Gasric cancer

1. Gastric Carcinoma
Dr. Lala Robin. MS Gen. Surgery,
CMC

2. EPIDEMIOLOGY
 Worldwide, gastric cancer is the fourth most common cancer and the second
leading cause of cancer death. An estimated 952,000 new cases are diagnosed
annually, and an estimated 723,000 deaths (10% of all cancer deaths) worldwide.
 Gastric cancer is the most common cancer in Japan.
 Prognosis remains poor except in a few countries where early screening is feasible
(East Asia). The decline in incidence has been limited to noncardia gastric cancers
and intestinal type.
 The number of newly diagnosed cases of proximal gastric and esophagogastric
junction (EGJ) adenocarcinomas has increased sixfold since the mid-1980s,
paralleling Barrett dysplasia geography. These proximal tumors are thought to be
biologically more aggressive and more complex to treat. The only chance of cure is
complete surgical resection.

3. PATHOLOGY
 Approximately 95% of all gastric cancers are adenocarcinomas. The term gastric
cancer refers to adenocarcinoma of the stomach.
 Other malignant tumors are rare and include squamous cell carcinoma,
adenoacanthoma, carcinoid tumors, small-cell carcinoma, mucinous carcinoma,
hepatoid adenocarcinoma, oncocytic (parietal gland) carcinoma, sarcomatoid
carcinoma, lymphoepithelioma-like carcinoma, adenocarcinoma with rhabdoid
features, gastric carcinoma with osteoclast-like giant cells, neuroendocrine tumor,
gastrointestinal stromal tumor, or leiomyosarcoma.
 The stomach is the most common site for lymphomas of the gastrointestinal tract.

5. MOLECULAR CLASSIFICATION OF GASTRIC
CANCER
 mesenchymal-like type (30%)  worst prognosis, tends to occur at an earlier age,
and has the highest frequency of recurrence
 microsatellite-unstable tumors(22%) best overall prognosis and the lowest
frequency of tumor recurrence
 tumor protein 53 (TP53)-active (24%)
 TP53-inactive (23%)

6. PATTERNS OF SPREAD
 local extension to involve adjacent structures  omentum, spleen, adrenal gland,
diaphragm, liver, pancreas, or colon
 lymphatic metastases,
 peritoneal metastases,
 distant metastases
 Extension into the esophagus occurs primarily through the submucosal lymphatics

7. CLINICAL PRESENTATION AND
PRETREATMENT EVALUATION
 Signs and Symptoms
 weight loss (22% to 61%);
 anorexia (5% to 40%);
 fatigue,
 epigastric discomfort, or pain (62% to 91%); and
 postprandial fullness, heart burn, indigestion, nausea, and vomiting (6% to 40%)
 Weight loss and abdominal pain are the most common presenting symptoms
at initial encounter.

8.  Up to 25% of the patients have history/symptoms of peptic ulcer disease.
 dysphagia or pseudoachalasia  tumor in cardia
 Early satiety is an infrequent symptom of gastric cancer but is indicative of a
diffusely infiltrative tumor that has resulted in loss of distensibility of the gastric
wall
 Delayed satiety and vomiting may indicate pyloric involvement
 hematemesis , anemia
 Ascites, jaundice, or a palpable mass indicate incurable disease

9.  The transverse colon is a potential site of malignant fistulization and obstruction
from a gastric primary tumor.
 Diffuse peritoneal spread of disease frequently produces other sites of intestinal
obstruction. A large ovarian mass (Krukenberg tumor) or a large peritoneal implant
in the pelvis (Blumer shelf), which can produce symptoms of rectal obstruction,
may be palpable on pelvic or rectal examination.
 Nodular metastases in the subcutaneous tissue around the umbilicus (Sister Mary
Joseph node)
 peripheral lymph nodes such as in the supraclavicular area (Virchow node) or
axillary region (Irish node)

10. Factors Associated with Increased Risk of
Developing Stomach Cancer
 Acquired Factors
 Nutritional
 ■ High salt consumption
 ■ High nitrate consumption
 ■ Low dietary vitamin A and C
 ■ Poor food preparation (smoked, salt cured)
 ■ Lack of refrigeration
 ■ Poor drinking water (well water)
 Occupational
 ■ Rubber workers
 ■ Coal workers

11.  ■ Cigarette smoking
 ■ Helicobacter pylori infection
 ■ Epstein-Barr virus
 ■ Radiation exposure
 ■ Prior gastric surgery for benign gastric ulcer disease
 ■ Prior treatment for mucosa-associated lymphoid tissue lymphoma

12. Genetic Factors
 ■ Type A blood
 ■ Pernicious anemia
 ■ Family history without known genetic factors (first-degree relative with gastric
cancer)
 ■ Hereditary diffuse gastric cancer (CDH1 mutation)
 ■ Familial gastric cancer
 ■ Hereditary nonpolyposis colon cancer
 ■ Familial adenomatous polyposis
 ■ Li-Fraumeni syndrome
 ■ BRCA1 and BRAC2

13. Precursor lesions
 ■ Adenomatous gastric polyps
 ■ Chronic atrophic gastritis
 ■ Dysplasia
 ■ Intestinal metaplasia
 ■ Menetrier disease

14.  ■ Ethnicity (in the United States, gastric cancer is more common among
Asian/Pacific Islanders, Hispanics, and African Americans)
 ■ Obesity (the strength of this link is not clear)

15. PRETREATMENT STAGING
 Endoscopy
 visualizes the gastric mucosa and allows biopsy for a histologic diagnosis
 Endoscopic ultrasound (EUS)
 assess the T and N stage of primary tumors
 Computed Tomography
 triphasic CT with oral and intravenous contrast of the abdomen, chest, and pelvis
 Whole-body FDG-PET
 In patients with FDG-avid tumors, PET may be useful in detecting metastatic
disease and follow-up for recurrence.

16.  Staging Laparoscopy and Peritoneal Cytology
 Laparoscopy directly inspects the peritoneal and visceral surfaces for detection of
CT-occult, small-volume metastases. Staging laparoscopy also allows for
assessment of peritoneal cytology and laparoscopic ultrasound.
 An unnecessary laparotomy can be avoided.

17. Regional lymph nodes of the stomach

24. Prognosis

25. TUMOR MANAGEMENT
 Surgery remains the only chance for cure, but it must be accompanied by
perioperative chemotherapy or postoperative chemoradiation.
 Palliation with radiation, chemotherapy, endoscopic stenting, or surgery are
indicated for appropriate patients with advanced or metastatic disease.
 Stage IA tumors may be managed endoscopically with endoscopic mucosal
resection (EMR) or endoscopic submucosal dissection (ESD)
 Stage IB to stage IIIC tumors are potentially curable with multimodality therapy

26. Non-resectable lesions
 Findings consistent with locoregionally advanced tumors exhibit disease infiltration
at the root of the mesentery, have paraaortic lymph node involvement on imaging
or biopsy, and invasion or encasement of major vascular structures excluding the
splenic vessels.
 In addition, the presence of distant metastases or peritoneal seeding (stage IV
tumors) negates the potential for operative cure, and these patients should receive
chemotherapy.

27. NEOADJUVANT THERAPY
 MAGIC trial - three cycles of chemotherapy (5-FU, epirubicin, and cisplatin) prior to
surgery with curative intent, followed by an additional three cycles of
chemotherapy
 There was a significant improvement in 5-year survival (36% vs 23%, P = .009), a
longer interval of progression-free survival, and a decrease in local recurrence rates
with pre- and postoperative chemotherapy compared to surgery alone. In addition,
tumor downstaging was observed.

28. SURGICAL THERAPY
 Curative intent gastrectomy requires an R0 resection.
 intragastric margins of 5 cm are recommended; however,
a margin of this distance may need to be increased for
diffuse-type cancers.
 omentectomy and lymph node dissection
 Proximal tumors of the cardia, including Siewert type III lesions, are best managed with total
gastrectomy with Roux-en-Y esophagojejunostomy reconstruction.
 Distal lesions, including those in the body and antrum, should be extirpated via subtotal (or near
total) gastrectomy to achieve negative margins. Reconstruction with a Billroth I
gastroduodenostomy is the reconstruction of choice because it preserves natural enteric flow.
 Placement of a temporary jejunal feeding tube to assist in postoperative nutritional recovery is
recommended for all patients.

29. TOTAL GASTRECTOMY

37. ADJUVANT THERAPY
 The Macdonald protocol, a regimen of 5-FU-based chemoradiotherapy, improves
disease-free and overall survival when compared to observation alone.

38. THANK YOU