Oral squamous cell carcinoma: Histologic risk assessment, but not margin status, is strongly predictive of local disease-free and overall survival

To analyze the impact of resection margin status and histologic prognosticators on local recurrence (LR) and overall survival (OS) for patients with oral squamous cell carcinoma (OSCC). This study was both retrospective and prospective in design. Cohort 1 refers to the entire group of 292 patients with OSCC. The slides from the earliest resection specimens from Cohort 1 were examined in an exploratory manner for multiple parameters. Cohort 2 refers to a subset of 203 patients, who did not receive any neoadjuvant therapy and had outcome data. Cohort 3 represents a subset of Cohort 2 (n = 168) wherein the histologic resection margin status could be reconfirmed. Cohort 4 refers a subset of 85 patients with tongue/floor of mouth tumors. Margin status was designated as follows: group 1, clearance of > or =5 mm with intraoperative analysis, no need for supplemental margins (n = 46); group 2, initial margins were measured as