The predictive value of depth of invasion and tumor size on risk of neck node metastasis in squamous cell carcinoma of the oral cavity: A prospective study.

BACKGROUND: Tumor depth is a reliable parameter to predict nodal metastasis in oral cancers; therefore, the authors embarked upon a prospective observational study to define the relationship between the tumor depth and the risk of cervical lymph node involvement as well to determine the optimal tumor depth cutoff point for nodal metastasis. AIMS: The aim was to study the predictive value of depth of invasion (DOI) and tumor size on risk of cervical node metastasis in squamous cell carcinoma of the oral cavity. MATERIALS AND METHODS: Biopsy-proven Stage I-Stage III oral cavity squamous cell carcinoma patients were included in this prospective, observational study. Various histopathological characteristics (DOI, tumor size, lympho-vascular invasion [LVI], perineural spread, and grade of differentiation) were analyzed to predict the cervical node metastasis. STATISTICAL ANALYSIS USED: The impact of the clinical and histopathological parameters of primary tumor on cervical lymph node metastasis was analyzed by univariate as well as multivariate logistic regression analyses using NCSS 12 version 12.0.5 statistical software. RESULTS: The independent predictors of cervical lymph node metastasis were DOI (P = 0.0014) and LVI (P = 0.0414). The incidence of cervical metastasis increased markedly when the DOI was over 5 mm, and it was a statistically significant (P < 0001) association. CONCLUSIONS: DOI is a significant predictor of cervical nodal metastasis and tumor depth 5 mm can be considered as a cutoff value in staging and management of early oral squamous cell carcinoma.