Omitting elective neck dissection in cT1/2N0 oral squamous cell carcinoma with sentinel lymph node metastasis: A prospective study

Objective: To examine the distribution of non-sentinel lymph nodes (SLNs) and to determine the feasibility of omitting elective neck dissection (END) in cases of cT1/2N0 oral cancer presenting with SLN metastasis. Methods: A prospective cohort of patients with cT1/2N0 oral cancer underwent SLN biopsy using a gamma-probe alongside methylene blue staining, followed by subsequent END. The primary outcome variable was non-SLN metastasis, with its predictors evaluated through logistic regression analysis. Results: A total of 200 patients with detectable SLNs were analyzed. Logistic regression revealed a significant odds ratio of 4.28 [95 % confidence interval: 2.11-14.56] for predicting non-SLN metastasis when comparing a depth of invasion greater than 4.0 mm to a DOI of 4.0 mm or less. Among the six cases of non-SLN metastasis, three patients with negative SLN biopsy results exhibited metastasis; one was found in ipsilateral level V and two in contralateral level Ib. In contrast, all three patients with positive SLN biopsy results had a DOI surpassing 4.0 mm, presenting with at least two positive SLNs. Non-SLN metastasis was detected in ipsilateral level III for one patient and at level IV for two others. Conclusion: END may be judiciously omitted in cases where only one positive SLN is identified in early-stage oral cancer with a depth of invasion of <= 4.0 mm.