Lymphoma is a type of blood cancer that develops in the lymphatic system. The lymphatic system is part of the immune system and helps fight infection and disease. Lymphoma occurs when lymphocytes, a type of white blood cell, grow and multiply uncontrollably. There are two main categories of lymphoma – Hodgkin lymphoma and non-Hodgkin lymphoma.
What is lymphoma?
Lymphoma refers to cancers that start in the lymphocytes, a type of white blood cell. Lymphocytes are part of the body’s immune system and are found in the lymph nodes, spleen, bone marrow, blood, and other parts of the lymphatic system. There are two main types of lymphoma:
- Hodgkin lymphoma – Named after Dr. Thomas Hodgkin, who first described it in 1832. This type accounts for about 10% of all lymphomas.
- Non-Hodgkin lymphoma – A diverse group of blood cancers that includes any lymphoma except Hodgkin’s. This type accounts for about 90% of all lymphomas.
Both types of lymphoma have a lot in common. They develop from lymphocytes, can spread to other parts of the lymphatic system and beyond, and may have similar symptoms. However, there are some key differences:
|Usually starts in lymph nodes in the upper body
|Can start anywhere lymphocytes are found
|Spreads in a predictable pattern from one group of lymph nodes to the next
|Spreads less predictably
|Reed-Sternberg cells are usually present
|Many subtypes without Reed-Sternberg cells
|Often curable, especially if caught early
|Treatment depends on subtype – some curable, others managed chronically
What causes lymphoma?
The exact causes of lymphoma are not fully understood. However, researchers have identified several factors that may increase the risk of developing the disease:
- Weakened immune system: HIV/AIDS, organ transplant, autoimmune disorders
- Infections: Epstein-Barr virus (EBV), Helicobacter pylori, hepatitis C, HHV-8
- Family history: Having a close relative with lymphoma
- Age: Most common in older adults, but some types affect children
- Chemical exposure: Pesticides, solvents, hair dyes
- Medications: Immunosuppressants after organ transplant
In many cases, it’s not clear exactly why one person develops lymphoma and another doesn’t. Research continues to try to identify causes and risk factors.
Who gets lymphoma?
Lymphoma can occur in people of any age, from children to older adults. Some key facts about who develops this disease:
- Age: Risk increases as people get older. Most cases occur in those ages 60-70.
- Gender: Slightly more common in men than women.
- Geography: More common in developed countries like the U.S., Canada, and Europe.
- Race/ethnicity: Slightly higher rates among whites compared to African Americans and Asian Americans.
- Family history: 5-10% have a first-degree relative with lymphoma.
- Infections: Higher rates in those with HIV/AIDS or hepatitis C.
- Autoimmune disorders: Increased risk with conditions like rheumatoid arthritis, celiac disease, psoriasis.
While lymphoma can happen to anyone, these factors may increase risk. Talk to your doctor about screening if you have any of these risk factors.
Lymphoma becomes more common as people age. About 50% of cases occur in those ages 55-75. However, lymphoma can develop at any age. Some key facts about age and lymphoma risk:
- Children: Lymphoma is one of the most common childhood cancers. Accounts for about 1 in 4 childhood cancers.
- Young adults: Rising rates of young adult lymphoma in recent decades for unclear reasons.
- Middle age: Risk starts going up around age 50 and peaks in late 60s.
- Elderly: Rates declines slightly in the elderly but still higher than young people.
So while lymphoma can happen at any age, the risk tends to go up as people get older. Subtypes also vary by age. Young people are more prone to fast-growing aggressive lymphomas, while elderly are more likely to get slower-growing types.
Men have a slightly higher risk of developing lymphoma compared to women. Some key gender differences include:
- Overall rates: About 55% of lymphoma cases occur in men vs. 45% in women.
- Subtypes: Men have higher rates of Burkitt, mantle cell, and T-cell lymphomas.
- Aggressive: Men more likely to develop aggressive fast-growing lymphomas.
- Survival: Women generally have better survival rates for most subtypes.
The reasons for these gender differences are not fully understood. Hormones, lifestyle factors, and later diagnosis in men may play a role. But in general, men have a moderately higher rate of lymphoma across most ages and subtypes.
Race and Ethnicity
In the United States, lymphoma rates vary by race and ethnicity:
- Whites: Highest rates of both Hodgkin and non-Hodgkin lymphoma.
- Hispanics: Lower rates than whites for most subtypes.
- Blacks: Slightly lower risk than whites overall, but higher rates of some aggressive subtypes.
- Asians: Lowest lymphoma rates of any racial group.
The reasons for these racial differences are unclear but may be related to genetic, socioeconomic, and environmental factors. Globally, lymphoma rates are highest in North America, Europe, and Australia.
Having a first-degree relative with lymphoma increases disease risk 2 to 4 fold. This suggests genetic factors play a role. Key facts about family history include:
- 5-10% of lymphoma patients have a first-degree relative with the disease.
- Risk is higher with more than one affected relative.
- Risk is higher the younger the age at diagnosis in the relative.
- Brothers and sisters have higher risk than parents.
- Risk is higher in siblings of young patients.
If you have a sibling or parent with lymphoma, discuss your risk with your doctor. Genetic testing and screening may be recommended for some families with multiple affected members.
Weakened Immune System
Anything that weakens the immune system increases lymphoma risk. Some key examples include:
- HIV/AIDS: Up to 10% lifetime risk of lymphoma in HIV patients. Higher CD4 counts reduce risk.
- Organ transplant recipients: Lymphoma risk is 4 times higher. Likely due to immunosuppressant drugs.
- Autoimmune diseases: Conditions like rheumatoid arthritis, lupus, celiac disease increase risk.
Cancer treatments like chemotherapy and radiation that damage the immune system also raise lymphoma risk. Discuss your risk with your doctor if you have a weakened immune system.
Symptoms of Lymphoma
Many symptoms of lymphoma are vague and nonspecific. Common signs and symptoms include:
- Swollen, painless lymph nodes in the neck, armpit, or groin
- Unexplained weight loss
- Fever and chills
- Night sweats
- Coughing or trouble breathing
- Abdominal pain or swelling
Symptoms depend on the location of affected lymph nodes. Talk to your doctor about persistent symptoms for evaluation and diagnosis.
Types of Lymphoma
There are over 60 subtypes of lymphoma. Some of the major categories include:
- Classical Hodgkin Lymphoma – Most common type.
- Nodular lymphocyte-predominant Hodgkin Lymphoma – Rare subtype.
B-cell Non-Hodgkin Lymphomas
- Diffuse large B-cell lymphoma – Most common lymphoma overall.
- Follicular lymphoma – Most common indolent (slow-growing) lymphoma.
- Burkitt lymphoma – Aggressive subtype more common in children.
- Mantle cell lymphoma – Rare subtype with poor prognosis.
T-cell Non-Hodgkin Lymphomas
- Peripheral T-cell lymphoma – Diverse group of aggressive lymphomas.
- Anaplastic large cell lymphoma – Rare subtype.
Other less common lymphomas include lymphoblastic lymphoma, marginal zone lymphoma, Waldenström macroglobulinemia, and primary central nervous system lymphoma.
If lymphoma is suspected, your doctor will order tests to help confirm the diagnosis:
- Imaging tests – CT scan, PET scan, MRI to look for swollen lymph nodes and masses.
- Biopsy – Removing part of an affected lymph node for microscopic examination.
- Blood tests – To evaluate blood cell counts and look for lymphoma markers.
- Bone marrow biopsy – To check for lymphoma in the bone marrow.
These tests allow doctors to confirm a lymphoma diagnosis and identify the subtype, which guides treatment options.
Treatment for Lymphoma
Treatment options for lymphoma include:
- Chemotherapy – Using drugs to kill cancer cells. May be used alone or combined with other treatments.
- Radiation – Using high-energy beams to kill cancer cells.
- Immunotherapy – Drugs that boost the immune system to fight lymphoma.
- Targeted therapy – Drugs that specifically target cancerous cells while sparing healthy cells.
- Stem cell transplant – Replacing a patient’s diseased bone marrow with healthy stem cells.
- Surgery – Removing a tumor or enlarged lymph node.
Treatment is tailored for each patient based on the subtype of lymphoma, its aggressiveness, and the patient’s overall health.
Outlook for Lymphoma Patients
The prognosis for lymphoma depends heavily on the specific subtype:
- Hodgkin lymphoma – Often curable, especially when treated early. 5-year survival is 85%.
- Aggressive lymphomas – Diffuse large B-cell lymphoma has a 5-year survival around 60%. But some aggressive subtypes have poorer outcomes.
- Indolent lymphomas – Slower growing, but often not curable. However, patients may live for many years with periodic treatment.
In general, lymphoma caught at an early stage, in younger patients, and treated promptly has the best prognosis. Research to improve lymphoma treatments and outcomes is ongoing.
There is no proven way to prevent lymphoma completely. But some steps may lower risk:
- Avoid tobacco and excess alcohol
- Eat a healthy diet and exercise regularly
- Avoid obesity
- Use sun protection
- Avoid unnecessary radiation exposure
- Treat infections like HIV, hepatitis C, Helicobacter pylori
- Avoid immunosuppressants if possible
- Get recommended vaccinations
Lowering overall cancer risk through a healthy lifestyle may also reduce lymphoma risk. People with risk factors like a family history or autoimmune disease should have regular checkups.
Lymphoma is a blood cancer that can occur at any age but becomes more common past age 50. It has many subtypes with different prognoses. Men, whites, people with weakened immune systems, and those with a family history have increased risk. Treatments like chemo, radiation, and bone marrow transplant can be curative if the lymphoma is diagnosed early. Research continues to improve prevention and outcomes for lymphoma patients.