Sentinel lymph node biopsy is associated with a significantly improved survival compared to level Iand II axillary lymph node dissection in node-negative breast cancer patients

Abstract

609 Background: The sentinel lymph node (SLN) biopsy has emerged as the standard of care in evaluating the axillary lymph node status in early stage breast cancer patients. It is well known that step sectioning and immunohistochemistry of the SLN allow for a more accurate histopathologic examination. Conversely, it remains to be elucidated whether or not the more accurate SLN staging is associated with improved survival. Therefore, the objective of the present investigation was to evaluate if patients undergoing a SLN biopsy have an improved disease-free and overall survival compared to those undergoing ALND. Methods: From our prospective database 355 node negative patients with early stage breast cancer (pT1 und pT2 <=3cm, pN0/pNSN0) were assessed. Patients underwent either ALND (n=178) in the years 1990–1997 or a SLN biopsy (n=177) in 1998–2004. Long-term disease-free and overall survival were analysed for both groups. Log-rank tests were used for unadjusted analyses, a Cox proportional hazard regression model for risk-adjusted analyses. Results: The median follow- up was 48.2 months in the SLN group and 120.0 months in the ALND group. Patients in the SLN group had a significantly better disease-free (p=0.012) and overall survival (p=0.04) compared to the ALND group. In Cox proportional hazard regression analysis, the performed procedure (SLN compared to ALND) was an independent predictor for improved disease-free survival (hazard ratio 0.28, 95% confidence interval 0.11–0.75, p=0.011) and overall survival (hazard ratio 0.36, 95% confidence interval 0.14–0.89, p=0.027). Conclusion: The present analysis - the first one in the literature - provides compelling evidence that patients with a negative SLN have a significantly improved disease-free and overall survival compared to node negative patients undergoing ALND. This relevant finding is most likely due to an improved histopathologic staging accuracy. The significant survival benefit of node negative patients having SLN biopsy highlights yet another important advantage of the SLN concept in breast cancer. No significant financial relationships to disclose.