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0981 Gastric Cancer Epidemiology

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0981 Gastric Cancer Epidemiology Powered By Docstoc
					    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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