Evaluation of an enhanced pathological examination protocol for sentinel lymph nodes from patients with breast carcinoma

Clinical trials have shown that many patients with breast cancer with limited sentinel lymph node (SLN) metastatic disease can safely avoid axillary lymph node dissection. Ultra-staging of initially negative SLNs may not confer additional clinical benefit. Despite this, protocols of 'enhanced pathological examination' (EPE) are still widely used. We evaluated the impact of our EPE protocol. If initial SLN H&Es are negative, we cut three additional H&E levels at 500 mu m intervals with two spare sections at each level, to allow for immunohistochemistry if necessary. Occult micrometastases or isolated tumour cells were identified, using this protocol, in 3.4%, resulting in change of N stage in 3%. 1% of patients had further axillary surgery based on these findings. Our SLN-EPE protocol provided additional information in a small number of cases and changed axillary management in a minority. It represented a significant workload for scientists and pathologists, and had time and cost implications. We concluded that emphasising careful gross examination along with judicious use of additional levels and immunohistochemistry may be more beneficial than our current protocol.