Sentinel lymph node biopsy and axillary dissection in breast cancer: Results in a large series

Background: Axillary lymph node dissection is an established component of t he surgical treatment of breast cancer, and is an important procedure in ca ncer staging; however, it is associated with unpleasant side effects, We ha ve investigated a radioactive tracer-guided procedure that facilitates iden tification, removal, and pathologic examination of the sentinel lymph node (i,e,, the lymph node first receiving lymphatic fluid from the area of the breast containing the tumor) to predict the status of the axilla and to ass ess the safety of foregoing axillary dissection if the sentinel lymph node shows no involvement, Methods: We injected 5-10 MBq of Tc-99m-labeled collo idal particles of human albumin peritumorally in 376 consecutive patients w ith breast cancer who were enrolled at the European Institute of Oncology d uring the period from March 1996 through March 1998. The sentinel lymph nod e in each case was visualized by lymphoscintigraphy, and its general locati on was marked on the overlying skin. During breast surgery, the sentinel ly mph node was identified for removal by monitoring the acoustic signal from a hand-held gamma ray-detecting probe. Total axillary dissection was then c arried out. The pathologic status of the sentinel lymph node was compared w ith that of the whole axilla, Results: The sentinel lymph node was identifi ed in 371 (98.7%) of the 376 patients and accurately predicted the state of the axilla in 359 (95.5%) of the patients, with 12 false-negative findings (6.7%; 95% confidence interval 3.5%-11.4%) among a total of 180 patients w ith positive axillary lymph nodes. Conclusions: Sentinel lymph node biopsy using a gamma ray-detecting probe allows staging of the axilla with high ac curacy in patients with primary breast cancer, A randomized trial is necess ary to determine whether axillary dissection may be avoided in those patien ts with an uninvolved sentinel lymph node.