The influence of axillary surgery and radiotherapeutic strategy on the risk of lymphedema and upper extremity dysfunction in early breast cancer patients.

Purpose: To explore the risk factors for breast cancer-related lymphedema (BCRL) and upper extremity dysfunction (UED) in patients with early breast cancer after modern comprehensive treatment and to compare the toxicity of different treatment strategies.

Methods: From 2017 to 2020, a total of 1369 female patients with pT1-3N0-1M0 breast cancer who underwent adjuvant radiotherapy in our centre were retrospectively reviewed. BCRL and UED were identified by the Norman and QuickDASH questionnaires. The incidence, severity and risk factors for BCRL and UED were evaluated.

Results: After a median follow-up of 25 months, a total of 249 patients developed BCRL; axillary lymph node dissection (ALND), increased number of dissected nodes, right-sided and hypofractionated radiotherapy containing RNI were found to be significant risk factors (all p values < 0.05). The sentinel lymph node biopsy (SLNB)+ regional nodal irradiation (RNI) group had a significantly lower BCRL risk than the ALND + RNI group (10.8% vs. 32.5%, HR = 0.426, p = 0.020), while there was no significant difference between ALND vs. ALND + RNI or SLNB vs. SLNB + RNI. A total of 193 patients developed UED, and ALND (p = 0.02) was the only significant risk factor. The SLNB + RNI group had a significantly decreased risk of UED compared with the ALND + RNI group (7.5% vs. 23.9%, HR = 0.260, p = 0.001), and there was no significant difference between SLNB vs. SLNB + RNI or ALND vs. ALND + RNI.

Conclusion: Aggressive ALND remains the primary risk factor for BCRL and UED while RNI does not. Thus, replacing ALND with tailored radiotherapy would be an effective preventive strategy in early breast cancer patients.