An analysis of two versus three grades for endometrial carcinoma

Introduction. The current grading of uterine endometrioid adenocarcinoma ut ilizes a three-grade system based on the amount of nonsquamous solid histol ogic architecture. Of these three grades, we questioned the practical clini cal utility of the intermediate grade. Methods. We retrospectively reviewed endometrial biopsy and uterine histolo gy specimens, quantifying the percentage amount of nonsquamous solid tumor by intervals of 10. We then compared these percentage values to other histo pathologic prognostic variables. Results. Eighty-five Stage I and II endometrioid adenocarcinoma patients ha d their preoperative endometrial curettings and operative hysterectomy path ology reviewed independently by two gynecologic pathologists for surgical s taging and outcome with a mean follow-up of 6 pears. Using a two-tiered sys tem for assessing uterine tumor grade with a delineating value of 20% nonsq uamous solid tumor, we found less interobserver variation (kappa = 0.966) c ompared to the current three-tiered grading system (kappa = 0.526), There w ere no differences between the two- and three-tiered grading systems regard ing myometrial invasion, lymph vascular space invasion, and survival. In th e diagnosis of endometrial biopsies, the two-tiered system also improved th e prediction of uterine histology grade over the three-tiered system, 90 an d 63%, respectively. Conclusion. A two-grade architecture system with a delineation value of 20% would be more reliable and less cumbersome and would have the same or bett er prognostic significance as the currently used three-grade system.