gastric neoplasms

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  • Gastric Neoplasms

    Dr. D.W. DaughertyDepartment of Surgery

  • Gastric Adenocarcinoma

    Epidemiology

    a. Among top 10 causes of cancer related deaths in the US.

    b. Highest incidence in Japan, where it accounts for approximately 50% of cancer-related deaths among men and 40% of cancer-related deaths among women.

    c. Incidence also high in Chile, Costa Rica, Hungary, Portugal, Singapore, and Romania.

    d. Migration from these areas appears to decrease incidence.

    e. Most strongly related to early infection with H. pylori.

    f. No conclusive evidence of correlation with diet.

  • Pre-malignant Lesions

    a. Highest risk is associated with polyps.

    b. Two main categories of gastric polyps: Hyperplastic and Adenomatous.

    c. Hyperplastic polypsare considered to have NO neoplastic potential.

    d. Adenomatous polyps carry a 10-20% risk for the development of carcinoma.

  • Hyperplastic polyps

    a. Common, occurring in 0.5-1% of general population and accounting for 70-80% of all gastric polyps.

    b. An overgrowth of histologically normal appearing gastric epthelium.

    c. Atypia is rare.

    d. Considered to have NO neoplastic potential.

    e. Most are asymptomatic.

    f. Dyspepsia and vague complaints of epigastric discomfort are most common.

    g. Co-existing gastroduodenal disease is frequently common.

    h. Complications are unsual. GI hemorrhage occurs in less than 20%.

    i. Endoscopic examination with removal is indicated and sufficient for treatment.

  • Adenomatous polpys

    a. Distinct risk for development of malignancy.

    b. Atypia is common, and risk for development of carcinoma is 10-20%. Risk is greatest in polyps over 2cm in diameter and with multiple polyps.

    c. Symptoms are similar for those of hyperplastic polyps - Dyspepsia and vague complaints of epigastric discomfort are most common.

    d. Endoscopic examination with removal for the pedunculated polyp is indicated and sufficient if histological exam shows no evidence of cancer.

    e. Operative excision is recommended for sessile polyps larger than 2cm, for polyps with biopsy-proven invasive carcinoma, and for polyps complicated by pain and/or bleeding.

    f. After removal, routine endoscopic surveillance is indicated.

  • Gastritis

    a. Malignancy appears to be increased in patients with gastritis associated with pernicious anemia.

    b. Characterized by fundic mucosal atrophy, loss of parietal and chief cells, hypochlorhydria, and hypergastrinemia. Is present in 3% of people older than 60 years of age.

    c. Risk of Gastric CA doubles in patients who have had pernicious anemia for 5 years or greater.

    d. Intestinal metaplasia, presence of intestinal glands in the gastric mucosa, is also commonly associated with gastritis and gastric cancer.

    e. NO direct evidence has been provided to show the evolution from metaplasia to dysplasia to carcinoma to invasive cancer in gastric cancer.

  • Helicobacter Pylori

    a. Associated with inflammatory conditions in the stomach.

    b. Seropositivity increases risk for gastric cancer three-fold.

    c. High risk for cancer in the antrum and body; however, NOT a risk factor for cancers at the esophagastric junction.

    d. Postulated that long term gastric inflammation, consequent to childhood acquisition of H. pylori, makes the gastric mucosa more susceptible to environmental carcinogens.

    e. Treated with triple therapy: Proton-pump Inhibitor, Amoxicillin, and Clarithromycin.

  • Gastric Remnant Cancer

    a. Theory that previous gastrectomy increases risk for subsequent cancer development.

    b. Several large, prospective studies show no real increased risk until after 25 years post-operatively when the relative risk is increased three-fold.

  • Clinical Features

    a. Symptoms not specific.

    b. Epigastric pain present in 70%. Pain is often constant, non-radiating, and unrelieved by food ingestion.

    c. Some patients report pain being relieved, at least temporarily, by antacids or gastric antisecretory drugs.

    d. Anorexia, nausea, and weight loss are present in less than 50% of patients with early gastric CA, but becomes increasingly common as the disease progresses.

    e. Dysphagia is present in less than 20%. GI hemorrhage is present in only 5%. Perforation is rare at 1%.

    f. Physical examination often unremarkable in early stages.

    g. Stools guiac positive in 33% of patients.

    h. Abnormal physical findings indicate late disease: Cachexia, abdominal mass, hepatomegaly, and supraclavicular adenopathy usually indicate advanced metastatic disease.

    i. Laboratory tests are un-revealing.

  • Diagnosis and Screening

    a. Endoscopy is the most definitive diagnostic method.

    b. Biopsy and brushings can be obtained at time of endoscopy.

    c. Use of CT is very limited, with poor accuracy for diagnosis and staging.

    d. Laparoscopy or explorative laparotomy provide only accurate staging methods.

  • Pathology of Adenocarcinoma: Two distinct histologic sub-types: Intestinal and Diffuse.

    a. Intestinal

    1. Malignant cells form glands.

    2. Associated with gastric mucosal atrophy, chronic gastritis, intestinal metaplasia, and dysplasia.

    3. Most common in populations at high risk e.g. Japan.

    4. More common in men and older patients.

    5. Bloodbourne metastases.

    b. Diffuse

    1. No gland formation.

    2. Infiltrates as a sheet of loosely adherent cells.

    3. Lymphatic invasion.

    4. Intraperitoneal metastases common.

    5. Occurs in younger patients, women, and in populations with a lower risk e.g. United States.

    6. Prognosis is less favorable with Diffuse form.

  • 5 year Survival Rates by Stage for Gastric Adenocarcinoma:

    a. Stage I:

  • Location

    a. Proximal: approximately 45% of tumors, defined as GE junction, fundus, and body.

    b. Distal: approximately 45% of tumors, defined as the antrum.

    c. Diffuse: approximately 10% diffusely involve the stomach.

  • Treatment

    a. Surgical resection is the only hope for cure.

    b. Surgical resection goals are two:

    1. Maximize chances for cure in pts with local tumor.

    2. Provide effective and safe palliation in those with metastatic disease.

    c. Laparoscopy: Diagnostic. Allows visualization of the liver, omentum, and peritoneal surfaces. Laparoscopy precludes resection in up to 25% of patients.

  • a. Laparotomy:

    1. For early lesions of distal or middle stomach, sub-total gastrectomy removing 80% of the stomach with gastro-jejunal anastomosis provides satisfactory 5 year survival.

    2. Proximal gastric lesions require total gastrectomy with esophagojejunostomy OR esophagogastrectomy with gastroesophageal re-anastomosis in the cervical or thoracic portion of the esophagus.

    3. Adequate disease free margins must be obtained.

    4. The value of extended lymphadectomy in the treatment of gastric CA is controversial. First large study in Japan.

    a. R1 Perigastric nodes

    b. R2 Celiac and periduodenal nodes

    c. R3 Celiac, aortic, and esophageal nodes

  • a. Palliative Treatment

    1. Does not usually require surgery.

    2. Use of endoscopic lasar very successful.

    3. Palliative resection has not been shown to increase survivial.

    4. Mean survival is 9 months with or without palliative treatment.

    5. Palliation of symptoms becomes primary role. Can usually be done non-surgically.

    6. For proximal obstructing lesions or those not able to be treated by lasar endoscopy, a palliative gastrectomy with Roux-en-Y esophagojejunal bypass may provide relief.

    7. Radiation therapy may play a significant role.

    8. Chemotherapy, whether single agent or multi-modality has proven to be of limited use.

  • Gastric Lymphoma

    Clinical Features

    a. Stomach is the most common organ involved in extra-nodal lymphoma.

    b. Non-Hodgkins lymphoma accounts for 5% of malignant gastric tumors.

    c. Uncommon in children and young adults. Usual presentation is during the sixth to seventh decades.

    d. Symptoms are indistinguishable from gastric adenocarcinoma: epigastric pain, weight loss, anorexia, nausea, and vomiting are common.

    e. Occult bleeding and anemia are observed in more than half of patients.

  • Diagnosis

    a. Endoscopic examination is the diagnostic method of choice.

    b. Appearance may be ulcerated, polypoid, or infiltrative.

    c. Most occur in the middle or distal stomach. Rare in the proximal stomach.

    d. Endoscopic biopsy with cytologic brushings and ultrasound provides the diagnosis in 90% of cases.

    e. Evidence of systemic lymphoma should be sought with CT of the chest and abdomen to detect lymphadenopathy, bone marrow biopsy, and biopsy of enlarged paripheral nodes.

    f. Ann Arbor Staging System is Used:

  • Sheet1

    Ann Arbor Staging for Gastric Lymphoma

    Stage ITumor confined to one lymph node region

    Stage IEOne extralymphatic organ or site

    Stage IITwo or more lymph node regions on the same side of the diaphragm

    Stage IIEOne extralymphatic organ or site and the criteria for stage II

    Stage IIILymph node regions on both sides of the diaphragm

    Stage IIIEOne extralymphatic organ or site and the criteria for stage III

    Stage IIISSplenic involvement and criteria for stage III

    Stage IIISESplenic involvement, one extralymphatic organ or site, and criteria for stage III

    Stage IVDiffuse or disseminated disease

    Sheet2

    Sheet3

  • Treatment

    a. Gastrectomy is the first line treatment: