Sentinel lymphadenectomy for breast cancer: experience with 180 consecutive patients: efficacy of filtered technetium 99m sulphur colloid with overnight migration time.

BACKGROUND

Axillary node status remains the most important prognostic indicator of survival in breast cancer patients. Only 25% to 35% of patients having standard level I/II axillary dissection have involved nodes, yet all accept the potential for morbidity after the operation. This study was conducted to assess whether status of the sentinel node(s) was an accurate predictor of the presence of metastatic disease in axillary or internal mammary nodes.

STUDY

DESIGN

In 180 patients, technetium 99m sulphur colloid was injected in a 4-quadrant peritumoral distribution. During the first phase of the study, 72 patients had sentinel node excision followed by a level I/II axillary dissection. During the second phase of the study, 108 patients had sentinel node excision and only those with positive nodes had completion axillary dissection. Nodes were examined after formalin fixation by taking 10 sections at 20-microm intervals and staining with hematoxylin-eosin.

RESULTS

Sentinel nodes were found in 162 (90%) of 180 patients. The mean number of sentinel nodes examined was 3.1. Of the 162 patients with successful lymphatic mapping, positive sentinel nodes were found in 44 (27%). In 23 (66%) of 35 patients with positive sentinel nodes who had a completion level I/II axillary dissection, the sentinel nodes were the only positive nodes. The concurrent negative predictive value was 4% in the first 72 patients who had completion axillary dissection after sentinel node excision, and 2% for the entire series. With evolution of technique, identification of sentinel nodes with radiolabeled colloid was successful in 97% of the last 100 patients.

CONCLUSIONS

Because the concurrent negative predictive value was low, sentinel node excision appeared to accurately identify node status, potentially avoiding the need for standard level I/II axillary dissection in sentinel node-negative patients.