Gastric Cancer

Gastric Cancer Professor Dr.

Bedii Berat APAYDIN

Epidemiology of Gastric Cancer  Gastric ca. is the 13th most common & the 10th most deadly cancer in US  Japan, Chile, China, Iceland & Finland have a high rate of incidence & death from this malignancy  Its true incidence has declined by more than 40 % in the last 30 years in the US  Its world wide frequency has albeit diminished less dramatically  Decline in mortality rate in Japan in the past years has been the result of mass screening  Location of the cancers has shifted from the distal to the proximal portion of the stomac  Is 2 times more common in men than in women  Its incidence & mortality increase with age (>50)

Risk Factors for Gastric Cancer         

Heredity Age Gender Diet Social habits Occupation Predisposing conditions H.pylori Hypogammaglobulinemia

Risk Factors for Gastric Cancer Heredity  The fact that the incidence in Japan, Chili Iceland & Finland is 5-6 times as great as those in other parts of the world, support racial differences  Certain families have demonstrated multiple occurences of Gastric cancer: Napoleon Bonaparte  4 % of patients with gastric cancer have a family history of gastric cancer  Patients with gastric cancer have frequently blood group A

Risk Factors for Gastric Cancer Diet  Foods high in sodium such as pickled vegetables, salted fishes & meat  Smoked foods  High fat  Items containing nitrite & nitrate  Elevated zinc level in the water  Gastric cancer is inversely associated with consumption of fresh vegetable, citrous fruits, vitamine C & whole milk  Refrigeration has contributed to the decline of Gastric Cancer

Risk Factors for Gastric Cancer Social Habits Cigarette smoking is associated with an increased risk for Gastric Cancer

Risk Factors for Gastric Cancer Social & Occupational Factors  Lower socioeconomic class  Coal mining  Timber processing  Rubber production  Fishermen  Ceramic workers  Textile workers  Painters  Asbesto exposure have been associated with gastric ca.

Risk Factors for Gastric Cancer Predisposing Conditions  Chronic atrophic gastritis & intestinal metaplasia  Helicobacter pylori infection  Gastric polyps  Previous gastrectomy  Pernicious anemia  Hypertrophic gastropathy (Menetrier disease) have been associated with Gastric ca

Microscopic Pathology  With only the rare exceptions of carcinoids & squamous carcinomas, gastric cancers are all adenocancer  The WHO’s histologic classification recognizes 4 patterns of adenocancer: - papillar - mucinous - tubular - signet ring cell  The most widely used histopathologic classification is described by Lauren

Lauren’s Classification of Gastric ca. Intestinal type:  Cells of this type forme glands resembling colonic glands  Manifested by polipoid mass or ulceration  Occurs usually in geographic areas where gastric ca incidence is high: worldwide distrubition is epidemic  Associated with atrophic gastritis,intestinal metaplasia & with diet induced dysplastic changes  Occurs more often in men & in patients over age 60  Metastasizes to the liver

Diffuse type:  Is composed of dispersed cells which are not organized in glandular pattern  It infiltrates stomach wall without forming mass & produces linitis plastica  It is endemic  It is less associated with dietary factors  It is found in young & in women  Has a greater tendency for peritoneal spreading

Early Gastric Cancer

Gastric ca. confined to mucosa or submucosa regardless of lymph node involvement  EGC ranges from 8-25 % in USA & 35-50 % all of gastric ca in Japan  70 % of EGC are well differentiated & 30 % are poorly differentiated & lymph node invasion is less than 5 %  5 year survival is 99 % when cancer is confined to the mucosa, 90 % when cancer is confined to the submucosa & survival drops to 70 % when lymph node involvement is present  EGC is divided to several types & subtypes

Advanced Gastric Cancer  Gross morphology of advanced gastric ca. (tumor extending beyond the submucosa) is classified by BORMANN  Bormann classification includes 4 distinct gross categories   

(%13) (%25) (%36)

Type 1 Type 2 Type 3

 (%26) Type 4

polypoid ulcerating with sharply defined margins combined ulcerating & infiltrating without clear cut margins infiltrating (%11) 4a : superficial spreading (%15) 4b: linitis plastica

Symptoms of Gastric Cancer

 Diagnosis is not made until there is an extensive involvement of the gastric wall & adjacent viscera  Initial symptoms are vague postprandial heaviness & epigastric discomfort not different from other dyspeptic symptoms  Anorexia -especially for beef products & smoking- with weight loss (6 kg) are the most common signs  At the beginning, patients complaint from epigastric pain which mimic peptic ulcer & responds transiently to medical therapy, persistent pain is a late complaint  Constipation frequently results from restricted foods  Anemia findings (fatigue & weakness) & occult blood in the stool are common whereas massive bleeding occurs in less than 5 % of the patients  Nausea & vomiting occur when distal lesions obstruct pylorus, dysphagia occurs when cancer arises from cardia

Signs of Gastric Cancer Anemia findings Palpable abdominal mass is common: 50 % Abdominal tenderness is a rare finding Hepatomegaly suggests metastatic spread Peritoneal seeding may cause massive ascites or Krukenberg’s tumor (involvement of ovaries) or Blummer’s shelf (involvement of Douglas)  A palpable lymph node in the left supraclavicular fossa (Wirchow’s node) & a metastatic deposit to the umblicus (Sister Joseph’s nodule) are sings of advanced disease     

Laboratory Studies  A microcytic anemia secondary to chronic GI bleeding or macrocytic anemia secondary to preexisting pernicious anemia can be found  Abnormal liver function tests suggest liver metastasis  CEA, CA19-9, α feto protein levels are commonly elevated  Studies of gastric acid secretion often reveal achlorhydria or hypochlorhydria  Serum gastrin level is elevated secondary to achlorhydria

Radiologic Studies  Single contrast barium study of the upper GI tract is the first diagnostic study to evaluate symptoms.This study detects more than 80% of gastric ca., but it frequently misses early ca.  Findings indicating gastric ca. are as follows:  A mass lesion in the gastric lumen  An obtructing lesion of the antrum and cardia  An ulcerated mass resembling a bening ulcer  Enlarged gastric folds  Nondistendible stomach  Early gastric ca. can be diagnosed by doublecontrast barium study

Endoscopic Evaluation  Upper GI endoscopy enables the direct visualisation,photograpic documentation & biopsy of gastric lesions  Visual diagnosis is accurate in 90% of patients with gastric ca. but biopsies must be done for histologic confirmation  A minimum of 6 biopsy samples should be obtained  In infiltrative type of gastric ca. diagnosis was made by biopsy in only 50% of patients

Preoperative Staging  Once the diagnosis of gastric ca. has been established, the extent of disease & its resectability should be evaluated  CT or MRI scans should be obtained to evaluate hepatic metastasis, extansion of tm into contiguous organs (pancreas, transverse mesocolon)  Endoscopic intraluminal US provides accurate information about the depth of penetration of tm  Laparoscopy can be used to detect small intraperitoneal & liver metastasis not seen on CT

Spread of Gastric Cancer  Intramural spread  Direct invasion  Metastasis by way of lymphatic vessels  Metastasis by way of blood vessels  Implantation onto peritoneal surfaces

Treatment of Gastric Cancer  Surgical therapy is the only curative treatment  85% of patients are operable  In 50% of patients, lesions are amenable to resection  Of the resectable lesions, half are potentially curable  The surgical objective is to remove the tumor, an adjacent uninvolved margin of stomach, the regional lymph nodes & if necessary portions of involved adjacent organs  Japanese surgeons recommend more agressive lymphadenectomy as a matter of routine in the resection of ca

For 1/3 distal stomach tumors Resection would entail distal gastrectomy (proximal margin should be a minimum of 6 cm from the gross tumor), with en bloc removal of omentum, a 3-4 cm cuff of duodenum & regional lymph nodes (N1+N2 LN), LN12, LN13, LN16

For 1/3 middle stomach tumors & multifocal tumors & linitis plastica • • • •

Total gastrectomy Splenectomy (if required) Omentectomy N1+N2 lymphadenectomy (LN1-12 complete)

For 1/3 proximal stomach cancer • • • • •

Proximal gastrectomy Distal esophagectomy (10 cm) Pancreas preserved Splenectomy 10) LN 1-10 LN16

Palliative Surgical Therapy Palliative resection is recommended if • the stomach is movable & • life expectancy is more than 2 months • Gastrojejunostomy can be done when resection is not feasible