Sentinel node biopsy: interpretation and management of patients with immunohistochemistry-positive sentinel nodes and those with micrometastases

The sentinel node procedure is an adequate tool to identify lymph node metastasis in breast cancer. Sentinel nodes are generally examined with greater attention mainly to exclude, as reliably as possible, lymph node metastasis. To achieve this, many protocols are used, resulting in different rates of micrometastasis or isolated tumor cells encountered. Since the prognostic significance of isolated tumor cells or micrometastasis in the sentinel nodes, and the risk of further axillary lymph node involvement in patients with isolated tumor cells, is uncertain and at most limited, these findings may pose difficulties for clinicians in clinical decision making. Protocols that identify lymph node metastasis, from which the clinical relevance is known, are warranted. Unnecessary lymph node dissections should be avoided.

Medium-term follow-up data after sentinel node biopsy alone for breast cancer

AIMS

In patients with early breast cancer sentinel node biopsy (SNB) proved to be an accurate procedure for axillary staging with significantly reduced morbidity. Medium- and long-term observational studies are needed to establish, whether SNB alone is able to prevent locoregional recurrence without impairing long-term survival.

METHODS

298 patients with invasive breast cancer were subjected to SNB in a prospective audit. Lymphatic mapping was performed with blue dye and radiocolloids. 180 patients had SNB alone (group 1), while 118 subsequently underwent axillary dissection (AD; group 2). In ten patients AD was omitted despite the tumor burden in the SN. Clinical follow-up studies were performed at regular intervals. The mean follow-up time was 47months in group 1 (range 7-90) and 46months in group two (range 1-87months).

RESULTS

Sentinel nodes were identified in 286 out of 298 patients (96%). One patient in group 1 developed axillary and simultaneous supraclavicular lymph node recurrence. After AD regional relapses have so far not been observed. One ipsilateral local recurrence was detected in each group. Five patients in group 1 and 15 patients in group 2 developed distant metastases. Three out of six and eight out of nine patients, respectively, died of their advanced disease. All patients with SN tumor infiltration not subjected to AD are alive and well.

CONCLUSIONS

Axillary recurrence is rare after sentinel node biopsy alone. Its rate is comparable to that after AD, even in patients with SN micrometastases. These conclusions are confirmed by reports in the literature.