Bioelectrical impedance phase angle as indicator and predictor of cachexia in head and neck cancer patients treated with (chemo)radiotherapy

BACKGROUND/OBJECTIVES: Malnutrition and cachexia have a negative impact on the course of treatment in patients with head and neck squamous cell carcinoma (HNSCC). Good evidence exists for the practical use of the bioelectrical impedance analysis (BIA) parameter phase angle (PA) for the evaluation of nutritional and overall health status in cancer patients. In the present study, two hypotheses were tested: that PA can distinguish between malnutrition and cachexia; in non-cachectic patients, pre-treatment PA is predictive for cachexia development during (chemo) radiation. SUBJECTS/METHODS: In 55 head and neck cancer patients, nutritional status was determined by the NRS-2002, anthropometric, laboratory tests and BIA before and after (chemo) radiotherapy. For the diagnosis of cachexia, the international consensus criteria were used. Patients were categorized as well-nourished, malnourished or cachectic. The resulting group distribution was compared with pre- and post-treatment PA values. RESULTS: Before treatment, 69.1% of patients were well-nourished, 16.4% malnourished and 14.5% cachectic; post-treatment proportions were 16.4%, 45.4% and 38.2%, respectively. Well-nourished patients had a higher pre-treatment mean PA value compared with the others (P = 0.045). The risk of malnutrition/cachexia increased by 1.71 (95% confidence interval (CI) 1.10-2.66) per mean PA decrease by one unit (P = 0.018). In 47 initially non-cachectic patients, PA failed to show any predictive value for cachexia (area under the receiver operating characteristic curve: 0.578, 95% CI 0.385-0.772, P>0.05). CONCLUSIONS: PA did not distinguish between malnourished and cachectic patients with HNSCC, and pre-treatment PA did not predict cachexia development during (chemo) radiation. Nevertheless, PA seems to be a good marker of nutritional status in HNSCC patients.