According to the results of a study published in the journal Epidemiology, smokers have an increased risk of developing Hodgkin’s lymphoma.
Hodgkin’s lymphoma is a cancer of the lymph system. It is diagnosed when a characteristic cell (the Reed-Sternberg cell) is identified under a microscope. Hodgkin’s lymphoma typically begins in the lymph nodes in one region of the body and then spreads through the lymph system in a predictable manner. It may spread outside the lymph system to other organs such as the lungs, liver, bone, and bone marrow.
Epstein-Barr virus (EBV) infects a majority of the world’s population and is the cause of infectious mononucleosis. In a small proportion of infected individuals, EBV is also thought to play a role in the development of certain types of cancers, including Hodgkin’s lymphoma, Burkitt’s lymphoma, and nasopharyngeal cancer.
In order to evaluate smoking and alcohol intake in relation to the risk of Hodgkin’s lymphoma, researchers in England conducted a study among 262 individuals with Hodgkin’s lymphoma and 1,137 individuals without Hodgkin’s lymphoma.
In addition to assessing the risk of Hodgkin’s lymphoma overall, the researchers also separately assessed the risk of EBV-positive and EBV-negative Hodgkin’s lymphoma. In EBV-positive Hodgkin’s lymphoma, EBV is found within the Reed-Sternberg or Hodgkin cells. Of the 262 Hodgkin’s patients, 18% had EBV-positive Hodgkin’s lymphoma, 42% had EBV-negative Hodgkin’s lymphoma, and 40% had unknown EBV status.
- Compared to never-smokers, those who had ever smoked had a 40% increased risk of developing Hodgkin’s lymphoma. Risk was highest among current smokers. Among former smokers risk declined with time since quitting.
- Smoking appeared to be most strongly related to EBV-positive Hodgkin’s lymphoma. Ever-smokers had a more than two-fold increased risk of developing EBV-positive Hodgkin’s lymphoma compared to never-smokers. There was not a clear link between smoking and EBV-negative Hodgkin’s lymphoma.
- There did not appear to be a link between alcohol intake and risk of Hodgkin’s lymphoma.
The study suggests that smoking, but not alcohol intake, increases the risk of Hodgkin’s lymphoma. The link between smoking and Hodgkin’s was particularly strong for EBV-positive Hodgkin’s lymphoma. The researchers recommend additional research to better understand how smoking may interact with EBV in development of Hodgkin’s lymphoma.
Reference: Willett EV, O’Connor S, Smith AG, Roman E. Does smoking or alcohol modify the risk of Epstein-Barr virus-positive or – negative Hodgkin lymphoma? Epidemiology. 2007;18:130-136.