Study Comparing Limited and Extensive Neck Surgery in Oral Cancer Patients With Neck Spread

Overview

Oral cavity squamous cell carcinoma (OCSCC) frequently metastasizes to cervical lymph nodes, and the extent of neck dissection remains an area of ongoing debate in patients with clinically node-positive (cN1) disease. While modified neck dissection (MND, levels I-V) is widely practiced, selective neck dissection (SND, levels I-IV) may provide equivalent oncologic outcomes with reduced surgical morbidity. However, high-quality randomized evidence comparing these approaches is lacking. The ExteNT N1 Trial is a prospective, randomized, open-label, parallel-group clinical trial designed to compare selective neck dissection (levels I-IV) with modified neck dissection (levels I-V, preserving the spinal accessory nerve, internal jugular vein, and sternocleidomastoid muscle) in patients with resectable cN1 oral cavity squamous cell carcinoma. Eligible participants will be randomized in a 1:1 ratio to either treatment arm. The primary endpoint is 3-year regional recurrence-free survival (RRFS), along with postoperative quality of life measured using the Neck Dissection Impairment Index (NDII). Secondary endpoints include overall survival, disease-free survival, level-wise nodal involvement, nodal yield, shoulder function (Constant-Murley Score, SPADI, and Arm Abduction Score), postoperative complications including chyle leak, and other surgical morbidities. This trial aims to generate level I evidence regarding the optimal extent of neck dissection for cN1 OCSCC, balancing oncologic safety with preservation of postoperative function and quality of life.

Cervical lymph node metastasis is the most important prognostic factor in oral cavity squamous cell carcinoma (OCSCC). Surgical management of the neck is an integral component of treatment; however, the optimal extent of neck dissection for patients with clinically node-positive (cN1) disease remains uncertain. Although modified neck dissection (levels I-V with preservation of non-lymphatic structures) has traditionally been recommended for node-positive disease, several retrospective studies have suggested that carefully selected patients with limited nodal disease may achieve comparable regional control with a less extensive selective neck dissection. Nevertheless, these studies are subject to selection bias, and no adequately powered randomized controlled trial has directly compared these surgical approaches. Dissection of lower cervical nodal levels may increase operative time and postoperative morbidity, including shoulder dysfunction, sensory deficits, chyle leak, and impairment in quality of life. Reducing the extent of neck dissection without compromising oncologic outcomes could improve postoperative functional recovery and patient-reported outcomes while maintaining regional disease control. The ExteNT N1 Trial is designed to address this evidence gap by comparing selective neck dissection (levels I-IV) with modified neck dissection (levels I-V) in patients with resectable cN1 OCSCC. In addition to evaluating oncologic outcomes, the study incorporates validated functional and quality-of-life assessments to comprehensively evaluate the impact of the two surgical strategies. Participants will receive standard treatment for the primary tumor, and adjuvant therapy will be administered according to final histopathological findings and contemporary treatment guidelines. The findings of this trial are expected to provide high-level evidence to guide the surgical management of the clinically N1 neck in OCSCC. If selective neck dissection demonstrates equivalent oncologic outcomes with lower morbidity, it may support a change in surgical practice by reducing unnecessary treatment while preserving function and quality of life.