Association Between Malnutrition and Therapy Intolerance in Cancer Patients: An Observational Cohort Study.

BACKGROUND: Optimal nutrition is integral for health, particularly in oncologic patients undergoing active treatment. However, the impact of inadequate nutrition on tolerance of medical therapy remains unclear. OBJECTIVE: This study aimed to discern whether patients with malnutrition have worse treatment tolerance and identify malnutrition risk factors to guide dietitian-implemented interventions. DESIGN: This retrospective observational study scored nutritional status throughout treatment using Box 3 + Worksheet 1 of the Patient-Generated Subjective Global Assessment (PG-SGA). Scores >3 out of 8 indicated need for dietitian involvement. PARTICIPANTS/SETTING: Eligible patients included those approached for the Moving Through Cancer initiative at the Hillman Cancer Center in Pittsburgh, Pennsylvania with an initial diagnosis between January 2015 and August 2025, no prior treatment, and at least one follow-up visit. MAIN OUTCOMES MEASURES: Main outcomes included early therapy termination and therapy changes secondary to intolerance. STATISTICAL ANALYSES PERFORMED: Linear and logistic regressions analysis were performed; significance was set a priori at 0.05 using Stata. RESULTS: Among 361 records: 169 (46.8%) were female; average age ± SD was 61.4 ± 14.0 years; 123 (34.1%) scored >3 on the PG-SGA. Patients scoring >3 had greater odds of terminating therapy early (adjusted odds ratio (AOR), 6.35 [95% CI, 3.30-12.21]; P < 0.001), changing therapy secondary to intolerance (AOR, 2.79 [95% CI, 1.55-5.02]; P = 0.001 for cytopenia; AOR, 1.93 [95% CI, 1.13-3.30]; P = 0.02 for fatigue; AOR: 2.97 [95% CI, 1.63-5.40]; P < 0.001 for gastrointestinal distress), and seeing outpatient dietitians (AOR, 1.96 [95% CI 1.18-3.25]; P = 0.01). Chemotherapy exposure was associated with 3.10 greater odds of malnutrition ([95% CI, 1.51-6.37]; P = 0.002). Patients with pancreatic cancer had 4.64 times greater odds of scoring >3 on the PG-SGA ([95% CI, 2.29-9.41]; P < 0.001). CONCLUSIONS: These study findings support that dietitian resources should be triaged to higher-risk groups, namely patients with pancreatic cancer or those receiving chemotherapy, to prevent early therapy termination or changes secondary to intolerance.