The evolution of axillary staging in breast cancer

PART 1 of the thesis presents two studies that evaluate accuracy of radiological modalities to select breast cancer patients with (one or more) positive axillary nodes. Although several recent randomised studies demonstrated that omitting cALND in selected early breast cancer patients with positive sentinel nodes is oncologically safe, the majority of early breast cancer patients do not meet the eligibility criteria of these trials. These patients should still be submitted for axillary treatment (either ALND or axillary irradiation) in case of one or more positive axillary nodes. In Chapter 2 we evaluated accuracy of AxUS and FNAC in the preoperative diagnosis of axillary lymph node metastases in 1132 women with breast cancer. We determined how many patients could bypass SNB by performing AxUS and FNAC. In Chapter 3 the diagnostic performance of preoperative axillary staging modalities in detecting axillary nodal involvement is reviewed. Modalities that were reviewed are AxUS, ultrasound-guided needle biopsy, MRI and PET-CT. In PART 2 of this thesis we focus on a subgroup of breast cancer patients with a higher risk of axillary lymph node metastases. In Chapter 4, a subgroup of breast cancer patients is identified who harbour a high risk of both axillary node metastases and false negative results of AxUS and FNAC. Preoperative knowledge of (positive) nodal status in these patients might result in a one-stage surgical procedure (breast surgery and ALND at once). Therefore, we hypothesised that this particular group of breast cancer patients might benefit from SNB under local anaesthesia. The results of a randomised clinical trial comparing SNB under local anaesthesia with usual care (SNB during breast surgery) in this subgroup of breast cancer patients are presented (Chapter 5, AMBULANT study). In selected early breast cancer patients with one or two positive sentinel nodes, cALND is no longer needed. Hence, either excluding or identifying patients with high axillary nodal burden (three or more positive axillary nodes) becomes increasingly important. In PART 3 of this thesis two studies are presented regarding selection of breast cancer patients with high nodal burden. In Chapter 6 we retrospectively evaluated 2130 breast cancer patients to determine accuracy of preoperative AxUS and FNAC in detecting high nodal burden. Not only AxUS and FNAC might be used to detect high nodal burden. Therefore, we reviewed whether the current preoperative diagnostic modalities can accurately identify or exclude high nodal burden in Chapter 7. In Chapter 8 we discuss the consequences of the data presented in this thesis for daily practice. In this concluding chapter we will also discuss future developments in the field, especially the ongoing significance of molecular biology in the staging of breast cancer.