Stomach


 * **Epidemiolgy:** || Relatively common in Japan, Chile and Iceland. Between 1930 and 1995, then incidence rate decreased in the US.[1] ||
 * **Etiology:** || Smoked and salted foods, lack of fruits and vegetables in diet, Helicobacter pylori infection, low socioeconomic status.[2] ||
 * **Signs & Symptoms:** || Loss of appetite, abdominal discomfort, weight loss, nausea and vomiting, tarry stools.[2] ||
 * **Diagnostic Procedures:** || Contrast enhanced x-rays and upper gastrointestinal (GI) endoscopy with biopsy is used for the diagnosis of stomach cancer. The upper endoscopy yields more than ninety percent accuracy in diagnosing gastric cancer. The computed tomography (CT) of the abdomen is used to examinethe extentof the disease. The use of positron emission tomography-computed tomography (PET-CT) is an optional work up for gastric cancer. The PET scancan benefit in determining local and distance metastases and pre and postoperative treatment response. [2,3] ||
 * **Histology:** || Most gastric cancers arise in the mid-portion of the lesser curvature and the distal stomach. The most common histological type is adenocarcinoma. It accounts for more than ninety percent of all tumors arising in the stomach. Other histologic tumors include squamous cell, adenosquamous, signet cell, and mucinous cell carcinomas. [3] ||
 * **Lymph node drainage:** || Lymph node involvement is very important in the prognoses of gastric cancer. The degree to which regional lymph nodes are involved is determined by the location of the primary site in the stomach. There are seven primary lymph node groups that may be involved with gastric cancer. The perigastric lymph nodes along the greater and lesser curvatures are; gastro duodenal, para aortic, celiac axis, portapepatic, and splenic hilum lymph nodes. Tumors located in the gastric esophageal junction may involve the distal paraesophageal lymph nodes. [2,3] ||
 * **Metastatic spread:** || Common sites of distant metastasis include abdominal lymph nodes, liver, lung, supraclavicular nodes, bone or adrenal glands.[2] ||
 * **Grading:** || Tumor Grading for Gastric Cancer.

G1: Well differentiated (low grade). G2: Moderately differentiated (intermediate grade). G3: Undifferentiated (high grade). || Stage A T1N0 Nodes negative; lesion limited to mucosa Stage B1 T2N0 Nodes negative; extension of lesion through mucosa but still within gastric wall Stage B2 T3N0 Nodes negative; extension through entire wall with or without invasion of surrounding tissues or organs Stage C1 T2N1-2 Nodes positive; lesion limited to wall Stage C2 T3N1-2 Nodes positive; extension of lesion through entire wall || This statistic reflects the fact that most cases of stomach cancer are diagnosed after the cancer has already spread to other parts of the body.If stomach cancer is found before it has spread and surgery is possible, the five-year survival rate is about 63% but depends on the stage of the cancer found during surgery.[2]
 * **Staging:** || Staging Systems for Gastric Cancer [2]
 * **Radiation side effects:** || Side effects include anorexia, nausea, fatigue, vomiting and diarrhea. The skin in the treated area may become red, dry, tender and itchy. ||
 * **Prognosis:** || The most prognostic factor is the tumor extent. * Lymph node involvement is important, as are the number and location of nodes affected.
 * The five-year survival rate (percentage of people who survive at least five years after the cancer is detected, excluding those who die from other diseases) of people with stomach cancer is about 26%.

The 5-year survival rates for stomach cancer by stage are as follows:

Stage IA 71% Stage IIA 45% Stage IIIA 20% Stage IV 4% Stage IB 57% Stage IIB 33% Stage IIIB 14% Stage IIIC 9% || Chemotherapy (5-FU and cisplatin) with concurrent radiation of 40 Gy in 15 factions, followed by surgical resection. [2] Field borders for gastic cancer.[4] || Kidney 23 Gy 30 Gy 50 Gy Liver 30 Gy 35 Gy 50 Gy Lung 17.5 Gy 30 Gy 45 Gy Small Intestine 40 Gy – 50 Gy Spinal cord 47 Gy(20 cm) 50 Gy(10 cm) 50(5 cm) [2] || [2] Chao KS, Perez CA, Brady LW. //Radiation Oncology Management Decisions.// 2nd ed. Lippincott Williams & Wilkins; 2002. [3] Hoppe TR, Phillips LT, Roach M. Leibel and Phillips Textbook of Radiation Oncology. 3rd Edition. Philadelphia: Saunders, Elsevier. 2010 [4] //Gastric surgical adjuvant radiotherapy consensus report:// rationale and treatment implementation. [|http://www.sciencedirect.com/science/article/pii/S0360301601026463. Accessed June 9], 2012 || Figure 1. Braium X-ray of abdomen showing a gastric cancer. [3] Figure 2. CT Scan of abdomen showing a gastric cancer. [3] Figure 3. Upper gastrointestinal (GI) endoscopy procedure. [3] Back to Week 3
 * **Treatments:** || Postoperative radiation and chemotherapy.Combined modality therapy increased the survival to 36 months.
 * **TD 5/5:** || __ORGAN WHOLE ⅔ ⅓ __
 * **References:** || [1]Lenhard RE, Osteen RT, Gansler T. //The American Cancer Society’s Clinical Oncology//. The American Cancer Society; 200.1