Poor tumor differentiation is an independent adverse prognostic variable in patients with locally advanced oral cavity cancer--Comparison with pathological risk factors according to the NCCN guidelines.

In addition to ENE, poor tumor differentiation was identified as the second most relevant adverse RF for patients with pT3-4 OCSCC. We suggest that the NCCN guidelines should include poor tumor differentiation as an adverse RF to refine and tailor clinical management.