Research Information System
Journal of Hacettepe University Physical Therapy and Rehabilitation Faculty, vol.4, no.1, pp.14-21, 2026 (Peer-Reviewed Journal)
Purpose: Advances in colorectal cancer (CRC) treatment have significantly increased patient survival rates. However, cancerspecific therapies can induce chronic adverse effects on the cardiovascular system, leading to various symptoms in survivors. The aim of this study was to investigate exercise capacity and cardiac responses to exercise in CRC survivors and compare them with healthy individuals. Methods: The study included twenty-three CRC survivors (aged 18–65 years) and twenty-two age and sex-matched healthy individuals. All participants underwent a Cardiopulmonary Exercise Test (CPET). Physical activity level (SF-IPAQ) and fatigue severity (BFI) were assessed. The chronotropic index (CI) was calculated using the formula (HRpeak-HRrest)/(220-age)(HRrest). Results: Maximal oxygen consumption and the difference between resting heart rate and the peak heart (ΔHR) rate achieved during exercise were lower in CRC survivors compared to healthy individuals (p<0.001, p=0.04, respectively). CI was observed insufficient in 11 (47.83%) CRC survivors and 3 (13.64%) healthy individuals (p=0.01). Whereas physical activity level was similar between the groups (p=0.10), fatigue was more common in CRC survivors (p<0.001). Discussion: Significant reduction in VO2peak, the objective measure of exercise capacity, and the statistically higher prevalence of CI (CI<80%) in CRC survivors highlight a compromise in the cardiovascular system's functional reserve. We suggest that CI acts as a sensitive functional marker of subclinical cardiotoxicity induced by cancer treatments, pointing to an impaired cardiac autonomic response, rather than solely structural heart damage. These findings underscore the long-term need for routine screening of cardiac functional response in this growing population of survivors.