Epidemiology
Carcinoma of the oesophagus is a common, aggressive tumour. Several
histological types are seen, almost all of which are epithelial in
origin. The vast majority of these tumours will be either squamous
cell carcinoma (SCC) or adenocarcinoma (AC).
Over a period of two decades the incidence of SCC has remained
relatively stable or declined (particularly associated with smoking
and alcohol), whilst there has been a rapid rise in the amount of AC
seen, particularly in Caucasian males. This has now overtaken SCC as
the most common form of oesophageal tumour in some developed
countries.
The majority of cases (80-85%) are diagnosed in less developed
countries; most of these are SCC.
Incidence
Carcinoma of the oesophagus is the 8th most common cancer in the
world. Annual incidence of 18.0 per 100,000 in men and 8.5 per
100,000 in women. The male:female ratio for the adenocarcinoma
subgroup is 52:10.
An average of 42% of cases were diagnosed in people aged 75 years and
over, with more than eight out of ten (83%) occurring in those aged
60 and over.
The incidence of oesophageal carcinoma varies considerably with
geographical location, with high rates in China and Iran, where it
has been directly linked to the preservation of food using
nitrosamines. AC is seen more frequently in Caucasian populations,
whereas SCC is more frequent in people of African descent.
Hazardous aspects
The use of tobacco and alcohol are strong risk factors for both SCC
and AC and have a synergistic effect in this respect for SCC and
additive effect for AC. Cigarette smoking is associated with a
10-fold increase in risk for SCC and a 2- to 3-fold increase in risk
for AC.
The relative increase in risk caused by smoking remains high for AC,
even after 30 years of giving up smoking, but reduces within 10 years
for SCC.
Barrett’s oesophagus, which is a precursor of AC.
Chronic inflammation and stasis from any cause increase the risk of
oesophageal SCC – eg, strictures due to caustic injury or
achalasia.
Tylosis and Paterson-Brown-Kelly syndrome are also associated with an
increased risk for SCC. Obesity has been linked with increased risk
for AC but reduced risk for SCC. Obesity increases the risk of
gastro-oesophageal reflux disease (GORD), in turn increasing the risk
of Barrett’s oesophagus.
The relationship between obesity and the rise in AC has, however,
been questioned. A review of the Connecticut Tumor Registry data
between 1940-2007 showed that the increase in AC seen in the 1960s
predated the rise in obesity by a decade. The authors of the review
propounded that this may have been linked to a decrease in the
incidence of Helicobacter pylori infection or environmental factors.
One Japanese study showed a link between oesophageal cancer and
tooth loss.
A family history of hiatal hernia is a risk factor for oesophageal
adenocarcinoma, and some people appear to have a genetic
predisposition to developing types of gastro-oesophageal cancers.
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More Information: Oesophageal
Cancer
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