Predictors of weight loss during radiotherapy in patients with stage I or II head and neck cancer.

Background: The purpose of the study was to identify predictors of weight loss during radiotherapy (RT) in patients with stage I or II head and neck (HN) cancer.

Methods: This study was conducted as part of a phase 3 chemoprevention trial. A total of 540 patients were randomized. The patients were weighed before and after RT. Their baseline characteristics, including lifestyle habits, diet, and quality of life, were assessed as potential predictors. Predictors were identified using multiple linear regressions. The reliability of the model was assessed by bootstrap resampling. A receiver operating characteristics curve was generated to estimate the model's accuracy in predicting critical weight loss (>or=5%).

Results: The mean weight loss was 2.2 kg (standard deviation, 3.4). Five factors were associated with a greater weight loss: all HN cancer sites other than the glottic larynx (P<.001), higher pre-RT body weight (P<.001), stage II disease (P = .002), dysphagia and/or odynophagia before RT (P = .001), and a lower Karnofsky performance score (P = .028). There was no association with pre-RT lifestyle habits, diet, or quality of life. The bootstrapping method confirmed the reliability of this predictive model. The area under the curve was 71.3% (95% confidence interval, 65.8-76.9), which represents an acceptable ability of the model to predict critical weight loss.

Conclusions: These results could be useful to clinicians for screening patients with early stage HN cancer treated by RT who require special nutritional attention.