Gastric MALT Lymphoma

Transcription

1 Gastric MALT Lymphoma

2 Gastric MALT lymphomas develop in the stomach. Helicobacter pylori ( H. pylori) infection has a critical role in the pathogenesis of this disease and its eradication can lead to tumor remission. Other MZLs have been shown to be associated with infectious agents, but this association has not been validated

3 Workup Special aspects of the workup for gastric MALT lymphoma include direct endoscopic assessment of the gastrointestinal tract evaluation of the tumor specimen for the presence ofh.pylori. The presence pf H.pylori infection must be confirmed by biopsy with PCR (polymerase chain reaction) and urea breath test. Nondiagnostic atypical lymphoid infiltrates that are H.pylori positive should be re-biopsied to confirm or exclude lymphoma prior to treatment of H.pylori. Appropriate imaging studies include CT of the chest, abdomen and pelvis, and in select cases, bone marrow biopsy

4 Staging In the Lugano staging system, Ann Arbor stage III has been removed and supradiaphragmatic nodal disease is included under stage IV. TNM (Tumor-Node-Metastasis) staging system corresponds to the staging in gastric cancer, and the depth of the lymphoma infiltration is measured by EUS. Involvement of multiple extranodal sites in MALT lymphoma appears to be biologically distinct from multiple extranodal involvements in other lymphomas, and these patients may be managed by treating each site separately with excision or RT. In contrast, cases with disseminated nodal involvement appear to behave more like nodal MZL or like disseminated FL.

5 Treatment

6 H.pylori infection plays a central role in the pathogenesis of some cases of gastric MALT lymphoma. The efficacy of antibiotic therapy for the treatment for gastric MALT lymphoma has been evaluated in numerous trials. Approximately two thirds of patients with localized gastric MALT lymphoma have a complete tumor remission after eradication of H.pylori infection with antibiotic therapy. However, there is increasing evidence that late relapses occur after antibiotic management and a long duration of follow-up is appropriate

7 For disease confined to the stomach (stage IE, H.pylori positive), treatment begins with antibiotics in combination with a proton pump inhibitor to block gastric acid secretion. The tumor response may be slow, and reevaluation with endoscopy should not be done until 3 months post treatment unless clinical deterioration is evident. If there is evidence of the treatment of the H.pylori infection with antibiotics may be ineffective and these patients should be considered for alternative therapy.

8 H. Pylori infection is not evident in approximately 10-40% of patients with gastric MALTLymphomas. IFRT is preferred for patients with disease that is extending to the muscularis or disease extending from the GI tract to adjacent organs (stages IE [T2 or T3] or IIE H.pylori negative),particularly if one of the t(11;18), t(1;10), or t(14;18)(q32;q21) translocations is present. Rituximab or chemoimmunotherapy are other treatment options.

9 In patients with disseminated disease (stage III or IV), treatment is similar to that for other advanced-stage indolent lymphomas. As with other indolent lymphoma, asymptomatic patients without indications for treatment are monitored without therapy. The decision to treat is guided by end-organ dysfunction or the presence of symptoms (such as bleeding,early satiety), bulky disease at presentation, steady progression of disease, or patient preference. Treatment may include single-agent or combination chemotherapy, or locoregional RT. If there is evidence of recurrence, patients are managed according to the FL guidelines (FOLL-3).

10 Surgical resection is generally limited to specific clinical situations. Though disease control is excellent with total gastrectomy, the long-term morbidity has precluded routine surgical resection. Total gastrectomy is necessary because of the multi-focal nature of the disease.

11 Follow-Up Endoscopy Following primary antibiotic therapy, patients are restaged with endoscopy and biopsy after 3-months. Patients with responsive disease (microbiologic and tumor response) are just observed. Patients with persistent lymphoma with no evidence of H.pylori are treated with RT, if they are symptomatic or if there is significant disease progression. Asymptomatic patients can be observed for 3 months.locoregional RT can be considered as early as 3 months after observation but observation can be prolonged for up to 18 months. Patients with persistent H.pylori and regressing or stable lymphoma are treated with second-line antibiotics

12 Follow up surveillance at 6 months consists of repeat endoscopy and biopsy. Patients can be subdivided into the same four groups, as above. Patients with complete tumor response continue to be observed if the H. pylori is negative, or they can be treated with other antibiotic therapy if H. pylori remains positive. Patients with persistent or recurrent lymphoma after antibiotic therapy, irrespective of their H.Pylori status, are treated with locoregional RT if not previously treated. Patients whose disease does not respond to radiation are managed with single agent or combination chemotherapy similar to FL. Following second line antibiotic therapy or RT, patients are again evaluated with endoscopy and biopsy to rule out large cell lymphoma. Systemic therapy as indicated in FOLL 3 is recommended for recurrence following CR to RT or antibiotic therapy, or for patients with no response to prior RT.

13 Non-gastric MALT Lymphomas

14 Nongastric MALT lymphomas can arise from a large number of non-gastric sites such as lung, thyroid, salivary glands, breast, and tissues surrounding the eye. For patients with stage IE -II disease or extranodal disease involving multiple sites, locoregional RT (20-30 Gy) is appropriate. Surgery may be considered for certain sites of disease (eg, lung, skin, thyroid, colon, small intestine, and breast). If there is no residual disease following surgery, patients are bserved, whereas those with positive surgical margins are treated with locoregional RT.

15 Recurrence following primary treatment is managed similar to advanced stage FL (FOLL-3). RT is an option for those with local recurrence. Patients with advanced-stage disease (stage III-IV) are managed the same as patients with FL (FOLL-2). Aggressive histologies, in which MALT lymphomas coexist with large cell