Transcript Slajd 1 - Med Files

Gastric Cancer
Gastric Cancer
Worldwide, gastric adenocarcinoma is the second most common cause of
cancer death (second to lung cancer).
Approximately 95% of all malignant gastric neoplasms are
adenocarcinomas.
The remaining tumors are lymphomas, carcinoids, or sarcomas.
Gastric adenocarcinomas are divided into 2 types:
1. An intestinal type, with well-formed glandular structures: This is more likely to involve
the distal stomach and to occur in patients with atrophic gastritis. This type has a strong
environmental association.
2. A diffuse type, with poorly cohesive cells that tend to infiltrate the gastric wall: Tumors
of this type may involve any part of the stomach, especially the cardia, and they have a
worse prognosis. Unlike type 1 gastric cancers, type 2 cancers have a similar frequency in
all geographic areas.
Gastric Cancer
Frequency:
In the US:
The incidence has decreased from 33
cases per 100,000 population in 1930 to
3.7 cases per 100,000 population in 1990.
Internationally:
• Worldwide, gastric adenocarcinoma is
the second most common cause of
cancer death (second to lung cancer).
• The highest incidence (>30 cases per
100,000 population) is in Russia, China,
South America, and Eastern Europe.
• The incidence of gastric cancer is
extremely high in Japan, Chile, and
Iceland.
• The lowest incidence (<3.7 cases per
100,000 population) is in Africa
Age-standardized Incidence Rates for Stomach Cancer.
From: Global Cancer Statistics, 2002 -- Parkin et al_ 55 (2) 74 -- CA A Cancer Journal for Clinicians
Gastric Cancer
Clinical Presentation:
Most patients present with advanced
disease because they are often
asymptomatic in the earlier stages.
Common presenting features are epigastric
pain, bloating, early satiety, nausea, vomiting,
dysphagia, anorexia, weight loss, and upper GI
bleeding (hematemesis, melena, iron
deficiency anemia, positive results with fecal
occult blood tests).
Gastric carcinoma is twice as common in men than in women.
Gastric carcinoma has a peak incidence in patients aged 50-70 years.
However, approximately 5% of patients with gastric cancer are younger
than 35 years and 1% are younger than 30 years.
Younger patients have more aggressive lesions with a worse prognosis.
Gastric Cancer
Preferred Examination:
1. Begin the evaluation with history taking and physical examination.
2. Perform blood tests, including a full blood count determination and liver function tests.
3. Inspect the stool, and test for occult blood.
4. Perform either fiberoptic endoscopy or a double-contrast study (barium
and gas) of the upper GI tract.
• Endoscopy has become the diagnostic procedure of
choice for patients with suspected gastric carcinoma. Biopsy
samples obtained during endoscopy enable histologic
diagnosis. However, endoscopy is more invasive and more
costly than a double-contrast study.
• Double-contrast examinations of the upper GI tract
remain a useful alternative to endoscopy and have
similar sensitivity in the detection of gastric cancer.
5. CT, MRI, and endoscopic ultrasonography (EUS) are used in staging but not
usually in the primary detection of gastric cancers
Gastric Cancer
Radiologic features
Early gastric cancer
- lesion confined to the mucosa or submucosa
In Western counties, early gastric cancers
account for only 5-20% of all gastric cancers.
In Japan, they represent 25-46% owing to the
population-screening program that was
implemented to combat the high incidence of
the disease.
Double-contrast upper GI examination is widely recognized as the radiologic
technique of choice for diagnosing early gastric cancers. These lesions are
confined to the mucosa or submucosa and are classified into 3 types.
Gastric Cancer
Radiologic features
Early gastric cancer
Type I lesions are elevated
and protrude more than 5
mm into the lumen.
From: http://www.kgan.minami.fukuoka.jp
Gastric Cancer
Radiologic features
Early gastric cancer
Type II tumors are superficial
lesions that are elevated (IIa),
flat (IIb), or depressed (IIc).
From: http://www.kgan.minami.fukuoka.jp
Gastric Cancer
Radiologic features
Early gastric cancer
Type III early gastric cancers
are shallow, irregular ulcers
surrounded by nodular,
clubbed mucosal folds.
Type 0/III (III+IIc)
Excavated and
superficial
depressed type
From: http://www.kgan.minami.fukuoka.jp
Gastric Cancer
Radiologic features
Advanced carcinoma
• On barium studies, gastric carcinomas may be polypoidal, ulcerative, or
infiltrating lesions.
Morphologic types of gastric cancer
Polypoidal
Ulcerative
Diffuse
Gastric Cancer
Advanced carcinoma
- polypoidal lesion
Polypoid carcinomas are lobulated
masses that protrude into the lumen.
They may contain 1 or more areas of
ulceration.
Extensive carcinoma involving
the cardia and fundus.
Gastric Cancer
Advanced carcinoma
- polypoidal lesion
Carcinoma of the cardia
with involvement of the distal
esophagus
Gastric Cancer
Advanced carcinoma
- ulcerative lesion
With ulcerated carcinomas, an
irregular crater is located in a rind of
malignant tissue.
Seen in profile, these lesions are
intraluminal, whereas benign ulcers
project beyond the contour of the
stomach.
Gastric Cancer
Advanced carcinoma infiltrating carcinoma
Infiltrating carcinomas
result in irregular
narrowing of the stomach
Gastric Cancer
Scirrhous carcinoma
• typically causes irregular narrowing of the stomach
Gastric Cancer
Scirrhous carcinoma
- narrowing of the pylorus
Gastric Cancer
Endoscopy is less reliable in the diagnosis of scirrhous tumors (35-70%) then
in the diagnosis of other types of carcinoma (95%).
„In conclusion, UGI series is definitely superior to endoscopic examination in
correct tumor localization and diagnosis of scirrhous gastric carcinoma.”
Double-contrast barium image obtained with
the patient in the supine position shows
thickened and irregular folds with relatively mild
loss of distensibility in the body.
Photograph obtained during endoscopy
reveals circumferentially infiltrating lesion with
erythematous mucosal change in the body of
the stomach. The biopsy specimen was
negative for malignancy.
From: Radiology 2004;231:421-426. Scirrhous Gastric Carcinoma: Endoscopy versus Upper Gastrointestinal Radiography, Mi-Suk Park, et al.
Gastric Cancer
Scirrhous carcinoma
Scirrhous carcinomas typically cause irregular narrowing and rigidity of the stomach,
giving rise to the typical linitis plastica, or leather-bottle appearance
Linitis plastica may be suggested by satiety, a never-changing shape of
the stomach on barium x-ray.
Gastric Cancer
Scirrhous carcinoma
Linitis Plastica:
- diffuse infiltration
- decreased peristalsis
- endoscopic biopsy
may be negative
There is a marked narrowing
of almost the complete
stomach.
This is due to diffuse
infiltration of the gastric
wall by a scirrhous
adenocarcinoma.
Gastric Cancer
Scirrhous carcinoma
Gastric carcinomas are occasionally seen on plain abdominal radiographs as
abnormalities in the gastric contour or as soft-tissue masses indenting the gastric
contour.
Gastric Cancer
CAT SCAN
CT is primarily used to preoperatively assess patients with gastric
carcinoma. The main role of CT is to identify patients who would not
benefit from radical surgery.
CT is used to stage the tumor and also to monitor the response to
treatment.
CT scans may show the following:
• Polypoidal mass with or without ulceration
• Focal wall thickening with mucosal irregularity or ulceration
• Wall thickening with the absence of normal mucosal folds
(infiltrative lesions)
• Focal infiltration of the gastric wall
• Variable thickening of the wall and marked contrast enhancement
(typical of scirrhous lesions)
• Mucinous carcinomas, which have low attenuation due to their high
mucin content and which may contain calcification
Gastric Cancer
CAT SCAN
T staging
• The depth of tumor invasion is not accurately assessed with CT.
• Invasion of the perigastric fat is seen as soft tissue stranding.
• Direct extension of the tumor is relatively common.
N staging
• CT depicts 75% of nodes larger than 5 mm in diameter
• In the new TNM classification, nodal staging is related to the number of
regional nodes involved in the perigastric group and around the celiac axis.
• Enlarged nodes elsewhere (eg, in the retroperitoneum and mesentery) are
classified as distant metastases.
• N1 indicates 1-4 nodes; N2: 7-15 nodes; and N3 more than 15 nodes.
Gastric Cancer
CAT SCAN
T3 gastric cancer:
Consecutive axial helical CT
scans show no significant change
in attenuation of pancreas and
relatively distinct fat plane
between pancreas and gastric
lesion.
From: AJR 2000; 174:1551-1557 Comparing MR Imaging and CT in the Staging of Gastric Carcinoma, Kyung-Myung Sohn et al.
Gastric Cancer
CAT SCAN
T4 gastric cancer
Tumor extension to the
distal esophagus and the
crural diaphragm
Gastric Cancer
CAT SCAN
T4 gastric cancer:
Axial helical CT image
shows pancreatic
invasion by gastric
tumor (CTT4)
(arrows).
Note poor
demarcation of lesion
from adjacent bowel.
P = head of pancreas.
From: AJR 2000; 174:1551-1557 Comparing MR Imaging and CT in the Staging of Gastric Carcinoma, Kyung-Myung Sohn et al.
Gastric Cancer
CAT SCAN
M staging
• Because the portal vein drains the stomach, the liver is the most common
site for hematogenous metastases. Less common sites are the lungs,
adrenal glands, and kidneys.
• Intraperitoneal and omental metastases are common in advanced gastric
cancer.
• Gastric carcinoma is the most common primary tumor to metastasize to the
ovaries. The ovarian metastases are usually bilateral and known as
Krukenberg tumors.
Gastric Cancer
MRI
Recent studies in which a breath-hold fast imaging technique and
water were as a luminal contrast agent have shown accuracy rates
comparable to those of helical biphasic CT.
MRI is limited by respiratory and peristaltic artifacts, the lack of suitable
oral contrast media, and is higher cost compared with CT.
Gastric Cancer
MRI
A
T4 gastric cancer.
Axial unenhanced (A) T1-weighted MR
images and helical CT scan (B) show
concentric tumor in gastric antrum.
Small tumor infiltration in gallbladder
wall (arrowheads, A) is well seen on A
but not on B.
B
From: AJR 2000; 174:1551-1557 Comparing MR Imaging and CT in the Staging of Gastric Carcinoma, Kyung-Myung Sohn et al.
Gastric Cancer
ULTRASOUND
• The primary role of transabdominal ultrasonography is to detect liver
metastases.
• CT and EUS are complementary.
• CT is used first to stage the gastric carcinoma. If CT shows no
metastases and no invasion of local organs, EUS is used to refine the
local stage.
• The depth of tumor invasion is not accurately assessed with CT, and the
investigation of choice for this indication is endoscopic EUS.
Gastric Cancer
ULTRASOUND
An irregular heterogenous polypoid tumor can be
seen extending into the submucosa. The underlying
hypoechoic layer corresponding to the muscularis
propria remains intact.
The hypoechoic layer corresponding to the
muscularis propria has been breached by an irregular
hypoechoic tumor (arrow) with complete disruption of
the gastric wall layer structure.
Gastric Cancer
Algorithm for the work-up
of a patient with symptoms
suspicious for gastric
cancer.
(CT = computed
tomography
EUS = endoscopic
ultrasonography)
From: Am Fam Physician. 2004 Mar 1;69(5):1133-40. Gastric cancer: diagnosis and treatment options. Layke JC, Lopez PP.