Clinical T staging accuracy and its prognostic relevance in oral squamous cell carcinoma.

Accurate clinical T-staging is essential for guiding surgical management in oral squamous cell carcinoma (OSCC), particularly when determining treatment escalation or de-escalation. This study evaluated its diagnostic accuracy and impact on potential over- and undertreatment. This retrospective single-center study included patients with histologically confirmed OSCC who underwent primary surgical resection with negative margins between 2012 and 2022. Clinical T-staging based on preoperative contrast-enhanced computed tomography and clinical examination was compared with pathological staging. The primary endpoint was the diagnostic accuracy of clinical T-staging, while secondary endpoints were overall survival and disease-free survival. A total of 637 patients were included in this study, from which 33.9% were inaccurately staged. Clinical stages T1 and T4a yielded the highest accuracy (81.6% and 84.1%), while stages T2 and T3 only had 69.2% and 64.3%. Midline tumors and patients with a clinically unsuspicious neck (cN0) were more frequently staged accurately. In survival analysis, inaccurate T-staging was not independently associated with worse overall survival (hazard ratio 0.91, 95% confidence interval 0.65-1.27, P = 0.59) or disease-free survival (1.02, 0.70-1.49, P = 0.93). Clinical T staging in OSCC was inaccurate in approximately one-third of cases, particularly in cT2-3 tumors, whereas cT1 and cT4a showed higher concordance. Although staging inaccuracies were not linked to survival, they may influence the extent of surgical resection and the overall invasiveness of the procedure.