In the September-October issue of CA-A Cancer Journal for Clinicians, Armando Giuliano, M.D., Eddy Hsueh, M.D., both of the John Wayne Cancer Institute in Santa Monica, Calif., and Nora Hansen M.D., of the Joyce Eisenberg Keefer Breast Center in Santa Monica, reviewed their results with sentinel lymph node dissection.  They also reported on the experiences of other doctors who have performed the operation at hospitals throughout the world.

The standard practice has been for women to undergo more extensive surgery called axillary lymph node dissection, which involves removing the lymph nodes from under the arm on the same side as the cancer.  This lets doctors know if the cancer has spread to the nodes.

If the cancer has spread, the woman usually will need more treatment, such as chemotherapy and/or tamoxifen.  But about one-fourth of women who have the procedure develop problems such as pain, trouble using the arm or chronic swelling of the arm, called lymphedema.

Sentinel node dissection was pioneered by Dr. Giuliano, who wanted to avoid performing axillary node dissection on all women with breast cancer because only one-third of them will turn out to have cancer in the nodes.  Learning from work done on melanoma by his associate, Donald Morton, M.D., Dr. Giuliano developed a theory that breast cancer will travel first to the sentinel, or first, node under the arm before it goes to the others.

By identifying the sentinel lymph node and removing it, surgeons could avoid more surgery as long as they find the cancer has not spread to the node.  If the cancer has spread, surgeons can then do axillary node dissection.  This means about two-thirds of women with breast cancer could be spared the more extensive surgery.

Dr Giulano and his associates used a technique that had been used successfully developed for melanoma.  He injected the breast tumor with a blue dye.  Then, after a few minutes, made an incision to find the blue-stained lymphatic channel through which the dye travels.

By tracing the channel, the sentinel node is identified because it’s the first lymph node to be stained by the dye.  When the technique was first tested, the surgeons would remove all the lymph nodes from under the arm as well as the stained node.

After surgery, the pathologist would examine all the lymph nodes for cancer.  If the sentinel node had no cancer, the same would usually be true for the other nodes.  To be absolutely sure, the pathologist also would use special stains that could detect extremely small amounts of cancer that normally cannot be seen under the microscope.

By 1997, Dr. Giuliano had operated on hundreds of women and had refined the technique so that it was accurate more than 95 percent of the time.  He then felt it was safe to abandon the axillary node dissection in women who did not have cancer in the sentinel node.  This lowers a woman’s chances of complications from 35 percent with axillary node dissection to 3 percent with the sentinel node biopsy.

In general, other surgeons have achieved results similar to Dr. Giuliano and his team, although they sometimes used a slightly different method.  Now many surgeons throughout the United States and the rest of the world are adopting the procedure.

Gerald L. Woolam, M.D., president of the American Cancer Society (ACS), wrote an editorial on the procedure in the same issue of the journal.  "If sentinel lymph node dissection is proved effective, it would generally reduce the extent of many breast cancer operations," he writes.  "The fact that much of the axillary lymph node tree might be spared should result in fewer postoperative short- and long-term complications among thousands of breast cancer patients."

A Learning Curve

Drs. Hsueh, Hansen and Giuliano recommend against widespread use of sentinel node dissection until the ongoing national clinical trials of this procedure are completed.

They also say surgeons need to learn the procedure by experience and that they didn’t become expert at performing it until after operating on more than 100 women.  The surgeon should perform the sentinel node procedure and then do the complete axillary node dissection until he or she can consistently identify the sentinel node, according to the researchers.

In addition, the pathology team at the hospital must be able to identify even the smallest trace of cancer in the sentinel node.