Residual lymph node disease after neoadjuvant chemotherapy predicts an increased risk of lymphedema in node-positive breast cancer patients.

BACKGROUND: Axillary lymph node dissection (ALND) is recommended for patients with clinically node-positive breast cancer and carries a risk of lymphedema>30%. Patients with node-positive breast cancer may consider neoadjuvant chemotherapy, which can reduce node positivity. We sought to determine if neoadjuvant chemotherapy reduced the risk of lymphedema in patients undergoing ALND for node-positive breast cancer.

METHODS: The 229 patients who underwent unilateral ALND and chemotherapy were divided into two groups: 30% (68/229) had neoadjuvant and 70% (161/229) had adjuvant chemotherapy. Prospective arm volumes were measured via perometry preoperatively and at 3- to 7-month intervals after surgery. Lymphedema was defined as relative volume change (RVC)≥10%, >3 months from surgery. Kaplan-Meier curves and multivariate regression models were used to identify risk factors for lymphedema.

RESULTS: Fifteen percent (10/68) of neoadjuvant patients compared with 23% (37/161) of adjuvant patients developed RVC≥10% (hazard ratio=0.76, p=0.39). For all patients, body mass index was significantly associated with lymphedema (p=0.0003). For neoadjuvant patients, residual lymph node disease after chemotherapy was associated with a ninefold greater risk of lymphedema compared to those without residual disease (p=0.038).

CONCLUSIONS: Patients who underwent neoadjuvant chemotherapy did not have a statistically significant reduction in risk of lymphedema. Among patients who receive neoadjuvant chemotherapy, residual lymph node disease predicted a greater risk of lymphedema. These patients should be closely monitored for lymphedema and possible early intervention for the condition.