Reassessing regional nodal radiotherapy strategies for breast cancer in the context of modern systemic treatments.
Journal
Journal of the Formosan Medical Association = Taiwan yi zhi
ISSN
0929-6646
Date Issued
2025-02-15
Author(s)
Abstract
The efficacy of radiotherapy to the internal mammary node (IMN-RT) and axillary lymph node regions (ALRT) in enhancing disease-free survival (DFS) among patients with breast cancer (BC) in the context of contemporary systemic chemotherapy has not been clearly established.
This retrospective study included 512 patients with BC who underwent primary breast surgery and regional nodal irradiation between 2008 and 2014. The patient cohort was divided into 160 early-stage (T1-T2, N0-N1) and 352 locally advanced-stage (T3-T4, N2-N3) cases. We employed Kaplan-Meier survival analysis to calculate locoregional recurrence-free survival (LRFS), DFS, and overall survival (OS). A propensity score-matched (PSM) analysis was performed for patients who received IMN-RT.
A high proportion of patients (95.9%) received adjuvant chemotherapy and 89.8% received taxane-based regimens. All HER2-positive patients were treated with anti-HER2 therapy, and hormone therapy was administered to 97.5% of the patients with ER-positive tumors. While all patients underwent supraclavicular fossa RT, only 20 patients (3.9%) received additional IMN-RT. ER-negative/HER2-negative patients demonstrated a significantly lower 10-year DFS (p = 0.036) and OS (p = 0.006). PSM analysis showed that there were no differences in LRFS (p = 0.308) and DFS (p = 0.388) between patients receiving IMN-RT and those who did not. For pathological N3 patients, the 10-year LRFS (67% vs. 81.7%, p = 0.153) and DFS (62.3% vs. 64.9%, p = 0.789) rates were similar between those who underwent ALRT and those without ALRT.
In the modern era of systemic therapy, RT to the IMN or axilla does not substantially improve the clinical outcomes in patients with LN-positive early- or locally advanced-stage BC.
Subjects
Breast cancer
Internal mammary lymph nodes radiotherapy
Regional nodal irradiation
SDGs
Type
journal article