Bioelectrical Impedance Analysis and Phase Angle in Cancer Care: Prognosis, Nutrition, and Clinical Utility in 19.151 Patient

Background: Cancer-related malnutrition and inflammation worsen clinical outcomes. Bioelectrical impedance analysis (BIA) provides raw parameters—resistance (R) and reactance (Xc)—from which phase angle (PhA) is derived as a proxy of cell‐membrane integrity and hydration. We reviewed the clinical utility of PhA (and related metrics) in oncology. Methods: We conducted an integrative review (PubMed/MEDLINE, Embase, Scopus, and Virtual Health Library; 2005–2025) including human studies reporting BIA with PhA in patients with cancer. Screening and reporting followed PRISMA 2020. Study design, tumor site, interventions, and outcomes (nutrition, complications, length of stay, treatment tolerance, and survival) were extracted and narratively synthesized. Results: We included 159 studies, predominantly observational. Across settings and tumor sites, lower PhA was consistently associated with worse overall survival, more postoperative and treatment-related complications, longer hospitalization, poorer functional status, and lower quality of life. In longitudinal analyses, PhA typically declined after surgery and along chemo/radiotherapy, whereas stabilization or increases occurred with structured nutritional support and multimodal care. Vector analysis (BIVA) showed the canonical right-downward displacement on the R/H × Xc/H plane, consistent with higher ECW/TBW, reduced body cell mass, and impaired membrane integrity. Standardized PhA (SPhA, age/sex-adjusted) improved comparability and prognostic performance in several cohorts. Methodological variability—device/frequency, posture, hydration control, and heterogeneous cut-offs—remains the main barrier to guideline-level adoption. Conclusions: PhA is an accessible, non-invasive, and responsive biomarker that adds prognostic and nutritional value across oncologic scenarios. We recommend integrating PhA (preferably SPhA), together with BIVA and fluid-distribution metrics, into routine screening, peri-treatment monitoring, and risk stratification. Future multicenter studies should establish tumor-, sex-, age-, and stage-specific cut-offs and standardized measurement/reporting protocols.