Pre- and Postdiagnosis Physical Activity and TV Viewing Affect Overall Survival in Colorectal Cancer


Key Points

  • Both pre- and postdiagnosis increased leisure-time physical activity were associated with reduced risk of overall mortality, as was decreased prediagnosis TV watching.
  • Pre- and postdiagnosis increased activity and reduced TV watching were associated with nonsignificant reductions in risk for colorectal cancer mortality.

In a study reported in the Journal of Clinical Oncology, Arem et al found that increased leisure-time physical activity prior to and increased activity after colorectal cancer diagnosis were associated with improved overall survival, as was less television watching prior to diagnosis.  

Study Details

The study involved data on prediagnosis (n = 3,797) and postdiagnosis (n = 1,759) leisure-time physical activity and TV watching for colorectal cancer patients in the National Institutes of Health–AARP Diet and Health Study.

Physical Activity

Risk of all-cause mortality was significantly reduced for patients reporting > 7 hours per week vs no leisure-time physical activity prior to diagnosis (hazard ratio [HR] = 0.80, 95% confidence interval [CI] = 0.68–0.95, P = .021 for trend) and after diagnosis (HR = 0.69, 95% CI = 0.49–0.98, P = .006 for trend).

For the prediagnosis comparison, greater activity was associated with nonsignificant reductions in risk for colorectal cancer mortality (HR = 0.84, 95% CI = 0.66–1.07, P = .28 for trend) and cardiovascular disease mortality (HR = 0.78, 95% CI = 0.52–1.15, P = .24 for trend). Among patients with postdiagnosis activity > 7 vs 0 hours/week, there was a nonsignificant reduction in risk of colorectal cancer mortality (HR = 0.53, 95% CI = 0.27–1.03, P = .04for trend) and no association with cardiovascular mortality (HR = 0.89, 95% CI = 0.42–1.86, P = .38 for trend).

TV Watching

Risk of all-cause mortality was significantly increased for ≥ 5 hours vs 0 to 2 hours per day of TV watching before diagnosis (HR = 1.22, 95% CI = 1.06–1.41, P = .002 for trend) and nonsignificantly increased in the postdiagnosis TV watching comparison (HR = 1.25, 95% CI = 0.93-1.67, P = .126 for trend). There was no significant increase in colorectal cancer mortality (HR = 1.18, 95% CI = 0.82–1.68, P = .09 for trend), but a significantly increased risk of cardiovascular mortality (HR = 1.55, 95% CI = 1.07-2.23, P = .01 for trend) for the prediagnosis comparison. For the postdiagnosis comparison, there were no significant increases in risk for colorectal cancer mortality (HR = 1.45, 95% CI = 0.85–2.47, P = .16 for trend) or cardiovascular mortality (HR = 0.72, 95% CI = 0.36–1.42, P = .38 for trend).

The investigators concluded: “[Leisure-time physical activity] was inversely associated with all-cause mortality, whereas more TV watching was associated with increased mortality risk. For both [leisure-time physical activity] and TV watching, postdiagnosis measures independently explained the association with mortality. Clinicians should promote both minimizing TV time and increasing physical activity for longevity among survivors of [colorectal cancer], regardless of previous behaviors.”

Hannah Arem, MHS, PhD, of the National Cancer Institute, is the corresponding author for the Journal of Clinical Oncology article.

The study was supported by the National Cancer Institute. Albert Hollenbec, AARP, reported a relationship with Love/Avon Army of Women.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.