1. Predicting the development of gastric cancer from combining Helicobacter pylori antibodies and serum pepsinogen status : prospective endoscopic cohort study H Watabe, T Mitsushima, Y Yamaji, M Okamoto, R Wada, T Kokubo, H Doi, H Yoshida, T Kawabe, M Omata Gut 2005;54:764–768

2. Background Pathogenic role of Helicobacter pylori for gastric cancer Pathogenic role of Helicobacter pylori for gastric cancer in a large number of epidemiological studies and basic researches in a large number of epidemiological studies and basic researches In earlier epidemiological studies In earlier epidemiological studies using H pylori antibody as a marker of infection using H pylori antibody as a marker of infection various risk ratios of H pylori infection for gastric cancer (0~≥10) various risk ratios of H pylori infection for gastric cancer (0~≥10) Recently, a follow up study by Uemura et al Recently, a follow up study by Uemura et al gastric cancer developed only in patients infected with H pylori gastric cancer developed only in patients infected with H pylori subjects with severe gastric atrophy, corpus predominant gastritis, or intestinal metaplasia were at increased risk for gastric cancer subjects with severe gastric atrophy, corpus predominant gastritis, or intestinal metaplasia were at increased risk for gastric cancer In our previous cross sectional study In our previous cross sectional study gastric atrophy status was essential for cancer development gastric atrophy status was essential for cancer development gastric atrophy was estimated by serum pepsinogen level gastric atrophy was estimated by serum pepsinogen level

3. Background Pepsinogen I and II Pepsinogen I and II two main precursors of pepsin two main precursors of pepsin produced by chief cells and mucous neck cells of the stomach produced by chief cells and mucous neck cells of the stomach Pepsinogen II Pepsinogen II also produced by pyloric gland cells also produced by pyloric gland cells Chief cells are replaced by pyloric glands Chief cells are replaced by pyloric glands decrease in pepsinogen I as gastric atrophy develops decrease in pepsinogen I as gastric atrophy develops decrease in pepsinogen II is minimal decrease in pepsinogen II is minimal Therefore, both low serum pepsinogen I and a low pepsinogen I/II ratio Therefore, both low serum pepsinogen I and a low pepsinogen I/II ratio recognized as serological markers of gastric atrophy recognized as serological markers of gastric atrophy

4. Background Combination of serum pepsinogen and H pylori antibody Combination of serum pepsinogen and H pylori antibody useful marker for the prevalence of gastric cancer in a cross sectional setting useful marker for the prevalence of gastric cancer in a cross sectional setting much simpler and less invasive than those using endoscopy much simpler and less invasive than those using endoscopy therefore suitable for a large general population therefore suitable for a large general population We aimed to evaluate We aimed to evaluate natural history of gastric cancer development according to H pylori infection and gastric atrophy status natural history of gastric cancer development according to H pylori infection and gastric atrophy status

5. Method 1995.3 ~ 1997.2 1995.3 ~ 1997.2 Health examination programmes Health examination programmes by Kameda General Hospital and Makuhari Clinic by Kameda General Hospital and Makuhari Clinic Excluding Excluding gastric cancer, peptic ulcer, past history of surgical resection of the stomach gastric cancer, peptic ulcer, past history of surgical resection of the stomach Candidates Candidates 9293 participants 9293 participants None had undergone None had undergone PPI or H2 blockers within last one month PPI or H2 blockers within last one month eradication therapy for H pylori eradication therapy for H pylori Endoscopic examination annually Endoscopic examination annually to check for the gastric cancer to check for the gastric cancer During the observation period During the observation period 6983 revisited the programme for follow up endoscopy 6983 revisited the programme for follow up endoscopy

6. Method Serum H pylori antibody Serum H pylori antibody commercial ELISA kit (GAP-IgG kit; Biomerica Inc., California, USA) commercial ELISA kit (GAP-IgG kit; Biomerica Inc., California, USA) seropositivity for H pylori antibody seropositivity for H pylori antibody defined by optical density values according to the manufacturer’s protocol defined by optical density values according to the manufacturer’s protocol in Japan in Japan sensitivity of 95% and specificity of 83% for H pylori infection sensitivity of 95% and specificity of 83% for H pylori infection Serum pepsinogen level Serum pepsinogen level commercial RIA kit (pepsinogen I/II RIA bead kit; Dainabot Co., Tokyo, Japan) commercial RIA kit (pepsinogen I/II RIA bead kit; Dainabot Co., Tokyo, Japan) serum pepsinogen status serum pepsinogen status atrophic - serum pepsinogen I level ≤70 ng/ml and a pepsinogen I/II ratio (serum pepsinogen I (ng/ml)/serum pepsinogen II (ng/ml)) ≤3.0 atrophic - serum pepsinogen I level ≤70 ng/ml and a pepsinogen I/II ratio (serum pepsinogen I (ng/ml)/serum pepsinogen II (ng/ml)) ≤3.0 normal - all other cases normal - all other cases in Japan in Japan sensitivity of 70.5% and specificity of 97.0% for atrophic gastritis sensitivity of 70.5% and specificity of 97.0% for atrophic gastritis

7. Method Classification by anti-H pylori antibody and serum pepsinogen status Classification by anti-H pylori antibody and serum pepsinogen status Group A - ‘‘normal’’ pepsinogen and were negative for H pylori antibody Group A - ‘‘normal’’ pepsinogen and were negative for H pylori antibody Group B - ‘‘normal’’ pepsinogen and were positive for H pylori antibody Group B - ‘‘normal’’ pepsinogen and were positive for H pylori antibody Group C - ‘‘atrophic’’ pepsinogen and were positive for H pylori antibody Group C - ‘‘atrophic’’ pepsinogen and were positive for H pylori antibody Group D - ‘‘atrophic’’ pepsinogen and were negative for H pylori antibody Group D - ‘‘atrophic’’ pepsinogen and were negative for H pylori antibody Endoscopic and clinicopathological examinations Endoscopic and clinicopathological examinations electronic panendoscopes (type XQ200 or P230; Olympus, Tokyo, Japan) electronic panendoscopes (type XQ200 or P230; Olympus, Tokyo, Japan) experienced endoscopists performed each examination experienced endoscopists performed each examination without knowledge of the serological data of the study subjects without knowledge of the serological data of the study subjects histopathological assessment of gastric cancer histopathological assessment of gastric cancer using surgically resected or endoscopically biopsied samples using surgically resected or endoscopically biopsied samples categorised as intestinal-type or diffuse-type, according to Lauren’s classification categorised as intestinal-type or diffuse-type, according to Lauren’s classification classified as cardiac or non-cardiac in terms of location classified as cardiac or non-cardiac in terms of location

8. Result

9. Gastric cancer development Gastric cancer development 43 (37 men, 6 women) during the follow up period 43 (37 men, 6 women) during the follow up period Annual incidence rate Annual incidence rate calculated by the person-year method calculated by the person-year method 0.13% (95% CI; 0.10%–0.18%) 0.13% (95% CI; 0.10%–0.18%) Histopathological feature Histopathological feature 34 - intestinal, 9 - diffuse 34 - intestinal, 9 - diffuse 2 - Gastric cardia 2 - Gastric cardia All of the cancers All of the cancers were localized within the submucosa were localized within the submucosa except for one invading the muscularis propria (group B) except for one invading the muscularis propria (group B) Management Management endoscopic resection – 23 cases endoscopic resection – 23 cases surgical operation - 20 cases surgical operation - 20 cases All were alive in August 2004 All were alive in August 2004

10. Kaplan-Meier analysis of the proportion of gastric cancer development Kaplan-Meier analysis of the proportion of gastric cancer development

11. ∮ no association between the groups and histopathological differentiation of cancer ∮ 34 9 2 41

14. Conclusion We prospectively observed the natural course of gastric cancer development in the Japanese general population We prospectively observed the natural course of gastric cancer development in the Japanese general population Combination of serum pepsinogen and anti-H pylori antibody provides a good predictive marker for the development of gastric cancer Combination of serum pepsinogen and anti-H pylori antibody provides a good predictive marker for the development of gastric cancer