Download
gastric cancer epidemiology n.
Skip this Video
Loading SlideShow in 5 Seconds..
Gastric Cancer Epidemiology PowerPoint Presentation
Download Presentation
Gastric Cancer Epidemiology

Gastric Cancer Epidemiology

278 Vues Download Presentation
Télécharger la présentation

Gastric Cancer Epidemiology

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Gastric Cancer Epidemiology • Suminori Kono, MD, PhDProfessor of Preventive MedicineKyushu Univ School of MedicineFukuoka 812-8582, Japanskono@phealth.med.kyushu-u.ac.jp

  2. Learning Objectives • Understand descriptive features • Learn protective and risk factors • Learn ways of interpreting epidemiological observation

  3. Reading Materials • Kono S, Hirohata T. Nutrition and stomach cancer. Cancer Causes Control 1996; 7: 41-55. • World Cancer Research. Food, nutrition and the prevention of cancer: a global perspective. Washington, DC: American Institute for Cancer Research, 1997.

  4. Descriptive Features of Gastric Cancer • 1) Second most common cancer • 2) Dramatic decline worldwide • 3) Wide variation in incidence • 4) Altered risk among migrants • 5) Male-to-female ratio: 1.5 to 2.0

  5. Histological Types • Intestinal type:more frequent in males and at older ages • Diffuse type:little difference between sexes and more frequent at younger ages • Intestinal type:environmental cancer (?)

  6. 5-year Relative Survival Rates • Japan (1987-89) 48 % US (1986-91) 19 % • Denmark (1983-85) 19 % • Source: Hanai A. Jpn J Cancer Clin 1998; 44: 49-59

  7. Screening for Gastric Cancer • Nationwide screening in Japan • Barium X-ray method • No randomized controlled trial • Benefit in case-control studies

  8. Smoking and Gastric Cancer • Japanese physician’s study • Cigarettes/dayRR (95% CI)* • Never/past 1.0 • 1-19 1.7 (1.1-2.6) • 20+ 1.8 (1.1- 3.0) • * Adjusted for age and alcohol use

  9. Alcohol Use and Gastric Cancer • Generally, no association between alcohol use and gastric cancer. • Exceptionally, increased risk in relation to a heavy use of red wine and vodka drinking

  10. Helicobacter pylori and Gastric Cancer: prospective studies • Study (year) PopulationRR (95% CI)*Parsonnet, et al. HMO subscribers 3.6 (1.8-7.3)(1991) in USA Nomura, et al. Japanese men 6.0 (2.1-17.3)(1991) in HawaiiForman, et al. British men 2.8 (1.0-8.0)(1991)

  11. Helicobacter pylori and Gastric Cancer: current interpretation • A definite cause of gastric cancer • African enigma • No sex difference in H. pylori

  12. Dietary Factors and Gastric Cancer • Protective Factor • Convincing: Vegetables and fruits, refrigerators • Probable: Vitamin C • Possible: Carotenoids, allium compounds, wholegrain cereals, green tea • Risk Factor • Convincing: None • Probable: Salt/salting • Possible: Starch, grilled meat and fish

  13. Vegetables and Fruits • Many case-control studies:decreased risk associated with high consumption • Few prospective studies: less consistent association • Antioxidant micronutrients: postulated constituents

  14. Vitamin SupplementsRandomized Controlled Trial • CountrySupplementsRelative risk • China beta-carotene 0.84 + vitamin E • Finland beta-carotene 1.25 vitamin E 1.25

  15. Salt and Salted Foods • Many case-control studies: increased risk with salt intake, use of table salt, or salty foods. • 1 of 2 prospective studies: increased risk with salted fish. • High salt intake promoted chemically-induced gastric carcinoma in rats. (Jpn J Cancer Res 1983; 74: 28-34)

  16. Green Tea and Gastric Cancer • AreaComparisonRR (95% CI) • Nagoya (Jpn) 4+ cups* vs. less 0.6 (n.s.)Saga (Jpn) 10+ cups vs. less 0.3 (0.1-0.7)Shanghai Use of strong tea 0.3 (0.1-0.7)Shanghai M 3+kg/yr vs 0 0.8 (0.6-1.3) F 1.2+kg/yr vs 0 0.8 (0.5-1.4)Shanghai 4+ batches vs 0 0.5 (0.3-0.9)Hawaii † 2+ cups vs. 0 1.5 (0.9-2.3) • * Per day. † Prospective study of Japanese men.

  17. Nitrate, Nitrite, and N-nitroso Compounds in Gastric Carcinogenesis