Associations of Postdiagnosis Physical Activity and Change from Prediagnosis Physical Activity with Quality of Life in Prostate Cancer Survivors

BACKGROUND: This prospective study examined the associations between postdiagnosis physical activity and change from prediagnosis physical activity with quality of life (QoL) in prostate cancer survivors. METHODS: Prostate cancer survivors (N = 830) who participated in a case-control study with invasive stage ≥II disease were followed up to 2007 to capture QoL outcomes. At baseline and three time points postdiagnosis (2000-2007), interviews/questionnaires were used to collect data on physical activity, general QoL measured by the SF-36, and other treatment/lifestyle factors. Multivariable linear regression was used to test the relation between postdiagnosis physical activity and QoL as well as the change in physical activity over the diagnostic period and QoL. RESULTS: Both total and recreational physical activities were positively associated with physical QoL. Furthermore, when comparing changes in physical activity levels from pre- to postdiagnosis, men who consistently met physical activity guidelines had significantly higher physical [β = 6.01; 95% confidence interval (CI), 4.15-7.86] and mental (β = 2.32; 95% CI, 0.29-4.34) QoL scores compared with those who did not meet guidelines pre- or postdiagnosis. Furthermore, those who adopted and met guidelines had increased QoL, whereas those who relapsed experienced decreased QoL. CONCLUSIONS: Postdiagnosis recreational physical activity is associated with better physical QoL in prostate cancer survivors. Moreover, prostate cancer survivors who maintain or adopt physical activity after diagnosis report substantially higher QoL than men who never exercised or stopped exercising after diagnosis. IMPACT: Future intervention studies should focus on achieving and maintaining adherence to physical activity guidelines postdiagnosis in prostate cancer survivors. Cancer Epidemiol Biomarkers Prev; 26(2); 179-87.