Prognostic assessment of different methods for eosinophils detection in oral tongue cancer

TATE has been proposed as a prognostic factor in oral cancer staging; however, the controversial literature data limit its application in the routine diagnosis. The aim of this study was to evaluate the prognostic value of TATE in patients with oral tongue cancer. The second aim was to identify any difference in the methods of eosinophil quantification or in the cutoff values reported in literature.

Clinic-pathological data of 204 patients treated at "Ospedali Riuniti" Hospital, Ancona, Italy, were collected. Evaluation of TATE was performed on hematoxylin-and-eosin-stained slides and correlation with survival outcomes was evaluated. The number of eosinophils per square millimeter was evaluated by using two methods, namely density (TATE-1) and classical (TATE-2) methods. For each of the 2 methods tested, patients were stratified into two or three groups, according to the most used cutoff values reported in literature.

Regardless of the method of eosinophil quantification or the cutoff values used, patients with high TATE had a significantly better disease-specific survival. The density method (TATE-1) showed a better predictive performance, in particular when applying a single cutoff of 67 eosinophils/mm² , two cutoffs of 10 and 100 eosinophils/mm² , or two cutoffs of 50 and 120 eosinophils/mm² .

The evaluation of TATE is simple, cost-effective, and easy to implement in daily practice with the aim of improving risk stratification of patients affected by oral tongue cancer. Results of prognostic performance analysis suggest using density (TATE-1) method as the standard approach to evaluate TATE in future studies, enhancing replicability.