The clinical relevance of positive sentinel nodes only versus positive nonsentinel lymph nodes in breast cancer patients

Abstract

Background: The purpose of this study was to determine the difference in clinical outcomes for patients with histologically positive sentinel lymph nodes (SLN+) compared with patients with histologically positive nonsentinel second echelon lymph nodes (NSLN+).

Methods: Eight hundred thirteen node positive patients from a prospectively accrued database of 3200 patients who underwent sentinel node mapping were evaluated. In all, 506 of the 813 patients (62%) were SLN+ only and 307 of the 813 patients (38%) were SLN+ plus at least one NSLN+. Patients' overall survival and disease-free survival were obtained and statistical analyses performed comparing the two groups.

Results: As the number of NSLN+ increased, there was a significant difference in disease-free survival (P = 0.001) and overall survival (P = 0.003) between those patients who had 0 to 4 NSLN+ and those who had 5 or more NSLN+. The SLN+ only patients did not show significant differences with respect to survival, based on the number of SLN+ (overall survival, disease-free survival; P = 0.742).

Conclusions: The survival (overall survival, disease-free survival) for patients with 3 or more SLN+ was not statistically different than for patients with 1 or 2 SLN+ (P = 0.742). However, an alteration of biologic behavior was observed when multiple NSLN+ contain metastatic breast cancer. Involvement of 5 or more NSLN+ portends a significantly (P = 0.001) worse prognosis, regardless of the number of SLN+.