Association Between Multi-frequency Phase Angle and Survival in Patients With Advanced Cancer

The ability to predict survival accurately has implications in clinical decision making.

We determined the association of phase angle obtained from multi-frequency bioelectric impedance analysis with overall survival in patients with advanced cancer.

We included consecutive patients with advanced cancer who had an outpatient palliative care consultation. Multi-frequency bioelectric impedance analysis assessed phase angle at three different frequencies (5/50/250 kHz) on each hemibody (right/left). Survival analysis was conducted using the Kaplan-Meier method, log-rank test, and multivariate Cox regression analysis.

Among 366 patients, the median overall survival was 250 days (95% confidence interval 191-303 days). The mean phase angle for 5, 50, and 250 kHz were 2.2°, 4.4°, and 4.2° on the right and 2.0°, 4.2° and 4.1° on the left, respectively. For all six phase angles, a lower value was significantly associated with a poorer overall survival (P < 0.001). After adjusting for cancer type, performance status, weight loss, and inflammatory markers, phase angle remained independently associated with overall survival (hazard ratio 0.85 per degree increase, 95% confidence interval 0.72-0.99; P = 0.048).

Phase angle represents a novel objective prognostic factor in outpatient palliative cancer care setting, regardless of frequency and body sides.