Physical activity in relation to quality of life in newly diagnosed colon cancer patients: a 24-month follow-up.

PURPOSE: Self-reported health status in cancer patients is an independent predictor of medical outcomes. This study investigated the association between changes in recreational physical activity in colon cancer survivors and quality of life (QoL) across a 24-month follow-up beginning at diagnosis. METHODS: Patients (n = 453) diagnosed with stage II colon cancer were recruited from the North Carolina Central Cancer Registry from 2009 to 2011. Patients were interviewed annually about health behaviors (e.g., dietary intake, physical activity, alcohol and tobacco use), socioeconomic variables, and treatment. To index QoL, the Functional Assessment of Cancer Therapy-Colorectal (FACT-C) and Short Form-12 (SF-12) were utilized. RESULTS: Baseline vigorous exercise showed a positive correlation with the Functional Assessment of Cancer Therapy-General (FACT-G) Colorectal Cancer Scale (CCS) (β = 0.15, 95% CI 0.07-0.23), FACT-C (β = 0.39, 95% CI 0.06-0.72), and Trial Outcome Index (TOI) (β = 0.28, 95% CI 0.01-0.55). Race modified the association between vigorous activity and the FACT-G (P interaction = 0.010), FACT-C (P interaction = 0.020), TOI (P interaction < 0.010), and the PCS (P interaction < 0.010). As compared to no change, increasing physical activity over a 24-month period following diagnosis significantly improved scores from the FACT-G (β = 3.13, 95% CI 0.48-5.77, P trend = 0.054), FACT-C (β = 3.51, 95% CI 0.35-6.68, P trend = 0.08) TOI (β = 2.46, 95% CI 0.16-4.75, P trend = 0.04), and PCS of the SF-12 (β = 3.28, 95% CI 0.93-5.63, P trend < 0.01). CONCLUSION: Vigorous exercise is a significant predictor of higher QoL in stage II colon cancer patients. Patients with increased recreational physical activity have significantly improved QoL over 24 months following diagnosis.