world cancer report - iarc

SCREENING FOR STOMACH
CANCER IN JAPAN
There has been a long history of
screening for stomach cancer in Japan.
Screening by indirect X-ray examination
started in around 1960 and has
been part of the “Health and Medical
Service Law for the Aged” since 1983.
The Ministry of Health and Welfare in
Japan reported that in 1997 4,273,000
residents participated in screening programmes
provided by local governments
based on this law. Moreover, the
Japanese system of annual health
check-ups in the workplace has provided
an opportunity for screening; about
16.7% of an estimated 6,759,000
employees were screened for stomach
cancer in 1997. In addition, screening
for stomach cancer is also undertaken
during the so-called “Human Dry Dock”,
which incorporates multiple screening
procedures, including measurement of
blood pressure, urine analysis, blood
tests, chest X-ray examination and
stomach X-ray examination.
Consequently, at least 11,032,000 individuals
(8.7% of the Japanese population)
are estimated to have participated
in screening for stomach cancer in
1997.
The main technique used to screen for
stomach cancer in Japan is an indirect
X-ray examination by the double contrast
method, “double” referring to barium
and air. When barium is swallowed,
a small amount of air is also taken into
the stomach. The barium makes the
positive contrast and the air the negative
contrast; this allows the detailed
morphological patterns of the gastric
surface to be visualized. This is usually
conducted in a specially designed
mobile unit equipped with a photofluorographic
apparatus. This enables peo-
Study author
Kaibara
Ohizumi
Abe
Ueda
0 20 40 60 80
Early stage cancers (%)
Fig. 4.55 Percentage of tumours detected at an early stage in Japanese patients diagnosed with stomach
cancer, either during a screening programme or on the basis of presentation of symptoms.
ple to participate in screening near their
homes or workplaces. Seven X-ray photographs
are usually taken according to
the standard method of the Japanese
Society of Gastroenterology. Record linkage
between participants in the screening
and the lists of population-based
cancer registry indicated that the sensitivity
and the specificity of an indirect Xray
method by image intensifier were
88.5% and 92.0%, respectively
(Murakami R et al., Cancer 65: 1255-
1260, 1990).
Measurement of serum pepsinogen I and
II levels has recently been introduced in
Japan as a further method of screening
for stomach cancer (Miki K, Annual
report 1997 of the research committee
of studies on study of gastric cancer
screening system using serum pepsinogen
test, 1998). However, a welldesigned
epidemiological evaluation of
the efficacy of the pepsinogen method
has not yet been conducted.
Randomized controlled trials to evaluate
the effectiveness of screening for stom-
Diagnosed on basis of
symptoms
Diagnosed on the
basis of screening
ach cancer have not been undertaken in
Japan. There have however been many
other types of studies, such as casecontrol
studies, cohort studies, and
time trend analyses to evaluate the
effectiveness of screening for stomach
cancer (Hisamichi S et al., Evaluation of
mass screening programme for stomach
cancer in Japan, in UICC Cancer
Screening, eds. Miller AB et al.,
Cambridge University Press, 1991;
Inaba S et al., Evaluation of a screening
program on reduction of gastric cancer
mortality in Japan: Preliminary results
from a cohort study. Prev Med, 29: 102-
106, 1999). There is an absolute confidence
among most Japanese people
that screening provides benefit. This
confidence might be a product of the
success of screening programmes for
tuberculosis during the decades following
the Second World War.
Stomach cancer prevention and screening
177