WASHINGTONSentinel lymph node (SLN) biopsy, which is "evolving as a possible alternative" to complete axillary node dissection in breast cancer, can be performed as successfully in patients who have received neoadjuvant chemotherapy as in patients who have not, said Eleftherios Mamounas, MD, of Aultman Cancer Center, Canton, Ohio, and the National Surgical Adjuvant Breast and Bowel Project (NSABP).
Neoadjuvant chemotherapy is often used before surgery to downstage breast cancers to permit lumpectomy rather than mastectomy, Dr. Mamounas said in his presentation at the 54th Annual Cancer Symposium of the Society of Surgical Oncology (plenary session III).
Although randomized comparisons of the two methods of axillary staging are currently underway, little was known about the usefulness of SLN biopsy after neoadjuvant chemotherapy. A number of small studies have yielded varying success rates and false-negative rates.
It was not known, for example, whether neoadjuvant chemotherapy affects lymphatic drainage and thus makes SLN biopsy more difficult, Dr. Mamounas commented.
He reported an analysis of data from NSABP B-27 that explored these questions. Patients in this trial received neoadjuvant chemotherapy before either lumpectomy and axillary lymph node dissection or modified radical mastectomy.
During the trial, some participating surgeons also performed SLN biopsy before doing axillary node dissection. This afforded an opportunity to study SLN biopsy in conjunction with neoadjuvant chemotherapy.
Of the 1,936 patients randomized from 1996 through 1999, 1,832 had complete surgical information available, and 325 of these patients had lymphatic mapping with an attempt at SLN biopsy before axillary node dissection.