Non-Hodgkin's Lymphoma - Risk Factors

Risk Factors

Non-Hodgkin’s lymphoma is the seventh most common cancer in the United States. Each year, about 66,000 Americans are diagnosed with non-Hodgkin's lymphomas, and about 20,000 people die of the disease. Since the 1970s, NHL incidence rates have doubled. Part of the reason for this dramatic rise may be due to AIDS, which increases the risk for high-grade lymphomas.

The cause of non-Hodgkin’s lymphoma is unknown, but certain factors may increase a person’s risk of developing this cancer.

Age

Non-Hodgkin’s lymphoma can develop in people of all ages, including children, but it is most common in adults. The most common types of NHL usually appear in people in their 60s and 70s.

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Gender

NHL is more common in men than women.

Race

Overall, the risk for NHL is slightly higher in Caucasians than in African-Americans and Asian Americans.

Family History

People who have close family relatives who have developed NHL may be at increased risk for this cancer. However, no definitive hereditary or genetic link has been established.

Infections

Viral or bacterial infections may play a role in some lymphomas. These include:

• Epstein-Barr virus (EBV), the cause of mononucleosis, is highly associated with Burkitt's lymphoma and NHLs associated with immunodeficiency diseases. It is also a risk factor for Hodgkin's disease.
• The human immunodeficiency virus (HIV), which causes AIDS, increases the risk for Burkitt's lymphoma and diffuse large B-cell lymphoma
• The hepatitis C virus (HCV) may increase the risk for certain types of lymphomas.
• The Helicobacter pylori bacterium, which causes stomach ulcers, is associated with increased risk for mucosa-associated lymphoid tissue lymphomas (MALT). (The use of antibiotics to get rid of the bacteria may cause remission in some patients who have an early stage of MALT lymphoma.)

Immune System Deficiency Disorders

Patients with diseases or conditions that affect the immune system may be at higher risk for lymphomas:

• HIV-positive patients and those with full-blown AIDS are at higher risk for NHL, and the disease is more likely to be widespread in these patients than in those without the immune disease. Most AIDS-related NHLs are high-grade lymphomas.
• People who have organ transplants are at higher risk for NHL, probably due to multiple factors, including the drugs used to suppress the immune system and the transplanted organ itself.
• Patients who have had high-dose chemotherapy with stem-cell transplantation are at higher risk.
• Other less common immunodeficiency syndromes that put people at risk for NHL.