How Gastric MALT Lymphoma is Treated

Gastric (MALT) lymphoma is a form of non-Hodgkin lymphoma that arises from tissue that forms the lining of the stomach: MALT stands for mucosa-associated lymphoid tissue. Because gastric MALT lymphoma usually is caused by a bacteria called Helicobacter pylori (H. pylori), it often can be treated successfully with antiobiotics. For the few cases not associated with H. pylori infection or those that do not respond to antibiotics, other treatment options include radiation, chemotherapy, and surgery. What's more, because gastric MALT lymphoma is such a slow-growing cancer, many people with the disease are able to forgo treatment altogether and instead be monitored closely by their doctor.

For people with gastric MALT lymphoma whose disease is not widespread and who do not have symptoms, the standard of care usually is active monitoring, also called "watch-and-wait."

Active monitoring entails close monitoring of a disease or condition to see if it will resolve or stabilize without treatment. Doing so can be an effective way to avoid potential side effects of treatment. For gastric MALT lymphoma, active monitoring typically involves regular endoscopies, physical exams, and lab tests.

For H. pylori-positive gastric MALT lymphoma the first-line treatment is a protocol called triple therapy which involves the combination of two antibiotics to fight the infection plus a proton pump inhibitor (PPI) to lower the production of gastric acid in the stomach and prevent ulcers. The antibiotics used most often are Amoxil (amoxicillin), Biaxin (clarithromycin), Sumycin (tetracycline), and Flagyl (metronidazole).

According to the Lymphoma Research Foundation, although it may take several months for this treatment to work, it is effective in about 90% of gastric MALT lymphoma cases.

For cases of MALT lymphoma not caused by H.pylori infection or for those that don't respond to antibiotics, radiation therapy can be an effective option.

This protocol involves directing relatively low doses of external beam radiation at tumors in the stomach. In more than 95% of people with gastric MALT lymphoma who undergo radiation, the treatment is successful enough that there is no need for other kinds of follow-up treatment.

Chemotherapy is used for early-stage gastric MALT lymphomas when antibiotics fail to control the disease, or when the lymphoma recurs after a period of remission.

The chemo drugs often used are a combination of four different medications that together are known by the acronym CHOP: Cytoxan (cyclophosphamide), Adriamycin (doxorubicin), Oncovin (vincristine), and prednisone. The first three of these drugs combat cancer cells in different ways and are usually are given as injections or infusions of veins on a single day. Prednisone is taken in pill form for five days.

Kinase inhibitors are chemotherapy drugs that target lymphoma cells and block kinases—proteins that cause cancer cells to grow and flourish. Two kinase inhibitors used to treat MALT non-Hodgkin lymphoma are Imbruvica (ibrutinib) and Calquence (acalabrutinib). These drugs are taken twice a day by mouth.

Immunotherapy wrangles the body's immune system to fight cancer. The most widely used immunotherapy drug for MALT lymphoma is a monoclonal antibody called Rituxan (rituximab). Typically it's given if antibiotics aren’t effective or if lymphoma worsens even after chemotherapy.

Rituxin targets an antigen called CD20 which is associated with H. pylori-positive gastric MALT lymphoma. (Antigens are toxins that trigger the immune response.) It's given intravenously (IV) or as an injection under the skin alone or in combination with chemotherapy drugs.

Two other immunotherapy drugs sometimes used for MALT lymphoma are Adcetris (brentuximab vedotin) and Campath (alemtuzumab).

Surgery to treat gastric MALT lymphoma is called a gastrectomy. This procedure involves removing part or all of the stomach (partial gastrectomy and total gastrectomy, respectively).

Gastrectomy is rarely if ever a first-line treatment for MALT lymphoma, given the inherent risks of surgery and the fact that the disease usually can be treated effectively non-surgically. However, it may be recommended in cases in which the lymphoma is limited to a distinct area and can be safely and easily removed.

Learning you or someone you care for has cancer is undoubtedly scary, even when the diagnosis is a slow-growing and easily treated disease such as gastric MALT lymphoma. Learning all you can about MALT lymphoma should help to alleviate your concerns to a large degree. So will being compliant with whatever treatment your medical provider feels is best for you—whether that means always showing up for tests if your disease is being actively monitored or taking medications such as antibiotics exactly as prescribed. Armed with knowledge and medical care you trust should see you through the ordeal of having gastric MALT lymphoma with a minimum or fear and maximum success.