Gastric adenocarcinoma is the most common type of stomach cancer, comprising over 90% of cases. Risk factors include H. pylori infection, smoking, low fruit/vegetable diet, and family history. It is classified based on growth pattern (exophytic, flat, excavated), depth of invasion (early vs. advanced), and histology (intestinal vs. diffuse). Early detection through screening endoscopy and surgical resection offer the best chance of cure, with 5-year survival rates over 90% for early cancer but below 20% for advanced cases. Prevention focuses on modifiable lifestyle risk factors and mass endoscopic screening programs.

1. Gastric carcinoma
Lecture 9

2. GASTRIC ADENOCARCINOMA
Adenocarcinoma is the
most common
90% -95%
• Lymphomas 4%
• Carcinoid
3%
• Stromal tumors 2%
malignancy of the stomach, comprising over
of all gastric cancers.

3. Epidemiology &
Classification
•
GC is the
second
leading cause of cancer-related deaths in the world after lung cancer.
• In Japan, Chile, Costa Rica, and Eastern Europe the
incidence is up to
20-fold
Africa, and Southeast Asia.
higher than in North America, northern Europe,

4. In the United States, gastric cancer rates
over 85%
dropped by
during the twentieth century. Similar declines have
been reported in many other Western countries, suggesting that
environmental and dietary
factors are responsible.
One possible explanation is
decreased consumption of dietary carcinogens.
Intake of green, leafy vegetables and citrus fruits.
the

5. more common in
lower socioeconomic groups and in individuals with
multifocal mucosal atrophy and intestinal metaplasia.
Gastric cancer is

6. • Although overall incidence of gastric
adenocarcinoma is falling,
•cancer of the
gastric cardia
is on the rise.

7. Classification:
GC show two morphologic types, called
intestinal & diffuse.
I.The intestinal type
• arise from gastric mucous cells that have undergone intestinal metaplasia in the setting of chronic
gastritis.
• better differentiated
•
the
more common type in high risk populations.

8. •
occurs primarily after age
years
2: 1 male predominance.
The incidence of intestinal –type carcinoma has
progressively diminished in the US.
• with a
•
50

9. II.The diffuse variant
arise de novo from native gastric mucous cells, is
not associated with chronic gastritis,
poorly differentiated.
occurs at an earlier age
with female predominance.
The incidence of diffuse GA has not changed significantly in the past 60
years and now constitutes approximately half of gastric carcinomas in the
US.

10. • The intestinal and diffuse forms of gastric carcinomas can be considered as
distinct entities, although their clinical outcome is
similar.

11. The incidence of
diffuse gastric cancer
across countries
,
there are
is relatively
uniform
no identified precursor lesions,
and
similar frequencies in males and
females.
the disease occurs at

12. Risk Factors
• Gender -- men have more than double the risk of
getting stomach cancer than women.
• Race -- being African-American or Asian may
increase your risk.
• Genetics -- genetic abnormalities and some
inherited cancer syndromes may increase your risk
• Geography -- stomach cancer is more common in
Japan, the former Soviet Union, and parts of Central
America and South America.
• Blood type -- individuals with blood group A may be
at increased risk.

13. • Advanced age -- stomach cancer occurs more often
around ages 70 and 74 in men and women,
respectively.
• Family history of gastric cancer can double or triple the
risk of stomach cancer.
• Lifestyle factors such as smoking, drinking alcohol, and
eating a diet low in fruits and vegetables or high in
salted, smoked, or nitrate-preserved foods may
increase your risk
• Helicobacter pylori
• Certain health conditions including chronic gastritis,
pernicious anemia, gastric polyps, intestinal metaplasia,
and prior stomach surgery.
• Work-related exposure due to coal mining, nickel
refining, and rubber and timber processing and
asbestos exposure.

14. • Diffuse Carcinoma (Risk factors)
• Risk factors undefined, except for a rare inherited mutation of
E-cadherin
• Infection with H. pylori and chronic gastritis often
absent

15. Pathogenesis
• The mechanisms of neoplastic transformation are not entirely clear.
• Chronic inflammation induced by H. pylori
• may release reactive oxygen species,
• which eventually cause DNA damage,
• leading to an imbalance between cell proliferation and apoptosis,
particularly in areas of tissue repair
.

16. Morphology
• The location of gastric carcinoma within the stomach is as follows:
• Pylorus and antrum, 50% to 60%;
• Cardia 25%; and
• the remainder (15-25%) in the body and
fundus.
• The lesser curvature is involved in about 40% and the
greater curvature in 12%.
• Thus, a favored location is
the lesser curvature of the antropyloric region.

17. Morphology cont.
• Though less frequent, an ulcerative lesion on the
greater curvature
malignant
than benign.
is more likely to be

18. Morphology cont.
• GC is classified on the basis of
• depth of invasion,
• Macroscopic growth pattern, and
• Histologic subtype.

19. Morphology cont.
Classification on the basis of
depth of Invasion
• Early gastric carcinoma
mucosa and submucosa,
is defined as a lesion confined to the
regardless of the presence or absence of perigastric lymph node metastases.

20. Morphology
Classification on the basis of depth of Invasion
cont.
• Advanced gastric carcinoma is a neoplasm that has extended
below the submucosa into the muscular wall
and has perhaps spread more widely.

21. Morphology cont.
Gastric mucosal dysplasia
the presumed precursor lesion of
early gastric cancer,
which then in turn progresses to
advanced lesions.
is

22. •Part II

23. Morphology cont.
Classification on the basis of
macroscopic growth patterns
• The three macroscopic growth patterns of gastric
carcinoma which may be evident at both the early and advanced stages, are
1.Exophytic
with protrusion of a tumor mass into the lumen;
2.Flat or depressed,
3.Excavated,
crater
in which there is no obvious tumor mass within the mucosa; and
whereby a shallow or deeply erosive
is present in the wall of the stomach.

24. Morphology cont.
• Exophytic tumors may contain portions of an
adenoma.
• Flat or depressed
l effacement
malignancy presents only as regiona
of the normal surface mucosal pattern.
• Excavated cancers may mimic, in size and
appearance, chronic peptic ulcers,
although more advanced cases show heaped-up
margins.

25. Morphology cont.
Classification on the basis of
histology
intestinal
& diffuse.

26. Morphology cont.
The intestinal variant is composed of
malignant cells forming
neoplastic
intestinal glands
those of
resembling
colonic adenocarcinoma.

27. • Gastric tumors with an intestinal
morphology tend to form
bulky tumors

28. Morphology cont.
• The diffuse variant is composed of
gastric –type mucous cells that
generally do not form glands but rather
permeate the mucosa and wall as scattered
individual
• signet-ring cells or
• small clusters in an infiltrative growth
pattern.

29. Morphology cont.
A mass may be difficult to appreciate in diffuse gastric cancer, but
these infiltrative tumors often evoke a
Desmoplastic
reaction that stiffens
the gastric wall
and
may provide a valuable
diagnostic clue.

30. Morphology cont.
The
rigid and thickened stomach
is termed a
leather bottle stomach, or linitis plastica
due to desmoplastic reaction ( in diffuse variant).
Brinton's disease

31. •
Whatever the histologic variant, all gastric carcinomas eventually penetrate the wall to
serosa,
spread to regional and more distant
lymph nodes,
metastasize
and
widely.
involve the

32. For obscure reasons, In advanced cases gastric carcinoma
the earliest lymph node metastasis
may sometimes involve a
Supraclavicular
lymph node
(Virchow node).

33. Rudolf Karl Virchow
Virchow - German pathologist
(1821-1902)

34. Gastric tumors can also metastasize to the
to form a
periumbilical region
subcutaneous nodule,
Sister
termed a
Mary Joseph nodule
after the nurse who first noted this lesion as a marker of
,
metastatic carcinoma.

35. • Another somewhat unusual mode of
intraperitoneal spread in females is to both
the ovaries, giving rise to the so called
Krukenburg tumor.

36. Local invasion into
the duodenum,
pancreas,
Retroperitoneum

37. Diffuse type
Gastric adenocarcinoma. A, Intestinal-type adenocarcinoma consisting of an elevated
mass with heaped-up borders and central ulceration. B, Linitis plastica. The gastric
wall is markedly thickened, and rugal folds are partially lost.

38. Clinical features
Early stage:
•
•
•
•
•
Indigestion and stomach discomfort
A bloated feeling after eating
Mild nausea
Loss of appetite
Heartburn

39. Clinical features
Advanced stage:
• Discomfort in the upper or middle part of the
abdomen.
• Blood in the stool (which appears as black, tarry
stools).
• Vomiting or vomiting blood.
• Weight loss.
• Pain or bloating in the stomach after eating.
• Weakness or fatigue associated with mild anemia
(a deficiency in red blood cells).

40. Diagnosis
•
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Signs& symptoms
Medical History & Physical exam
Upper endoscopy
Biopsy
Testing Biopsy
Imaging tests
Endoscopic Ultrasound
CT scan
MRI
PET
Chest X-ray
Laparoscopy
Lab tests

41. Treatment
Chemotherapy or
radiation therapy
palliative care.
surgical resection
treatment
and
However, when possible,
for gastric adenocarcinoma.
remains the
preferred

42. Prognosis
• After surgical resection, the 5-year survival
rate of
can
early gastric cancer
exceed
90
%,
even if lymph node metastases are present.

43. Prognosis
cont
.
• In contrast, the 5-year survival rate for
advanced gastric cancer
remains
below
20%.

44. Prevention
General Measures
Screening
(Mass endoscopic screening programs)
The only hope for cure is
early detection and
surgical removal, because the most important
prognostic indicator is stage of the tumor at the time of
resection.