Nutritional Interventions in Head and Neck Cancer Patients Undergoing Chemoradiotherapy: A Systematic Review and Meta-Analysis

<b>Background:</b> Head and neck cancer patients frequently encounter nutritional deterioration, culminating in poor clinical and treatment-related outcomes and reduced quality of life. This systematic review and meta-analysis aim to examine the effects of non-invasive nutritional interventions on nutritional status and clinical, biochemical, and patient-reported outcomes. <b>Methods:</b> A comprehensive literature search across five databases (PubMed, CINAHL, ProQuest, Medline, and Scopus) was carried out to identify potentially relevant randomized control trials published in English between 2019 and 2024. Screening, extraction of data, and quality check were carried out separately by two reviewers. The Joanna Briggs Critical Appraisal tools assessed the quality of the included studies and evidence certainty was appraised using the GRADE framework. Depending on the amount of heterogeneity present, a random or fixed-effects model was used to conduct the meta-analysis. <b>Results:</b> Eleven studies were included, involving 1000 participants. Pooled estimates showed significant effects on weight (SMD = 0.171, 95%CI: 0.008, 0.335, <i>p</i> = 0.04), serum albumin (SMD = 0.539, 95%CI: 0.150, 0.927, <i>p</i>= 0.007), and patient-generated subjective global assessment score (SMD = -0.518, 95%CI: -0.931, -0.106, <i>p</i> = 0.014) in the intervention group compared to controls. Bias concerns were observed in some studies, largely stemming from inadequate blinding and deviations from intention-to-treat analysis. Evidence certainty ranged from moderate to very low. <b>Conclusions:</b> Non-invasive, patient-directed nutritional interventions may lead to clinically meaningful benefits in patients with head and neck cancer receiving chemoradiotherapy, particularly for the maintenance of body weight and nutritional status. However, robust, adequately powered trials with standardized reporting of intervention components and outcome measures are needed in the future to strengthen the evidence base for clinical application.