The occult nodal metastasis rate of early tongue cancer (T1-T2): A protocol for a systematic review and meta-analysis.

The meta-analysis revealed that the early-stage oral tongue squamous cell carcinoma had a rate of 24.4% for occult nodal metastasis. The occult nodal metastasis rate was not significantly affected by neither T2 ratio among T1-T2 nor reported year of the studies.