The Sentinel Node in Breast Cancer -- A Multicenter Validation Study
Krag D, Weaver D, Ashikaga T, Moffat F, Klimberg VS, Shriver C, Feldman S, Kusminsky R, Gadd M, Kuhn J, Harlow S, Beitsch P,
Abramson Cancer Center of the University of Pennsylvania
Last Modified: November 1, 2001
Reviewers: Kenneth Blank, MD and John Han-Chih Chang, MD
Source: The New England Journal of Medicine -- October 1, 1998 -- Volume 339, Number 14
BackgroundThe treatment of invasive breast cancer always includes dissection of the axilla (the area of tissue under the armpit) to determine if lymph nodes in this area have been invaded by cancer. An axillary dissection guides therapy in the post-operative period: the number of lymph nodes positive, if any, may determine what type and how long chemotherapy is dosed. In addition, most doctors believe that if there are no lymph nodes with cancer then radiation to the axilla can be avoided. However, an axillary dissection is not without morbidity, the most concerning of which is arm edema (swelling) which occurs to varying degrees in about 10% of women.
Sentinel node biopsy is an investigational technique to determine the status of the axillary lymph nodes without performing a full axillary dissection. Using radioisotpes or blue dye surgeons identify and remove just one or two lymph nodes (the sentinel nodes) for pathologic evaluation. While this procedure avoids the morbidity of a full axillary dissection, is relies on the theory that cancer spreads in an orderly progression from the breast tissue into the sentinel node then into other nodes in the axilla. However, it remains to be proven whether the status of the sentinel node is indicative of other lymph nodes in the axilla. Towards this end several papers have reported on cohorts of women who undergo sentinel lymph node biopsy followed immediately by an axillary dissection, which allows investigators to determine if the pathologic status of the sentinel lymph node is indicative of rest of the lymph nodes.