Total axillary node dissection for breast cancer can lead to edema of the affected arm as well as pain and decreased mobility. Now that mammography has helped diagnose many breast cancers at earlier stages, when lymph node metastases are less common, routine total lymph node dissection may be unwarranted. Previous studies of sentinel nodes have revealed some false negatives (i.e., women with a normal sentinel node who nonetheless had other axillary node metastases revealed on total dissection). Veronesi and colleagues compared the incidence of subsequent breast cancer metastases among patients undergoing sentinel node biopsy or total dissection.

This single-center study screened 649 consecutive patients with newly diagnosed breast cancer who were candidates for breast-conserving surgery. The investigators excluded 117 women (18 percent) for a variety of reasons, including tumor size greater than 2 cm in diameter, multicentric cancer, or declined consent. Final data analysis was available for 516 patients (97 percent of those randomized). All participants were injected with radiolabeled colloidal albumin around the tumor mass, with subsequent sentinel node identification by scintigraphic imaging. A gamma-ray probe was used intraoperatively to confirm the sentinel node position before excision. A sentinel node could not be identified or confirmed in 11 (1.7 percent) out of 649 patients. Patients with intraoperatively confirmed sentinel nodes were randomized to total axillary node dissection or sentinel node biopsy followed by total dissection only if frozen sections of the sentinel node revealed metastatic cancer.

Over a median follow-up period of 46 months, no axillary metastases subsequently were identified in the total dissection or sentinel node groups. Slightly fewer women with only sentinel node examinations had later spread of cancer (eight women) than those who received total dissection (12 women). Of the patients randomized to total dissection regardless of sentinel node status, 9 percent had normal sentinel nodes but subsequently identified metastases on total dissection. The authors noted that this false-negative rate was similar to the rate seen in previous studies of sentinel node sampling.

The average length of hospital stay for patients receiving total node dissection was 4.3 days compared with a 2.1-day stay after only sentinel node removal. Patients with only sentinel node dissection were more likely to be pain-free six months after surgery than those who underwent total dissection (84 versus 9 percent, respectively), more likely to have no arm swelling (89 versus 31 percent), and less likely to have numbness or paresthesias at the operative site (2 versus 85 percent).

The authors conclude that in women with tumors smaller than 2 cm in diameter, reserving total lymph node dissection for only those with positive sentinel nodes does not increase the subsequent rates of breast cancer metastases and does decrease pain, swelling, and paresthesias in the arm undergoing nodal surgery.