Top Line: Does peritumoral injection of lidocaine prior to breast cancer surgery improve treatment outcomes?
The Study: In this multicenter, randomized phase 3 trial from India, patients with operable, cN0-N1 breast cancer who were undergoing primary surgical resection were randomized to have a peritumoral lidocaine anesthetic injection roughly 10 minutes prior to surgery. Obviously, lidocaine injection may reduce postoperative pain, but the authors hypothesized that the anesthetic may suppress pro-metastatic cellular pathways activated during the cellular stress of surgery. The trial was designed with the bold hypothesis that lidocaine injection would significantly improve DFS at 5 years. A long list of patient and treatment characteristics were balanced between the lidocaine and no lidocaine arms. Similar proportions had breast conservation (60.3% v 63.0%), 57.1% v 59.2% had RT after BCS, and 17.1% v 17.4% had PMRT. At 5 years, the rate of DFS was deemed significantly higher in the lidocaine arm (86.6% v 82.6%). In addition, OS was also significantly higher in the lidocaine arm (90.1% v 86.4%). There were also trends toward improvement in locoregional recurrence (3.2% v 4.1%) and distant recurrence (8.1% v 10.9%). These findings are impressive, but they also raise questions. The first question of how peritumoral lidocaine translates to improved DFS and OS remains unclear. Then there are the statistical considerations. The study design originally assumed a 5-year DFS rate of 60%. Fortunately and unfortunately, the actual rate of DFS was much higher than anticipated. Despite accruing the planned 1600 patients needed to power the original design, fewer than half the number of DFS events were observed. A revised statistical plan was then designed to detect a 6% improvement in 5-year DFS (80→86%) with a HR of 0.68. The actual 4% difference and HR of 0.74 did not reach those marks. Despite these questions, there was very little downside with no adverse events attributable to lidocaine injection in the trial. So, whether or not you’re convinced of the findings of this trial, the potential benefits seem to far outweigh the risks.
TBL: In this large, randomized, phase 3 trial, peritumoral injection of lidocaine prior to breast cancer surgery was associated with a higher rate of DFS and OS at 5 years. | Badwe, J Clin Oncol 2023
The Study: In this multicenter, randomized phase 3 trial from India, patients with operable, cN0-N1 breast cancer who were undergoing primary surgical resection were randomized to have a peritumoral lidocaine anesthetic injection roughly 10 minutes prior to surgery. Obviously, lidocaine injection may reduce postoperative pain, but the authors hypothesized that the anesthetic may suppress pro-metastatic cellular pathways activated during the cellular stress of surgery. The trial was designed with the bold hypothesis that lidocaine injection would significantly improve DFS at 5 years. A long list of patient and treatment characteristics were balanced between the lidocaine and no lidocaine arms. Similar proportions had breast conservation (60.3% v 63.0%), 57.1% v 59.2% had RT after BCS, and 17.1% v 17.4% had PMRT. At 5 years, the rate of DFS was deemed significantly higher in the lidocaine arm (86.6% v 82.6%). In addition, OS was also significantly higher in the lidocaine arm (90.1% v 86.4%). There were also trends toward improvement in locoregional recurrence (3.2% v 4.1%) and distant recurrence (8.1% v 10.9%). These findings are impressive, but they also raise questions. The first question of how peritumoral lidocaine translates to improved DFS and OS remains unclear. Then there are the statistical considerations. The study design originally assumed a 5-year DFS rate of 60%. Fortunately and unfortunately, the actual rate of DFS was much higher than anticipated. Despite accruing the planned 1600 patients needed to power the original design, fewer than half the number of DFS events were observed. A revised statistical plan was then designed to detect a 6% improvement in 5-year DFS (80→86%) with a HR of 0.68. The actual 4% difference and HR of 0.74 did not reach those marks. Despite these questions, there was very little downside with no adverse events attributable to lidocaine injection in the trial. So, whether or not you’re convinced of the findings of this trial, the potential benefits seem to far outweigh the risks.
TBL: In this large, randomized, phase 3 trial, peritumoral injection of lidocaine prior to breast cancer surgery was associated with a higher rate of DFS and OS at 5 years. | Badwe, J Clin Oncol 2023