world cancer report - iarc

CANCERS OF THE FEMALE REPRODUCTIVE TRACT
SUMMARY
> Cervical cancer is the second most common
cancer of women worldwide with
more than 470,000 new cases per year.
Of about 230,000 deaths every year,
more than 80% occur in developing
countries. Five-year survival rates are up
to 70%.
> Sexually transmitted infection with
human papillomavirus is fundamental to
development of carcinoma of the cervix.
> Population-based screening has greatly
reduced mortality in developed countries
> Endometrial cancer mainly affects postmenopausal
women in developed countries;
188,000 new cases are diagnosed
annually and obesity is a major risk factor.
> About 190,000 cases of ovarian cancer
occur each year, predominantly among
postmenopausal women in developed
countries; five-year survival rates are
about 40%.
CERVICAL CANCER
Definition
The majority of epithelial tumours of the
cervix are squamous cell carcinomas
(85%). Adenocarcinomas are less common.
Most cervical carcinomas arise at
the junction between the columnar epithelium
of the endocervix and the squamous
epithelium of the ectocervix, a site of continuous
metaplastic change, especially in
utero, at puberty and during a first pregnancy.
Epidemiology
Cancer of the cervix is the second most
common cancer among women worldwide,
second only to breast cancer; about
< 9.3
< 16.1
Fig. 5.57 The global burden of cervical cancer. Note the high incidence rates in Central and South
America, Southern Africa and India. Today, more than 80% of all cervical cancers occur in developing
countries.
470,000 new cases are diagnosed each
year. 80% of cases of cervical cancer occur
in developing countries where, in many
regions, it is the most common cancer of
women. The highest incidence rates are in
South America and the Caribbean, sub-
Saharan Africa, and South and South-
Eastern Asia (Fig. 5.57). However, very low
rates are observed in China, and in
Western Asia. In developed countries, the
incidence rates are generally low, with agestandardized
rates of less than 15 per
100,000, with the exception of Eastern
Europe, where incidence rates range from
18-35 per 100,000. The incidence of cancer
of the cervix begins to rise at ages 20-
29, and then increases rapidly to reach a
peak at around ages 45-49 in European
populations, but often rather later in developing
countries.
Incidence and mortality have declined
markedly in the last 40 years in Western
Europe, USA, Canada, Australia and New
Zealand, mainly in relation to extensive
screening programmes based on exfolia-
< 23.8
< 35.8
Age-standardized incidence/100,000 population
< 93.9
tive cervical cytology, typically by means of
the Pap smear (Screening for cervical cancer,
p167). Nevertheless, in several countries,
notably the UK, Australia, New
Zealand, and in central Europe, there have
been increases in risk in younger women,
probably the result of changes in exposure
to risk factors. These changes are most
evident for adenocarcinomas, which share
to some extent the etiological agents of
squamous cell carcinomas, but for which
cytological screening is ineffective in countering
the increase in risk. In developing
countries the situation is more mixed, with
high rates persisting in some areas (Latin
America, India, Africa), and declines elsewhere,
most notably in China.
Etiology
Molecular epidemiological studies have
shown that certain human papillomavirus
types (HPV) are the central cause of cervical
cancer and cervical intraepithelial neoplasia
(CIN) [1, 2, 3]. It is now clear that
the well-established risk factors associat-
Cancers of the female reproductive tract
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