People who have had eczema at some time in their lives appear to be less likely than others to develop lung cancer. A self-reported history of eczema appears to reduce the risk of lung cancer. The following findings might help to shed light on mechanisms of lung carcinogenesis in humans. According to researchers from the International Agency for Research on Cancer in Lyon, France, persons with a history of eczema have been shown to have a reduced risk of lung cancer, but the evidence has been inconclusive because of the small size of previous studies and their limited ability to control for confounding by smoking. To investigate further, the researchers examined data on 2854 people with lung cancer and 3116 matched controls recruited between 1998 and 2001. A total of 156 of the lung cancer cases (5 percent) and 275 controls (9 percent) reported a history of eczema. After factoring in age, sex, and cumulative tobacco smoking, it was found that a history of eczema reduced the chances of developing lung cancer by 39 percent. Overall, the observed risk reduction was relatively large and might be of significant clinical importance.
American Journal of Epidemiology,
October 2005