Surgical margins in oral squamous cell cancer : intraoperative evaluation and prognostic impact

Purpose of review: To summarize recent findings regarding surgical management of oral squamous cell cancer (OSCC) through analysis of different intraoperative techniques for assessment of margins, evaluate the pros and cons of each, and ensuing prognostic impact. Recent findings: 'En bloc' OSCC resection and histopathologic evaluation of margins on the formalin-fixed specimen remain the 'gold standard' for oral oncologic surgery, whereas assessment of intraoperative surgical margins and its overall clinical value are still questioned and debated in the literature. The commonly applied evaluation of frozen sections still raises concerns regarding its efficacy and reproducibility; therefore, several ancillary diagnostic methods have entered the field of head and neck oncology in the last decades, aiming to support the surgeon in achieving tumor-free margins during ablative procedures. Summary: Poor prognosis of OSCC is strongly associated with residual tumor after surgery. Negative surgical margins are one of the strongest prognosticators for disease-free survival and locoregional control, but their intraoperative determination seems still to be suboptimal and needs better refinement. The most studied techniques to assess intraoperative margins include fluorescence, Raman spectroscopy, narrow band imaging, optical coherence tomography, and cytological bone margins analysis; each has its unique characteristics that are described in detail herein.