Splenic marginal zone lymphoma

Splenic marginal zone lymphoma (SMZL) is a slow-growing (indolent) B-cell non-Hodgkin lymphoma (NHL). It usually affects the spleen, bone marrow and blood. It can sometimes affect lymph nodes in the abdomen, but in most cases SMZL doesn’t affect lymph nodes.

SMZL is linked with viral infections, especially hepatitis C virus (HCV) and Kaposi sarcoma herpes virus (KSHV). It usually occurs in the elderly, most often in older men. SMZL is uncommon before age 50. The average age at diagnosis is between 65 and 70. Most people have advanced stage disease (stage IV) when they are diagnosed.

SMZL can change into a fast-growing (aggressive) type of NHL, but this is not very common.

People with SMZL often have:

• a larger than normal spleen
• low red blood cell count (called anemia)
• low platelet count (called thrombocytopenia)
• a larger than normal liver (in some cases)

The following are treatment options for SMZL.

Watchful waiting (called active surveillance) may be an option for SMZL because it develops slowly and may not need to be treated right away. The healthcare team carefully monitors the person with SMZL and starts treatment when symptoms appear or there are signs that the disease is progressing more quickly.

Surgery to remove the spleen (called a splenectomy) may be offered for SMZL. It is done to improve red blood cell or platelet counts. It is also done to relieve discomfort if the larger than normal spleen puts pressure on other organs.

When a splenectomy is not an option, external beam radiation therapy to the spleen may be used to treat SMZL.

SMZL doesn’t respond as well to chemotherapy as other slow-growing (indolent) types of NHL, but it may still be offered to some people.

The combinations of chemotherapy drugs that may be used to treat SMZL include:

• CHOP – cyclophosphamide (Cytoxan, Procytox), doxorubicin (Adriamycin), vincristine (Oncovin) and prednisone
• R-CHOP – CHOP with rituximab (Rituxan)
• CVP – cyclophosphamide, vincristine and prednisone
• R-CVP – CVP with rituximab
• FND – fludarabine (Fludara), mitoxantrone (Novantrone) and dexamethasone (Decadron, Dexasone)
• BR – bendamustine (Treanda) and rituximab

Targeted therapy uses drugs to target specific molecules (such as proteins) on the surface of cancer cells. These molecules help send signals that tell cells to grow or divide. By targeting these molecules, the drugs stop the growth and spread of cancer cells while limiting harm to normal cells.

Rituximab is a targeted therapy drug used to treat SMZL. It can be used alone or in combination with chemotherapy.

Immunotherapy helps to strengthen or restore the immune system’s ability to fight cancer. It is sometimes used to treat NHL.

Some people with SMZL will also have HCV infection. They may be given interferon alfa (Intron A, Wellferon), which is a type of immunotherapy. It may be used alone or in combination with a drug called ribavirin, which is used to treat viral infections like HCV.