Ultraviolet radiation exposure and risk of non-Hodgkin's lymphoma.

Sun exposure has been suggested to increase the risk of non-Hodgkin's lymphoma. The authors analyzed data from a population-based, case-control study of Connecticut women between 1996 and 2000 to study the hypothesis. Women who reported having had a suntan experienced an increased risk of non-Hodgkin's lymphoma with increasing duration (p(trend) = 0.0062) compared with women who reported never having had a suntan. An almost threefold increased risk of non-Hodgkin's lymphoma was observed among women who reported having had a suntan for less than 3 months per year and a suntan history of more than 60 years (odds ratio = 2.8, 95% confidence interval: 1.6, 4.9) compared with those who reported never having had a suntan. For women who reported having spent time in strong sunlight between 9 a.m. and 3 p.m. during the summer, a 70% increased risk of non-Hodgkin's lymphoma was observed for the highest tertile of duration compared with the lowest (odds ratio = 1.7, 95% confidence interval: 1.2, 2.4). The risk increased with increasing duration of time spent in strong sunlight in summer (p(trend) = 0.0051). The risk appears to vary by non-Hodgkin's lymphoma subtypes. Further investigations of the role of ultraviolet radiation on the risk of non-Hodgkin's lymphoma are warranted.