A randomized controlled trial to verify the efficacy of the use of ultrasonography in breast cancer screening aged 40-49 (J-START): 76 196 women registered

摘要

Objective: The objective of the Japan Strategic Anti-cancer Randomized Trial was to verify the efficacy of the use of ultrasonography in breast cancer screening among women aged 40-49 years. The purpose of this paper was to report the design and recruitment result of this study. Methods: In this study of women in their 40s, the participants were divided into two groups, one of which (the intervention group) was subjected to mammography and ultrasonography (using a standardized ultrasonography examination), while the other (the control group) was examined with mammography, in a randomized controlled trial, with the objective of verifying the accuracy and efficacy of examinations by comparing the two groups. Results: The cumulative total number of participants registered in the study was 76 196 (38 313 in the intervention group and 37 883 in the control group). 71.0% of participants registered to the study were under individual randomized controlled trial, 25.0% were under cluster randomized controlled trial and 3.9% were under non-randomized controlled group. The study was designed so that participants registered at their first examination underwent examinations by the same method for the subsequent two years. 74.1% of participants scheduled for a second examination had undertaken it, while information regarding the presence of interval cancer had been obtained from a further 20.6% using a questionnaire. At July 2013, the status of 5.3% of all participants was unclear. Conclusions: It was the first large-scale randomized controlled trial carried out in Japan. The scheduled second examinations were completed at the end of fiscal 2012. Once the proportion of participants whose status is unclear has fallen to ≤5%, the authors plan to collate the data relating to the primary end points, and publish the results.