Does tumor depth affect nodal upstaging in squamous cell carcinoma of the head and neck?

Abstract

The aim of this study was to determine whether tumor depth affects upstaging of the clinically node-negative neck, as determined by sentinel lymph node biopsy with full pathologic evaluation of harvested nodes including step-serial sectioning (SSS) and immunohistochemistry (IHC). One hundred seventy-two patients with cT1/2 N0 squamous cell carcinoma (SCC) of the oral cavity/oropharynx undergoing primary resection and either sentinel node biopsy (SNB) or SNB-assisted neck dissection as a staging tool for the cN0 neck. Harvested nodes were examined with hematoxylin-eosin staining, SSS, and IHC. Patients upstaged by SSS/IHC were denoted pN1mi. One hundred one of 172 patients were staged pN0, with 71 (41%) patients upstaged. Increasing tumor depth was associated with higher likelihood of upstaging (P < .001). Tumor depth showed a positive correlation with nodal stage according to TNM classification (P < .001). Tumor depth greater than 4 mm appears to be the most appropriate cutoff for risk stratification, although tumors in the oropharynx may require a lower value. Tumor depth is an important prognostic factor for patients with SCC of the oral cavity or oropharynx. Tumors greater than 4 mm are associated with greater risk of upstaging; however, this optimum cutoff value may vary between primary tumor sites.