Gastric cancer
Gastric cancer: Excerpt from Professional Guide to Diseases (Eighth Edition)
Gastric cancer can be classified as polypoid, ulcerating, ulcerating and infiltrating, or diffuse, according to gross appearance. The parts of the stomach affected by gastric cancer, listed in order of decreasing frequency, are the pylorus and antrum, the lesser curvature, the cardia, the body of the stomach, and the greater curvature. (See Sites of gastric cancer.)
Gastric cancer infiltrates rapidly to regional lymph nodes, omentum, liver, and lungs by the following routes: walls of the stomach, duodenum, and esophagus; lymphatic system; adjacent organs; bloodstream; and peritoneal cavity.
Causes and incidence
The cause of gastric cancer is unknown. It's commonly associated with gastritis with gastric atrophy, which may result from gastric cancer and may not be a precursor state. Predisposing factors include environmental influences, such as smoking and high alcohol intake. Genetic factors have also been implicated because this disease occurs more commonly among people with type A blood than among those with type O; similarly, it's more common in people with a family history of gastric cancer. Dietary factors also seem related, including types of food preparation, physical properties of some foods, and certain methods of food preservation (especially smoking, pickling, or salting). There's a strong correlation between infection with Helicobacter pylori and distal gastric cancer.
Gastric cancer is common throughout the world and affects all races; however, unexplained geographic and cultural differences in incidence occur — for example, a higher mortality in Japan, Iceland, Chile, and Austria. In the United States, during the past 25 years, incidence has decreased by 50% and the resulting death rate is one-third what it was 30 years ago. Incidence is higher in males older than 40. Hispanic, Native, and African Americans are twice as likely to develop gastric cancer than Whites. The prognosis depends on the stage of the disease at the time of diagnosis; however, the overall 5-year survival rate is approximately 19%.
The decrease in gastric cancer in the United States has been attributed, without proof, to the balanced American diet and to refrigeration, which reduces nitrate-producing bacteria in food.
Signs and symptoms
Early clues to gastric cancer are chronic dyspepsia and epigastric discomfort, followed in later stages by weight loss, anorexia, feeling of fullness after eating, anemia, and fatigue. If the cancer is in the cardia, the first sign or symptom may be dysphagia and, later, vomiting (commonly coffee-ground vomitus). Affected patients may also have blood in their stools.
The course of gastric cancer may be insidious or fulminating. Unfortunately, the patient typically treats himself with antacids or histamine blockers until the symptoms of advanced stages appear.
Diagnosis
Diagnosis depends primarily on reinvestigations of any persistent or recurring GI changes and complaints. To rule out other conditions producing similar symptoms, diagnostic evaluation must include the testing of blood, stools, and stomach fluid samples.
Diagnosis of gastric cancer generally requires these studies:
❑Barium X-rays of the GI tract with fluoroscopy show changes (tumor or filling defect in the outline of the stomach, loss of flexibility and distensibility, and abnormal gastric mucosa with or without ulceration).
❑ Gastroscopy with fiber-optic endoscopy helps rule out other diffuse gastric mucosal abnormalities by allowing direct visualization and gastroscopic biopsy to evaluate gastric mucosal lesions.
❑ Photography with fiber-optic endoscope provides a permanent record of gastric lesions that can later be used to determine disease progression and effect of treatment.
Certain other studies may rule out specific organ metastasis: computed tomography scans, chest X-rays, liver and bone scans, and liver biopsy. (See Staging gastric cancer, page 84.)
Treatment
In many cases, surgery is the treatment of choice. Excision of the lesion with appropriate margins is possible in over one-third of patients. Even in patients whose disease isn't considered surgically curable, resection offers palliation and improves potential benefits from chemotherapy and radiation.
The nature and extent of the lesion determine what kind of surgery is most appropriate. Common surgical procedures include subtotal gastric resection (subtotal gastrectomy) and total gastric resection (total gastrectomy). When carcinoma involves the pylorus and antrum, gastric resection removes the lower stomach and duodenum (gastrojejunostomy or Billroth II). If metastasis has occurred, the omentum and spleen may also have to be removed.
If gastric cancer has spread to the liver, peritoneum, or lymph glands, palliative surgery may include gastrostomy, jejunostomy, or a gastric or partial gastric resection. Such surgery may temporarily relieve vomiting, nausea, pain, and dysphagia, while allowing enteral nutrition to continue.
Chemotherapy for GI cancers may help to control symptoms and prolong survival. Adenocarcinoma of the stomach has responded to several agents, including fluorouracil, paclitaxel, doxorubicin, cisplatin, methotrexate, and mitomycin. Antiemetics can control nausea, which increases as the cancer advances. In the more advanced stages, sedatives and tranquilizers may be necessary to control overwhelming anxiety. Opioids are commonly necessary to relieve severe and unremitting pain.
Radiation has been particularly useful when combined with chemotherapy in patients who have unresectable or partially resectable disease. It should be given on an empty stomach and shouldn't be used preoperatively because it may damage viscera and impede healing.
Treatment with antispasmodics and antacids may help relieve GI distress.
Special considerations
❑Before surgery, prepare the patient for its effects and for postsurgical procedures such as insertion of a nasogastric (NG) tube for drainage and I.V. lines.
❑Reassure the patient who's having a partial gastric resection that he may eventually be able to eat normally. Prepare the patient who's having a total gastrectomy for slow recovery and only partial return to a normal diet.
❑Include the family in all phases of the patient's care.
❑Emphasize the importance of changing position every 2 hours and of deep breathing.
❑After surgery, give meticulous supportive care to promote recovery and prevent complications.
❑After any type of gastrectomy, pulmonary complications may result, and oxygen may be needed. Regularly assist the patient with turning, coughing, and deep breathing. Turning the patient hourly and administering analgesic opioids, as ordered, may prevent pulmonary problems. Incentive spirometry may also be needed for complete lung expansion. Proper positioning is important as well; semi-Fowler's position facilitates breathing and drainage.
❑After gastrectomy, little (if any) drainage comes from the NG tube because no secretions form after stomach removal. Without a stomach for storage, many patients experience dumping syndrome. Intrinsic factor is absent from gastric secretions, leading to malabsorption of vitamin B12. To prevent vitamin B12 deficiency, the patient must take a replacement vitamin for the rest of his life as well as an iron supplement.
❑During radiation treatment, encourage the patient to eat high-calorie, well-balanced meals. Offer fluids such as ginger ale to minimize such radiation adverse effects as nausea and vomiting.
Watch for the following complications of surgery:
❑Patients who experience poor digestion and absorption after gastrectomy need a special diet: frequent feedings of small amounts of clear liquids, increasing to small, frequent feedings of bland food. After total gastrectomy, patients must eat small meals for the rest of their lives. (Some patients need pancreatin and sodium bicarbonate after meals to prevent or control steatorrhea and dyspepsia.)
❑Wound dehiscence and delayed healing, stemming from decreased protein, anemia, and avitaminosis, may occur. Preoperative vitamin and protein replacement can prevent such complications. Observe the wound regularly for redness, swelling, failure to heal, or warmth. Parenteral administration of vitamin C may improve wound healing.
❑Vitamin deficiency may result from obstruction, diarrhea, or an inadequate diet. Ascorbic acid, thiamine, riboflavin, nicotinic acid, and vitamin K supplements may be beneficial. Good nutrition promotes weight gain, strength, independence, a positive outlook, and tolerance for surgery, radiation therapy, or chemotherapy. Aside from meeting caloric needs, nutrition must provide adequate protein, fluid, and potassium intake to facilitate glycogen and protein synthesis. Anabolic agents such as methandrostenolone may induce nitrogen retention. Steroids, antidepressants, wine, or brandy may boost the appetite.
❑When all treatments have failed, concentrate on keeping the patient comfortable and free from pain, and provide as much psychological support as possible. If the patient is going home, discuss continuing care needs with the caregiver or refer the patient to an appropriate home health care agency or hospice. Encourage the patient and the caregivers to express their feelings and concerns. Answer their questions honestly with tact and sensitivity.
Pictures
Book Source Details
- Book Title: Professional Guide to Diseases (Eighth Edition)
- Author(s): Springhouse
- Year of Publication: 2005
- Copyright Details: Professional Guide to Diseases (Eighth Edition), Copyright © 2005 Lippincott Williams & Wilkins.
More About Testicular Cancer
More Medical Textbooks Online about Testicular Cancer
Review other book chapters online related to Testicular Cancer:
Medical Books Excerpts
- Scrotal swelling
- "Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series" (2007)
- [ read ]
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
» Next page: Scrotal swelling (Professional Guide to Signs & Symptoms (Fifth Edition))
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
