Research shows that survivors of Hodgkin's disease are to 2- to 3-times more likely to suffer a stroke or mini-stroke, also known as "transient ischemic attack" or TIA, compared with people in the general population.

Much of the increased risk is related to radiation therapy of the neck and mediastinum, the space in the chest behind the sternum (breastbone) between the lungs, the study team reports in the Journal of the National Cancer Institute.

Hodgkin's disease, also known as Hodgkin's lymphoma, is a cancer of the lymphatic system, a part of the immune system. Compared with some other types of lymphoma, Hodgkin's lymphoma usually responds to treatment and most patients can be cured. Because it frequently affects children and young adults, there is a prolonged period in which long-term side effects can develop.

In the current study, Dr. Flora E. van Leeuwen, from the Netherlands Cancer Institute, Amsterdam, and colleagues looked at 2201 five-year survivors of Hodgkin's lymphoma who were treated before they were 51 years old, from 1965 to 1995.

During a median follow-up period of 17.5 years, 55 patients suffered a stroke, 31 had a TIA, and 10 had both.

Relative to the general population, Hodgkin's lymphoma survivors were 2.2- and 3.1-times more likely to experience a stroke or TIA, respectively. Moreover, little change in these risks was noted after prolonged follow-up. Thirty years following treatment for Hodgkin's lymphoma, the cumulative incidence of stroke or TIA was 7%.

Receipt of radiation therapy to the head and neck independently raised the risk of stroke more than 2-fold. Radiation exposure to the neck, the investigators note, might be expected to cause narrowing or "stenosis" of the carotid arteries in the neck, which, in turn, would increase the risk of stroke and TIA.

Chemotherapy was not significantly linked with an increased risk of stroke or TIA.

Other factors increasing the risk of stroke and TIA included high blood pressure, diabetes, and high cholesterol levels.

"For young survivors of Hodgkin's lymphoma, who are at especially increased risk of stroke and TIA," Dr. van Leeuwen's group suggests, "physicians should consider appropriate risk-reducing strategies, such as treatment of hypertension (high blood pressure) and lifestyle changes to reduce the risk of stroke and TIA."