Breast Cancer Detected at Screening US: Survival Rates and Clinical-Pathologic and Imaging Factors Associated with Recurrence

Abstract

Purpose To determine the survival rates and clinical-pathologic and imaging factors associated with recurrence in women with breast cancer detected at screening ultrasonography (US). Materials and Methods This study was approved by the institutional review board, and the requirement to obtain informed consent was waived. A retrospective review of the databases of four institutions identified 501 women (median age, 47 years; range, 27-74 years) with breast cancer (425 invasive cancers and 76 ductal carcinoma in situ) detected at screening US between January 2004 and March 2011. Five-year overall survival (OS) and recurrence-free survival (RFS) rates were estimated, and the clinical-pathologic and imaging data were collected. Multivariate analysis was performed by using Cox proportional hazard regression to determine factors associated with recurrence. Results At a median follow-up of 7.0 years (range, 5.0-12.1 years), 15 (3.0%) recurrences were detected: five in ipsilateral breast and 10 in contralateral breast. The 5-year OS and RFS rates were 100% and 98.0% (95% confidence interval [CI]: 96.8%, 99.2%), respectively. In patients with invasive cancers, age younger than 40 years (hazard ratio: 3.632 [95% CI: 1.099, 11.998]; P = .032), the triple-negative subtype (hazard ratio: 7.498 [95% CI: 2.266, 24.816]; P = .001), and Breast Imaging Reporting and Data System (BI-RADS) category 4A lesions (hazard ratio: 5.113 [95% CI: 1.532, 17.195]; P = .008) were associated with recurrence. Conclusion Women with breast cancers detected at screening US have excellent outcomes, with a 5-year RFS rate of 98.0%. However, in patients with invasive breast cancer, age younger than 40 years, the triple-negative subtype, and BI-RADS category 4A lesions were associated with recurrence.