Pathological Risk Factors for Occult Nodal Metastasis in Early-Stage Squamous Cell Carcinoma of the Oral Cavity

Occult neck metastasis is the presence of metastasis in the cervical lymph nodes that cannot be radiologically or clinically identified. Presence of metastasis in any neck node can have a significant impact on overall survival of patients with oral squamous cell carcinoma (OSCC). Our aim was to analyze the correlation of various histopathological parameters with occult nodal metastasis in early-stage OSCC and to obtain an optimal DOI cut-off value for predicting its increased risk. We conducted a retrospective study on patients who reported to our institute with clinical stage I and II OSCC. The patients having well-differentiated and moderately differentiated OSCC were included. Association of various histopathological parameters with occult nodal metastasis was assessed using statistical analysis. A total of 102 patients of early-stage well-differentiated and moderately differentiated OSCC with clinically negative necks who underwent elective neck dissection at our institute from the year 2018 to 2023 were enrolled in the study. Depth of invasion (DOI), perineural invasion (PNI), worst pattern of invasion (WPOI), and grade of tumor differentiation were the histopathological parameters entered into the univariate regression analysis as predictive variables, and they were found to be predictors of occult nodal metastasis. An optimal DOI cut-off value of 5.5 mm was obtained for predicting the increase in the risk of occult nodal metastasis. DOI, PNI, WPOI, and grade of tumor differentiation are predictors of occult nodal metastasis. There is a need for searching methods for preoperative and intraoperative detection of all these histopathological factors so that unnecessary elective neck treatment can be avoided.