Invasive breast carcinoma - IARC

Epithelial tumours and related lesions
S.G. Silverberg G.L. Mutter
R.J. Kurman R.A. Kubik-Huch
F. Nogales F.A. Tavassoli
Endometrial carcinoma
Definition
A primary malignant epithelial tumour,
usually with glandular diff e re n t i a t i o n ,
arising in the endometrium that has the
potential to invade into the myometrium
and to spread to distant sites.
ICD-O codes
Endometrioid adenocarcinoma 8380/3
Variant with squamous
differentiation 8570/3
Villoglandular variant 8262/3
Secretory variant 8382/3
Ciliated cell variant 8383/3
Mucinous adenocarcinoma 8480/3
Serous adenocarcinoma 8441/3
Clear cell adenocarcinoma 8310/3
Mixed adenocarcinoma 8323/3
Squamous cell carcinoma 8070/3
Transitional cell carcinoma 8120/3
Small cell carcinoma 8041/3
Undifferentiated carcinoma 8020/3
Epidemology
Endometrial carcinoma is the most common
malignant tumour of the female genital
system in developed countries, where
e s t rogen-dependent neoplasms account
for 80-85% of cases and the non-estro g e n
dependent tumours make up the re m a i n-
ing 10-15% of cases. The estro g e n -
dependent tumours are low grade, i.e.
well or moderately diff e rentiated and predominantly
of endometrioid type. Patients
with this form of endometrial cancer frequently
are obese, diabetic, nulliparo u s ,
h y p e rtensive or have a late menopause.
Obesity is an independent risk factor
{388}, and in We s t e rn Europe, is associated
with up to 40% of endometrial cancer
{241a}. On the other hand, patients with a
large number of births, old age at first
b i rth, a long birth period and a short premenopausal
delivery - f ree period have a
reduced risk of postmenopausal endometrial
cancer, emphasizing the pro t e c t i v e
role of pro g e s t e rone in the horm o n a l
b a c k g round of this disease {1212}.
In contrast, the non-estrogen dependent
type occurs in older postmenopausal
women; the tumours are high grade and
consist predominantly of histological
subtypes such as serous or clear cell as
well as other carcinomas that have high
grade nuclear features. They lack an
association with exogenous or endogenous
hyperoestrinism or with endometrial
hyperplasia and have an aggressive
behaviour {497,2005,2646}.
Pathogenesis
Endometrial cancer is made up of a biologically
and histologically diverse group
of neoplasms that are characterized by a
d i ff e rent pathogenesis. Estro g e n -
dependent tumours (type I) are low
grade and frequently associated with
endometrial hyperplasias, in particular
atypical hyperplasia. Unopposed estrogenic
stimulation is the driving forc e
behind this group of tumours. It may be
the result of anovulatory cycles that
occur in young women with the polycystic
ovary syndrome or due to normally
occurring anovulatory cycles at the time
of menopause. The iatrogenic use of
unopposed estrogens as horm o n e
replacement therapy in older women
also is a predisposing factor for the
development of endometrial cancer. The
second type (type II) of endometrial cancer
appears less related to sustained
estrogen stimulation.
Clinical features
Signs and symptoms
Although endometrial carcinoma and
related lesions can be incidental findings
in specimens submitted to the pathologist
for other reasons (for example, endometrial
biopsy for infertility or hystere c t o m y
for uterine prolapse), in the great majority
of cases they present clinically with
a b n o rmal uterine bleeding. Since most of
these lesions are seen in postmenopausal
women, the most common presentation is
postmenopausal bleeding, but earlier in
life the usual clinical finding is menometrorrhagia
{1104}. The most common type
of endometrial carcinoma, endometrioid
a d e n o c a rcinoma, may be manifested by
such clinical findings as obesity, infert i l i t y
and late menopause, since it is often
related either to exogenous estro g e n
Fig. 4.01 Global incidence rates of cancer of the uterine corpus which occurs predominantly in countries
with advanced economies and a Western lifestyle. Age-standardized rates (ASR) per 100,000 population
and year. From Globocan 2000 {846}.
Epithelial tumours and related lesions 221