Randomized controlled trial on effectiveness of ultrasonography in breast cancer screening(Japan Strategic Anti-Cancer Randomized Trial) - RCT on ultrasonography in breast cancer screening(J-START)

A. Study Results 1. Standardization and propagation of breast cancer screening with ultrasonography: We formulated "Guidelines for Ultrasonography in Breast Cancer Screening" (Japanese and English versions) in 2007. Further, we developed a breast ultrasonography workshop in line with the Guidelines in order to disseminate the use of breast ultrasonography and provide education, training, and quality control for the institutions. 2. Implementation of a randomized controlled trial (RCT) to examine the effectiveness of ultrasonography: a. A total of 76,196 women in their 40's given informed-consent and participated in the RCT after the study were initiated. b. This is a nationwide study, with participation of 41 institutions from 23 prefectures. Study participation of the groups began in 2007, respectively, demonstrating the feasibility of large-scale clinical trials in Japan.