Patient assessed symptoms are poor predictors of objective findings. Results from a cross sectional study in patients treated with radiotherapy for pharyngeal cancer

Introduction. The aim of the study was to assess the value of the EORTC questionnaires C30 and H&N35, as an instrument for the study of side effects. Patients and methods. We invited all recurrence free patients, treated with radical radiotherapy for pharyngeal cancer between 1998 and 2002 at our institution, to participate in the study. Data was retrieved using questionnaires, functional endoscopic evaluation of swallowing, dental examination with orthopantomography and saliva flow measurements. Thirty-five (55% of invited) participated. Results. Side effects were omnipresent and often severe. The value of patient assessed symptom scores to predict equivalent objective changes was varied: We found a sensitivity of 0.59-0.93, specificity of 0.40-0.81, positive predictive value of 0.28-0.81 and a negative predictive value of 0.46-0.94. Conclusion. The questionnaire should be used to retrieve information on subjective side effects and objective examination should be used for objective changes. One cannot conclude from one to the other.