Tumour thickness as a predictor of nodal metastases in oral cancer: comparison between tongue and floor of mouth subsites

Oral Oncol. 2014 Dec;50(12):1165-8. doi: 10.1016/j.oraloncology.2014.09.012. Epub 2014 Oct 11.


Objectives: To identify whether tumour thickness as a predictor of nodal metastases in oral squamous cell carcinoma differs between tongue and floor of mouth (FOM) subsites.

Materials and methods: Retrospective review of 343 patients treated between 1987 and 2012. The neck was considered positive in the presence of pathologically proven nodal metastases on neck dissection or during follow-up.

Results: There were 222 oral tongue and 121 FOM tumours. In patients with FOM tumours 2.1-4mm thick, the rate of nodal metastases was 41.7%. In contrast, for tongue cancers of a similar thickness the rate was only 11.2%. This increased to 38.5% in patients with tongue cancers that were 4.1-6mm thick. Comparing these two subsites, FOM cancers cross the critical 20% threshold of probability for nodal metastases between 1 and 2mm whereas tongue cancers cross the 20% threshold just under 4mm thickness. On logistic regression adjusting for relevant covariates, there was a significant difference in the propensity for nodal metastases based on tumour thickness according to subsite (p=0.028).

Conclusion: Thin FOM tumours (2.1-4mm) have a high rate of nodal metastases. Elective neck dissection is appropriate in FOM tumours ⩾2mm thick and in tongue tumours ⩾4mm thick.

Keywords: Head and neck cancer; Lymph node metastases; Oral squamous cell carcinoma; Tumour thickness.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Carcinoma, Squamous Cell / pathology*
  • Female
  • Follow-Up Studies
  • Humans
  • Lymph Nodes / pathology*
  • Lymphatic Metastasis
  • Male
  • Middle Aged
  • Mouth Floor / pathology
  • Mouth Neoplasms / pathology*
  • Neck
  • Neoplasm Staging
  • Retrospective Studies
  • Tongue Neoplasms / pathology
  • Young Adult