Follicular Lymphoma

August 15, 2024

This page was reviewed under our medical and editorial policy by Alex Herrera, M.D., professor, Division of Lymphoma, Department of Hematology & Hematopoietic Cell Transplantation, City of Hope^® Cancer Center Duarte

Follicular lymphoma is the most common form of slow growing non-Hodgkin lymphoma, accounting for about 20% to 30% of all non-Hodgkin lymphomas in the United States and Europe.

What Is Follicular Lymphoma?

Follicular lymphoma is a type of non-Hodgkin lymphoma. It is classified as indolent, which means it is slow-growing. It affects B cell lymphocytes, part of the body’s immune system, which fights infection. It usually starts in the lymph nodes and may spread to the bone marrow or other organs.

Follicular Lymphoma Symptoms

Many people with follicular lymphoma have no symptoms. Their doctor may find a painless, swollen lymph node during a checkup.

As the disease progresses, some symptoms like the ones below may develop.

Enlarged lymph nodes: Lymph nodes are small, bean-like organs found in the neck, armpits, stomach and groin. They fight infections. As cancer cells multiply, one or more lymph nodes may enlarge (swell).

Extreme tiredness: Extreme tiredness makes it hard to do daily chores.

Fever: Fevers typically are those with no known cause.

Night sweats: This is characterized by sweating that soaks clothes, usually at night.

Weight loss: Weight loss for no reason, especially if more than 10% of body weight is lost, may be a symptom.

What Causes Follicular Lymphoma?

The exact cause of follicular lymphoma remains unclear. Researchers suspect that changes in DNA, the genetic information inside cells, allow lymphoma cells to develop. They have linked follicular lymphoma to the switching of sections of chromosomes 14 and 18. More research is needed to understand why these changes occur.

Follicular Lymphoma Risk Factors

Follicular lymphoma risk factors have been hard to define. Some have been identified as those listed below.

Older age: This is a cancer of older people and is most often diagnosed between 65 and 74 years of age. The median age at diagnosis is 64. Gender: Females have a slightly higher chance of developing this type of lymphoma.

Ethnicity: The rate of follicular lymphoma is much higher among white people, especially in the United States.

Chemical exposure: Exposure to certain chemicals, such as benzenes, or chemicals used in herbicides and pesticides, may increase a person’s risk. Some chemotherapy drugs have also been linked to an increased risk of developing non-Hodgkin lymphoma.

Weakened immune system: People with diseases that weaken their immune system and those receiving treatments that suppress their immune response have a higher risk.

Follicular Lymphoma Diagnosis

The first step in diagnosing follicular lymphoma involves a thorough physical exam and review of the patient’s family history. Several tests are used, including those listed below.

Blood tests: Samples of blood will be taken to examine red and white blood cells. The laboratory will also check for evidence of infections that may have the same symptoms. Lactate dehydrogenase (LDH) blood levels and other cancer markers are also examined.

Imaging tests: Imaging tests such as computed tomography (CT) scans, chest X-rays and positron emission tomography (PET) scans may be used to check for enlargement of organs or lymph nodes, as well as concentrated areas of cancer cells. Magnetic resonance imaging (MRI) helps measure a tumor’s size.

Biopsy: A small incision may be made to remove an enlarged lymph node. The node is examined to learn what type of lymphoma cells are there, and how many.

Bone marrow biopsy: A hollow needle is inserted into the hipbone or breastbone to remove a sample of the bone marrow for examination.

Biomarker testing: This test looks for proteins, genes and other factors unique to follicular lymphoma.

Follicular Lymphoma Stages

Follicular lymphoma uses the same cancer staging approach as other non-Hodgkin lymphomas. Stages indicate whether the cancer is in the early stages or whether it has spread.

The Lugano classification defines four stages outlined below.

Stage 1: This stage involves a single group of lymph nodes, such as in the neck or armpit. Statistics from the National Cancer Institute (NCI) show that 24% of patients are diagnosed at this stage.

Stage 2: Two or more groups of lymph nodes on the same side of the diaphragm (the muscle separating the chest and abdomen) are involved. Health care providers diagnose 15% of patients at this stage, according to the NCI.

Stage 3: Lymphoma has spread to lymph nodes above and below the diaphragm and to the spleen. In all, 26% of patients are diagnosed at this stage, according to the NCI.

Stage 4: The disease has spread beyond the lymphatic system to another organ, such as the bone marrow, liver or lung. Diagnosis for 28% of patients happens at Stage 4, according to the NCI.

Follicular Lymphoma Treatment

Treatment plans for patients with follicular lymphoma are based on several factors, including subtype, disease stage, prognosis and overall health. Some patients may never require treatment, and some may go years between treatments. The medical team may decide to use a combination of approaches, depending on test results.

Treatment options may include those listed below.

Watchful waiting: No treatment may be needed in the early stages. The patient will have regular checkups for any changes. Although waiting to start treatment does not affect survival, many patients struggle emotionally with not knowing whether or when things may change.

Radiation therapy: Radiation may include external beam therapy (EBT), which uses a focused beam of radiation aimed at the affected nodes.

Immunotherapy: Immunotherapy treatment is used to give the patient’s own immune system a boost or relies on engineered versions of normal parts of the immune system to assist. Monoclonal antibodies use proteins made to destroy the cancer cell or slow its growth. Chimeric antigen receptor (CAR) T cell therapy, where a patient's T cells are enhanced in a lab, may also be an option.

Chemotherapy: Chemotherapy uses powerful anti-cancer drugs given by mouth or injected intravenously (IV). They enter the bloodstream, reaching all areas of the body. Therapy may include using one drug or a combination of several.

Targeted therapy: Targeted therapy uses drugs designed to “target” parts of cancer cells. The drugs either block signals to multiply or turn on signals telling target areas to destroy themselves.

Stem cell transplant: Powerful chemotherapy and/or radiation therapy is given to destroy the cancerous cells. They are then replaced with healthy cells taken from the patient before treatment (autologous transplant) or from a donor (allogeneic transplant).

Clinical research studies: As researchers discover more about how follicular lymphoma cells behave, they may develop treatments to slow them down or destroy them.

Follicular Lymphoma Survival Rate

Follicular lymphoma survival rates are higher than those for many other forms of non-Hodgkin lymphoma.

Researchers use a statistical tool to estimate the percentage of patients who would survive five years or more after their cancer diagnosis, compared to people without that cancer type. This is called the five-year relative survival rate.

For follicular lymphoma, the overall five-year relative survival rate is 89%, according to the American Cancer Society. When diagnosed in the early stages, the survival rate is even higher – 97% for Stage 1 and 89% for Stage 2.

Doctors use a tool known as the Follicular Lymphoma International Prognostic Index (FLIPI) to understand the patient’s outlook better and fine-tune their treatment plan. It considers factors such as age, number of affected lymph nodes, hemoglobin level, stage and LDH blood levels to decide whether the patient is low, medium or high risk, which helps to shed light on each patient’s prognosis.

It is important to remember that these numbers are estimates and do not account for more recent advances in treatment. The patient’s cancer care team will customize treatment plans to address the unique needs of each patient.