Questions About Cancer? 1-800-4-CANCER

Clinical Trial Results

Summaries of Newsworthy Clinical Trial Results
  • Posted: 11/04/2010

Less-Invasive Lymph Node Surgery Safe for Women with Breast Cancer

Adapted from the NCI Cancer Bulletin.

In the largest randomized surgical trial in breast cancer patients to date, women with biopsies that detected no cancer cells in their sentinel lymph nodes (SLN) who forwent axillary lymph node dissection (ALND) had the same overall survival 8 years after treatment as women who had ALND. The trial results were reported online September 20, 2010, in Lancet Oncology.

Researchers led by David Krag, M.D., of the University of Vermont enrolled 5,611 women between 1999 and 2004 in the NSABP B-32 trial, which was designed to test whether women with negative SLN biopsies would have the same survival as women who had negative SLNs followed by ALND, a more invasive procedure that carries a greater risk of side effects including lymphedema and nerve damage. The women studied were randomly assigned to undergo SLN surgery plus ALND (group 1), or SLN surgery followed by ALND only if cancer cells were detected in the sentinel nodes (group 2).

A total of 3,986 patients had no apparent cancer cells in their sentinel lymph nodes. After 8 years of follow-up, 54 women in group 1 had a local recurrence of their cancer, compared with 49 women in group 2. Eight women in group 1 had cancer recur in the lymph nodes closest to the site of surgery (the regional lymph nodes), compared with 14 women in group 2. The estimated 8-year overall survival was 91.8 percent in group 1 and 90.3 percent in group 2. These differences were not statistically significant.

In an accompanying editorial, John Benson, M.D., of the University of Cambridge in the United Kingdom explained that more than 80 percent of the women in the trial had small tumors (2 centimeters or less in diameter), which tend to have a lower risk of recurrence. Therefore, “the conclusions of this trial in terms of the appropriateness, safety, and effectiveness of SLN biopsy are justified for this population but might not necessarily apply to patients with larger…or multifocal tumors who commonly undergo SLN biopsy,” he cautioned.