Sentinel Node Biopsy Versus Limited Elective Neck Dissection in Early Cancers of Oral Cavity NoDe Negative

Sentinel Node Biopsy Versus Limited Elective Neck Dissection in Early Cancers of Oral Cavity NoDe Negative (SECOND N0): Non-inferiority Phase III Trial

The goal of this clinical trial is to compare the survival outcomes, morbidity and cost-effectiveness of sentinel node biopsy versus limited elective neck dissection in node-negative early oral cancers.

The main questions it aims to answer are:

• Survival outcomes
• Morbidity outcomes
• Cost-effectiveness

Participants will either undergo sentinel node biopsy followed by completion neck dissection if sentinel node is reported to be metastatic (SNB) or limited elective neck dissection where level IIb will be cleared only if level IIa is metastatic (limited END). The study will compare the outcomes in the two cohorts.

Based on the current literature, we know that elective neck dissection (END) is mandatory in clinically node-negative early oral cancers. However, this leads to overtreatment and morbidity in about 55-80% of patients. The emergence of recent level I evidence makes SNB the standard of care in this setting. However, its limitation of being a two-staged procedure, steep learning curve, the burden on resources, lack of infrastructure, short-lasting decrease in morbidity and lack of cost-effectiveness data limits its wide applicability. It is our routine departmental practice of performing limited neck dissection clearing level I-III/IV sparing level IIb which is cleared only if level IIa is metastatic. It is hypothesized that limited END would limit the morbidity of shoulder dysfunction and be a more feasible and cost-effective treatment option which could be a suitable alternative to SNB in this setting without compromising the survival outcomes. With this background, we propose to embark upon a phase III RCT comparing the oncologic outcomes and morbidity of SNB versus limited END. We hypothesize that limited END would have survival outcomes non-inferior, morbidity similar to SNB with higher cost-effectiveness.

Aims and objectives:

Aim To compare the survival outcomes, morbidity and cost-effectiveness of SNB versus limited END in node-negative early oral cancers

Primary objective

1) Overall survival

Secondary objectives

1. Shoulder morbidity (key secondary endpoint) longitudinally up to 2 years
2. Disease-free survival
3. Neck nodal recurrence-free survival
4. Other side effects (chyle leak, hematoma, lymphoedema)
5. Longitudinal Quality of life up to 2 years
6. Cost-effective analysis

Exploratory objectives Blood and tumour tissue will be collected and banked for biomarker studies. Exploratory analyses will be conducted at a later date. Efforts may be directed to identify the biomarkers to predict nodal metastasis.

Inclusion Criteria:

1. Age >18 years of age
2. Biopsy-proven invasive squamous cell carcinoma involving the site tongue and buccal mucosa
3. T1 and T2 lesions as per AJCC TNM 8 edition
4. Clinicoradiologically node negative
5. Amenable to per oral excision
6. Treatment naïve
7. No other site of malignancy

Exclusion Criteria:

1. Previous surgery in the head and neck region,
2. Upper alveolar or palatal lesions
3. Large heterogeneous leukoplakia or other premalignant lesions
4. Previous malignancy in the head and neck region
5. Patients requiring the free flap reconstruction