Gastric Cancer Epidemiology
Suminori Kono, MD, PhD Professor of Preventive Medicine Kyushu Univ School of Medicine Fukuoka 812-8582, Japan
skono@phealth.med.kyushu-u.ac.jp
Learning Objectives
Understand descriptive features Learn protective and risk factors Learn ways of interpreting epidemiological observation
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.
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
80 60 40 20 0
Japan Denmark US White
1955 1960 1965 1970 1975 1980 1985 1990
0
20
40
60
80
100
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20
40
Ma le
Fe ma le
1000 Male Female 100
10
1
20
30
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50
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70
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Age
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 (?)
5-year Relative Survival Rates
Japan (1987-89) US (1986-91) Denmark (1983-85) 48 % 19 % 19 %
Source: Hanai A. Jpn J Cancer Clin 1998; 44: 49-59
Screening for Gastric Cancer
Nationwide screening in Japan Barium X-ray method No randomized controlled trial Benefit in case-control studies
Smoking and Gastric Cancer Japanese physician’s study Cigarettes/day RR (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
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
Helicobacter pylori and Gastric Cancer: prospective studies
Study (year) Population RR (95% CI)*
Parsonnet, et al. HMO subscribers 3.6 (1.8-7.3) (1991) in USA Nomura, et al. (1991)
Forman, et al. (1991)
Japanese men in Hawaii
British men
6.0 (2.1-17.3)
2.8 (1.0-8.0)
Helicobacter pylori and Gastric Cancer: current interpretation A definite cause of gastric cancer African enigma No sex difference in H. pylori
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
Vegetables and Fruits Many case-control studies: decreased risk associated with high consumption Few prospective studies: less consistent association Antioxidant micronutrients: postulated constituents
Vitamin Supplements Randomized Controlled Trial
Country Supplements China beta-carotene + vitamin E Finland beta-carotene vitamin E Relative risk 0.84
1.25 1.25
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 chemicallyinduced gastric carcinoma in rats. (Jpn J Cancer Res 1983; 74: 28-34)
Green Tea and Gastric Cancer
Area Nagoya (Jpn) Saga (Jpn)
Shanghai Shanghai M F Shanghai Hawaii †
Comparison 4+ cups* vs. less 10+ cups vs. less
Use of strong tea 3+kg/yr vs 0 1.2+kg/yr vs 0 4+ batches vs 0 2+ cups vs. 0
† Prospective
RR (95% CI) 0.6 (n.s.) 0.3 (0.1-0.7)
0.3 (0.1-0.7) 0.8 (0.6-1.3) 0.8 (0.5-1.4) 0.5 (0.3-0.9) 1.5 (0.9-2.3)
* Per day.
study of Japanese men.
Nitrate, Nitrite, and N-nitroso Compounds in Gastric Carcinogenesis