UNASSIGNED: This study aims to identify the rate of occult nodal metastasis (ONM), risk factors associated with ONM, and compare regional recurrence (RR), 2-year disease-free survival (DFS) in patients treated with elective neck dissection (END) versus expectant management (OBS) for primary T1-T2 gingival squamous cell carcinoma (GSCC) of the maxilla and mandible.
UNASSIGNED: A retrospective analysis was conducted and included patients from 2014 to 2021 who were treated at a tertiary referral center.
UNASSIGNED: Twenty patients underwent END and 36 were managed expectantly, with a mean follow-up period of 28 months. ONM was observed in 26% of the study cohort with 16.7% occurring in the maxilla and 36.4% in the mandible. No specific histopathologic features were predictive for ONM. No regional recurrence occurred. Local recurrence occurred in 5% and 2.8% of END and OBS groups, respectively. Two-year DFS were comparable between the END (93.8%) versus OBS (83.9%) as well as maxilla (90.9%) versus mandible (83.4%), P > 0.05.
UNASSIGNED: ONM remains variable in cT1-T2N0 GSCC with a greater incidence occurring in the mandible when compared to the maxilla, respectively. An END should be strongly considered for mandibular GSCC. Overall, END for the N0 neck has been shown to provide significant overall and disease-free survival benefits. However, further prospective randomized studies are needed to verify risk factors for ONM and validate the disease-related survival benefit of an elective neck dissection in this patient population.

According to the NCCN guidelines, there is weak evidence to support the use of elective neck dissection (END) in early-stage oral cavity squamous cell carcinoma (OCSCC). We sought to examine the indications for END in patients with cT1N0M0 OCSCC defined according to the AJCC Staging Manual, Eight Edition.
Of the 3886 patients diagnosed with cT1N0M0 included in the study, 2065 underwent END and 1821 neck observation.
The 5-year outcomes for patients who received END versus neck observation before and after propensity score matching (n = 1406 each) were as follows: neck control, 96 %/90 % (before matching), p < 0.0001; 96 %/90 % (after matching), p < 0.0001; disease-specific survival (DSS), 93 %/92 % (before matching), p = 0.0227; 93 %/92 % (after matching), p = 0.1436. Multivariable analyses revealed that neck observation, depth of invasion (DOI) > 2.5 mm, and poor differentiation were independent risk factors for 5-year outcomes. Upon the application of a scoring system ranging from 0 (no risk factor) to 3 (presence of the three risk factors), the following 5-year rates were observed: neck control, 98 %/95 %/84 %/85 %; DSS, 96 %/93 %/88 %/85 %; and overall survival, 90 %/86 %/79 %/59 %, respectively (all p < 0.0001). The survival outcomes of patients with scores of 0 and 1 were similar. The occult metastasis rates in the entire study cohort, DOI > 2.5 mm, and poor differentiation were 6.8 %/9.2 %/17.1 %, respectively.
Because all patients who received neck observation had a score of 1 or higher, END should be performed when a DOI > 2.5 mm or poorly differentiated tumors are present. Under these circumstances, 48.6 % (1888/3886) of cT1N0M0 patients may avoid END without compromising oncological outcomes.

OBJECTIVE: To compare the therapeutic results between selective neck dissection (SND) and conversion modified radical neck dissection (MRND) for the occult nodal metastasis cases in head and neck squamous cell carcinoma.
METHODS: Forty-four cases with occult nodal metastasis were enrolled in this observational cohort study. For twenty-nine cases, SNDs were done and for fifteen cases, as metastatic nodes were found in the operative field, conversion from selective to MRNDs type II were done. Baseline data on primary site, T and N stage, extent of SND, extracapsular spread of occult metastatic node and type of postoperative adjuvant therapy were obtained. We compared locoregional control rate, overall survival rate and disease specific survival rate between two groups.
RESULTS: Among the 29 patients who underwent SND, only one patient had a nodal recurrence which occurred in the contralateral undissected neck. On the other hand, among the 15 patients who underwent conversion MRND, two patients had nodal recurrences which occurred in previously undissected neck. According to the Kaplan Meier survival curve, there was no statistically significant difference for locoregional control rate, overall survival rate and disease specific survival rate between two groups (P=0.2719, P=0.7596, and P=0.2405, respectively).
CONCLUSIONS: SND is enough to treat occult nodal metastasis in head and neck squamous cell carcinoma and it is not necessary to convert from SND to comprehensive neck dissection.