II. Epidemiology
- Gender: More common in men
- Age: 40 to 70 years
III. Pathophysiology
- Adenocarcinoma accounts for 95% of cases
- Atrophic Gastritis precedes metaplasia and malignancy
IV. Risk Factors
- Familial Adenomatous Polyposis
- Non-polyposis hereditary Colon Cancer
- Gastric adenoma
- Helicobacter Pylori (distal Stomach tumors)
- Barrett's Esophagus (cardiac and esophageal border)
- Prior subtotal gastrectomy (after 15-20 years)
- Pernicious Anemia
- Tobacco Abuse
- Chronic atrophic Gastritis
- Racial predisposition (twice as common as caucasians)
- Native americans
- Hispanic patients
- Black patients
V. Symptoms
- Asymptomatic in early stages in 80% of cases
- Late stage symptoms
- Weight loss
- Nausea and Vomiting
- Abdominal Pain
- Early satiety
VI. Signs
- Palpable epigastric mass
- Hepatomegaly
- Lymphadenopathy (e.g. periumbilical or supraclavicular)
VII. Differential Diagnosis
VIII. Radiology
- Double contrast barium swallow
- May be a cost effective for initial evaluation
IX. Diagnostic Testing
- Upper endoscopy (Esophogastroduodenoscopy or EGD)
- Best tool for Gastric Cancer diagnosis
- Sydney system recommends 5 biopsies
- Endoscopic Ultrasonography (EUS)
- Used to stage Gastric Cancer
X. Staging: TNM Classification
- Staging system
- Primary Tumor (T)
- TX: Cannot assess
- Tis: Carcinoma in situ
- T0 - T4: Increasing degrees of local tumor invasion
- Regional Lymph Nodes (N)
- NX: Cannot assess
- N0 - N3: Increasing degrees of Lymph Nodes involved
- Distant metastases (M)
- MX: Cannot assess
- M0: No metastases
- M1: Distant metastases
- Primary Tumor (T)
- Stages (Summary of AJCC Staging - not an exact list)
- Stage 0: Tis, N0, M0 (Carcinoma in-situ)
- Stage IA: T1, N0, M0 (Submucosa involved)
- Stage IB: T1-T2b, N0-N1, MO (subserosa involved)
- Stage II: T1-T3, N0-N2, M0 (visceral peritoneum)
- Stage IIIA: T2a-T4, N0-N2, M0 (local tumor invasion)
- Stage IIIB: T3, N2, M0 (7-15 Lymph Nodes involved)
- Stage IV: T1-T4, N1-N3, M0-1 (increased metastases)
XI. Management
-
Radiation Therapy
- Modestly effective
-
Chemotherapy
- Not effective as sole therapy
- Used as adjunct to surgery and radiation
- Surgery based on tumor location in Stomach
XII. Prognosis: Five year survival
- Stage O: 90%
- Stage I: <78%
- Stage II: 34%
- Stage III: <20%
- Stage IV: 7%
XIII. Prevention
- Tobacco Cessation
- Dietary changes (possible benefit)
- Decrease Alcohol intake
- Decrease smoked, pickled or salted food intake
- Increase fruit and vegetable intake
- Aggressively treat and monitor associated conditions
- Barrett's Esophagus
- Atrophic Gastritis
- Helicobacter Pylori infection
- Screening EGD for high risk patients every 1-3 years
- See Risk factors above
XIV. References
- Gunderson in Abeloff (2000) Oncology, p. 1545-79
- Toh in Feldman (2002) Sleisenger GI, p. 829-47
- Layke (2004) Am Fam Physician 69(5):1133-40 [PubMed]