Marginal Zone Lymphoma
What is marginal zone lymphoma?
Marginal zone lymphoma belongs to a group of diseases called non-Hodgkin’s lymphomas, which are related cancers that affect the lymphatic system. The term “marginal zone” describes the specific type of B-cell that is affected and the compartment of the body that these cells defend.
Specifically, marginal zone lymphoma is a slow-growing (indolent) B-cell lymphoma that develops from cancerous lymphocytes (white blood cells) within a region of the lymph nodes known as the mantle zone. These cancerous lymphocytes result from errors in the production of the lymphocyte itself or errors in the transformation of a lymphocyte into a malignant cell. They can then multiply uncontrollably, leading to enlargement of specific lymph node regions, spreading to other parts of the body, and potentially resulting in life-threatening complications.
There are three types of marginal zone lymphomas:
- Extranodal marginal zone B-cell lymphoma a.k.a. mucosa-associated lymphoid tissue (MALT) lymphoma, which is the most common type of marginal zone lymphoma and begins in parts of the body other than the lymph nodes
- Nodal marginal zone B-cell lymphoma, which starts and usually stays in the lymph nodes
- Splenic marginal zone B-cell lymphoma, which is only found in the spleen and bone marrow
What causes marginal zone lymphoma?
Marginal zone lymphoma has been linked to infection with the hepatitis C virus, with the Helicobacter pylori infection, and with a history of other inflammation or autoimmune disorders. However, the exact cause of the disease is still unknown.
What are the symptoms of marginal zone lymphoma?
Many people with marginal zone lymphoma may be asymptomatic during the early stages of the disease, but persistent swelling in the areas affected by the lymphoma is usually the first sign.
In addition to this inflammation, affected individuals may have a series of “non-specific” signs and symptoms, such as the following:
- Lack of appetite and a sense of fullness from enlarged tonsils, liver, or spleen
- Indigestion, bloating, or heart burn
- Repeated fever
- Unexplained weight loss
How is marginal zone lymphoma diagnosed?
After a thorough clinical examination to feel the affected areas and a detailed patient and family history, a healthcare provider will use several tests to diagnose marginal zone lymphoma. These include:
- Blood tests to reveal the number of white blood cells present and to evaluate proteins in the blood
- Biopsies to see if any cancer cells are present
- CT scans
- PET scans
- Colonoscopy to stage the potential cancer
What are the available treatments for marginal zone lymphoma?
There is a range of available treatment and management options for patients with marginal zone lymphoma, but since the cancer is slow-growing, a doctor may want to treat the cancer conservatively until symptoms and the disease progress. Antibiotic therapy is usually the first treatment step for patients who have infection-associated marginal zone lymphoma. After this, a combination of chemotherapy, radiation therapy, targeted therapy, and stem cell transplantation can be used to potentially cure the cancer.
Most excitingly, new combinations of drugs are currently being tested. In recent studies, 66% of 32 marginal zone lymphoma patients in a clinical trial responded to a new and effective Revlimid and Rituxan combination. Of these, cancer was completely eradicated in 44% of them. Scientists are still looking to enroll 500 patients to continue this combination drug trial.
Another phase 2 trial of an oral drug, duvelisib, has shown significant results in patients with follicular lymphoma (FL0, small lymphocytic lymphoma (SLL), or marginal zone lymphoma. The treatment is an oral, dual inhibitor that is designed to target phosphoinositide-3-kinase and PI3K-gamma enzymes (known to help promote cancer growth and survival). Of the patients tested, 33% of patients with marginal zone lymphoma were responsive to this treatment.
To read more about these newest clinical trials, check out our latest Patient Worthy article here!