Longitudinal network dynamics of nutrition-impact symptoms in nasopharyngeal carcinoma during concurrent chemoradiotherapy: A cross-lagged panel analysis.

PURPOSE: This study applied a longitudinal patient network framework to model time-varying interdependencies among nutrition-impact symptoms in nasopharyngeal carcinoma patients receiving concurrent chemoradiotherapy, seeking to identify the most influential symptoms at each treatment stage and their directional links over time. METHOD: This longitudinal study was conducted from February 2023 and February 2024 at a Grade A tertiary specialized cancer hospital in Guangdong, China. Patients with nasopharyngeal carcinoma undergoing concurrent chemoradiotherapy were recruited and assessed at four time points using the Head and Neck Patient Symptom Checklist. Temporal associations among symptoms were modelled in a cross-lagged panel network, and centrality indices were computed to gauge each symptom's relative influence. RESULTS: A total of 198 patients completed all questionnaires in this study. In the T1-T2 phase, anxiety showed the highest out-expected influence (out-EI = 0.41) and diarrhea showed the highest in-expected influence (in-EI = 0.53). In the T2-T3 and T3-T4 phases, difficulty chewing had the highest out-EI values (out-EI = 1.01; 0.90), while anxiety (in-EI = 0.35) and dry mouth (in-EI = 0.52) yielded the highest in-EI values, respectively. Stability analyses validated the overall reliability of centrality metrics, though the T1-T2 out-EI (CS = 0.126) and T3-T4 in-EI (CS = 0.000) demonstrated poor stability and should be interpreted cautiously. Significant autoregressive effects and reciprocal symptom associations were also observed, indicating dynamic interrelationships among symptoms throughout treatment. CONCLUSIONS: This study explored stage-specific longitudinal associations between psychological related nodes and physical nutrition-impact symptoms in dynamic symptom networks among nasopharyngeal carcinoma patients receiving chemoradiotherapy. Early-stage anxiety related predictive associations should be interpreted cautiously given limited network stability, whereas difficulty chewing emerged as the most influential symptom in the middle and late phases with stable rankings. These correlational findings provide preliminary clues for developing stage-adapted symptom management plans combining psychological and somatic support.