One of the easiest ways to reduce your risk of cancer is to exercise.
A growing number of studies has shown that for many types of the disease. What's less clear is how much physical activity – the intensity and duration – makes a difference.
Now, Roswell Park Comprehensive Cancer Center researchers have looked at the question from a different angle, showing in two new studies that physical inactivity significantly increases the risk of cancers of the lung, and head and neck. Indeed, there was an almost doubling of lung cancer risk and a tripling of risk for head and neck cancer in the least active individuals.
Their work indicates you don't have to turn into a gym rat to benefit.
"The data suggest that any amount of regular exercise seems to be protective," said Rikki Cannioto, assistant professor of oncology and co-first author on the studies, one in Cancer Treatment Research Communications and the other in the European Archives of Oto-Rhino-Laryngology.
"You don't have to run a marathon. Just get off the couch. Take the stairs instead of the elevator," said Kirsten Moysich, a distinguished professor of oncology who led the research teams.
They examined hundreds of Roswell Park patients from 1990 to 1998 who completed a questionnaire assessing their level of physical activity throughout adulthood, comparing those with lung or head/neck cancer with individuals who came to the cancer center with a suspicion of cancer but were determined to be cancer-free. Both studies found that those who reported no history of regular recreational physical activity had a higher risk of cancer than those with a habit of at least one regular weekly session of physical activity.
Inactivity increased the risk of these cancers regardless of the individuals' weight or whether they smoked cigarettes, two risk factors for cancer. In lung cancer, the researchers also found that the study participants who exercised regularly over many years tended to live longer.
The research received support from the Roswell Park Alliance Foundation, the state Health Department, and National Cancer Institute. This was an observational study, meaning it can't establish a cause and has limitations, such as the information about exercise being self-reported by the patients.
Lung cancer is the second most common cancer in both men and women, with an estimated 234,030 new cases and 154,050 deaths expected in the United States this year, according to the American Cancer Society. Head and neck cancer is less common, with 51,540 new cases and 10,030 deaths expected in 2018.