Functional Mobility as a Prognostic Marker in Geriatric Oncology: A Prospective Study Using Gait Speed

Background and Objectives: Functional impairment is common in older adults with cancer and may influence treatment outcomes. This study aimed to evaluate the prognostic value of objectively measured functional mobility, with gait speed as the primary analytical variable, for survival, treatment response, and chemotherapy-related toxicity in geriatric cancer patients. Materials and Methods: In this single-center prospective study, 102 patients aged 65 years and older who were chemotherapy-naive were enrolled. Before treatment initiation, functional mobility was assessed using a 3-m gait-speed test at the patient's usual pace. Gait speed was analyzed primarily as a continuous variable; the sample-median cutoff was retained for secondary descriptive analyses, and 0.8 m/s was evaluated in a sensitivity analysis. Associations with survival, treatment response, and toxicity were evaluated using survival and regression analyses. Results: The mean gait speed was 0.481 ± 0.176 m/s. Among patients with metastatic disease, higher continuous gait speed was associated with lower mortality in univariable analysis (HR = 0.752, 95% CI: 0.605-0.934, p = 0.010) and after adjustment for age, sex, and ECOG performance status (adjusted HR = 0.647, 95% CI: 0.490-0.853, p = 0.002). Gait speed was not significantly associated with metastatic PFS, non-metastatic OS or DFS, or grade ≥ 3 toxicity. The 0.8 m/s sensitivity analysis was limited by marked group imbalance. Conclusions: Higher baseline gait speed was associated with lower mortality in metastatic geriatric cancer patients, whereas statistically significant associations were not detected for PFS, non-metastatic survival outcomes, or grade ≥ 3 toxicity. These exploratory findings require validation in larger and more homogeneous cohorts.