Interval cancer in mammogram screening: Incidence and diagnostic value of additional ultrasonography in Thai women.

ABSTRACT

Objective: The purpose of this study was to characterize the mammographic and ultrasonographic ( US) findings in interval cancer and to evaluate incidence and additional diagnostic value of US in interval breast cancer. Methods: A retrospective study involved three women who had negative results in both screening mammogram and US within 18 months before a diagnosis of breast cancer. The mammographic and US findings were classified according to Breast Imaging Reporting and Data System, categories 0-5. The method of detection, tumor histologic grade, axillary node status and tumor size were analyzed. Results: The interval cancer incidence in our institute was 3.14 per 10,000 screens. Three interval cancers were found. All patients had heterogenous dense breasts. Two of the three interval cancers could only be identified by US. All of them were invasive cancer with a high-to-intermediate grade (grade 2-3). Conclusions: Adjunctive US is noninvasive and valuable a modality for detection and characterization of interval cancer.