83.8% (p=0.053).Multivariate logistic analysis regarding diffuse type showed reverse relationship with age and it was more frequent under age 50 all the time (Figure).It significantly increased in female over time.Family history of GC (OR, 0.420) became lower and ever smoking was higher (OR, 4.032) at 2013-2018.However, there was no change in HP infection and alcohol. .Conclusion: Over 16 years, there are several change of trends of GC.The proportion of EGC increased but HP infection decreased.The diffuse type GC became more common in female but family history of GC in this tissue type decreased.