A multi-centre randomised trial comparing ultrasound vs mammography for screening breast cancer in high-risk Chinese women

BACKGROUND: Chinese women tend to have small and dense breasts and ultrasound is a common method for breast cancer screening in China. However, its efficacy and cost comparing with mammography has not been evaluated in randomised trials. METHODS: At 14 breast centres across China during 2008-2010, 13 339 high-risk women aged 30-65 years were randomised to be screened by mammography alone, ultrasound alone, or by both methods at enrollment and 1-year follow-up. RESULTS: A total of 12 519 and 8692 women underwent the initial and second screenings, respectively. Among the 30 cancers (of which 15 were stage 0/I) detected, 5 (0. 72/1000) were in the mammography group, 11 (1. 51/1000) in the ultrasound group, and 14 (2. 02/1000) in the combined group (P=0. 12). In the combined group, ultrasound detected all the 14 cancers, whereas mammography detected 8, making ultrasound more sensitive (100 vs 57. 1%, P=0. 04) with a better diagnostic accuracy (0. 999 vs 0. 766, P=0. 01). There was no difference between mammography and ultrasound in specificity (100 vs 99. 9%, P=0. 51) and positive predictive value (72. 7 vs 70. 0%; P=0. 87). To detect one cancer, the costs of ultrasound, mammography, and combined modality were 7876, 45 253, and 21 599, respectively. CONCLUSIONS: Ultrasound is superior to mammography for breast cancer screening in high-risk Chinese women.