[Reevaluation of benefit and risk of mass screening for stomach cancer--comparison between X-ray diagnosis and endoscopy as the screening test].
Mass screening for stomach cancer has been widely performed throughout Japan, since stomach cancer is the most important disease among various malignant diseases in Japan. As a screening test, the X-ray diagnosis with barium contrast medium is used and the risk of X-ray exposure must be considered in order to compare with the benefit of the mass screening. We have reported in the previous article in 1977 that the benefit and risk of stomach cancer mass screening become equal at age of 40 y.o. Since then, various conditions with the mass screening of stomach cancer have changed so that reevaluation of the benefit and risk relationship is necessary. Especially the risk coefficient of radiation-induced stomach cancer has been revised drastically in the report of United Nations Scientific Committee on the effects of radiation in 1988. So, in this report, the benefit of mass screening of stomach cancer is defined as the net elongation of average life expectancy due to the life saved, and the risk of the screening is defined as the net shortage of average life expectancy due to the radiation-induced stomach cancer and leukemia. Since the benefit increases rapidly with age and the risk decreases with age, a certain age at which the benefit and risk become identical should be found and under this age the mass screening is not justified to be performed. Assuming X-ray dose equivalent to stomach of 10 mSv and risk coefficient of stomach cancer of 12.6 X 10(-3) Sv-1 from the United Nations report, the critical age is found to be about 35 y.o. for men and women.(ABSTRACT TRUNCATED AT 250 WORDS)
Iinuma
T
T
Division of Clinical Research, National Institute of Radiological Sciences.
Tateno
Y
Y
D000293:Adolescent; D000328:Adult; D000368:Aged; D005069:Evaluation Studies as Topic; D005260:Female; D005773:Gastroscopy; D006801:Humans; D007564:Japan; D008017:Life Expectancy; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011859:Radiography; D012306:Risk; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000517:prevention & control*