Breast ultrasound in 22,131 asymptomatic women with negative mammography.

PURPOSE: To evaluate increment cancer detection rate generated by ultrasound (US).

MATERIALS AND METHODS: US only detected cancers were assessed for 22,131 self-referring asymptomatic women with negative mammography and subgroups by age, previous cancer, breast density. Invasive assessment and surgical biopsy rate were evaluated.

RESULTS: The overall US detection was 1.85 per thousand (41/22,131). In the subgroups it was: 1.95 per thousand (22/11,274) in women <50 years vs 1.75 per thousand (19/10,857) in women ≥ 50 years (p = 0.42), 5.49 per thousand (12/2183) in women with previous cancer vs 1.45 per thousand (29/19,948) in women without cancer history (p = 0.0004), 2.21 per thousand (22/9960) in dense breasts (p = 0.17) vs 1.56 per thousand (19/12,171) in fatty breasts. The US generated invasive assessment was 1.9% (422/22,131). The benign to malignant open surgical biopsy ratio was 0.17 (7/41).

CONCLUSION: Adding US to negative mammography allowed for substantial incremental cancer detection rate (1.85 per thousand), particularly at age <50 years, in women with previous breast cancer and in dense breasts.