Elective versus therapeutic neck dissection in the clinically node negative early oral cancer: A randomised control trial (RCT).

Abstract

LBA3 Background: Management of the neck in early oral cancers has been a matter of debate with clinical equipoise between elective (END) or therapeutic neck dissection (TND). Methods: This is a prospective phase III RCT (NCT00193765) to test the superiority of END at the time of primary surgery over TND (neck dissection at the time of nodal relapse) in patients with lateralized T1 or T2 squamous carcinoma of oral cavity, amenable to peroral excision. Patients were stratified based on size, site, sex and preoperative neck ultrasound. The primary end point was overall survival (OS) and secondary end point was disease-free survival (DFS). The trial was planned to demonstrate a 10% superiority (1-sided α = 0.05 and β = 0.2) in OS for END vs. TND, assuming 60% 5-year OS in TND arm, with a planned sample size of 710. Results: This trial was terminated after 596 patients were randomized between January 2004 and June 2014. An interim intent-to-treat analysis of initial 500 patients (255 in TND, 245 END) with a minimum follow-up of 9 months was performed as mandated by Data and Safety Monitoring Committee based on the number of observed deaths in each arm. Both arms were balanced for site and stage. There were 427 tongue, 68 buccal mucosa and 5 floor of mouth tumors; 221 were TI and 279 T2. At a median follow-up of 39 months there were 146 recurrences in TND and 81 in END arms respectively. The 3-year OS was significantly higher in END compared to TND arm (80.0% vs. 67.5%, HR = 0.63, 95%CI 0.44-0.89, p = 0.01) as was 3-year DFS (69.5% vs. 45.9%, HR = 0.44, 95%CI 0.34-0.58, p < 0.001). After adjusting for stratification factors in Cox regression, END continued to be significantly superior to TND for both OS and DFS. Conclusions: There were 8 excess deaths for every 15 excess recurrences in the TND arm. Elective neck dissection in patients with early oral SCC results in 37% reduction in mortality and should be considered the standard of care. Clinical trial information: NCT00193765.