Abstract
Objective: The combination of mammography and ultrasonography for breast cancer screening has recently become more common. We aimed to evaluate the value of the combined assessment by analyzing breast cancer cases that were positive only on either mammography or ultrasonography.
Methods: Of the 27,449 patients who underwent combined screening for breast cancer using mammography and ultrasonography at our institution, 117 were diagnosed as having breast cancer. We analyzed the characteristics of 28 patients with ultrasonography-positive and mammography-negative cancer and 19 patients with mammography-positive and ultrasonography-negative cancer.
Results: The detection of breast cancer by mammography and ultrasonography in combination was 1.3 times higher than that by single-modality screening. High breast density accounted for 78.6% of the cancers cases that were positive only on ultrasonography during screening. The diameters of the cancers that were positive only on ultrasonography were 4–20mm and 4.5–8mm in high- and non-high-density breasts, respectively. Ultrasonography screening permitted the detection of early-stage invasive ductal carcinoma and changes in lesions of even 1–2mm. The most common finding and site of the cancer that showed positive results on only mammography were calcification (63.2%) and periphery of the breast and below the nipple (52.6%), respectively.
Conclusions: Owing to the specific characteristics of each modality, the use of mammography and ultrasonography in combination is valuable for breast cancer screening.
