Lymphomas are cancers of the lymph system, a part of your immune system that helps to fight off infections. In lymphoma, white blood cells, either B lymphocytes or T lymphocytes, grow out of control because of a mutation. In LPL, abnormal B lymphocytes reproduce in your bone marrow and displace healthy blood cells.
LPL vs. other lymphomas
Hodgkin’s lymphoma and non-Hodgkin’s lymphoma are distinguished by the type of cells that become cancerous.
- Hodgkin’s lymphomas have a specific kind of abnormal cell present, called a Reed-Sternberg cell.
- The many types of non-Hodgkin’s lymphomas are distinguished by where the cancers start and the genetic and other characteristics of the malignant cells.
LPL is a non-Hodgkin’s lymphoma that starts in the B lymphocytes. It’s a very rare lymphoma, comprising only about 1 to 2 percent of all lymphomas.
The most common type of LPL is Waldenström macroglobulinemia (WM), which is characterized by an abnormal production of immunoglobulin (antibodies). WM is sometimes mistakenly referred to as identical with LPL, but it’s actually a subset of LPL. About 19 out of 20 people with LPL have the immunoglobulin abnormality.
What happens to the immune system?
When LPL causes B lymphocytes (B cells) to overproduce in your bone marrow, fewer normal blood cells are produced.
Normally, B cells move from your bone marrow to your spleen and lymph nodes. There, they may become plasma cells producing antibodies to combat infections. If you don’t have enough normal blood cells, it compromises your immune system.
This may result in:
- anemia, a shortage of red blood cells
- neutropenia, a shortage of a type of white blood cell (called neutrophils), which increases infection risk
- thrombocytopenia, a shortage of blood platelets, which increases bleeding and bruising risks
What are the symptoms?
LPL is a slow-growing cancer, and about one-third of people with LPL don’t have any symptoms at the time they’re diagnosed.
Up to 40 percent of people with LPL have a mild form of anemia.
Other symptoms of LPL may include:
- weakness and fatigue (often caused by anemia)
- fever, night sweats, and weight loss (generally associated with B-cell lymphomas)
- blurred vision
- nose bleeds
- bleeding gums
- elevated beta-2-microglobulin, a blood marker for tumors
About 15 to 30 percent of those with LPL have:
- swollen lymph nodes (lymphadenopathy)
- liver enlargement (hepatomegaly)
- spleen enlargement (splenomegaly)
What causes it?
The cause of LPL isn’t fully understood. Researchers are investigating several possibilities:
- There may be a genetic component, as about 1 in 5 people with WM have a relative who has LPL or a similar type of lymphoma.
- Some studies have found that LPL may be associated with autoimmune diseases like Sjögren syndrome or with the hepatitis C virus, but other studies haven’t shown this link.
- People with LPL commonly have certain genetic mutations that aren’t inherited.
How is it diagnosed?
The diagnosis of LPL is difficult and usually one made after excluding other possibilities.
LPL can resemble other B-cell lymphomas with similar types of plasma cell differentiation. These include:
- mantle cell lymphoma
- chronic lymphocytic leukemia/small lymphocytic lymphoma
- marginal zone lymphoma
- plasma cell myeloma
Your doctor will examine you physically and ask for your medical history. They’ll order blood work and possibly a bone marrow or lymph node biopsy to look at the cells under a microscope.
Watch and wait
LBL is a slow-growing cancer. You and your doctor may decide to wait and monitor your blood regularly before starting treatment. According to the American Cancer Society (ACS), people who delay treatment until their symptoms are problematic have the same longevity as people who start treatment as soon as they’re diagnosed.
Several drugs that work in different ways, or combinations of drugs, may be used to kill the cancer cells. These include:
- chlorambucil (Leukeran)
- fludarabine (Fludara)
- bendamustine (Treanda)
- cyclophosphamide (Cytoxan, Procytox)
- dexamethasone (Decadron, Dexasone), rituximab (Rituxan), and cyclophosphamide
- bortezomib (Velcade) and rituximab, with or without dexamethasone
- cyclophosphamide, vincristine (Oncovin), and prednisone
- cyclophosphamide, vincristine (Oncovin), prednisone, and rituximab
- thalidomide (Thalomid) and rituximab
The particular regimen of drugs will vary, depending on your general health, your symptoms, and possible future treatments.
Biological therapy drugs are manmade substances that act like your own immune system to kill the lymphoma cells. These drugs may be combined with other treatments.
Some of these manmade antibodies, called monoclonal antibodies, are:
- rituximab (Rituxan)
- ofatumumab (Arzerra)
- alemtuzumab (campath)
Other biological drugs are immunomodulating drugs (IMiDs) and cytokines.
Targeted therapy drugs aim to block particular cell changes that cause cancer. Some of these drugs have been used to combat other cancers and are now being researched for LBL. In general, these drugs block proteins that allow the lymphoma cells to keep growing.
Stem cell transplants
In general, blood-forming stem cells are removed from the bloodstream and stored frozen. Then a high dose of chemotherapy or radiation is used to kill all the bone marrow cells (normal and cancerous), and the original blood-forming cells are returned to the bloodstream. The stem cells may come from the person being treated (autologous), or they may be donated by someone who is a close match to the person (allogenic).
Be aware that stem cell transplants are still in an experimental stage. Also, there are short-term and long-term side effects from these transplants.
As with many kinds of cancer, new therapies are under development, and you may find a clinical trial to participate in. Ask your doctor about this and visit ClinicalTrials.gov for more information.
What’s the outlook?
LPL as of yet has no cure. Your LPL may go into remission but later reappear. Also, although it’s a slow-growing cancer, in some cases it can become more aggressive.
The ACS notes that 78 percent of people with LPL survive five years or more.