Clinical axillary nodal staging in breast cancer using preoperative ultrasonography

Abstract

Purpose: Among preoperative imaging modalities for axillary nodal staging in patients with breast cancer, Ultrasonography has been shown in many studies to have superior diagnostic accuracy. However, most of them are focused in ultrasonographic criteria toward abnormal nodes. We attempted to compare the differences in ultrasonographic findings according to the nodal stages. Methods: We divided consecutive 140 invasive breast cancer patients with axillary node metastases operated without neo-adjuvant therapy at our institution between January 2004 and June 2008 into pN1 (n= 83, 59.3%) and pN2-3 stages (n= 57, 40.7%), classified ultrasonographic findings into 8 categories, and statistically analyzed differences between the two groups. Results: Complete loss of central echogenicity/fatty hilum and abnormally rounded/irregular shape were statistically significantly higher in pN2-3 stage (P= 0.017 and P= 0.026, respectively). Odds ratios were 2.443 and 2.485, respectively. The number of mean metastatic nodes was more statistically significant in patients with abnormally rounded/irregular shape (P= 0.021). Conclusion: Patients whose ultrasonographic surveys show complete loss of central echogenicity/fatty hilum or abnormally rounded/irregular shape will most likely have a higher metastatic tumor burden in their axillae (≥ 4 positive nodes). Classifications in ultrasonographic findings of axillary node may be of help toward more exact pretreatment clinical axillary nodal staging, especially in neo-adjuvant setting.