The relative propensity for regional metastasis in floor of mouth squamous cell carcinoma versus other oral cavity subsites.

There are previous papers suggesting that floor of mouth (FOM) oral squamous cell carcinomas (OSCC) metastasise earlier than other oral cavity subsites. This report further evaluates that hypothesis. Between February 2006 and December 2019, 825 patients underwent curative resection of OSCC. Data on nodal metastases and depth of invasion (DOI) of the primary tumour were collated. The relationship between tumour DOI and likelihood of nodal metastases was examined. A total of 203 patients had a FOM OSCC, 75 of which had nodal metastases. No difference was found in the incidence of, or correlation with DOI, and occurrence of regional metastases when FOM was compared to other OSCC subsites. We conclude that FOM OSCC has a similar regional metastatic propensity as other subsites in the oral cavity.