Effect of Peritumoral Infiltration of Local Anesthetic Before Surgery on Survival in Early Breast Cancer

PURPOSE Preventing metastases by using perioperative interventions has not been adequately explored. Local anesthesia blocks voltage-gated sodium channels and thereby prevents activation of prometastatic pathways. We conducted an open-label, multicenter randomized trial to test the impact of presurgical, peritumoral infiltration of local anesthesia on disease-free survival (DFS). METHODS Women with early breast cancer planned for upfront surgery without prior neoadjuvant treatment were randomly assigned to receive peritumoral injection of 0.5% lidocaine, 7-10 minutes before surgery (local anesthetics [LA] arm) or surgery without lidocaine (no LA arm). Random assignment was stratified by menopausal status, tumor size, and center. Participants received standard postoperative adjuvant treatment. Primary and secondary end points were DFS and overall survival (OS), respectively. RESULTS Excluding eligibility violations, 1,583 of 1,600 randomly assigned patients were included in this analysis (LA, 796; no LA, 804). At a median follow-up of 68 months, there were 255 DFS events (LA, 109; no LA, 146) and 189 deaths (LA, 79; no LA, 110). In LA and no LA arms, 5-year DFS rates were 86.6% and 82.6% (hazard ratio [HR], 0.74; 95% CI, 0.58 to 0.95; P 5.017) and 5-year OS rates were 90.1% and 86.4%, respectively (HR, 0.71; 95% CI, 0.53 to 0.94; P 5.019). The impact of LA was similar in subgroups defined by menopausal status, tumor size, nodal metastases, and hormone receptor and human epidermal growth factor receptor 2 status. Using competing risk analyses, in LA and no LA arms, 5-year cumulative incidence rates of locoregional recurrence were 3.4% and 4.5% (HR, 0.68; 95% CI, 0.41 to 1.11), and distant recurrence rates were 8.5% and 11.6%, respectively (HR, 0.73; 95% CI, 0.53 to 0.99). There were no adverse events because of lidocaine injection. CONCLUSION Peritumoral injection of lidocaine before breast cancer surgery significantly increases DFS and OS. Altering events at the time of surgery can prevent metastases in early breast cancer (CTRI/2014/11/005228).