A study performed in 16 institutions in Japan shows that sentinel lymph node biopsy (SLNB)-navigated neck dissection is not inferior and it is less invasive than elective neck dissection in patients with early stage oral cavity squamous cell carcinoma (OCSCC). The study results may promote a widespread use of SLNB-navigated and replace elective neck dissection without a survival disadvantage and reducing also postoperative neck disability in this population. The findings are published on 20 April 2021 in the Journal of Clinical Oncology.
Potential strategies for managing patients with early OCSCC include observation, elective neck dissection, and SLNB. A large-scale randomised controlled trial reported previously the superiority of elective neck dissection over observation. However, avoiding unnecessary neck dissection prevents risks and complications, thus reducing surgical intervention and prolonged hospitalisation. The authors wrote in the background that there is insufficient evidence supporting a single strategy.
SLNB has been established as the method for staging patients with clinically N0 breast cancer and cutaneous melanoma and provides useful information of the nodal status. Appropriate neck dissection might be achieved if SLNB is used for treating OCSCC. Since reports of SLNB for OCSCC are limited and detection methods vary, a prospective multi-institutional study with numerous cases constituting unified methodologies is essential for verifying the validity of SLNB.
In this randomised, multicentre, noninferiority, phase III study, patients of age ≥18 years with histologically confirmed, previously untreated early OCSCC were randomly assigned to undergo elective neck dissection (n=137) or SLNB-navigated neck dissection (n=134).
The primary endpoint was the 3-year overall survival (OS) rate, with a 12% noninferiority margin; secondary endpoints included postoperative neck functionality and complications and 3-year disease-free survival (DFS). The SLNs underwent intraoperative multislice frozen section analyses for the diagnosis. Patients with positive SLN underwent either one-stage or second-look neck dissection.
The study team reported that pathologic metastasis-positive nodes were observed in 24.8% (34 of 137) and 33.6% (46 of 134) of patients in the elective neck dissection and SLNB groups, respectively (p = 0.190).
The 3-year OS in the SLNB group (87.9%) was noninferior to that in the elective neck dissection group (86.6%); p for noninferiority < 0.001.
The 3-year DFS was 78.7% and 81.3% in the SLNB and elective neck dissection groups, respectively (p for noninferiority < 0.001).
The scores of neck functionality in the SLNB group were significantly better than those in the elective neck dissection group.
The authors also commented that performing SLNB appropriately requires the expertise of a skilled head and neck surgeon, along with the collaborative efforts of a radiologist and a pathologist for pre-, post-, and intraoperative diagnoses.
Hasegawa Y, Tsukahara K, Yoshimoto S, et al. Neck Dissections Based on Sentinel Lymph Node Navigation Versus Elective Neck Dissections in Early Oral Cancers: A Randomized, Multicenter, and Noninferiority Trial. JCO; Published online 20 April 2021. DOI: 10.1200/JCO.20.03637