world cancer report - iarc
world cancer report - iarc
world cancer report - iarc
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CANCERS OF THE FEMALE REPRODUCTIVE TRACT<br />
SUMMARY<br />
> Cervical <strong>cancer</strong> is the second most common<br />
<strong>cancer</strong> of women <strong>world</strong>wide with<br />
more than 470,000 new cases per year.<br />
Of about 230,000 deaths every year,<br />
more than 80% occur in developing<br />
countries. Five-year survival rates are up<br />
to 70%.<br />
> Sexually transmitted infection with<br />
human papillomavirus is fundamental to<br />
development of carcinoma of the cervix.<br />
> Population-based screening has greatly<br />
reduced mortality in developed countries<br />
> Endometrial <strong>cancer</strong> mainly affects postmenopausal<br />
women in developed countries;<br />
188,000 new cases are diagnosed<br />
annually and obesity is a major risk factor.<br />
> About 190,000 cases of ovarian <strong>cancer</strong><br />
occur each year, predominantly among<br />
postmenopausal women in developed<br />
countries; five-year survival rates are<br />
about 40%.<br />
CERVICAL CANCER<br />
Definition<br />
The majority of epithelial tumours of the<br />
cervix are squamous cell carcinomas<br />
(85%). Adenocarcinomas are less common.<br />
Most cervical carcinomas arise at<br />
the junction between the columnar epithelium<br />
of the endocervix and the squamous<br />
epithelium of the ectocervix, a site of continuous<br />
metaplastic change, especially in<br />
utero, at puberty and during a first pregnancy.<br />
Epidemiology<br />
Cancer of the cervix is the second most<br />
common <strong>cancer</strong> among women <strong>world</strong>wide,<br />
second only to breast <strong>cancer</strong>; about<br />
< 9.3<br />
< 16.1<br />
Fig. 5.57 The global burden of cervical <strong>cancer</strong>. Note the high incidence rates in Central and South<br />
America, Southern Africa and India. Today, more than 80% of all cervical <strong>cancer</strong>s occur in developing<br />
countries.<br />
470,000 new cases are diagnosed each<br />
year. 80% of cases of cervical <strong>cancer</strong> occur<br />
in developing countries where, in many<br />
regions, it is the most common <strong>cancer</strong> of<br />
women. The highest incidence rates are in<br />
South America and the Caribbean, sub-<br />
Saharan Africa, and South and South-<br />
Eastern Asia (Fig. 5.57). However, very low<br />
rates are observed in China, and in<br />
Western Asia. In developed countries, the<br />
incidence rates are generally low, with agestandardized<br />
rates of less than 15 per<br />
100,000, with the exception of Eastern<br />
Europe, where incidence rates range from<br />
18-35 per 100,000. The incidence of <strong>cancer</strong><br />
of the cervix begins to rise at ages 20-<br />
29, and then increases rapidly to reach a<br />
peak at around ages 45-49 in European<br />
populations, but often rather later in developing<br />
countries.<br />
Incidence and mortality have declined<br />
markedly in the last 40 years in Western<br />
Europe, USA, Canada, Australia and New<br />
Zealand, mainly in relation to extensive<br />
screening programmes based on exfolia-<br />
< 23.8<br />
< 35.8<br />
Age-standardized incidence/100,000 population<br />
< 93.9<br />
tive cervical cytology, typically by means of<br />
the Pap smear (Screening for cervical <strong>cancer</strong>,<br />
p167). Nevertheless, in several countries,<br />
notably the UK, Australia, New<br />
Zealand, and in central Europe, there have<br />
been increases in risk in younger women,<br />
probably the result of changes in exposure<br />
to risk factors. These changes are most<br />
evident for adenocarcinomas, which share<br />
to some extent the etiological agents of<br />
squamous cell carcinomas, but for which<br />
cytological screening is ineffective in countering<br />
the increase in risk. In developing<br />
countries the situation is more mixed, with<br />
high rates persisting in some areas (Latin<br />
America, India, Africa), and declines elsewhere,<br />
most notably in China.<br />
Etiology<br />
Molecular epidemiological studies have<br />
shown that certain human papillomavirus<br />
types (HPV) are the central cause of cervical<br />
<strong>cancer</strong> and cervical intraepithelial neoplasia<br />
(CIN) [1, 2, 3]. It is now clear that<br />
the well-established risk factors associat-<br />
Cancers of the female reproductive tract<br />
215