Chapter 1: Screening, diagnosis & staging of breast cancer and multidisciplinary team working
Percutaneous needle biopsy and axillary staging
A CNB or a vacuum-assisted biopsy (VAB) is taken from the breast. The biopsy is frequently guided by US, sometimes by stereotactic mammography or magnetic resonance imaging (MRI). Sensitivity of biopsies exceeds 98% and false-positive findings are rare.
Figure 1.7: Histopathological assays from core needle biopsy. A core needle biopsy shows grade 3 invasive ductal carcinoma with negative ER staining.
Abbreviations: ER, oestrogen receptor; HER2, human epidermal growth factor receptor 2; ISH, in situ hybridisation.
Credit: Dr Mazen Sudah, Department of Radiology, Kuopio University Hospital, Dr Katja Hukkinen, Department of Radiology, Helsinki University Hospital and Dr Päivi Heikkilä, Department of Pathology, Helsinki University Hospital.
The tissue material obtained with CNB and VAB usually allows detection of invasive tumour growth, histological classification of cancer and the completion of assays for biological features such as hormone receptor status, human epidermal growth factor receptor 2 (HER2) status and Ki-67 expression.
The diagnostic accuracy of fine needle aspiration cytology (FNAC) is lower than that of CNB and depends on the skill of the investigator. FNAC may be used to detect LN metastases and is also useful in the diagnosis and treatment of breast cysts.
The axillary nodal status is considered the most important single prognostic factor and may help in the selection of patients for (neo)adjuvant systemic treatments and radiotherapy (RT).
Axillary US is performed prior to starting cancer treatment. A needle biopsy is taken from the nodes suspected to be cancerous on US.
Figure 1.8: Axillary ultrasound and sentinel lymph node biopsy.
Credit: Dr Mazen Sudah, Department of Radiology, Kuopio University Hospital, Dr Katja Hukkinen, Department of Radiology, Helsinki University Hospital and Dr Päivi Heikkilä, Department of Pathology, Helsinki University Hospital.
A sentinel lymph node biopsy (SLNB) is carried out when metastases are not detected at axillary US.
The sentinel node is the first node to receive lymph drainage from the tumour site in the breast. SLNB is currently the gold standard in nodal staging of patients without metastases at axillary US.
Figure 1.9: Sentinel node detection and dissection.
Credit: Dr Mazen Sudah, Department of Radiology, Kuopio University Hospital, Dr Katja Hukkinen, Department of Radiology, Helsinki University Hospital and Dr Päivi Heikkilä, Department of Pathology, Helsinki University Hospital.
Sentinel nodes are usually detected following injection of a radioactive tracer and/or a blue dye into the breast.
Patients with axillary node metastases, detected before surgery, undergo axillary LN dissection or may be offered neoadjuvant treatment, and, if clinically downstaged, may undergo SLNB or targeted axillary dissection to confirm pathological staging.
Revision questions
- What are the advantages of CNB when compared with FNAC?
- What methods are used for axillary nodal staging?
- What is the sentinel node?
