Association between Number of Retrieved Sentinel Lymph Nodes and Breast Cancer-related Lymphedema

PURPOSE: Sentinel lymph node biopsy (SLNB) has become a standard axillary staging surgery for early breast cancer, and the proportion of patients requiring axillary lymph node dissection (ALND) is decreasing. We aimed to evaluate the association between the number of sentinel lymph nodes (SLNs) retrieved and the risk of lymphedema of the ipsilateral arm. METHODS: Prospectively collected medical records of 910 patients were reviewed. Lymphedema was defined as a difference in circumference > 2 cm compared to the contralateral arm and/or having clinical records of lymphedema treatment in the rehabilitation clinic. RESULTS: Together with an objective and subjective assessment of lymphedema, 36 patients (6.1%) had lymphedema in the SLNB group and 85 patients (27.0%) had lymphedema in the ALND group (p < 0.001). In a multivariate analysis of the whole cohort, risk factors significantly associated risk with the development of lymphedema were body mass index, mastectomy (vs. breast-conserving surgery), ALND, and radiation therapy. In logistic regression models in the SLNB group only, there was no correlation between the number of retrieved SLNs and the incidence of lymphedema. In addition, in the Pearson correlation analysis, no correlation was observed between the number of retrieved SLNs and the difference in circumference between the ipsilateral and contralateral upper extremities (correlation coefficients = 0.067, p = 0.111). CONCLUSION: The risk of lymphedema in breast cancer surgery and adjuvant treatments is multifactorial. The number of retrieved lymph nodes during sentinel biopsy was not associated with the incidence of lymphedema.