The symptoms of both cancer and cancer treatment (eg, pain, fatigue, poor appetite, sleep disturbance, and cognitive impairment), like the symptoms of other chronic diseases, can significantly impair a patient's quality of life, comfort, and ability to function. The inability to tolerate treatment-related symptoms often preempts full and effective treatment, and residual symptoms of treatment may limit the functioning of those who are otherwise cured of the disease.

Reducing the severity and impact of symptoms is naturally an endpoint for clinical trials that include symptom-focused interventions. In contrast, symptom management during clinic visits requires planning that is based on the clinician's having the best possible information about the patient's symptom status. Because clinicians and patients commonly face choices among treatments that are similarly effective for tumor control and prolonging survival, differences in the patient's symptoms during the survival period have become critical variables in making individualized treatment choices and in developing new therapies. Thus, having the ability to compare treatment-related symptoms provides an additional benchmark for appraising various cancer treatments. Policy planning and quality assurance also depend on information about the extent and severity of symptoms. All of these objectives require symptom measurement, the focus of this chapter.

Although symptoms are based on complex biological and behavioral phenomena, as subjective experiences their measurement is typically restricted to self-report. This chapter presents a status report on characterizing and measuring cancer-related symptoms by asking the patient about them using single items, single-symptom multi-item measures, and multisymptom questionnaires.