The new technique, which involves injection of a blue dye into a tumor before it is surgically removed, makes it easier for surgeons to determine whether the cancer has metastasized -- or spread into the lymph glands -- Dr. Armando Giuliano and his colleagues report today in the journal Annals of Surgery.
If the dye-mapping procedure shows that cancer has not spread, the patient is spared the painful necessity of having her lymph glands removed, thereby speeding her recovery and reducing costs, Dr. Giuliano said.
The technique is already the subject of an international study examining its use against melanoma, the most deadly form of skin cancer, and Dr. Giuliano is planning a similar trial against breast cancer, he said. He and his colleagues are also studying the potential for using the technique with other types of cancer as well.
Breast cancer is the leading form of cancer in women, striking an estimated 182,000 each year and killing 46,000, according to the American Cancer Society. Experts predict that one woman out of every nine will develop breast cancer.
The standard treatment for breast cancer is the surgical removal of either the tumor itself or the entire affected breast. Surgeons also routinely remove all of the 25 to 30 lymph glands that are associated with the affected breast and inspect them for signs of spread. If metastasis has occurred, the patient generally receives chemotherapy, radiation or both.
In today's paper, the team reports on the examination of 174 women who were undergoing conventional breast cancer surgery and who had all their glands removed. In 114 of them, doctors were able to identify the key gland before the others were removed. In 109 of those 114 cases, the presence or absence of tumor cells in this "sentinel" gland correctly showed whether the cancer had metastasized.