Study Comparing Limited and Extensive Neck Surgery in Oral Cancer Patients With Neck Spread (ExtentN1)

Extent of Neck Treatment in Clinically N1 Oral Cancer: A Randomized Controlled Trial

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Oral Cavity Squamous Cell Carcinoma
• Intervention / Treatment: Procedure: Selective Neck Dissection (Levels I-IV); Procedure: Modified Neck Dissection (Levels I-V)

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Maroti B Wadewale, MDS, FHNO; Phone Number: +918483851334; Email: dr.marotiwadewale59@gmail.com
• Study Contact Backup: Name: Parag J Watve, MS, FHNS; Phone Number: +919823109918; Email: paragwatve@kolhapurcancercentre.com

Study Locations

• India
  • Maharashtra
    • Kolhāpur, Maharashtra, India, 416004
      • Kolhapur Cancer Centre
      • Contact: Maroti B Wadewale, MDS, FHNO; Phone Number: +918483851334; Email: dr.marotiwadewale59@gmail.com
      • Contact: Yogesh Anap, MD; Phone Number: +919867155930; Email: yogesh.anap1@gmail.com
      • Principal Investigator: Maroti B Wadewale, MDS, FHNO
      • Sub-Investigator: Parag Watve, MS, FHNS

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Histologically proven squamous cell carcinoma of oral cavity will be included
• Clinical stage T1-T4, N1, M0
• cN1 neck on clinical examination and imaging (CT/MRI)
• Single node which is FNAC proven without any other significant nodes.
• Patients with ASA grade II and I.
• Understands the protocol and able to give informed consent.

Exclusion Criteria:

• Recurrent cases
• Multiple significant nodes
• Nodes clinical/radiological with ENE
• Single metastatic node at level III/IV/V
• Single metastatic node with other suspicious nodes
• Patients with a history of head and neck radiation therapy treatment
• Previous history of any malignancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm 1- Selective neck dissection level I to level IV; Participants randomized to this arm will undergo surgical resection of the primary oral cavity squamous cell carcinoma along with ipsilateral selective neck dissection involving cervical lymph node levels I-IV. Contralateral neck management, reconstruction, and adjuvant therapy will be performed according to standard institutional protocols and final histopathological findings.	Procedure: Selective Neck Dissection (Levels I-IV); Selective neck dissection will include removal of cervical lymph node levels Ia, Ib, IIa, IIb, III, and IV on the ipsilateral side while preserving uninvolved non-lymphatic structures. The primary oral cavity tumor will be resected according to oncologic principles with reconstruction as required. Contralateral neck management and adjuvant therapy will be provided according to institutional protocols and final histopathological findings.
Active Comparator: Arm 2- Modified Neck Dissection (Levels I-V); Participants randomized to this arm will undergo surgical resection of the primary oral cavity squamous cell carcinoma along with ipsilateral modified neck dissection involving cervical lymph node levels I-V while preserving the spinal accessory nerve, internal jugular vein, and sternocleidomastoid muscle whenever oncologically appropriate. Contralateral neck management, reconstruction, and adjuvant therapy will be performed according to standard institutional protocols and final histopathological findings.	Procedure: Modified Neck Dissection (Levels I-V); Modified neck dissection will include removal of cervical lymph node levels Ia, Ib, IIa, IIb, III, IV, and V on the ipsilateral side while preserving the spinal accessory nerve, internal jugular vein, and sternocleidomastoid muscle whenever oncologically appropriate. The primary oral cavity tumor will be resected according to oncologic principles with reconstruction as required. Contralateral neck management and adjuvant therapy will be provided according to institutional protocols and final histopathological findings.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Regional Recurrence-Free Survival (RRFS)	Regional recurrence-free survival is defined as the time from the date of definitive surgery to the first documented regional recurrence in the cervical lymph nodes or death from any cause, whichever occurs first. Regional recurrence will be confirmed by clinical examination, imaging, and histopathological evaluation whenever feasible.	3 years after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Survival (OS)	Overall survival is defined as the time from definitive surgery until death from any cause.	Up to 3 years after surgery
Disease-Free Survival (DFS)	Disease-free survival is defined as the time from definitive surgery to the first documented local, regional, or distant recurrence, or death from any cause.	Up to 3 years after surgery
Level-wise Cervical Lymph Node Metastasis	Distribution of histopathologically confirmed metastatic lymph nodes according to cervical nodal level.	At the time of surgery (histopathological examination)
Nodal Yield	Total number of lymph nodes retrieved during neck dissection and confirmed by histopathological examination.	At the time of surgery
Shoulder Function assesment	Shoulder function will be assessed using the Constant-Murley Score (0-100 points), with higher scores indicating better shoulder function.	Preoperatively; 1 month; 3 months; 6 months, 1 and 2 year
Postoperative Surgical Morbidity	Incidence of postoperative complications, including chyle leak, hematoma, wound infection, seroma, cranial nerve injury	Within 30 days after surgery
Shoulder function assesment with Shoulder pain and disability index	Shoulder pain and disability will be assessed using theShoulder pain and disability index questionnaire. Scores range from 0 to 100, with higher scores indicating greater pain and disability.	Preoperatively; 1 week; 1 month; 3 months; 6 months; 1 year; and 2 years after surgery

Collaborators and Investigators

• Sponsor: Kolhapur Cancer Centre - Cancer Centers of America

Publications and helpful links

General Publications

• Pantvaidya GH, Pal P, Vaidya AD, Pai PS, D'Cruz AK. Prospective study of 583 neck dissections in oral cancers: implications for clinical practice. Head Neck. 2014 Oct;36(10):1503-7. doi: 10.1002/hed.23494. Epub 2014 Jan 13.
• Liang L, Zhang T, Kong Q, Liang J, Liao G. A meta-analysis on selective versus comprehensive neck dissection in oral squamous cell carcinoma patients with clinically node-positive neck. Oral Oncol. 2015 Dec;51(12):1076-81. doi: 10.1016/j.oraloncology.2015.10.005. Epub 2015 Oct 23.
• Hashmi SS, Abbas A, Bukhari A, Saeed J, Shafqat A, Siddique AH, Buksh AR, Murtaza G. Selective Neck Dissection for Node-Positive Oral Cavity Squamous Cell Carcinoma: A Retrospective Cohort Study. Int Arch Otorhinolaryngol. 2022 Feb 22;26(4):e630-e635. doi: 10.1055/s-0041-1741437. eCollection 2022 Oct.
• Shin YS, Koh YW, Kim SH, Choi EC. Selective neck dissection for clinically node-positive oral cavity squamous cell carcinoma. Yonsei Med J. 2013 Jan 1;54(1):139-44. doi: 10.3349/ymj.2013.54.1.139.

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): April 22, 2031
• Study Completion (Estimated): April 23, 2031

Study Registration Dates

• First Submitted: July 11, 2026
• First Submitted That Met QC Criteria: July 16, 2026
• First Posted (Actual): July 21, 2026

Study Record Updates

• Last Update Posted (Actual): July 21, 2026
• Last Update Submitted That Met QC Criteria: July 16, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Head and Neck Cancer; Oral Cancer; Oral Cavity Squamous Cell Carcinoma; Neck Dissection; Modified Neck Dissection; Cervical Lymph Node Metastasis
• Additional Relevant MeSH Terms: Mouth Diseases; Stomatognathic Diseases; Neoplasms by Site; Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Carcinoma; Carcinoma, Squamous Cell; Squamous Cell Carcinoma of Head and Neck; Head and Neck Neoplasms; Mouth Neoplasms
• Other Study ID Numbers: ExteNTN1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: No individual participant data (IPD) will be shared with other researchers. The study investigators do not have a plan to make de-identified participant-level data publicly available.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No