However, a meta-analysis of second-look US following a suspicious finding on MRI showed heterogeneity in US performance, with the detection rate ranging from 22.6% to 82.1% (pooled detection rate 57.5%) and an 87.8% pooled NPV [110]. Therefore, a negative US is insufficient to obviate the need for an MRI biopsy in this setting. There is no evidence supporting US as an accurate method for determining disease extent in those diagnosed with the ILC subtype. Conventional imaging with mammography and/or US can significantly underestimate the span of ILC [26,111-114]. For example, US specifically underestimated ILC tumor size by 27% (95% CI, 17%-37%) in a study [113], and a different study showed that the greatest discrepancy between tumor size and pathologic size using US measurements was for those with the ILC subtype [26]. Variant 4: Newly diagnosed. Clinical stage IIB-III (late stage) breast cancer at presentation. Evaluation for distant disease. IDC or ILC that is ER+/HER2-. It has long been recognized that steroid receptor expression reflects intrinsic biologic diversity in breast cancer with treatment and survival implications, also determining patterns of metastatic spread. The specific response patterns and outcomes associated with ER/PR/HER2 status occur despite the known limitation of pathologic sampling and receptor expression heterogeneity [142]. Historically, bone is the most likely site of breast cancer metastases (51%), followed by liver/soft tissue (19%), pleura (16%), lung (14%), and brain (4%) [115]. The higher percentage of bone metastases from breast cancer appears to be driven primarily by the majority of primary tumors expressing ER and/or PR. In 1 large multidecade study, 82% of patients with breast cancer who developed bone metastases had either ER and PR or ER positivity in the primary tumor [115].
Imaging of Invasive Breast Cancer. However, a meta-analysis of second-look US following a suspicious finding on MRI showed heterogeneity in US performance, with the detection rate ranging from 22.6% to 82.1% (pooled detection rate 57.5%) and an 87.8% pooled NPV [110]. Therefore, a negative US is insufficient to obviate the need for an MRI biopsy in this setting. There is no evidence supporting US as an accurate method for determining disease extent in those diagnosed with the ILC subtype. Conventional imaging with mammography and/or US can significantly underestimate the span of ILC [26,111-114]. For example, US specifically underestimated ILC tumor size by 27% (95% CI, 17%-37%) in a study [113], and a different study showed that the greatest discrepancy between tumor size and pathologic size using US measurements was for those with the ILC subtype [26]. Variant 4: Newly diagnosed. Clinical stage IIB-III (late stage) breast cancer at presentation. Evaluation for distant disease. IDC or ILC that is ER+/HER2-. It has long been recognized that steroid receptor expression reflects intrinsic biologic diversity in breast cancer with treatment and survival implications, also determining patterns of metastatic spread. The specific response patterns and outcomes associated with ER/PR/HER2 status occur despite the known limitation of pathologic sampling and receptor expression heterogeneity [142]. Historically, bone is the most likely site of breast cancer metastases (51%), followed by liver/soft tissue (19%), pleura (16%), lung (14%), and brain (4%) [115]. The higher percentage of bone metastases from breast cancer appears to be driven primarily by the majority of primary tumors expressing ER and/or PR. In 1 large multidecade study, 82% of patients with breast cancer who developed bone metastases had either ER and PR or ER positivity in the primary tumor [115].