Lymphoma, Gastric

Key Features

• Second most common gastric malignancy, 3–5% of gastric cancers

• Distinguish between primary gastric lymphoma with adjacent nodal spread and advanced systemic lymphoma with secondary gastric involvement

• More than 95% are non-Hodgkin B-cell lymphomas consisting of

  • Mucosa-associated lymphoid tissue (MALT) lymphoma, or

  • Diffuse large B-cell lymphoma, or

  • Gastric T-cell lymphoma (rare)

• Gastric T-cell lymphoma, associated with human T-lymphotropic virus (HTLV) type 1 infection, is rare and makes up 7% of primary gastric lymphomas

• Infection with Helicobacter pylori is an important risk factor for primary gastric lymphoma; > 90% of low-grade primary gastric lymphomas are associated with H pylori

Clinical Findings

• Dyspepsia

• Abdominal pain

• Weight loss

• Upper gastrointestinal bleeding

• Anemia

• Patients with diffuse large B-cell lymphoma are more likely to have systemic symptoms and to present at an advanced stage

Diagnosis

• Upper gastrointestinal series or endoscopy show thickened folds, ulcer, mass, or diffusely infiltrating lesion; diagnosis established with endoscopic biopsy

• Biopsies of both suspicious and normal-appearing areas are recommended

• Biopsy specimens should be tested for H pylori and, if positive, for gene translocations that might be harbored by the tumor (eg, t[11;18])

• Endoscopic ultrasonography is the most sensitive test for determining the depth of invasion and presence of perigastric lymphadenopathy

• CT scanning of chest, abdomen, and pelvis useful in staging

• For patients with gastric MALT lymphomas, the Lugano staging system is most frequently used

• For patients with diffuse large B-cell lymphomas involving the stomach, the following may be required for staging and management:

  • Combination PET-CT imaging

  • Bone marrow aspirate with biopsy

  • Tumor lysis laboratory tests

  • Hepatitis B and HIV serologies

Treatment

• Depends on tumor histology, grade, and stage

• MALT-type lymphomas

  • Regression after successful H pylori eradication occurs in ~ 75% of cases of stage I and ~ 55% of stage IIE low-grade lymphomas

  • Remission may take as long as a year, and relapse occurs in ~ 2% of cases per year

  • Many patients with minimal disease after successful H pylori eradication may be observed closely without further therapy

  • Failure of antibiotic treatment to achieve lymphoma regression may be due to gene translocations harbored by the tumor

    • Of cancers positive for t(11;18), 95% do not respond to antibiotics

  • Patients with localized marginal zone (MALT-type) lymphomas who are not infected with H pylori may be treated with radiation therapy

  • Endoscopic surveillance is recommended every 3–6 months for 5 years

  • Surgical resection is not recommended

  • Long-term survival for stage I is > 90% and for stage II, 35–65%

• Diffuse large B-cell lymphoma

  • Usually presents at an advanced stage with widely disseminated disease and is treated according to stage and subtype of lymphoma

  • Surgery has been associated with a better prognosis than conservative treatment

  • Chemoimmunotherapy or radiation therapy is used for gastrointestinal bleeding, threatened end-organ function, bulky disease, or progression

    • Two chemotherapeutic ...