The presence of Epstein-Barr virus in tumor cells is associated with better survival among young Hodgkin’s lymphoma patients and worse survival among older Hodgkin’s lymphoma patients, according to a study published in the Journal of Clinical Oncology.
Hodgkin’s lymphoma is a cancer of the lymph system and is diagnosed by the identification of a characteristic cell under the microscope (the Reed-Sternberg cell). 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. Evidence of EBV is found in the Reed-Sternberg cells of roughly 30% of patients with Hodgkin’s lymphoma in the U.S.
In order to assess the relationship between the presence of EBV in tumor cells and survival with Hodgkin’s lymphoma, researchers evaluated 922 patients who were diagnosed with Hodgkin’s lymphoma in the San Francisco Bay Area between 1988 and 1997. Patients were followed for a median of 8 years after diagnosis. Overall, EBV was present in the Reed-Sternberg cells of 27% of patients, but this varied by age. EBV was found in 40% of children and older adults and 19% of young adults.
The relationship between EBV presence in tumor cells and survival varied by age.
o In patients under the age of 15 years, EBV appeared to result in better survival, but the small number of deaths in this age group made it difficult to assess survival differences.
o In young adults (15-44 years), there was no relationship between EBV and survival.
o In older adults (45 years or older), the presence of EBV in Reed-Sternberg cells appeared to result in worse survival, but only among patients with a particular subtype of Hodgkin’s disease (nodular sclerosis).
The researchers conclude that the presence of EBV in the Reed-Sternberg cells of patients with Hodgkin’s lymphoma may provide prognostic information. The effect on survival, however, appears to vary by the age of the patient and the subtype of Hodgkin’s lymphoma. The presence of EBV in tumor cells is associated with better survival in young patients, and worse survival in older patients with the nodular sclerosis subtype of Hodgkin’s lymphoma.
Reference: Keegan THM, Glaser SL, Clarke CA et al. Epstein-Barr virus as a marker of survival after Hodgkin’s lymphoma: A population-based study. Journal of Clinical Oncology. 2005;Early online publication September 26, 2005.