Strong cardiorespiratory fitness might help patients who smoke or used to smoke survive lung cancer, according to new research.
"I would like to see more doctors refer patients with risk factors, such as smoking, to an exercise specialist before they are actually diagnosed with lung cancer, other cancers, or chronic conditions," said Baruch Vainshelboim, MD, from Saint Francis University in Loretto, Pennsylvania.
"It's better to prevent than to treat," he told Medscape Medical News, so the aim is to "get them to change their lifestyle to be more physically active, rather than waiting until they are actually diagnosed."
Findings from the study, conducted when Vainshelboim was a post doc at the VA Palo Alto Hospital at Stanford University in California, was presented at the American College of Sports Medicine 2019 Annual Meeting in Orlando.
For their study, Vainshelboim and his colleagues assessed 1602 former smokers (40 pack-years) and 1377 current smokers (43 pack-years). All were men free from lung cancer at baseline, and age in the study cohort ranged from 42 to 76 years.
During the follow-up period, which ranged from 4.6 to 18.6 years, 46 former smokers and 53 current smokers developed lung cancer. Of this group, 40 former smokers and 39 current smokers died.
Men who had higher fitness levels at baseline, measured with a maximal treadmill exercise test, had a lower incidence of lung cancer during follow-up and had better survival if they did get lung cancer.
Among former smokers, the incidence of lung cancer was 60% lower in men with moderate cardiorespiratory fitness than in those with low cardiorespiratory fitness, and was 83% lower in men with high cardiorespiratory fitness (P for trend = .001).
Among current smokers, the incidence of lung cancer was 81% lower in men with moderate cardiorespiratory fitness than in those with low cardiorespiratory fitness, and was 82% lower in men with high cardiorespiratory fitness (P for trend = .001).
"This is an interesting study," said I-Min Lee, MBBS, SCD, from the Harvard T.H. Chan School of Public Health in Boston.
These data support the position of the World Cancer Research Fund that there is some evidence suggesting that physical activity is associated with a decreased risk for lung cancer, Lee, who was not part of the study, told Medscape Medical News.
However, "it is difficult to completely take into account the dose of cigarettes smoked and other tobacco products," she explained. "The findings may be reflecting that lighter users are more likely to be fit and also less likely to develop lung cancer."
Vainshelboim and Lee have disclosed no relevant financial relationships.
American College of Sports Medicine (ACSM) 2019 Annual Meeting: Abstract 1634. Presented May 30, 2019.
Medscape Medical News © 2019
Cite this: Physical Fitness Offsets Harmful Effects of Smoking - Medscape - May 30, 2019.