16 Background: Cancer-related fatigue (CRF) is a prevalent and debilitating symptom among patients with colorectal cancer. Engaging in physical activity (PA) may help reduce fatigue. This study aims to evaluate longitudinal associations between self-reported PA, CRF, and quality of life (QoL) across the cancer journey. Methods: We analyzed data from 1718 participants in the International ColoCare Study, a prospective multicenter cohort of newly diagnosed colorectal cancer patients across all disease stages. PA was assessed at baseline and at 6-, 12-, and 24-month post-diagnosis using a validated IPAQ-based questionnaire. MET-minutes/week were calculated for walking, moderate, and vigorous activities, and total PA was categorized as low ( 3000). CRF and QoL were measured using the EORTC QLQ-C30 scale. Generalized linear models and mixed-effects models were used to evaluate associations between PA and fatigue over time, stratified by disease stage. Results: Among patients with non-metastatic colorectal cancer, walking showed the most consistent benefit in reducing fatigue (β = -2.69, 95% CI: -4.85 to -0.53), particularly during the first year after diagnosis (β = -2.29, 95% CI: -4.32 to -0.25). Moderate and vigorous activity showed benefits primarily in later survivorship (β = -1.94, 95% CI: -3.77 to -0.11; β = -1.79, 95% CI: -3.65 to 0.06, respectively). PA at 12 months post-diagnosis, rather than baseline, was the strongest independent predictor of lower fatigue and better QoL at 24+ months (OR = 0.79; p = 0.041). In patients with metastatic disease, PA was non-significantly linked to improved outcomes. Conclusions: Greater PA, particularly walking, was associated with reduced CRF and improved QoL in colorectal cancer patients, with stronger effects observed in early-stage disease. Maintaining PA following completion of first-line treatment (approximately 1 year post-diagnosis) may be a critical window for behavioral intervention to reduce risk of fatigue. Our results support the integration of stage- and recovery phase-specific PA recommendations into survivorship care and highlight walking as a scalable, low-risk intervention. Subgroup Time Point Walking Moderate Vigorous Fatigue Score Quality of Life N Non-Metastatic Baseline 156.8 ± 326.0 112.1 ± 284.6 115.8 ± 439.8 32.5 ± 26.9 62.2 ± 23.2 1111 6 Months 321.1 ± 371.3 170.7 ± 322.1 160.0 ± 505.3 37.0 ± 27.2 64.0 ± 21.1 710 12 Months 344.2 ± 389.9 224.8 ± 358.1 175.3 ± 457.1 29.0 ± 25.0 70.1 ± 20.6 641 24 Months 351.3 ± 384.3 220.1 ± 345.3 187.6 ± 489.1 26.8 ± 24.0 71.5 ± 21.6 284 Metastatic Baseline 149.7 ± 304.0 101.8 ± 272.0 119.9 ± 458.9 40.7 ± 28.2 57.3 ± 23.6 208 6 Months 270.0 ± 286.6 132.0 ± 273.5 98.4 ± 370.6 42.2 ± 26.9 61.2 ± 20.5 115 12 Months 310.4 ± 379.1 133.0 ± 295.4 127.0 ± 459.7 37.1 ± 24.8 65.3 ± 21.0 96 24 Months 508.6 ± 424.8 203.4 ± 266.0 244.6 ± 641.5 36.4 ± 27.0 62.7 ± 25.1 31
Liu et al. (Sat,) studied this question.