Peer-reviewed article

Phase angle during paediatric cancer treatment: Associations with complications and micronutrients in a multicentre international prospective cohort study.

Nubia Maria Oliveira, Alexis Ross, David C Wilson, Mark Brougham, Jonathan C Wells et al. · 10 Aug 2026

Abstract

BACKGROUND & AIMS: Phase angle (PhA), derived from bioelectrical impedance analysis, is consistently associated with fat-free mass and cellular integrity and has been widely studied as a prognostic marker in several diseases; however, evidence in paediatric oncology remains limited. This study aimed to describe longitudinal changes in PhA during cancer treatment in children and young people (CYP) and to examine associations with treatment-related complications, nutritional status, and micronutrient biomarkers. METHODS: Data were drawn from two prospective cohort studies conducted in Scotland and New Zealand. CYP (<18 years) undergoing cancer treatment were assessed at baseline and at 3, 6, 9, and 12 months. PhA was measured using single-frequency (50 kHz) bioelectrical impedance analysis, and Z-scores (PhA-Z) were calculated. Treatment-related complications were recorded prospectively, and participants were classified into tertiles according to the cumulative number of complications over 12 months (≤3, >3-≤7, and >7). Nutritional status categories (eutrophic, overweight and obese) were defined through body mass index and mid-upper arm circumference. Circulating plasma biomarkers included albumin; vitamins A, E, and B12; magnesium; selenium; and zinc. Mixed-effects models were used to assess longitudinal changes and associations. RESULTS: A total of 115 participants were included, with baseline PhA-Z data available for 68. PhA-Z declined from baseline to 3 months (B = -0.82, 95% CI -1.32, -0.32) and to 6 months (B = -0.63, 95% CI -1.17, -0.08). Post hoc analyses indicated recovery at 12 months compared with 3 (p = 0.001, effect size [ES] = 0.63, 95% CI: 0.32 to 0.96) and 6 months (p = 0.019, ES = 0.54, 95% CI: 0.22 to 0.86). Compared with the >7 complications group, participants with ≤3 and >3-≤7 complications showed higher estimated PhA-Z at 6 (B = 2.04; 2.30), 9 (B = 2.79; 2.07), and 12 months (B = 2.20; 1.82) (p < 0.05). Anthropometric nutritional status classifications were not associated with PhA-Z, while albumin, zinc, and selenium were positively associated. CONCLUSIONS: PhA-Z declined early and recovered later during therapy. Associations with complication burden and selected micronutrients suggest that PhA may be a promising marker of treatment-related alterations in body composition and physiological status, warranting confirmation in larger prospective studies.