Relationship between weakness and phase angle in advanced cancer patients with fatigue

This study aims to determine the relationship between weakness and bioimpedance analysis (BIA)-derived phase angle in a population of untreated cancer patients with fatigue. We prospectively evaluated 41 treatment-naive cancer patients of several origins that presented with performance status 1-2, weight loss > 5 % in the last 6 months, and Fatigue Numeral Scale score > 4. Weakness was considered a physical component of the multidimensional fatigue syndrome and was evaluated through several parameters utilizing hand grip strength technique by dinamometry. The same assessment was also performed on a healthy control population (n = 20). BIA-derived phase angle was also determined by BIA. Compared to healthy controls, cancer patients exhibited significant differences in all the parameters: median fatigue was 6 (range 5-9), evaluated maximal strength mean was 27 +/- 10.71 vs. 42 +/- 10.74 kg (p < 0.0001 for patients vs. control, respectively), and muscle strength difference (max-min muscle strength) was also statistically different (p < 0.0001). We also determined parameter associations within the patient population. We found statistical significant correlations between median phase angle score and endurance muscle with percentage of weight loss (r = 0.43, p = 0.03) for head and neck cancer patients, and in non-small cell lung cancer patients, grip work correlated significantly with normal or decreased phase angle (r = 0.85), p = 0.006 (Spearman Rank Correlation). Weakness could be correlated with normal or decreased phase angle in a population with ambulatory advanced cancer with fatigue naive of treatment. We also found a significant relationship between median phase angle score and endurance muscle with percentage of weight loss in the subpopulation of patients with head and neck carcinoma.