137MO - Effect of peri-tumoral infiltration of local anaesthetic prior to surgery on survival in early breast cancer

Background

Preventing initiation of micro metastases from early breast cancer by peri-operative intervention has not been explored adequately. Local anaesthesia blocks voltage gated sodium channels which prevents activation of pro-metastatic pathways. A Cochrane review of using local anaesthesia before surgery for breast cancer concluded inadequate data on its efficacy. We conducted a multi-centre randomized trial to test the impact of peri-tumoral infiltration of local anaesthesia before surgery on survival in women with early breast cancer.

Methods

Women with early breast cancer were randomized, to receive peri-tumoral injection of 0.5% lidocaine, 5-10 minutes before surgery (LA arm) or surgery without lidocaine(No-LA arm). Randomisation was stratified by menopausal status and tumour size. Women on neo-adjuvant chemotherapy were not included in the study. Participants underwent breast conservation or modified radical mastectomy and received standard post-operative adjuvant radiotherapy and systemic therapy. The primary endpoint was disease-free survival(DFS) and the secondary endpoint was overall survival(OS).

Results

The study included 1600 patients randomized to LA(N=796) and No-LA(N=804) arms, of whom 1583 were included in the analysis. At 72 months there were 255 DFS events (109 LA arm, 146 No-LA arm). At 6-year DFS were 86.1% and 81.7% in LA and No-LA arms, respectively (HR 0.74, 95% CI 0.58-0.95, p=0.017) and OS were 89.9% and 86.2%, respectively (HR 0.71, 95% CI 0.53-0.94, p=0.019). The impact of LA was similar in subgroups defined by menopausal status, tumour size, lymph node metastases, hormone receptor and HER2neu status. In the LA and no-LA arm, the loco-regional DFS were 94.8% and 92.3%, respectively (HR=0.67, 95%CI 0.45-0.99, p=0.04) and distant DFS were 89.2% and 85.1%, respectively (HR=0.70, 95%CI 0.53 – 0.94, p=0.013). There were no adverse events due to lidocaine injection.

Conclusions

Peri-tumoral injection of lidocaine before surgery is a simple implementable intervention that can reduce 1 of 4 recurrences and 3 of 10 deaths in women with early breast cancer. Altering events at the time of surgery can prevent metastases in women with early breast cancer(CTRI/2014/11/005228).

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Tata Memorial Centre, Mumbai, India.

Funding

Department of Atomic Energy, Government of India.

Disclosure

All authors have declared no conflicts of interest.