An increasing body of evidence suggests that a lack of exercise can cause a wide variety of diseases, but physical inactivity is not currently recognized as a risk factor for cancer. Two research teams led by Kirsten Moysich, PhD, MS, Distinguished Professor of Oncology in the Department of Cancer Prevention and Control at Roswell Park Comprehensive Cancer Center, have identified a direct association between physical inactivity and two different types of cancer: lung cancer and head and neck squamous cell carcinoma (HNSCC) -; adding to a growing list of cancers linked to sedentary lifestyles.
The researchers used a large database of Roswell Park patients who had completed a questionnaire assessing their level of physical activity throughout adulthood. They compared those diagnosed with lung cancer or head/neck cancer with individuals who had come to Roswell Park with a suspicion of cancer but were determined to be cancer-free. Both studies found that those who reported no history of regular, weekly, recreational physical activity had a higher risk of cancer than those with a habit of at least one regular weekly session of physical activity.
"What is significant is that this increased risk was found even in people who had never smoked and were not overweight," says Rikki Cannioto, PhD, EdD, MS, Assistant Professor of Oncology in the Department of Cancer Prevention and Control at Roswell Park and first author on both studies. "This adds to the growing body of evidence that, much like smoking or obesity, physical inactivity is an independent but modifiable risk factor for cancer."
Although many studies have reported an association between physical inactivity and cancer, this is the first to systematically examine lifetime physical inactivity as an independent risk factor. "This different approach allowed us to identify the most sedentary segment of the population that is most at risk," adds Iris Danziger, MD, Clinical Assistant Professor in the Department Otolaryngology at the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, co-author of the study in head/neck cancer.
Considering that current reports suggest that the majority of Americans are not sufficiently active, these findings have broad and significant implications.
"The link between physical inactivity and cancer was consistently found in both men and women, normal-weight and overweight individuals, and among both smokers and nonsmokers," adds Dr. Moysich. "Our findings strongly suggest that physical activity should be actively encouraged as part of a multidisciplinary cancer care, survivorship and prevention program."