Purpose: To confirm which modality, ultrasonography (US) or mammography (MMG), is useful to detect breast cancer in women aged 30 to 39 years, and to compare the sensitivity and findings of these two modalities for invasive carcinoma and ductal carcinoma in situ (DCIS) in the diagnostic setting.
Methods: We retrospectively evaluated the sensitivity and findings of these two modalities in 165 patients aged 30 to 39 years, who underwent surgery at the Cancer Institute Hospital between 2001 and 2003. US or MMG were performed after obtaining information on the other modalities previously used and physical examination. The abnormal findings of US were defined as mass lesions and focal hypoechoic areas due to breast cancer. The abnormal findings of MMG were defined as category 3 to 5 (Japanese Mammography Guidelines) masses, calcifications, and other findings due to cancer.
Results: Of 165 patients, 147 patients (89%) mammographically showed dense breasts. Histologically, 146 (88%) were invasive carcinomas and 19 (12%) were DCIS. In all carcinomas, the sensitivity of US (95%) was higher than that of MMG (85%). The sensitivity of US for invasive carcinoma (99%) was higher than that of MMG (85%). On the other hand, the sensitivity of MMG for DCIS (89%) was much higher than that of US (68%).
Conclusions: US is more sensitive to detect breast cancers than MMG in this age range, especially for invasive carcinoma. On the other hand, MMG is useful for detecting DCIS, especially when it manifests with microcalcifications.