Department of Public Health, Erasmus MC, PO Box 2040, Rotterdam 3000 CA, The Netherlands.
Br J Cancer. 2011 Sep 27;105(7):1082-8. doi: 10.1038/bjc.2011.300. Epub 2011 Aug 23.
The optimal interval between two consecutive mammograms is uncertain. The UK Frequency Trial did not show a significant difference in breast cancer mortality between screening every year (study group) and screening every 3 years (control group). In this study, the trial is simulated in order to gain insight into the results of the trial and to predict the effect of different screening intervals on breast cancer mortality.
UK incidence, life tables and information from the trial were used in the microsimulation model MISCAN-Fadia to simulate the trial and predict the number of breast cancer deaths in each group. To be able to replicate the trial, a relatively low sensitivity had to be assumed.
The model simulated a larger difference in tumour size distribution between the two groups than observed and a relative risk (RR) of 0.83 of dying from breast cancer in the study group compared with the control group. The predicted RR is lower than that reported from the trial (RR 0.93), but within its 95% confidence interval (0.63-1.37).
The present study suggests that there is benefit of shortening the screening interval, although the benefit is probably not large enough to start annual screening.
两次连续乳房 X 光检查之间的最佳间隔时间尚不确定。英国频率试验并未显示出在每年（研究组）和每 3 年（对照组）筛查之间乳腺癌死亡率有显著差异。在这项研究中，对试验进行了模拟，以便深入了解试验结果，并预测不同筛查间隔对乳腺癌死亡率的影响。
使用英国发病率、生命表和试验信息，通过 MISCAN-Fadia 微观模拟模型对试验进行模拟，并预测每组中死于乳腺癌的人数。为了能够复制试验，必须假设相对较低的敏感性。
模型模拟的两组之间肿瘤大小分布差异大于观察结果，与对照组相比，研究组死于乳腺癌的相对风险（RR）为 0.83。预测的 RR 低于试验报告的 RR（RR 0.93），但在其 95%置信区间（0.63-1.37）内。
本研究表明，缩短筛查间隔有一定的益处，尽管这种益处可能不足以开始每年进行筛查。
