Guidelines Summary
Gastric MALT Lymphoma
National Comprehensive Cancer Network (NCCN) guidelines recommend the following studies to establish a diagnosis of gastric MALT lymphoma [18] :
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Endoscopic biopsy; fine needle aspiration (FNA) is never acceptable
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Immunohistochemistry panel: CD20, CD3, CD5, CD10, BCL2, kappa/lamda, CD21 or CD23, cyclin D1, BCL6
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Cell surface marker analysis by flow cytometry: kappa/lambda, CD19, CD20, CD5, CD23, CD10
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Helicobacter pylori stain; if positive, then polymerase chain reaction (PCR) or fluorescence in situ hybridization (FISH) for t(11;18)
The following studies may be useful in select circumstances:
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Molecular analysis for detection of antigen receptor gene rearrangements or if plasmacytic differentiation is present, MYD88 mutation status
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FISH or cytogenetics for detection of t(1;14), t(3;14), t(11;14), t(11;18)
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FISH or PCR: t(14;18)
The European Society for Medical Oncology (ESMO) recommends serology, urea breath test, and/or stool antigen test for H pylori in cases where immunohistochemistry findings are negative. [38]
The NCCN guidelines recommend antibiotic therapy for stages I and II in H pylori–positive patients, followed by endoscopy/biopsy for restaging at 3 months or sooner if symptomatic. Further treatments include second-line antibiotics, if H pylori testing remains positive, and involved-site radiation therapy (ISRT) if lymphoma positive. Patients who are t(11;18) positive can be treated with rituximab if ISRT is contraindicated. For patients who are H pylori negative, ISRT is the preferred treatment. Rituximab is the alternative if ISRT is contraindicated. [18]
Patients with advanced stage disease should be observed unless they have one of the following indications for treatment [18] :
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Candidate for a clinical trial
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Symptoms
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GI bleeding
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Threatened end-organ function
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Bulky disease
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Steady or rapid progression
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Patient preference
For first-line therapy, the NCCN prefers the following regimens [18] :
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Bendamustine + rituximab
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RCHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone)
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RCVP (rituximab, cyclophosphamide, vincristine, prednisone)
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Rituximab
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Lenalidomide + rituximab (category 2B)
For second-line therapy, the Bruton tyrosine kinase (BTK) inhibitors acalabrutinib and zanubrutinib are approved for use.
The ESMO guidelines are in general agreement with NCCN for the treatment of gastic MALT lymphoma. [38]
Nongastric MALT Lymphoma
The NCCN guidelines recommend the following studies to establish a diagnosis of nongastric MALT lymphoma [18] :
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Immunohistochemistry panel: CD20, CD3, CD5, CD10, BCL2, kappa/lamda, CD21 or CD23, cyclin D1
-
Cell surface marker analysis by flow cytometry: kappa/lambda, CD19, CD20, CD5, CD23, CD10
The following studies may be useful in select circumstances:
-
Molecular analysis for detection of antigen receptor gene rearrangements or if plasmacytic differentiation is present, MYD88 mutation status
-
FISH or cytogenetics for detection of t(3;14), t(11;14), t(11;18)
-
FISH or PCR: t(14;18)
For stage I and II, the preferred treatment is ISRT. Surgery may be considered for certain sites (ie, thyroid, colon/small bowel and lumpectomy for breast). Rituximab and observation are options in select cases. [18]
For advanced stages, the treatment options are ISRT, observation in select cases or first-line therapy regimens as listed above for gastric MALT lymphoma. [18]
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Low magnification micrograph of a lymphoepithelial lesion of the gastrointestinal tract in the setting of a primary gastrointestinal tract lymphoma. H&E stain. Colonic biopsy (descending colon). Lymphoepithelial lesions are strongly associated with mucosa-associated lymphoid tissue lymphomas (MALT lymphomas); however, they may appear in other types of lymphomas.
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High magnification micrograph of a lymphoepithelial lesion of the gastrointestinal tract in the setting of a primary gastrointestinal tract lymphoma. H&E stain. Colonic biopsy (descending colon). Lymphoepithelial lesions are strongly associated with mucosa-associated lymphoid tissue lymphomas (MALT lymphomas); however, they may appear in other types of lymphomas.
