Comparing supraclavicular surgery with radiotherapy versus radiotherapy alone in breast cancer patients with ipsilateral supraclavicular lymph node metastasis: a two-center retrospective cohort study

Background: This study aimed to assess combined supraclavicular lymph node dissection (SLND) and radiotherapy (RT) versus standalone radiotherapy for efficacy in newly diagnosed breast cancer patients with ipsilateral supraclavicular lymph node metastasis (ISLNM).

Methods: Totally 143 ISLNM patients treated between 2014 and 2021 in two medical institutions were examined retrospectively. Patients were divided into two groups to undergo combined SLND and radiotherapy (surgery + RT, n = 73) or radiotherapy alone (RT, n = 70). The effects of SLND on disease-free survival (DFS), breast cancer-specific survival (BCSS), and overall survival (OS) were assessed by Kaplan-Meier analysis and Cox regression models.

Results: During a median follow-up of about 35 months, 18.2% of patients died. Five-years OS, BCSS, and DFS rates in the RT and surgery + RT groups were 79.2% and 69.4% (P = 0.21), 82.2% and 79.4% (P = 0.29), and 56.1% and 53.1% (P = 0.70), respectively. In multivariable analysis, SLND didn't significantly impact these outcomes, a finding consistent across multiple subgroups. However, Estrogen receptor expression, the presence of vascular cancer emboli, and surgical approach differentially affected DFS, BCSS, and OS. Furthermore, patients with residual supraclavicular lymph node tumors post-surgery had lower DFS (43.7% vs. 73.2%) and OS (68.7% vs. 90.2%) rates compared with counterparts without residual lymph nodes. Residual supraclavicular lymph node tumor was an independent risk factor for DFS (HR = 4.191, 95%CI 1.755-10.007; p = 0.001) and OS (HR = 3.781, 95%CI 1.025-13.486; p = 0.046) in breast cancer patients with ISLNM.

Conclusions: Breast cancer patients with synchronous ISLNM may not benefit from SLND. The clinical decision-making for ISLNM patients should be carefully considered. Prospective studies are needed to validate the results.