Invasive breast carcinoma - IARC

Fig. 5.02 A marked decrease in the mortality of
uterine cancer (cervix and corpus) has been
achieved in many countries. Upper curves: age
group 35-64 years. Lower curves: all age groups
combined. From F. Levi et al. {1637}.
Fig. 5.03 Deregulation of the restriction point (R) by HPV16 E7. In quiescent cells, pRb is present in a
hypophosphorylated form and is associated with transcription factors, e.g. members of the E2F family,
inhibiting their transcriptional activity. When quiescent cells are exposed to mitogenic signals, G1 specific
cyclin D/CDK complexes are activated and phosphorylate pRb in mid-G1 phase, causing release of active
E2F and progression through the restriction point (R). E7 binding to pRb mimics its phosphorylation. Thus, E7
expressing cells can enter S phase in the absence of a mitogenic signal. From M. Tommasino {2938a}.
and E7. The viral oncoproteins are able
to form stable complexes with cellular
proteins and alter, or completely neutralize,
their normal functions.
The best understood interactions of E6
and E7 with cellular proteins are those
involving the tumor suppressor proteins
TP53 and pRb, respectively. Both interactions
lead to a rapid degradation of the
cellular proteins via the ubiquitin pathway.
The major role of TP53 is to safeguard
the integrity of the genome by
inducing cell cycle arrest or apoptosis,
while pRb plays a key role in controlling
the correct G1/S transition acting at the
restriction point (R) of the cell cycle.
Therefore, loss of TP53 and pRb functions
results in abrogation of apoptosis
and in unscheduled proliferation. Both
events greatly increase the probability of
H P V-infected cells evolving toward s
malignancy.
Clinical features
Signs and symptoms
Early invasive cancers can be asymptomatic.
As the tumour grows and
becomes exophytic, vaginal bleeding
and discharge are the two most common
symptoms. With lateral growth into the
parametrium, the ureters become
obstructed. If both ureters are obstructed,
the patient presents with anuria and
uraemia. Pelvic sidewall involvement can
cause sciatic pain and, less commonly,
lymphoedema of the lower extremities.
Anterior tumour growth in advanced
Table 5.01
Risk factors for cervical cancer: HPV infection vs. persistence and malignant transformation.
Risk factor HPV HPV persistence Reference
infection and transformation
Multiple sex partners + n.e. {320}
Partner’s multiple partners + n.e. {320}
Poor hygiene + n.e. {193}
Absence of male circumcision + + {423}
Immunodeficiency, HIV + + {920}
High parity n.e. + {1944}
Oral contraceptives n.e. + {1911}
Smoking n.e. + {2826}
STDs other than HPV n.e. + {108,2734}
Poor nutritional status n.e. + {2324}
STDs = Sexually transmitted diseases (especially C. trachomatis).
n.e. = No evidence for being a risk factor at this time.
Epithelial tumours 263