SAN ANTONIO--Identification of the "sentinel" lymph
node can eliminate the need for total axillary node dissection
in a substantial number of women with primary breast cancer, Peter
D. Beitsch, MD, said at the San Antonio Breast Cancer Symposium.
In studies performed at the John Wayne Cancer Institute, Santa
Monica, Calif, the sentinel node was identified in 128 of 173
breast cancer patients. In 122 of the 128 cases, the pathology
was identical to that obtained with total axillary dissection.
Though the technique has a definite learning curve, a false-negative
rate of 1% is possible in experienced hands, Dr. Beitsch said
at the meeting's closing general session.
The sentinel node concept was developed by Dr. Donald Morton over
the past decade and has become an accepted part of treatment for
early-stage melanoma, said Dr. Beitsch, who was with the John
Wayne Cancer Institute at the time of the study and is now clinical
professor, University of Texas Southwestern Medical Center, Dallas.
The concept is based on the belief that lymphatic drainage is
not a random event, but that the precise node that drains an area
of skin can be identified. "This lymph node will be the first
to harbor metastases from a primary melanoma," he said.
In breast cancer, using a technique pioneered by Dr. Armando Giuliano,
the sentinel lymph node is found by injecting 3 cc to 5 cc of
isosulfan blue dye directly into a tumor or biopsy cavity. Five
minutes later, an axillary incision is made, and the blue lymphatic
channel is identified and traced to the corresponding blue sentinel
node (see figure).
Dr. Beitsch's study comprised 173 consecutive patients undergoing
surgery for primary breast cancer. Of the total, 153 had segmental
mastectomy and complete axillary dissection, and the remainder
had modified radical mastectomy. The same surgeon performed all
Reflecting the learning curve, the sentinel node was identified
in 56 of the first 96 patients (58%). The success rate rose to
74% (72 of 97) in the second half, including 41 of the final 50