Abstract
SLNB has revolutionized staging and treatment in breast cancer patients, several issues provoked renewed attention. If small lymph node metastases are relevant, the pathologist should detect them. The current Dutch pathology guideline is not sensitive enough to detect them. To obtain a 95% detection probability for 200μm metastasesthe interval between
... read more
sections should be 200μm and the number of sections should be at least 20 from each half in a median sized SLN. Is small metastases are irrelevant, serial sectioning with 2mm is preferable.
Intra-operative frozen section analysis of the SLN has the advantage of avoiding a second operation for an ALND, but it carries the risk of tissue loss and missing metastases. However, the detection probability is not negatively influenced by FS analysis in the majority of the protocols. Only in extensive protocols the detection probability diminishesdue to tissue loss.
Patient- and primary tumor characteristics associated with pN0(i+) and pN1mi were studied. Younger patients, patients with larger tumors and with an intermediate BR-grade had an increased risk of pN1mi and ≥pN1a. Patients with a triple negative tumor had a decreased risk on pN1mi and ≥pN1a. The frequency of the smallest metastases was fairly constant in relation to increasing tumor size. pN0(i+) seems to bare resemblance to pN0, while the resemblance between pN1mi and ≥pN1a seems less clear.
The need for removal of IM SLNs remains subject of discussion. Adjustment of post-surgical treatment as the result of IM SLNB was advised in 20% of patients in whom the IM SLN was harvested. Adjustments mainly implied expansion of the radiotherapy field.
How to manage the axillais not clear for patients with exclusive IM drainage. In 1.1% of the patients exclusive IM lymphoscintigraphic drainage was observed and axillary staging by other means revealed additional axillary metastases in 4/14 patients, post-surgical treatment was adjusted in two. Staging the axilla thus appears sensible.
Only a very small group of patients has metastases in the IM SLNs, therefore it is difficult to establish if they affect overall survival. In a large multicenter cohort the impact of IM metastases on outcome was addressed, they were observed in 3.5% of patients and OS was not significantly worse for these patients (HR 1.23; CI 0.75 - 2.01).
ER+/her2neu negative breast tumors are associated with favorable outcome and may have an even better prognosis than based on ER positivity alone. In a large cohort three groups of ER+ patients were compared: her2neu+, her2neu- and her2neu not determined. ER+/her2- patients did have a significant better outcome than ER+/her2 not determined patients. These results suggest that the her2neu receptor should be includedin prognostic models.
The use of SLNB in patients with breast cancer has definitely led to a more refined lymph node staging, but the heydays of optimal lymph node staging that started with the introduction of SLNB may soon be past
show less
