Study Comparing Different Neck Treatment Approaches in Patients With Oral Cancer Without Visible Neck Spread

Overview

The goal of this clinical trial is to learn whether selective neck dissection involving lymph node levels I-III is as effective as selective neck dissection involving levels I-IV in treating adults with clinically node-negative (cN0) oral squamous cell carcinoma undergoing curative surgery. It will also evaluate whether extending the neck dissection to level IV affects cancer control, surgical complications, shoulder function, and quality of life. The main questions it aims to answer are: * Does selective neck dissection of levels I-III provide regional recurrence-free survival comparable to selective neck dissection of levels I-IV? * Does extending the neck dissection to level IV improve overall survival, disease-free survival, or reduce regional recurrence? * Does selective neck dissection of levels I-III result in less postoperative morbidity, better shoulder function, and improved quality of life compared with selective neck dissection of levels I-IV? Researchers will compare patients undergoing selective neck dissection of levels I-III with those undergoing selective neck dissection of levels I-IV to determine whether routine removal of level IV lymph nodes provides additional oncological benefit while maintaining acceptable functional outcomes. Participants will: * Undergo surgery for oral squamous cell carcinoma with random assignment to selective neck dissection of either levels I-III or levels I-IV. * Receive standard postoperative treatment, including radiotherapy or chemoradiotherapy when indicated according to the final pathology report. * Attend scheduled follow-up visits for clinical examinations and surveillance for cancer recurrence. * Undergo assessments of shoulder function, sensory function, postoperative complications, and quality of life using validated questionnaires at predefined follow-up intervals.

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies of the head and neck, with cervical lymph node metastasis being the most important prognostic factor affecting survival. In patients with clinically node-negative (cN0) neck disease, elective selective neck dissection is the standard of care because of the substantial risk of occult cervical metastasis. However, the optimal inferior extent of elective neck dissection remains controversial. Selective neck dissection involving levels I-III is widely accepted for early-stage oral cavity cancer, while some surgeons routinely extend the dissection to level IV based on concerns regarding skip metastasis and the potential for improved regional disease control. Extending the dissection may increase operative time and postoperative morbidity, including shoulder dysfunction and sensory impairment, without providing additional oncological benefit. High-quality prospective evidence comparing these two approaches is limited. The EXTENT N0 Trial is a prospective, parallel-group, randomized controlled trial designed to compare selective neck dissection of levels I-III with selective neck dissection of levels I-IV in adults with clinically node-negative oral squamous cell carcinoma undergoing primary curative surgery. Eligible participants will be randomly assigned in a 1:1 ratio to one of the two surgical approaches. Tumor resection, reconstruction, perioperative care, and adjuvant treatment will be provided according to institutional standards and multidisciplinary tumor board recommendations. Participants will undergo regular postoperative follow-up with clinical examination and appropriate imaging according to the study schedule. Functional outcomes, postoperative complications, and quality of life will be assessed using validated instruments at predefined time points. The study aims to determine whether limiting elective neck dissection to levels I-III provides regional disease control comparable to levels I-IV while reducing treatment-related morbidity and preserving postoperative function and quality of life.