[Multiple Endpoints in Oncology Clinical Trials].

Like most complex(or multifactorial)diseases, cancer results not from a single factor, but rather from the interaction of multiple genes and environmental factors. Thus patients can experience different signs and symptoms that reflect more than one consequence of suffering the disease. When evaluating the effects of new treatments in cancer clinical trials, the multidimensional assessment using multiple outcomes to measure improvements in the patients' signs and symptoms associated with treatments would be preferred. Most cancer clinical trials use more than one clinical outcome as multiple primary, or primary and(key)secondary endpoints, such as overall survival, endpoints based on tumor assessments(e.g., disease-free survival, event-free survival, objective response rate, time to progression, progression-free survival), and endpoints involving symptom assessment. Utilizing multiple endpoints may provide the opportunity for characterizing the intervention's multidimensional effects, but also creates challenges, specifically controlling the Type Ⅰ and/or Type Ⅱ errors in hypotheses testing and trial designs associated with multiple endpoints. In this article, we review issues in design, monitoring, analysis and reporting of clinical trials with multiple endpoints, with illustrating examples in oncology disease settings. We outline several methods for controlling the Type Ⅰ error associated multiple tests, which have been commonly used in clinical trials. We also briefly discuss issues in interim analyses and group sequential designs for clinical trials with multiple endpoints.