已经提出了采用接收器操作特征表面来测量生物标记准确性的生物标记，该生物标记将患者分为三组之一：健康、良性或侵袭性疾病。接收器操作特征表面下的体积总结了此类配置中生物标志物的整体辨别能力，但包括与临床不相关的真实分类率相关的截止值。由于胰腺癌的致命性，与识别胰腺癌患者的低真实分类率相关的截止值可能是不可取的，并且不适合在临床环境中使用。在这个项目中，我们研究了一个更集中的标准的属性，即接收器操作特征表面下的部分体积，它总结了标记物在仅限于临床感兴趣的区域的三类设置中的诊断准确性。我们提出了在参数和非参数框架下估计和推断接收者操作特征表面下的部分体积的方法，并将这些方法应用于评估用于诊断胰腺癌的潜在生物标志物。

measures of biomarker accuracy that employ the receiver operating characteristic surface have been proposed for biomarkers that classify patients into one of three groups: healthy, benign, or aggressive disease. The volume under the receiver operating characteristic surface summarizes the overall discriminatory ability of a biomarker in such configurations, but includes cutoffs associated with clinically irrelevant true classification rates. Due to the lethal nature of pancreatic cancer, cutoffs associated with a low true classification rate for identifying patients with pancreatic cancer may be undesirable and not appropriate for use in a clinical setting. In this project, we study the properties of a more focused criterion, the partial volume under the receiver operating characteristic surface, that summarizes the diagnostic accuracy of a marker in the three-class setting for regions restricted to only those of clinical interest. We propose methods for estimation and inference on the partial volume under the receiver operating characteristic surface under parametric and non-parametric frameworks and apply these methods to the evaluation of potential biomarkers for the diagnosis of pancreatic cancer.