Current controversies concerning sentinel lymph node biopsy for breast cancer

The objectives of this article are to review existing controversies regarding sentinel lymph node (SLN) biopsy and to identify potential areas of consensus in order to eliminate routine axillary lymph node dissection (ALND).

A combination of peritumoral injection with radioisotopes and subdermal or subareolar injection with blue dye may result in enhanced success rates of SLN identification. Preoperative lymphoscintigraphy is most useful for detecting an internal mammary SLN, but the practicability of internal mammary SLN biopsy is still in the investigative stage. Intraoperative diagnosis of SLN is useful because patients with SLN metastases may be treated immediately with ALND, but it is unreasonable to expect that either examination of frozen sections or imprint cytology will detect every metastatic disease. SLN micrometastases may be of prognostic importance and these can be identified with H and E staining on permanent sections of 200 micro m intervals. While ALND is preferable for patients even with a small tumor (T1) and SLN micrometastases, radiation therapy is an acceptable alternative. SLN biopsy may be indicated for patients with DCIS detected as a palpable mass or those with large calcification areas in the breast. The accuracy of SLN biopsy after neoadjuvant chemotherapy is considered to be unproven.

Since SLN biopsy has been adopted by surgeons around the world, consistency of technique and case selection has attained great significance.