Symptom-Heavy Nutritional Insecurity in Older Adults Initiating Chemotherapy

Background: Older adults initiating chemotherapy are highly vulnerable to symptom burden and treatment interference. Nutritional insecurity (NI), barriers in food access, preparation, tolerance, and consumption, is a potentially modifiable determinant of treatment vulnerability, yet its role in shaping symptom pathways during chemotherapy is poorly understood. Objective: To characterize NI as a symptom phenotype and examine associations between NI and symptom burden, functional limitations, life interference, and inflammatory biomarkers in older adults undergoing chemotherapy. Methods: In a cross-sectional analysis nested within a prospective cohort, 79 adults ≥55 years newly diagnosed with cancer and receiving first-line chemotherapy completed NI screening and assessments of physical, psychological, and cognitive symptoms; functional limitations; inflammatory biomarkers (NPAR, NLR, MLR, PLR); and life interference at either pre-chemotherapy (T1) or final chemotherapy (TFinal). Participants were categorized as nutritionally secure (NS) or nutritionally insecure (NI). Group differences were evaluated using chi-square tests, Cramér's V, Mann-Whitney U tests, ANOVA, and risk differences. Results: NI prevalence was 34.2%. Participant demographic and clinical characteristics were largely similar between NI and NS groups in both cohorts. NI participants reported higher prevalence of nearly all symptoms at both time points, with the strongest separation in continuous symptom burden at TFinal (mean rank 33.53 vs. 21.36; p = 0.005). Functional limitations showed minimal NI-related differences. Life interference was greater among NI participants in the T1 cohort but not in TFinal. Inflammatory biomarkers did not differ by NI status, and exploratory analyses showed no biomarker-symptom associations. Conclusions: NI represents a distinct symptom-heavy phenotype marked by elevated symptom burden and early-life interference, without corresponding functional decline or inflammatory abnormalities. Findings support universal NI surveillance in oncology and motivate longitudinal research to clarify NI-symptom-interference pathways and inform targeted interventions for older adults initiating chemotherapy.