Patel AV et al. -Physical activity, underweight, and obesity are associated with a lower lung cancer risk; however, the associations between physical activity and obesity with lung cancer in smokers have not been established. In the current study physical activity and maintaining a healthy body weight were shown not to be associated with lung cancer risk, regardless of smoking status.

Methods

• 162,679 men and women who were cancer-free at enrollment in the American Cancer Society Cancer Prevention Study-II Nutrition Cohort were studied.
• The associations betweebn baseline recreational physical activity, baseline BMI, and waist circumference in relation to lung cancer risk stratified by smoking status were determined.

Results

• 4669 men and women were diagnosed with lung cancer.
• Physical activity was not associated with lung cancer risk within any of the smoking strata except in former smokers less than 10 years since quitting.
• BMI was inversely associated with lung cancer in former smokers less than 10 years since quitting (RR = 0.68) and to a lesser extent in former smokers who quit 10–19 and 20+ years ago.
• Waist circumference was not associated with lung cancer risk in any smoking category.