Results of a randomized controlled trial of level IIb preserving neck dissection in clinically node-negative squamous carcinoma of the oral cavity

Abstract

Background: The lymphatic spread from the cancers of the oral cavity follows an orderly progression and involvement of lower nodes without involvement of upper nodes and skip metastasis is rare. Selective neck dissections are increasingly being performed for node-positive patients; however, in node-negative patients the options of wait and watch, prophylactic radiotherapy, and prophylactic elective node dissections are debated. Quality of life and shoulder functions are important to choose the appropriate therapeutic modality.

Patients and methods: Patients with oral squamous carcinoma with clinically and radiologically negative neck were randomized to IIb preserving superselective neck dissection or conventional supraomohyoid neck dissection. The primary end point of the study was recurrence of disease (clinical or radiological) and shoulder function as demonstrated by the clinical examination and electromyography. The secondary end point was quality of life as measured by the FACT-HN version 4 questionnaire at the end of 1 year follow-up.

Results: The mean number of lymph node harvested per patient was 25.6 (range 8-85). Of the 32 patients, 3 had histologically positive node in level Ib, one of these patients had single positive node while the remaining two had three positive nodes in level Ib. At median follow-up of 36 months disease-free survival in IIb, sparing group was 83% compared to 91% in control arm, the difference in survival between two groups was statistically not significant (p = 0.694). EMG of the shoulder showed denervation pattern in 45% patients undergoing IIb preserving surgery at 1 month follow-up compared to 95% in conventional surgery group, this recovered in all patients but one at 3 months and 100% recovery was seen at 6 months.

Conclusions: The results of the present study indicate that superselective IIb preserving neck dissections are technically feasible and appear to be oncologically safe procedures when performed as elective prophylactic procedures in highly select group of patients. A significant number of occult metastasis seen in the present study suggests prophylactic dissection to be better than wait and watch policy. Results also show initial higher shoulder morbidity at 1 month in patients undergoing IIb preserving dissections; however, at the end of 1 year recovery is complete and both procedures are comparable.

Trial registration: The trial is registered at clinicaltrials.gov with registration no NCT00847717 ; registered on February 19, 2009.