Lifetime inactivity may be an independent risk factor for renal and bladder cancers

A lifetime of physical inactivity may be positively associated with both renal and bladder cancers, according to study results published online ahead of print in the journal Cancer Epidemiology, which add to accumulating data that suggest that physical inactivity may be an important independent risk factor for cancer.

“Our findings underscore how important it is to maintain a healthy lifestyle, including getting and staying active,” said lead author Rikki Cannioto, PhD, EdD, MS, assistant professor of oncology, Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, NY. “The Department of Health and Human Services recommends 150 minutes each week of moderate physical activity or 75 minutes each week of vigorous physical activity as a way to generate significant, lasting health benefits.”

In this hospital-based, case-control study, researchers studied the possible associations between lifetime recreational physical inactivity and risk for renal and bladder cancers. They included 160 renal cancer patients, 208 bladder cancer patients, and 766 age frequency-matched controls without cancer.

They classified patients as physically inactive based on patient self-reports of never participating in regular/weekly recreational physical activity throughout their lifetime.

Using multivariable logistic regression models, researchers found significant positive associations between lifetime recreational physical inactivity and risk for renal (OR: 1.77; 95% CI: 1.10-2.85) and bladder cancers (OR: 1.73; 95% CI: 1.13-2.63). Even in patients who were not obese (< 30 kg/m²), the associations were similar for both renal (OR: 1.75; 95% CI: 1.03-2.98) and bladder cancers (OR: 1.70; 95% CI: 1.08-2.69).

“We hope that findings like ours will motivate inactive people to engage in some form of physical activity,” said senior author Kirsten Moysich, PhD, MS, Distinguished Professor of Oncology in the Departments of Cancer Prevention and Control and Immunology, Roswell Park Cancer Institute. “You don’t have to run marathons to reduce your cancer risk, but you have to do something—even small adjustments like taking the stairs instead of the elevator, walking around the block a couple of times on your lunch hour or parking the car far away from the store when you go to the supermarket.”

This work was supported by grants from the New York State Department of Health, Roswell Park Alliance Foundation and National Cancer Institute (project no. T32CA108456).