3. SUMMARY
Gastric cancer refers to neoplasms in the stomach, including cancers of the
esophagogastric junction. The incidence is declining in the United States and
Europe, while it is rising in Japan and South Korea. Gastric cancer is associated
with several risk factors (e.g., consumption of foods high in nitrates,
increased nicotine intake, Helicobacter pylori infection). In its early stages, the
disease is often asymptomatic or accompanied by nonspecific symptoms (e.g.,
epigastric discomfort, postprandial fullness, or nausea). Late-stage disease may
present with gastric outlet obstruction (mechanical obstruction of the pyloric canal),
leading to weight loss and vomiting. Biopsy during endoscopy confirms the
diagnosis. Adenocarcinomas are the most common form of gastric cancer.
Treatment includes endoscopic or surgical resection. Depending on
staging, chemotherapy may be indicated before or after surgery (neoadjuvant or
adjuvant chemotherapy), or as a palliative therapy.
4.
5. PATHOLOGY OF GASTRIC CARCINOMA TYPES
Borrmann’s Classification
Type I: for the well-circumscribed
polypoid lesions
Type II: for polypoid tumors with
marked central ulcerations
Type III: for the ulceration tumors
with infiltrative margins
Type IV: for the LINITIS PLASTICA
(stomach wall becomes thicker and
more rigid)
6. EPIDEMIOLOGY
• Sex: ♂ > ♀
• Peak incidence: 70 years
• Geographical distribution: strong regional
differences
• High incidence in South Korea and Japan
• Declining incidence in the United States
and Europe
7.
8. ETIOLOGY
• Exogenous risk factors
• Diet rich in nitrates and/or salts (e.g., dried, preserved food)
• Nicotine use
• Low socioeconomic status
• Endogenous risk factors
• Diseases associated with a higher risk of gastric cancer
• Atrophic gastritis
• H. pylori infection: associated with a higher risk of intestinal gastric cancer but not with diffuse gastric cancer
• Gastric ulcers
• Partial gastrectomy
• Gastroesophageal reflux disease (GERD; for cancers of the gastroesophageal junction)
• Adenomatous gastric polyps
• Hereditary factors (positive family history, hereditary non-polyposis colorectal cancer)
• Higher incidence in individuals with blood type A.
9. CLINICAL FEATURES
Gastric cancer is often asymptomatic. Early signs are nonspecific and often go unnoticed. At later stages the
following symptoms may occur:
• General signs
• Weight loss
• Chronic iron deficiency anemia (paleness, fatigue, headaches)
• Gastrointestinal signs
• Abdominal pain
• Early satiety
• Nausea or vomiting
• Dysphagia
• Acute gastric bleeding (hematemesis or melena)
10. Clinical features contd.
• Late-stage gastric cancer: Palpable tumor in epigastric region
• Gastric outlet obstruction
• Hepatomegaly, ascites
• Troisier’s sign -: Virchow's node: left supraclavicular adenopathy, located where
the thoracic duct joins the subclavian vein at the venous angle.
• Sister Mary Joseph's node: umbilical node indicating metastasis from a
gastrointestinal or abdominopelvic malignancy
• Malignant acanthosis nigricans (associated with gastric adenocarcinoma)
11. Troisier’s sign
Troisier's sign is the finding of a
palpable left supraclavicular
lymph node; this is
called Virchow's node. It may
indicate
gastrointestinal malignancy,
commonly of the stomach, or less
commonly, lung cancer.
12. Sister Mary Joseph's node
Sister Mary Joseph's
nodule refers to a
palpable nodule bulging into
the umbilicus as result of a
malignant cancer in the
abdomen or pelvis. It is
associated with multiple
peritoneal metastases and
usually indicates an
advanced stage of disease
with a poor prognosis. It can
be painful at times.
13. SUBTYPES AND VARIANTS
METASTATIC DISEASE
• Lymphangitic spread
• All local lymph nodes (lesser and greater curvature)
• Celiac, paraaortic, and mesenteric lymph nodes
• Carcinoma of the cardia may spread to mediastinal lymph nodes.
• Hematogenous spread to liver, lung, skeleton, brain
• Local invasion of adjacent structures
• Peritoneal carcinomatosis
• Esophagus, transverse colon, pancreas, etc.
• Direct seeding
• To the ovaries (Krukenberg tumor): an ovarian malignancy comprised of signet ring cells (is a cell with a large
vacuole) that has metastasized from a primary site, most commonly the stomach
• To the pouch of Douglas
14. KRUKENBERG
TUMOR
Krukenberg
tumor is a
metastatic
disease to the
ovaries
composed of
mucin-rich
signet-ring cells.
The most
common
primary site for
this tumor is the
stomach.
These tumors s
pread most
likely through
the lymphatic
channels.
15. DIAGNOSTICS
Diagnostic procedures
• Upper endoscopy with biopsy (best initial test)
• : Biopsy confirms the diagnosis
• Barium upper GI series may be considered and would show loss of intestinal folds and
stenosis
Laboratory test
• Iron deficiency anemia
• Serologic markers
• Tumor necrosis factor – alpha (TNF-α) as possible future tumor marker
16. Diagnostics contd.
Staging
• Abdominal ultrasound
• Endosonography
• Assessment of tumor depth and local lymph nodes
• Abdominal and pelvic CT-scan using intravenous and oral contrast;
• Thoracic CT-scan
• Diagnostic laparoscopy
17. Gastric cancer
Endoscopy view of the gastric
antrum
There is a gastric mass at the
level of the lesser curvature with
an irregular margin (perimeter
marked by green outline) and
central ulceration (green
overlay).
These findings are consistent
with gastric cancer.
19. Gastric cancer
Fluoroscopy of the
stomach (with oral
contrast) and CT
abdomen (axial; with IV
contrast)
The gastric wall is
thickened and irregular
(green overlay) with an
abnormal narrowing.
These findings are
consistent with gastric
cancer with stenosis.
20. PATHOLOGY
• Adenocarcinoma (90% of cases)
• Typically localized, exophytic lesion +/- ulceration
• Arise from glandular cells in the stomach; usually located on the lesser curvature of the stomach
• Signet ring cell carcinoma
• Diffuse growth
• Multiple signet ring cells = round cells filled with mucin, with a flat nucleus in the cell periphery
• Less common
• Adenosquamous carcinoma
• Squamous cell carcinoma
21. DIFFERENTIAL DIAGNOSIS
• Gastric ulcer
• Gastroesophageal reflux disease (GERD)
• MÉNÉTRIER'S DISEASE (Giant hypertrophic gastritis): gastritis featuring
massive enlargement of the mucosal folds
• Non-ulcer dyspepsia
• Other types of cancer
• mucosa-associated lymphoid tissue (MALT) lymphoma
• Sarcoma: a malignant cancer of cells of mesenchymal origin (e.g.,
cartilage, fat, muscle)
22. Gastrointestinal stromal
tumor
Endoscopy of the
stomach (pyloric window)
A submucosal mass
(green overlay) with an
intact gastric mucosa can
be seen within the gastric
body.
This finding is consistent
with gastric lipoma,
gastrointestinal stromal
tumor (GIST), or fibroma
of the stomach. Further
diagnostics confirmed a
GIST.
P: pylorus; C: gastric
body
23. Liver metastasis of a gastrointestinal stromal tumor (GIST)
Ultrasound of the liver
A round, hyperechoic lesion (circled in green) with a hypoechoic margin (green overlay) can be seen within the liver
parenchyma. There are two hypoechoic areas in the center of the lesion (red overlay), which likely indicate central
necrosis. The hypoechoic margin is also referred to as the halo sign and is a typical feature of a malignant lesion on
liver ultrasound.
These findings are consistent with liver metastasis of a gastrointestinal stromal tumor
24. TREATMENT
• Exact therapy, which may be either curative or palliative, depends on
staging and the type of tumor. Endoscopic resection
• Surgery
• Perioperative chemotherapy, sometimes radiotherapy
• Trastuzumab (a monoclonal antibody against the HER2 tyrosine kinase
receptor that inhibits cellular signaling and causes cytotoxicity) is
indicated for HER2+(human epidermal growth factor receptor 2, a
growth-promoting protein on the outside of all breast
cells) gastric adenocarcinomas
25. Treatment contd.
Surgery
• Radical gastrectomy and lymphadenectomy (operative standard)
• Resection of the lesser and greater omentum and radical lymphadenectomy
• Roux-en-Y gastric bypass
• The surgeon separates the proximal jejunum from the duodenum and creates an end-to-
end anastomosis of the jejunum with the remaining part of the stomach (gastrojejunostomy),
or in the case of a total gastrectomy, with the esophagus (esophagojejunostomy).
• Duodenal stump is connected distally with the jejunum using an end-to-side anastomosis.
• Alternative: subtotal gastrectomy
26. Total gastrectomy (with Roux-en-Y
anastomosis)
Total gastrectomy w/ blind closure of
duodenal stump (left):
- Removal of the stomach leaving the distal
esophagus and proximal duodenum open
- The duodenal stump (purple line) is closed
Roux-en-Y anastomosis (right):
- A segment of the proximal jejunum is
divided (blue and green dashed lines)
- Creation of esophagojejunostomy: The
distal cut end of the jejunal loop is
anastomosed via an end-end with the distal
esophagus (green dashed line)
- Creation of jejunojejunostomy: The proximal
jejunal stump is anastomosed end-to-side to
a distal jejunal loop (blue dashed line), this
anastomosis is made distal to the
esophagojejunostomy site to prevent bile
reflux
27. Subtotal gastrectomy (with Roux-en-Y
anastomosis)
Subtotal gastrectomy:
- Subtotal gastrectomy involves the
resection of the body and pyloric channel
of the stomach (transparent portion of the
stomach in this image).
- The cardia and fundus of the stomach
and their blood supply is preserved
(opaque portion of the stomach here).
- The duodenal stump (dashed red line) is
closed.
Roux-en-Y anastomosis:
- A segment of the proximal jejunum is
divided.
- Gastrojejunostomy creation: The distal
cut end of the jejunal loop (black I) is
anastomosed side-to-side to the gastric
stump (purple dashed line; I–I).
- Jejunojejunostomy creation: The
proximal jejunal stump (green II) is
anastomosed end-to-side to a distal
jejunal loop (green dashed line, II–II).
28. COMPLICATIONS
Malignant acanthosis nigricans
• A paraneoplastic syndrome: a group of rare disorders that are triggered by an
abnormal immune system response to a cancerous tumor known as a
"neoplasm." seen in adenocarcinomas of GI origin, especially in gastric adenocarcinoma
• Pathophysiology: caused by exogenous transforming growth factor TGF-α and epidermal
growth factor (GF)
• Clinical findings
• Brown to black, intertriginous and/or nuchal hyperpigmentation that can turn into
itching, papillomatous, poorly-defined efflorescence
• Rapid growth and verrucous or papulous surface helps to differentiate it from benign
acanthosis nigricans
• Localization: axilla, groin, neck
30. Complications contd.: Postgastrectomy syndromes
Related to resorption
• Maldigestion
• Consequences and management
• Iron deficiency → supplement iron
• Pernicious anemia due to lack of intrinsic factor, usually
produced by gastric parietal cells → supplement vitamin
B12
31. Related to anastomosis
• Small intestinal bacterial overgrowth (SIBO)Definition: bacterial overgrowth within the small intestine
• Causes
• Anatomic abnormalities: (e.g., surgery causing blind intestinal loops – blind loop syndrome ),
• strictures
• Motility disorders
• Pathophysiology: bacterial overgrowth → bacteria deconjugate bile acids, increase vitamin B12 turnover, and produce
increased amounts of vitamin K and folic acid
• Clinical features: diarrhea, steatorrhea, weight loss, malabsorption (e.g., deficiency of vitamin B12, A, E, D, zinc,
and iron)
• Diagnostics
• Jejunal aspirate cultures collected during endoscopy
• Positive lactulose breath test
32. Related to motility
• Dumping syndrome: rapid gastric emptying due to either defective gastric reservoir function or pyloric emptying
mechanism, or anomalous post-surgery gastric motor functions. Early dumping
• Cause: rapid emptying of undiluted chyme into the small intestine caused by a dysfunctional or
bypassed pyloric sphincter
• Clinical features
• Appears within 15–30 minutes after ingestion of a meal
• Symptoms may include nausea, vomiting, diarrhea, and cramps, as well as vasomotor symptoms such
as sweating, flushing, and palpitations.
• Management
• Dietary modifications: Small meals that include a combination of complex carbohydrates and foods rich
in protein and fat to cover protein and energy requirements are preferable.
• 30–60 min of rest in the supine position after meals
• Often spontaneous improvement after a couple of months
33. Related to motility contd.
Late dumping
• Cause: postprandial hypoglycemia; dysfunctional pyloric sphincter → chyme containing
glucose immediately reaches the small intestine → glucose is quickly resorbed
→ hyperglycemia → excessive release of insulin → hypoglycemia and release
of catecholamines
• Treatment
• Dietary modifications
• OCTREOTIDE (a somatostatin analog that inhibits growth hormone secretion and
causes splanchnic vasoconstriction via decreased secretion of vasodilatory peptides
such as glucagon) and surgery are second and third-line therapies
34. PROGNOSIS
• Since there are no early signs, gastric cancer is often diagnosed very late.
At diagnosis, 60% of cancers have already reached an advanced stage
that does not allow for curative treatment. Early gastric cancer has the
best prognosis .
• Distant metastases or peritoneal carcinomatosis dramatically worsen the
prognosis and are lethal most of the time.
35. REFERENCES
1. Karimi P, Islami F, Anandasabapathy S, Freedman ND, Kamangar F. Gastric Cancer: Descriptive Epidemiology,
Risk Factors, Screening, and Prevention. Cancer Epidemiol Biomarkers Prev .2014; 23(5): p.700-
713. doi: 10.1158/1055-9965.EPI-13-1057.| Open in Read by QxMD
2. Le T, Bhushan V, Chen V, King M. First Aid for the USMLE Step 2 CK. McGraw-Hill Education; 2015
3. Chan AOO, Wong B. Risk factors for gastric cancer. In: Post TW, ed. UpToDate .Waltham,
MA: UpToDate.https://www.uptodate.com/contents/risk-factors-for-gastric-
cancer?source=search_result&search=gastric%20cancer&selectedTitle=2~150. Last updated September 26, 2016.
Accessed January 31, 2017.
4. Tsugane S. Salt, salted food intake, and risk of gastric cancer: Epidemiologic evidence. Cancer Sci .2005; 96(1):
p.1-6. doi: 10.1111/j.1349-7006.2005.00006.x.| Open in Read by QxMD
5. Ladeiras-Lopes R, Pereira AK, Nogueira A, Pinheiro-Torres T, Pinto I, Santos-Pereira R, Lunet N. Smoking and
gastric cancer: systematic review and meta-analysis of cohort studies. Cancer Causes Control .2008; 19(7): p.689-
701. doi: 10.1007/s10552-008-9132-y.| Open in Read by QxMD
6. Le T, Bhushan V, Sochat M, Chavda Y, Zureick A. First Aid for the USMLE Step 1 2018. New York, NY: McGraw-Hill
Medical; 2017
