Comparison of Diagnostic Accuracy of Ultrasound and Mammography in Detecting Breast Cancer in Radiographically Dense Breasts.

BACKGROUND

Breast density significantly reduces the sensitivity of mammography, complicating early cancer detection. Ultrasound has emerged as a supplemental imaging modality, especially valuable in women with dense breasts.

OBJECTIVES

This study aimed to evaluate and compare the diagnostic performance, including sensitivity, specificity, and overall accuracy, of ultrasound and mammography in detecting breast cancer among women with radiographically dense breast tissue (Breast Imaging Reporting and Data System (BI-RADS) categories C and D).

METHODS

This prospective, comparative observational study was conducted at Family Health Hospital, Islamabad, Pakistan, from June 2023 to January 2024. A total of 240 female patients (mean age 48.6 ± 9.2 years; range 30-70) were enrolled. Of these, 142 (59.2%) had heterogeneously dense breasts (BI-RADS C) and 98 (40.8%) had extremely dense breasts (BI-RADS D). Mammography included standard two-view digital imaging (craniocaudal and mediolateral oblique), interpreted by radiologists using the BI-RADS classification system.

RESULTS

Out of 240 patients, 68 (28.3%) were histologically confirmed to have breast cancer. Ultrasound showed a sensitivity of 85.3% (58/68) and specificity of 88.4% (152/172), while mammography demonstrated a sensitivity of 61.8% (42/68) and specificity of 91.9% (158/172). Sensitivity analysis by breast density revealed that mammography performed better in heterogeneously dense breasts (77.8% (14/18)) but dropped markedly in extremely dense breasts (43.8% (28/64)). Ultrasound maintained high sensitivity across both groups (86.1% (31/36) in BI-RADS C and 84.4% (27/32) in BI-RADS D). The area under the receiver operating characteristic (ROC) curve (AUC) was 0.89 for ultrasound and 0.78 for mammography.

CONCLUSION

It is concluded that ultrasound significantly improves breast cancer detection in women with dense breasts compared to mammography alone.