world cancer report - iarc

OESOPHAGEAL CANCER
SUMMARY
>Cancer of the oesophagus is the sixth
most common cancer worldwide (more
than 400,00 cases per year). Incidence
varies markedly, and is highest in
Western and South Central Asia.
> Squamous cell carcinoma is most common
in developing countries, and is typically
associated with tobacco smoking
and alcohol abuse. Other risk factors
include consumption of very hot beverages
and malnutrition.
> Adenocarcinoma occurs predominantly
in white men from developed countries,
the most important etiological factors
being obesity and chronic gastrooesophageal
reflux.
> Most cancers of the oesophagus are
detected at an advanced stage; five-year
survival rates are less than 15%.
Definition
The great majority of oesophageal cancers
(over 95%) are either squamous cell
carcinomas or adenocarcinomas. Tumours
of the cardia, which arise within the
gastro-oesophageal junction, are sometimes
classified in the same group as
adenocarcinomas of the oesophagus.
Epidemiology
Cancers of the oesophagus are the sixth
most frequent cancers worldwide. In
2000, the number of deaths due to
oesophageal cancer amounted to some
337,500 out of a total of 6.2 million cancer
deaths worldwide. About 412,000
cases of cancer of the oesophagus occur
each year, of which over 80% are in developing
countries. While squamous cell
carcinoma occurs at high frequency in
many developing countries, adenocarci-
< 1.9 < 3.2
Fig. 5.72 The global burden of oesophageal cancer in men. High incidence rates occur in Northern Iran, the
Central Asian republics, North-Central China, parts of South America and in Southern and Eastern Africa.
noma is essentially a tumour of more
developed, industrialized countries.
The differences between incidence of
oesophageal cancer in distinct geographical
areas are more extreme than
observed for any other cancer. Regions
of high incidence of squamous cell carcinoma
in Asia [1] stretch from the
Turkoman plain in northern Iran through
the central Asian republics to Henan
province in North-Central China, characterized
as the “oesophageal cancer belt”
(Fig. 5.72). Incidence rates are as high as
200 per 100,000 and in some areas
there is a female predominance. Other
high-incidence areas are found in parts
of South America and in Southern and
Eastern Africa. Even within these highrisk
areas, there are striking local variations
in risk. Studies of migrant populations
suggest that when they move to
areas of low-risk, they lose their high
rates, confirming the importance of local
environmental factors in causation.
In Europe and the USA, the age-standardized
annual mortality from squa-
< 5.9
< 10.0
Age-standardized incidence/100,000 population
< 38.7
mous cell carcinoma is up to five in
males and one in females per 100,000
population. However, in particular areas,
such as Normandy and Brittany in France
and in the north-east of Italy, the incidence
rates are much higher in males (up
to 30 per 100,000), while remaining relatively
low in females. The incidence of
adenocarcinoma is steadily increasing in
Europe and the USA at a rate of 5-10%
per year. This type of cancer now
accounts for more than 50% of all
oesophageal cancers in the USA and in
some European countries [2]. Trends in
incidence of all oesophageal cancers
vary greatly (Fig. 5.75).
Etiology
Consumption of tobacco and alcohol,
associated with low intake of fresh fruit,
vegetables and meat, is causally associated
with squamous cell carcinoma of the
oesophagus worldwide. However, the relative
contribution of these risk factors
varies from one geographic area to another.
In more developed countries, it is esti-
Oesophageal cancer
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