Defining replicability and evaluating reliability of intra-operative cytological bone margins assessment. A study to strengthen previous findings in advanced oral cancer

Introduction: Curative intent in advanced oral cavity squamous cell cancer (OCSCC) implies clear resection margins (R0). Controlling resection margin is a pivotal point as R status, which is under the direct control of surgeons, continues to be the most important predictor for survival. However, intra-operative bone resection margin analysis still presents technical challenges preventing its routine clinical application. Objective: To introduce intra-operative cytological bone margins analysis by overcoming the previously reported technical limitations and confirming its reproducibility and reliability, to support intra-operative microscopically-guided resection. Methods: A total amount of 296 cytological samples and 148 cytological controls were obtained intra-operatively from surgical resection bone-margins in 74 patients affected by OCSCC with pre-operative suspicious bone cancer infiltration. Both techniques ICAB (intra-operative cytological assessment of bone margins) and ICICAB (intra-operative cell isolation cytological assessment of bone margins) were compared with the corresponding histological final report and evaluated as potential diagnostic intra-operative tool. Results: ICICAB demonstrated perfect accuracy, correctly identifying all positive and negative results as confirmed by the histological exam. Accordingly ICICAB could reliably identify cancer cells from the region of interest (ROI) analyzed. Discussion: The development and assessment of a reproducible and standard intra-operative bone margins analysis, would help in reducing the discrepancy between pre-operative and final cancer-infiltrative bone status, with a following significant difference in both functional and survival outcomes for advanced OCSCC patients, through an additional reduction in costs and time-consuming rates.