Histologic assessment of tumor budding in preoperative biopsies to predict nodal metastasis in squamous cell carcinoma of the tongue and floor of the mouth.

BACKGROUND In squamous cell carcinoma (SCC) of the tongue and the floor of the mouth (FOM), it is important to predict lymph node metastasis, including occult metastasis, before operating. The purpose of this study was for us to determine practical histopathologic parameters as predictive factors for lymph node metastasis in preoperative SCC biopsy specimens. METHODS We examined 91 cases of SCC for conventional histopathologic assessment and a new factor, tumor budding, and their relationship with lymph node metastasis. RESULTS Significant factors via univariate analysis (p < .01) were budding (score ≥3) and tumor depth (≥3 mm) and these were associated with lymph node metastasis. Moreover, both budding and tumor depth significantly correlated with relapse-free survival; however, evaluating biopsy specimens often proved inaccurate for predicting true tumor depth of cancer invasion. CONCLUSION Tumor budding using immunohistochemistry for cytokeratin should be added to routine histologic assessments as a new criterion factoring into the decision as to whether neck dissection is indicated. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1582-E1590, 2016.