High levels of sedentary behavior, such as reading or watching television, seem to raise the risk of ovarian cancer, new research shows. By contrast, engaging in light or moderate physical activity had no effect on the risk.
The numerous studies that have looked at the impact of physical activity on ovarian cancer risk have produced conflicting results, note Dr. Alpa V. Patel and colleagues at the American Cancer Society in Atlanta. Only one study, conducted in China, examined the role of sedentary activity, which was associated with a minimally increased risk of ovarian cancer risk.
Patel’s group evaluated data from the American Cancer Society Cancer Prevention Study II Nutrition Cohort, which followed nearly 60,000 postmenopausal women from 1992 until 2001. During that time, 314 women developed ovarian cancer, the researchers report in the American Journal of Epidemiology.
The subjects had completed questionnaires every 2 years asking about time spent in recreational and non-recreational physical activities. The women were also questioned about the average number of hours per day spent sitting (apart from time at work).
As noted, the authors observed no significant relationships between type or degree of physical activity and ovarian cancer risk.
However, women who spent more than 3 hours per day sitting during leisure time had a 55 percent higher risk of developing ovarian cancer than did women who were less sedentary.
According to the authors, a sedentary lifestyle could lead to hormone changes that promote the development of cancerous cells. They call for further research in this area.