Risk Factors for Lymphedema After Breast Surgery: a Prospective Cohort Study in the Era of Sentinel Lymph Node Biopsy

Abstract Introduction: We aimed to investigate the incidence of lymphedema after breast cancer treatment, to analyze the risk factors involved, and to improve existing protocols for the prevention of lymphedema. Patients and methods: This was a prospective cohort study of 232 patients undergoing surgery for breast cancer at our institution between September 2013 and February 2018. Sentinel lymph node biopsy (SLNB) or axillary lymphadenectomy (ALND) were mandatory in this cohort. Lymphedema was diagnosed by circumferential measurements and truncated cone calculations. Patients and tumor characteristics, as well as local and systemic therapies, were analyzed as possible risk factors for lymphedema. Results: In total, 201 patients met the inclusion criteria and had a median follow-up of 31 months (range, 1–54 months). Most cases of lymphedema cases appeared in the first 2 years. 13.9% developed lymphedema: 31% after ALND and 4.6% after SLNB (p < 0.01), and 46.7% after mastectomy and 11.3% after breast-conserving surgery (p < 0.01). The lymphedema rate increased when axillary radiotherapy (RT) was added to radical surgery: 4.3% for SLNB alone, 6.7% for SLNB + RT, 17.6% for ALND alone, and 35.2% for ALND + RT (p < 0.01). In the multivariate analysis, the only risk factors associated with the development of lymphedema were ALND and mastectomy, which had hazard ratios (95% confidence intervals) of 7.28 (2.92–18.16) and 3.9 (1.60–9.49), respectively. Conclusions: The main risk factors for lymphedema were the most radical surgeries (ALND and mastectomy), while the risk associated with these appeared to be worsened by the addition of axillary radiotherapy. A follow-up protocol in patients with ALND for at least two years, where these risk factors are recognized, is necessary to guarantee a comprehensive control of lymphedema that provides early detection and treatment.