Cancer symptom response as an oncology clinical trial end point.

INTRODUCTION: A critical challenge in oncology is interpreting clinical trial results to inform clinical decision making. Clinical trials typically focus on overall survival (OS) and progression-free survival (PFS) as primary endpoints, which do not reflect early signs of meaningful patient benefit or harm. Cancer symptom response (CSR) can provide information about early treatment response, and studies show that CSR predicts long-term health outcomes. AREAS COVERED: CSR requires careful consideration of its measurement and interpretation to facilitate integration into clinical practice. We describe considerations for the evaluation, analysis, and interpretation of CSR in clinical trials. To illustrate the potential clinical value of CSR, we performed a retrospective analysis of a three-arm randomized cooperative-group clinical trial. EXPERT COMMENTARY: Evaluation of CSR provides a meaningful assessment of early cancer treatment effects. It can act as an early signal of disease progression and death and thus can identify which patients with stable disease will have a more favorable prognosis. Future research will include development of methods for more accurate assessment of CSR, reduction of the number of symptoms used as signals for disease progression or survival by tumor type, and statistical methods that effectively correct for missing data and informative censoring.