Background:Physical activity is associated with reduced mortality and higher quality of life in breast cancer survivors; however, limited data on the prevalence of activity and long-term trends after diagnosis are available. Methods:A multi-ethnic cohort of 631 women (18-64 years) with stage 0-IIIA breast cancer were followed for 10 years. Recreational aerobic activity (MET-hrs/week) was ascertained for the year before diagnosis (baseline), 24 months, 5 and 10 years after enrollment. Women were classified according to U.S. physical activity guidelines (≥150 mins/week moderate or ≥75 mins/week vigorous activity). The odds ratios (OR) for meeting guidelines at 5 and 10 years according to baseline factors was estimated using logistic regression. The change in MET-hrs/wk was predicted using linear regression. Results:Pre-diagnosis, 34% of women met physical activity guidelines; 34.0%, 39.5%, and 21.4% met guidelines at 24 months, 5 years, and 10 years post-enrollment, respectively. Fewer than 8% of survivors met guidelines at all follow-up periods. Over 10 years, recreational aerobic activity decreased by a mean(SD) 4.3(16.2) MET-hrs/wk. . Meeting guidelines pre-diagnosis was strongly associated with meeting guidelines at 5 years [OR (95% CI): 2.76 (1.85-4.1)] and 10 years [OR (95% CI): 3.35 (2.13-5.28)]. No other demographic or prognostic factors were significantly associated with the 10-year change in MET-hrs/wk. Conclusions:The majority of early breast cancer survivors do not meet national exercise recommendations 10 years post-diagnosis. Impact:Physical activity levels are low in breast cancer survivors across the 10 years post-diagnosis, yet the predictors of activity in this population remain poorly understood.
- Received February 4, 2013.
- Revision received March 19, 2013.
- Accepted March 22, 2013.
- Copyright © 2013, American Association for Cancer Research.