Prognostic significance of sentinel nodes metastases in breast cancer patients without axillary node dissection or axillary radiotherapy: CBCSG-001 trial.

Abstract

#1015 Background: China multicenter study of sentinel lymph node biopsy (SLNB) substituting axillary lymph node dissection (ALND) in breast cancer– CBCSG-001 trial was conducted from Jan. 2002 to Jun. 2007, with 1,970 SLNB pts recruitment. One of the second objectives of the CBCSG–001 trial was to evaluate the optimal methods and intervals for the detection of SLN macrometastases, MMs and isolated tumor cells (ITCs) and their prognostic significance in patients received SLNB without ALND or axillary radiotherapy.
 Material and Methods: Two hundred and forty-five continuous breast cancer patients with 569 SLNs identified “negative” with routine standard HE stain carried on initial 4 levels were retrospectively analyzed. All the patients received SLNB only, without ALND or axillary radiotherapy after the diagnoses of metastases in their SLNs later. All SLNs were step sectioned (SS) at 100µm interval, and for each level both HE and IHC with AE1/AE3 were performed. Forty-nine patients were identified to have metastases, with macrometastases of 12.2%, micrometastases of 61.2%, and isolated tumor cells of 26.5%. All patients had received SLNB only, with no ALND and axillary radiotherapy.
 Results: Of the 245 patients, breast conserved surgery and SLNB were performed on 106 patients (43.3%), and mastectomy and SLNB in 139 patients. With a median follow up of 50 months, there were 20 breast related events occurred. The disease free survival (DFS) of patients with routine negative SLNs was 91.6%, and 93.9% for patients with positive SLNs after SS with HE+IHC (p>0.05). The overall survival (OS) were 97.4% and 98.0 for each group, respectively (p>0.05). The results were the same for patients with macrometastases, micrometastases, and isolated tumor cells. Due to the relatively less events occurred, the DFS and OS had not been calculated for macrometastases, micrometastases, and isolated tumor cells, separately.
 Discussion and Conclusions: Without ALND and axillary radiotherapy, there were no significant differences of DFS and OS between patients with routine negative SLNs and patients with positive SLNs after SS with HE+IHC. It might be safe for these patients to receive SLNB only. The possible reasons might include: SLNs were the only positive lymph nodes in more than 60% patients, effective adjuvant systemic therapy for regional lymph nodes just as neoadjuvant chemotherapy, axillary coverage of radiotherapy in patients with breast conserved therapy, and the relatively less events occurred during the 50 months follow up period. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1015.