0981 Gastric Cancer Epidemiology
Document Sample


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 Japan
Denmark
60 US White
40
20
0
1955 1960 1965 1970 1975 1980 1985 1990
0 20 40 60 80 100 0 20 40
Ma le Fe ma le
1000
Male
Female
100
10
1
20
30
40
50
60
70
80
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) 48 %
US (1986-91) 19 %
Denmark (1983-85) 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. Japanese men 6.0 (2.1-17.3)
(1991) in Hawaii
Forman, et al. British men 2.8 (1.0-8.0)
(1991)
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 Relative risk
China beta-carotene 0.84
+ vitamin E
Finland beta-carotene 1.25
vitamin E 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 chemically-
induced gastric carcinoma in rats. (Jpn J
Cancer Res 1983; 74: 28-34)
Green Tea and Gastric Cancer
Area Comparison RR (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.
Nitrate, Nitrite, and N-nitroso
Compounds
in Gastric Carcinogenesis
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