Chang Chung, Hsieh Meng-Ke, Chang Wen-Yi, Chiang An Jen, Chen Jiabin
Department of Applied Mathematics, National Sun Yat-sen University, Kaohsiung, Taiwan, ROC.
Department of Obstetrics and Gynecology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ROC.
PLoS One. 2017 Apr 27;12(4):e0176231. doi: 10.1371/journal.pone.0176231. eCollection 2017.
It is often helpful to classify biomarker values into groups of different risk levels to facilitate evaluation of a biological, physiological, or pathological state. Stratification of patients into two risk groups is commonly seen, but there is always need for more than two groups for fine assessment. So far, there are no standard methods or tools to help decide how many cutoff points are optimal. In this study, we developed a comprehensive package that included methods to determine both the optimal number and locations of cutoff points for both survival data and dichotomized outcome. We illustrated workflow of this package with data from 797 patients with cervical cancer. By analyzing several risk factors of cervical cancer such as tumor size, body mass index (BMI), number of lymph nodes involved and depth of stromal invasion, in relation to survival and clinical outcome such as lymph nodal metastasis and lymphovascular invasion, we demonstrated that the best choice for BMI and stromal invasion was two cutoff points and one for the others. This study provided a useful tool to facilitate medical decisions and the analyses on cervical cancer may also be of interest to gynecologists. The package can be freely downloaded.
将生物标志物值分类为不同风险水平的组，通常有助于评估生物学、生理学或病理状态。将患者分为两个风险组很常见，但为了进行精细评估，往往需要两个以上的组。到目前为止，还没有标准的方法或工具来帮助确定最佳的截断点数量。在本研究中，我们开发了一个综合软件包，其中包括确定生存数据和二分结局的截断点的最佳数量和位置的方法。我们用797例宫颈癌患者的数据说明了该软件包的工作流程。通过分析宫颈癌的几个风险因素，如肿瘤大小、体重指数（BMI）、受累淋巴结数量和间质浸润深度，以及与生存和临床结局（如淋巴结转移和淋巴管浸润）的关系，我们证明BMI和间质浸润的最佳选择是两个截断点，其他因素为一个截断点。本研究提供了一个有助于医疗决策的有用工具，对宫颈癌的分析可能也会引起妇科医生的兴趣。该软件包可免费下载。
