world cancer report - iarc

Fig. 5.63 The global incidence of endometrial cancer. Affluent populations are predominantly affected.
UTERINE CANCER
Definition
Tumours of the uterine corpus are predominantly
adenocarcinomas, arising from the
endometrium, or lining, of the uterus.
Epidemiology
Cancer of the uterus is the seventh most
common cancer of women with 189,000
Fig. 5.65 Five-year relative survival rates after
diagnosis of cancer of the uterus.
218 Human cancers by organ site
< 2.4 < 4.2 < 7.7 < 13.2 < 28.9
Age-standardized incidence/100,000 population
new cases and 45,000 deaths occurring
worldwide each year; about 60% of these
occur in more developed countries. The
highest incidence rates are in the USA and
Canada, while other regions with age-standardized
rates in excess of 10 per 100,000
include Europe, Australia and New Zealand,
the southern part of South America, and the
Pacific Island nations. Low rates occur in
Africa and Asia (Fig. 5.63).
Some countries, such as the USA and
Canada, are experiencing a clear decline in
incidence and mortality from cancer of the
uterus, particularly among young women. In
Europe, rates appear stable in the south and
to be decreasing in the north. Uterine cancer
occurs primarily in elderly women, the
median age of onset being around 60 years
old; only 5% of cases develop before age 40.
Etiology
Cancer of the endometrium is linked to
reproductive life with increased risk
among nulliparous women and women
undergoing late menopause (Reproductive
factors and hormones, p76). The
endometrium is normally a hormonally
responsive tissue, responding to estrogens
with growth and glandular proliferation and
to progesterones with maturation.
Exogenous estrogens, as in unopposed
estrogen therapy for menopause or prior
oophorectomy, increase the risk of cancer
whereas oral contraceptives containing an
estrogen-progesterone combination
decrease it. Syndromes of increased
endogenous estrogen exposure, such as
granulosa-theca cell tumours of ovary and
polycystic ovary, are also associated with
an increased risk. Other risk factors
include a history of colon or breast carcinoma.
Use of tamoxifen as a therapeutic or
chemopreventive agent is a risk factor
[15]. The disease is clearly associated with
obesity, diabetes and hypertension.
Detection
The most common sign is metrorragia
(uterine bleeding), especially after
menopause. Irregular or postmenopausal
bleeding is the presenting symptom in at
least 75% of patients. At the time of diagnosis,
75% of patients have disease confined
to the uterus although up to 20% of
patients have no symptoms [16, 7].
Other signs include those linked to a mass
in the lower abdomen, such as dysuria (difficult
urination), constipation or bloating.
Histological sampling of the endometrium
and cervix, either through biopsy or dilation
and curettage, should be undertaken
in the event of symptoms. Endovaginal
echography and hysteroscopy are useful
adjuncts in the diagnosis of endometrial
pathology.
Pathology and genetics
Endometrioid adenocarcinoma (Fig. 5.64)
is the most common histology (60-65%).
This tumour type is characterized by the
disappearance of stroma between abnor-
Fig. 5.64 A well-differentiated mucus-secreting
endometrial adenocarcinoma with a glandular
architecture.