The sensitivity ranges from 26.4% to 94%, and the specificity ranges from 53% to 98% [94-97]. Although axillary US alone has a relatively low NPV to rule out metastatic disease [36,98], axillary imaging is significantly more likely to identify metastatic disease in patients with pN2-3 disease compared with low volume burden (ie, those eligible for axillary preservation according to the Z0011 trial). Therefore, detection of nodal disease can help identify patients who would benefit from neoadjuvant systemic therapy to help downstage and de-escalate their axillary surgery and avoid axillary lymph node dissection. However, imaging is less sensitive in detecting invasive lobular cancer metastasis compared with ductal type [140]. A meta-analysis of 21 studies showed that US combined with needle biopsy improved the sensitivity from 61% to 79% [99-101]. US- guided core needle biopsy was superior to US-guided FNA in a meta-analysis of 1,353 patients with newly diagnosed invasive breast carcinoma, with a reported sensitivity of 88% for core biopsy and 74% for FNA [102]. Axillary US and an MRI performed similarly at evaluating axillary lymph nodes in an additional study [103]. In a meta-analysis of 9,232 cases of preoperative axillary staging procedures in 9,212 patients with breast cancer, preoperative axillary US-guided biopsy was able to identify approximately 50% of women with axillary involvement, but the false-negative rate was 25% [141]. An additional meta-analysis reported similar findings [100]. The NCCN does recommend consideration of axillary US, with marker placement if biopsy is performed, prior to preoperative systemic therapy [126]. US Breast Diagnostic mammography and US together can assess for extent of disease and tumor size. These imaging tests are usually already completed as part of the diagnostic workup (prior to pathological diagnosis). The sensitivity of US for detecting cancer ranges from 79% to 94% [22,25,104,105].
Imaging of Invasive Breast Cancer. The sensitivity ranges from 26.4% to 94%, and the specificity ranges from 53% to 98% [94-97]. Although axillary US alone has a relatively low NPV to rule out metastatic disease [36,98], axillary imaging is significantly more likely to identify metastatic disease in patients with pN2-3 disease compared with low volume burden (ie, those eligible for axillary preservation according to the Z0011 trial). Therefore, detection of nodal disease can help identify patients who would benefit from neoadjuvant systemic therapy to help downstage and de-escalate their axillary surgery and avoid axillary lymph node dissection. However, imaging is less sensitive in detecting invasive lobular cancer metastasis compared with ductal type [140]. A meta-analysis of 21 studies showed that US combined with needle biopsy improved the sensitivity from 61% to 79% [99-101]. US- guided core needle biopsy was superior to US-guided FNA in a meta-analysis of 1,353 patients with newly diagnosed invasive breast carcinoma, with a reported sensitivity of 88% for core biopsy and 74% for FNA [102]. Axillary US and an MRI performed similarly at evaluating axillary lymph nodes in an additional study [103]. In a meta-analysis of 9,232 cases of preoperative axillary staging procedures in 9,212 patients with breast cancer, preoperative axillary US-guided biopsy was able to identify approximately 50% of women with axillary involvement, but the false-negative rate was 25% [141]. An additional meta-analysis reported similar findings [100]. The NCCN does recommend consideration of axillary US, with marker placement if biopsy is performed, prior to preoperative systemic therapy [126]. US Breast Diagnostic mammography and US together can assess for extent of disease and tumor size. These imaging tests are usually already completed as part of the diagnostic workup (prior to pathological diagnosis). The sensitivity of US for detecting cancer ranges from 79% to 94% [22,25,104,105].