world cancer report - iarc

Fig. 5.120 Age-specific incidence and mortality of pancreatic cancer in men and women in North
America. The small differences between incidence and mortality reflect the very poor prognosis of this
disease. Men are somewhat more frequently affected than women.
ease. These include unexplained weight
loss, nausea, diarrhoea, weakness, jaundice
(caused by compression of the intrapancreatic
common bile duct) and upper
abdominal and back pain. Mature onset
diabetes in the absence of a family history
may also indicate the possibility of pancreatic
cancer. Insulin antagonism by
tumour-produced factors (islet amyloid
peptide, glucagon and somatostatin) is
believed to be the cause [4]. Whilst 85% of
patients have systemic disease or locally
unresectable tumours on clinical evaluation,
some 25% have symptoms compatible
with upper abdominal disease up to six
months prior to diagnosis and 15% of
patients seek medical attention more than
six months prior to diagnosis [5].
Ultrasonography is the initial diagnostic
imaging system currently employed,
although visualization of the body and tail
of the pancreas is often unsatisfactory due
to the presence of intestinal gas. Computed
tomography (CT) scanning allows
clearer imaging of the tail and body and
can detect lesions of >1 cm with accuracy,
as well as secondary signs of pancreatic
cancer, such as dilation of common bile
and main pancreatic ducts, invasion of surrounding
structures, liver secondaries,
lymphadenopathy and ascites (Fig. 5.122).
Cytological or histological confirmation is
obtained from samples taken during endoscopic
retrograde cholangiopancreatography,
or by fine needle aspiration and core
biopsy under radiological guidance. However,
it is often difficult to obtain histological
proof for small lesions, which have the
best potential for curative surgery.
Patients who are candidates for surgery
undergo ultrasound and laparoscopy,
which identify those with small peritoneal
and liver nodules below the resolution of
current imaging.
Pathology and genetics
The first stage of neoplasia (Fig. 5.124),
flat hyperplasia, entails the columnarization
of the ductal epithelium. It is estimated
that as many as half the normal elderly
population may exhibit flat hyperplasia [6].
This may advance to papillary hyperplasia,
the presence of a crowded mucosa with a
folded structure, which may possess varying
degrees of cellular and nuclear abnormalities.
True carcinoma is characterized
by invasion of the ductal wall and a
desmoplastic response, i.e. acollagenous,
inflammatory reaction, such that the
tumour may comprise less than 25% cancer
cells. The major histological types
include benign microcystic serous adeno-
Fig. 5.121 Cigarette smoking is one of the main
risk factors for pancreatic cancer.
L
G
K
S
Fig. 5.122 A CT image of a mucinous cystic neoplasm
in the pancreas. The thick wall shows focal
calcification. T = tumour, K = kidney, L = liver, S =
spinal cord, G = gallbladder.
T
Fig. 5.123 Surgical specimen of a pancreatic ductal
adenocarcinoma (T) in the head of the pancreas.
SI = small intestine.
ma, tumours of uncertain biological
behaviour, including mucinous cystic
tumour and solid cystic tumour, as well as
malignant forms, such as adenocarcinoma,
microcystic serous adenocarcinoma
and mucinous cystadenocarcinoma.
T
K
SI
Pancreatic cancer
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