Performance and survival outcomes of defect-driven versus specimen-driven method of frozen section intraoperative margin assessment in oral cancers.

Margin status is one of the most important prognostic factors in oral cancers. Intraoperative frozen section (FS) can be performed to ensure a margin-negative resection, however the method of FS assessment is debatable. The aim of this study was to compare the defect-driven (DDA) versus specimen-driven (SDA) approach for intraoperative assessment of tumour margins in oral cancer resections and their impact on loco-regional recurrence and survival. The primary study endpoint was margin status determined from the final histopathological examination report. Secondary endpoints were disease recurrence and survival. This retrospective cohort study compared the two methods of FS in terms of their performance and survival outcomes. All oral squamous cell carcinoma patients who underwent surgery as the primary treatment from January 2018 to February 2019 were included. The involved margin rate was slightly lower with SDA than DDA (7.5% vs 11.8%), however the difference was not statistically significant. The recurrence rate was higher with DDA (19/51, 37.2%) than SDA (14/53, 26.4%), although this was not statistically significant. Local recurrence-free survival (DDA 62% vs SDA 75%; P = 0.653) and overall survival (DDA 76% vs SDA 78%; P = 0.300) at 18 months of follow-up were comparable. There was no significant difference in sensitivity or specificity of intraoperative FS for margin assessment between SDA and DDA. The type of intraoperative FS technique used did not affect loco-regional recurrence or overall survival.