Correlating the depth of invasion at specific anatomic locations with the risk for regional metastatic disease to lymph nodes in the neck for oral squamous cell carcinoma

ABSTRACT Background The purpose of this study was to investigate the critical primary tumor depth of invasion in oral squamous cell carcinoma that would lead to a 20% or greater risk of nodal metastasis. Methods An institutional review board approved retrospective review of our head and neck database was performed from 2009 to 2014 and the data were statistically analyzed. Results Two hundred eighty‐six patients with a diagnosis of oral squamous cell carcinoma who met our inclusion criteria underwent primary excision and neck dissection. For a depth of invasion of 1 mm or less, there were no patients with a positive node. From 1.1 mm to 2 mm of depth of invasion, there was 1 of 11 patients (9%) who had at least 1 positive node. At 2.1 mm to 3 mm, 5 of 25 patients (20%) had at least 1 positive node. Conclusion Depth of invasion and the location of the tumor are 2 important variables to consider when making treatment recommendations to patients with clinical N0 disease. © 2017 Wiley Periodicals, Inc. Head Neck 39: 974–979, 2017