world cancer report - iarc

HEAD AND NECK CANCER
SUMMARY
> The most common cancer of the head
and neck, namely oral cancer, ranks
eleventh worldwide (390,000 new cases
per year), while cancers of the pharynx
(65,000 cases) and larynx (160,000
cases) are less common.
> Head and neck cancers mainly afflict
men, with sex ratios exceeding 10:1, and
are typically caused by smoking, together
with alcohol abuse. In some regions
(e.g. India) oral cancer is mainly due to
tobacco chewing. Multiple primary carcinomas
are not uncommon.
> Early-stage tumours can be surgically
resected, but many patients are diagnosed
with advanced disease and prognosis
is poor. Oral cancer patients have
a five-year survival rate of less than 50%.
>Nasopharyngeal cancer is largely
restricted to Southern Chinese populations
and strongly associated with
Epstein-Barr virus infection.
Definition
Head and neck cancers as described here
will be restricted to squamous cell carcinomas
of the upper aerodigestive tract (which
extends from the surface of the lips to the
neck region of the oesophagus) and include
the oral cavity, larynx and pharynx (comprising
the oropharynx, hypopharynx and
nasopharynx). Other tumours which occur in
this area, such as those of the brain and thyroid
and melanoma, are conventionally dealt
with separately (Tumours of the nervous system,
p265; Thyroid cancer, p257; Melanoma,
p253).
Epidemiology
Cancers of the oral mucosa and oro- and
hypopharynx can be considered together, as
there are similarities in their epidemiology,
treatment and prognosis. The geographic
232 Human cancers by organ site
< 2.9
< 4.6
Fig. 5.88 The global incidence of oral cancer in men. Oral cancer is common in India, Australia, Hungary,
France, Brazil and Southern Africa.
patterns and trends in incidence for these
cancers vary depending upon the anatomical
sub-sites concerned, a phenomenon that is
often explicable by the influence of risk factors,
such as tobacco use and alcohol consumption.
A high incidence of these cancers
is observed in the Indian subcontinent,
Australia, France, South America (Brazil) and
Southern Africa (Fig. 5.88). Oral cancer is the
11th most common cancer in the world in
terms of number of cases, while cancer of
the pharynx (apart from nasopharynx) ranks
as 20th. Worldwide, about 389,000 new
cases occurred in 2000, two-thirds of which
were in developing countries, and these cancers
are responsible for some 200,000
deaths each year.
The male:female ratio of occurrence varies
from 2-15:1 depending on the anatomical
sub-site, with extreme ratios characteristic of
tongue, floor of mouth and pharyngeal cancers.
The highest incidence among males is
reported in Bas-Rhin and Calvados in France,
whereas among females the highest occurrence
is observed in India. Cancers of the
mouth and anterior two-thirds of the tongue
< 6.2
< 9.7
Age-standardized incidence/100,000 population
< 45.8
generally predominate in developing countries,
whereas pharyngeal cancers are common
in developed countries and in Central
and Eastern Europe. In most countries,
oral/pharyngeal cancer incidence and mortality
rates have either been stable or increasing
in the last four decades. Sharp increases
in incidence have been reported in Germany,
Denmark, Scotland, Central and Eastern
Europe, and there are increases in Japan,
Australia and New Zealand, and in the USA
among non-whites.
New cases of cancer of the larynx occurring
worldwide number about 160,000, i.e. about
2% of the total world cancer cases, making
laryngeal cancer the 18thmost common cancer.
The disease is markedly more frequent in
males than in females (male:female ratio of
12:1 and 6:1 in developing and developed
countries respectively). There is a large geographic
variability in disease frequency, highrisk
countries being in Southern Europe
(France, Italy, Spain), Eastern Europe (Russia,
Ukraine), South America (Uruguay,
Argentina), and Western Asia (Turkey, Iraq)
(Fig. 5.89). Mortality from laryngeal cancer is