Should health-related quality of life be measured in cancer symptom management clinical trials? Lessons learned using the functional assessment of cancer therapy.

There are several advantages to including comprehensive health-related quality of life (HRQL) in symptom trials in oncology. The most obvious is to test the hypothesis that HRQL will be improved in addition to the symptom benefit. We should not "require," however, that a successful symptom intervention also improve other dimensions of HRQL. On the other hand, we should expect that it will not make other dimensions worse through side effects or exacerbation of disease, even if it improves the symptom. HRQL assessment in the trial helps evaluate the competing risks of any therapy. Furthermore, assessment of HRQL is now accomplished with very brief assessment (usually 30 questions or less), and the knowledge gained is valuable. With HRQL, one can compare cancer patients with those with other conditions and can determine the contribution of symptoms and side effects to the more broadly defined HRQL. Examples using the Functional Assessment of Cancer Therapy measurement system will demonstrate how HRQL assessment has contributed to our understanding of common cancer symptoms and their place in the conceptualization of HRQL. The prevalence of clinically significant symptoms is greatest in poor performance status (PS) patients compared with patients with good PS. Symptom improvement trials specifically designed for these patients should be encouraged, particularly with interventions that can provide symptomatic relief and improve multidimensional HRQL.