Quality of Life and Patient-Reported Outcomes During First-Line Chemotherapy in Older Patients with De Novo Metastatic Gastrointestinal Cancers: A Prospective Longitudinal Study

Background/Objectives: This study was conducted to prospectively evaluate quality of life (QoL), patient-reported outcomes, and geriatric domains during the first 3 months of first-line systemic therapy in older patients with de novo metastatic gastrointestinal cancers. Methods: This prospective longitudinal study included 90 patients aged ≥65 years receiving first-line chemotherapy-based systemic therapy. Assessments were performed at baseline, Month 1, and Month 3 using validated QoL, sleep, anxiety, cognitive, and nutritional instruments. The primary endpoint was change in EORTC QLQ-C30 Global Health Status/QoL from baseline to Month 3. Treatment tolerability, initial radiologic response, and exploratory survival outcomes were also assessed. Results: Mean Global Health Status/QoL increased from 68.1 at baseline to 71.0 at Month 3; the model-estimated mean change was +3.0 points (95% CI, −0.3 to 6.2; p = 0.071). Fatigue and appetite loss improved significantly, and normal nutritional status increased from 31.1% to 62.2% (p < 0.001). Clinically meaningful QoL improvement and deterioration occurred in 38.9% and 18.9%, respectively. Treatment intolerance occurred in 46.7%. Disease control was associated with more favorable QoL change than progressive disease (difference, 17.8 points; 95% CI, 6.0–29.7; FDR-adjusted p = 0.008). Baseline nutritional impairment (adjusted HR, 3.58) and poor sleep quality (adjusted HR, 3.30) were associated with shorter progression-free survival. Conclusions: Mean global QoL did not change significantly during the first 3 months, while several symptom and nutritional domains improved. More favorable QoL trajectories were observed with disease control, and baseline nutritional impairment and poor sleep quality were associated with shorter progression-free survival.