Injecting lidocaine around a breast tumor prior to surgical removal may reduce the risk for metastases and death in patients with early breast cancer, a new prospective randomized study suggests.
The technique, which has shown some promise in preclinical and clinical settings, was associated with a significant improvement in 5-year disease-free survival (DFS) and overall survival, with relative risk reductions of 26% and 29%, respectively.
“These findings support the use of peritumoral lidocaine as a low-cost intervention that can be easily implemented into the care of patients with breast cancer,” Tessa Higgins, BA, of Brigham and Women’s Hospital in Boston, and Elizabeth A. Mittendorf, MD, PhD, of Dana-Farber Brigham Cancer Center and Harvard Medical School, Boston, write in an accompanying editorial.
And given the estimated 2.3 million new cancer cases diagnosed globally each year — as many of half of which involve operable-stage disease — the use of peritumoral local anesthetic at the time of surgery could potentially save more than 100,000 lives annually, the study authors estimated.
The study and editorial were published online April 6 in the Journal of Clinical Oncology.
Perioperative interventions to prevent metastases have not been well studied, but the use of local anesthesia for that purpose has a scientific basis. Researchers have found that local anesthetics block voltage-gated sodium channels, which can inhibit metastatic pathways, the study authors explained.
However, retrospective study findings have been mixed, with some showing improved outcomes in patients who receive regional or local anesthesia during primary breast cancer surgery and others not.
The study team, led by Rajendra A. Badwe, MD, of Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India, conducted a randomized, open-label study to help clarify the literature. The team randomly assigned 1583 women with early breast cancer and no prior neoadjuvant treatment from 11 centers in India to receive 0.5% lidocaine up to 4.5 mg/kg of body weight (n = 786) or no lidocaine (n = 797). Lidocaine was injected around all tumor surfaces after administration of general anesthesia, and surgery was initiated within 7-10 minutes of injection.
All patients received standard postoperative adjuvant treatment, and there were no adverse events associated with lidocaine injection.
At a median follow-up of 68 months following mastectomy or breast conserving surgery, 5-year DFS rates were 86.6% in the lidocaine group and 82.6% in the no-lidocaine group (hazard ratio [HR], 0.74; P = .017). Five-year overall survival rates were also significantly improved among those who received lidocaine: 90.1% and 86.4%, respectively (HR, 0.71; P = .019).
The authors also found that the 5-year cumulative incidence rates of locoregional recurrence were significantly lower for those who received lidocaine — 3.4% vs 4.5% (HR, 0.68) — as were distant recurrence rates — 8.5% vs 11.6% (HR, 0.73).
The effect of lidocaine administration was not significantly different in patients who underwent mastectomy (HR, 0.73) or breast conserving surgery (HR, 0.70).
The lidocaine benefits observed in the overall study population were consistent across subgroups defined by menopausal status, tumor size, nodal metastases, and hormone receptor and HER-2 status, the investigators found.
“Whatever the mechanisms, the results of this study suggest the possible role of modulating processes that may confer metastatic potential on breast cancer cells at the time of surgery to reduce the onset of metastases and improve surgical cure rates,” the authors say.
The authors noted that, because of a revision to the study design, the final achieved absolute difference between the two arms of 4% was less than the planned difference of 6%, the investigators explained. However, “an absolute difference of 4% in DFS with a relative risk reduction of 26% is meaningful in the context of current advancements in the adjuvant setting in breast cancer,” as is the absolute overall survival benefit of 3.7%, which “makes the potential clinical utility of this intervention quite compelling,” the authors say.
The editorialists agreed that the perioperative use of local anesthetics has potential to “reduce the rates of recurrence and death in women with early-stage breast cancer” and noted it would be “reasonable to introduce” this easy, cost-effective intervention into breast cancer care.
This study was supported by the Department of Atomic Energy, Government of India. Badwe and Higgins report no relevant financial relationships. Mittendorf reported honoraria, a consulting or advisory role, and/or research funding from Physicians’ Education Resource, BioNTech SE, and Merck. She reported uncompensated relationships with Bristol-Myers Squibb and Roche/Genentech.
J Clin Oncol. Published online April 6, 2023. Abstract
Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at [email protected] or on Twitter: @SW_MedReporter
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