The importance of combining of ultrasound and mammography in breast cancer diagnosis

Objective. The aim of this study was to analyse individual and combined sensitivity and specificity of ultrasound and mammography in breast cancer diagnosis and emphasize the importance of combining breast imaging modalities. Patients and methods. By means of a cross-sectional study, ultrasound and mammographic examinations of 148 women (mean age 51.6 ± 10.8 years) with breast symptoms were analysed. All women underwent surgery and all lesions were examined by histopathology analysis which revealed the presence of 63 breast cancers, and 85 benign lesions. In relation to age, the women were separated in to a group under 50 years and a group 50 years and older. Ultrasound and mammographic findings were classified on the BI-RADS categorical scale of 1-5. Categories 1, 2 and 3 were considered negative, while categories 4 and 5 were positive for cancer. For statistical data processing the McNemar chi-square test for paired proportions was used. The differences on the level of p<0.05 were considered statistically significant. Results. In the group under 50 years, the ultrasound sensitivity was significantly higher than the mammographic sensitivity (p=0.045, c2=4), without a statistically significant difference in specificity (p=0.24, c2=1.39). In the women over 50, a significant difference between sensitivity of ultrasound and mammography was not proved (p=0.68, c2=0.17), nor any difference in the specificities (p=0.15, c2=2.08). In the group consisting of all patients, the sensitivity of ultrasound was statistically significantly higher in comparison with the sensitivity of mammography (p=0.04, c2=4.27) with higher specificity (p=0.04, c2=4). By combining the two methods in all patients sensitivity of 96.8% was achieved, in patients up to 50 sensitivity was 90.47% and in patients over 50, sensitivity was 100%. When the two methods were combined in all patients, a decrease in specificity was noted. Conclusion. The combination of ultrasound and mammography in breast cancer diagnosis achieves high sensitivity and the number of undetected breast cancers is reduced to minimum.