Abstract P2-12-15: The role of neck dissection in breast cancer patients with synchronous and metachronous ipsilateral supraclavicular lymph node metastasis
Authors: Xiao C , Qi X , Chen A , Zhang W , Zhang P , Cao X 
Published: May 2016

Abstract
Purpose: To evaluate the effect of neck dissection in breast cancer patients who present with ipsilateral supraclavicular lymphnode metastasis (ISLM) without distant metastasis and to reveal the outcomes of neck dissection in different molecular subtypes.
Methods: A total of 90 patients with synchronous ISLM and 36 patients with metachronous ISLM without distant metastasis between 2000 and 2009 were retrospectively analyzed. Combined-modality treatments were performed, and patients were respectively divided into two parts according to whether they received neck dissection or not.
Results: In the synchronous ISLM group, there was no significant difference between the neck dissection and non-dissection group with respect to age, menstrual status, tumour size, and histological type, PR and HER2 status. Patients with negative ER status and a higher number of positive axillary nodes were more common in the neck dissection group. The five-year locoregional relapse free survival (LRFS) was 63.6% in the neck dissection group VS. 48.9% in the non-dissection group, respectively (P=0.359). The 5-year distant metastasis free survival (DMFS) was 37.3% in the neck dissection group VS. 38.5% in the non-dissection group, respectively (P=0.882). Further analyses were performed by the site of metastases. Results showed that the incidence of bone metastasis was lower in neck dissection patients (14.7% vs. 28.6%, P=0.132). Due to the limited amount of patients, subgroup analysis was just performed in the subtypes with negative ER status, negative PR status and negative HER2 status, respectively. The five-year LRFS of patients receiving neck dissection in the subtypes with negative ER status, negative PR status and negative HER2 status was 63.7%, 59.8%and 61.2%, which was much better than their matched non-dissection group, respectively. However, the difference was not statistically significant. The 5-year overall survival (OS) was similar between the neck dissection and non-dissection group in the subtypes of negative ER status and negative PR status, respectively. However, the 5-year OS of HER2 negative subtype significantly decreased in the neck dissection group (37.2% vs. 65.4%, P=0.032). Besides, it's worth mentioning that in the HER2 positive subtype, the mean time to relapse, metastasis and death was shorter in the neck dissection subgroup compared with the non-dissection subgroup. In the metachronous ISLM group, a trend of better regional control, with similar PFS and OS, was achieved in the neck dissection group.
Discussion: Neck dissection is an effective approach to improve the regional control for the patients with ISLM, especially for the subtypes with negative ER status, negative PR status and probably positive HER2 status in the synchronous ISLM. But, it might not be comfortable for the patients with negative HER2 status, because of the unfavorable effect on its overall survival. In addition, neck dissection, with better regional control, might be helpful for the control of bone metastasis, which is beneficial for long term survival.
Citation Format: Xiao C, Qi X, Chen A, Zhang W, Zhang P, Cao X. The role of neck dissection in breast cancer patients with synchronous and metachronous ipsilateral supraclavicular lymph node metastasis. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-12-15.