Predictive factors of occult cervical lymph node metastasis in tongue cancer

Abstract

AbstractIntroductionCervical lymph node metastasis is the most important prognostic factor in tongue carcinoma. Prophylactic neck dissection improves patient survival, but there are negative impacts on quality of life; consequently, we investigated the predictive factors of occult neck metastasis.ObjectivesFirst, we wanted to identify the rate of occult nodal metastases in patients with squamous cell carcinoma (SCC) of the tongue who had been diagnosed with clinically negative lymph nodes. Second, we explored possible factors that could predict cervical lymph node metastasis.MethodsThe present study was observational and included 62 patients with clinically node‐negative (cN0) oral tongue SCC between September 2019 and December 2020. Clinical presentation, radiological characteristics (tumor size, depth of invasion [DOI], neck lymph node), and pathology (histological grade, DOI, lymphovascular space invasion [LSVI], perineural invasion [PNI], worst patterns of invasion [WPOI‐5], and number of metastasis nodes) were analyzed.ResultsThe rate of occult metastasis was 24.2%. Multivariate analysis indicated WPOI‐5 was an independent prognostic factor. Clinical and histological parameters such as DOI on computerized tomography (CT) (> 7 mm)and DOI on pathology (> 7 mm) showed a significant correlation with the risk of lymph node metastasis but were not strong enough to be independent prognostic factors. The DOI values measured on CT showed a strong correlation with the DOI values on pathology (correlation coefficient = 0.788).ConclusionPatients with positive WPOI‐5, CT‐DOI, and pathological DOI > 7 mm were at high risk of developing cervical lymph node metastasis. We suggest prophylactic neck dissection for these patients.