Long-range effect of clinical trial interventions on quality of life

Phase III randomized clinical trials have been designed primarily to answer questions of clinical efficacy. Although the primary outcome for most clinical trials is improved survival or disease free survival, recent studies have also compared the efficacy of treatments with no anticipated effects on survival but with different toxicities or rehabilitation outcomes. By identifying treatments with less morbidity, clinical trials have contributed to improving the quality of life of patients with cancer. This paper will highlight several clinical trials that have produced outcomes with quality-of-life implications, including limb-salvage therapy in patients with bone tumors, conservation surgery for patients with breast cancer, and conservation treatment for patients with bladder and laryngeal cancers. Although quality of life has rarely been measured explicitly in these trials, the demonstration that more conservative treatments are equally efficacious permits the discussion of these less radical treatments with patients. However, conservation treatment does affect quality of life, in that combined modality treatment is usually more complex and may not lead to improvement in quality of life in all patients. In the future, we can expect the explicit incorporation of patient-rated quality-of-life assessments in Phase III clinical trials, especially when maintenance of or improvement in quality of life is a specific objective of the trial.