Wu Dongfeng
Department of Bioinformatics and Biostatistics, University of Louisville.
Stat Interface. 2022;15(4):503-514. doi: 10.4310/21-sii716. Epub 2022 Mar 4.
A probability method is developed to decide when to initiate cancer screening for asymptomatic individuals. The probability of incidence is a function of screening sensitivity, time duration in the disease-free state and sojourn time in the preclinical state; and it is monotonically increasing as time increases, given a person's current age. So a unique solution of the first screening time can be found by limiting this probability to a small value, such as 10% or 20%. That is, with 90% or 80% probability, one will not be a clinical incident case before the first exam. After this age is found, we can further estimate the lead time distribution and probability of over-diagnosis if one would be diagnosed with cancer at the first exam. Simulations were carried out under different scenarios; and the method was applied to two heavy smoker cohorts in the National Lung Screening Trial using low-dose computerized tomography. The method is applicable to other kinds of cancer screening. The predictive information can be used by physicians or individuals at risk to make informed decisions on when to initiate screening.
开发了一种概率方法来确定何时开始对无症状个体进行癌症筛查。发病率概率是筛查敏感性、无病状态持续时间和临床前状态停留时间的函数；在给定一个人当前年龄的情况下，随着时间的增加，它会单调增加。因此，通过将这个概率限制在一个较小的值，比如10%或20%，可以找到首次筛查时间的唯一解。也就是说，有90%或80%的概率，一个人在首次检查之前不会成为临床发病病例。找到这个年龄后，如果一个人在首次检查时被诊断出患有癌症，我们可以进一步估计提前期分布和过度诊断的概率。在不同场景下进行了模拟；该方法应用于国家肺部筛查试验中使用低剂量计算机断层扫描的两个重度吸烟者队列。该方法适用于其他类型的癌症筛查。医生或有风险的个体可以使用这些预测信息，以便就是否开始筛查做出明智的决定。
